As filed with the Securities and Exchange Commission on May 13, 2002

                                                     Registration No. 333-83278

================================================================================
                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

                               -----------------


                                AMENDMENT NO. 4

                                      TO
                                   FORM S-3
                            REGISTRATION STATEMENT
                                     Under
                          THE SECURITIES ACT OF 1933

                               -----------------

                                SONOSITE, INC.
            (Exact name of registrant as specified in its charter)

                     Washington                            91-1405022
           (State or other jurisdiction of              (I.R.S. Employer
           incorporation or organization)            Identification Number)

                              21919 30th Drive SE
                        Bothell, Washington 98021-3904
                                (425) 951-1200
  (Address, including zip code, and telephone number, including area code, of
                   registrant's principal executive offices)

                               -----------------

                               KEVIN M. GOODWIN
                     President and Chief Executive Officer
                                SonoSite, Inc.
                              21919 30th Drive SE
                        Bothell, Washington 98021-3904
                                (425) 951-1200
(Name, address, including zip code, and telephone number, including area code,
                             of agent for service)

                               -----------------

                                  Copies to:

           STEPHEN M. GRAHAM                       DONALD J. MURRAY
  Orrick, Herrington & Sutcliffe LLP             Dewey Ballantine LLP
     719 Second Avenue, Suite 900             1301 Avenue of the Americas
       Seattle, Washington 98104               New York, New York 10019
            (206) 839-4300                          (212) 259-8000

                               -----------------

   Approximate date of commencement of proposed sale to the public: As soon as
practicable after this registration statement becomes effective.

   If the only securities being registered on this Form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box. [_]

   If any of the securities being registered on this Form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or
interest reinvestment plans, check the following box. [_]

   If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act of 1933, please check the
following box and list the Securities Act registration statement number of the
earlier effective registration statement for the same offering. [_]__________

   If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act of 1933, check the following box and list the
Securities Act registration statement number of the earlier effective
registration statement for the same offering. [_] __________

   If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. [_]

                               -----------------

The registrant hereby undertakes to amend this registration statement on such
date or dates as may be necessary to delay its effective date until the
registrant shall file a further amendment that specifically states that this
registration statement shall thereafter become effective in accordance with
Section 8(a) of the Securities Act of 1933 or until this registration statement
shall become effective on such date as the Securities and Exchange Commission,
acting pursuant to Section 8(a), may determine.

================================================================================



The information in this preliminary prospectus is not complete and may be
changed. We may not sell these securities until the registration statement
filed with the Securities and Exchange Commission is effective. This
preliminary prospectus is not an offer to sell these securities and is not
soliciting offers to buy these securities in any state where the offer or sale
is not permitted.



 PRELIMINARY PROSPECTUS      Subject to completion                May 13, 2002
 -----------------------------------------------------------------------------


2,700,000 Shares

[LOGO] SONOSITE, INC.

Common Stock

--------------------------------------------------------------------------------

We are selling all of the 2,700,000 shares of common stock offered by this
prospectus.


Our common stock is quoted on the Nasdaq National Market under the symbol
"SONO." On May 10, 2002, the last reported sales price of our common stock on
the Nasdaq National Market was $16.48 per share.


Investing in our common stock involves a high degree of risk. Before buying any
shares you should read the discussion of material risks of investing in our
common stock in "Risk factors" beginning on page 5.

Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved of these securities or passed upon the
accuracy or adequacy of this prospectus. Any representation to the contrary is
a criminal offense.



                                                                 Per share Total
--------------------------------------------------------------------------------
                                                                     
Public offering price                                            $         $
--------------------------------------------------------------------------------
Underwriting discounts and commissions                           $         $
--------------------------------------------------------------------------------
Proceeds, before expenses, to us                                 $         $
--------------------------------------------------------------------------------


The underwriters may also purchase up to an additional 405,000 shares of our
common stock at the public offering price, less the underwriting discount to
cover over-allotments, if any, within 30 days of the date of this prospectus.

The underwriters are offering the common stock as set forth under
"Underwriting." Delivery of the shares will be made on or about       , 2002.

              UBS Warburg                Deutsche Bank Securities



--------------------------------------------------------------------------------


You should rely only on the information provided in this prospectus, including
information incorporated by reference. We have not authorized anyone to give
you different information or representations. You should not assume that the
information in this prospectus is accurate as of any date after the date of
this prospectus. This prospectus is an offer to sell, and a solicitation of
offers to buy, the shares offered by this prospectus only in jurisdictions
where such offers and sales are permitted.

TABLE OF CONTENTS
--------------------------------------------------------------------------------

                                  

Prospectus summary..................  1

Risk factors........................  5

Forward-looking statements.......... 18

Use of proceeds..................... 18

Capitalization...................... 19

Market price of common stock........ 20

Dilution............................ 21


                                   

Underwriting......................... 22

Where you can find more information.. 24

Incorporation of certain documents by
  reference.......................... 24

Legal matters........................ 25

Experts.............................. 25


SonoSite(R) is the registered trademark of SonoSite, Inc. The stylized SonoSite
logo, SonoHeart ELITE(TM) and SonoSite 180PLUS(TM) are trademarks of SonoSite,
Inc. This prospectus also contains or incorporates by reference trademarks and
service marks of other companies.



Prospectus summary

This summary highlights selected information appearing elsewhere in this
prospectus and may not contain all of the information that is important to you.
This prospectus includes information about the shares we are offering, as well
as information regarding our business and detailed financial data. We encourage
you to read this prospectus in its entirety, including the documents
incorporated by reference.

BUSINESS OVERVIEW

We are a leading provider of high performance, highly miniaturized,
hand-carried, all-digital ultrasound imaging devices for use in a variety of
clinical applications and settings. Our proprietary technologies have enabled
us to design hand-carried diagnostic ultrasound devices that combine
all-digital, high resolution imaging with advanced features and capabilities
traditionally found on cart-based ultrasound systems. We believe that the
portability, high quality and cost effectiveness of our products are expanding
existing markets and will create new markets for ultrasound imaging by:

..  bringing ultrasound out of the imaging center to the patient's bedside or
   the physician's examining table; and

..  enabling physicians to conduct an "imaging physical" by incorporating
   ultrasound imaging into routine physical examinations.

The size and complexity of traditional ultrasound systems typically compel
physicians to refer patients to a highly trained sonographer employed by an
imaging center, such as a hospital's radiology department. By providing
ultrasound at the primary point of care, our hand-carried, easy-to-use devices
can eliminate delays associated with the referral process and enable physicians
to use ultrasound more frequently and in a wider variety of clinical settings.
This increased accessibility creates the potential for enhanced patient care
through earlier diagnosis of diseases and conditions.


We have incurred losses since our inception, although our net loss per share
has decreased in each of the last three fiscal years to $1.59 per share in
2001, compared to $2.01 per share in 2000 and $3.08 per share in 1999. As of
March 31, 2002, we had an accumulated deficit of $81.6 million. We have
experienced increased sales revenue in each of our last three fiscal years:
$45.7 million in 2001, compared to $32.0 million in 2000 and $10.2 million in
1999. Although we will continue to incur losses in the near term, we expect to
achieve one or more profitable quarters within the next several quarters. Even
if we do achieve one or more profitable quarters, however, we may be unable to
sustain or increase future profitability on a quarterly or annual basis. You
should carefully consider this and other risks discussed in "Risk factors"
beginning on page 5 before investing in our common stock.


OUR INDUSTRY

Ultrasound uses low power, high frequency sound waves to provide noninvasive,
real-time images of the body's soft tissue, organs and blood flow. Ultrasound
can be cost effective by eliminating the need for more invasive and expensive
procedures and allowing for earlier diagnosis of diseases and conditions.
According to Klein Biomedical Consultants, Inc., the worldwide market for
ultrasound imaging devices was approximately $3.1 billion in the year 2000. We
believe that our products compete in market segments representing approximately
22% of this market. In addition, we believe that the expansion of this market
to new users and new applications, enabled by the capabilities of our
hand-carried ultrasound devices, will lead to substantial additional demand for
our products.

                                                                             1



In recent years, technological advances have greatly improved the image quality
of ultrasound systems and substantially increased their diagnostic utility,
encouraging growth in ultrasound procedure volume. Prior to our products'
availability, however, high quality images could be produced only by highly
trained sonographers using traditional cart-based ultrasound imaging devices
weighing up to 300 pounds and costing in excess of $80,000.

OUR PRODUCTS

Our products feature high quality, all-digital ultrasound imaging in an
easy-to-use, hand-carried device. Our proprietary technologies have enabled us
to substantially reduce the overall size and cost of our ultrasound devices
while maintaining high resolution image quality and performance. We currently
focus on six key market segments: radiology, obstetrics and gynecology,
cardiology, emergency medicine, surgery and vascular medicine. Our current
ultrasound devices are the SonoSite 180PLUS, for general ultrasound imaging,
and the SonoHeart ELITE, specifically configured for cardiovascular
applications. These products are highly portable, weigh under six pounds, run
on battery or AC power and feature imaging capabilities ordinarily found only
on traditional cart-based ultrasound devices. These products are used together
with any of our five interchangeable handheld components, or transducers, that
are designed for specific clinical applications. This interchangeability allows
our customers to purchase a single hand-carried ultrasound device for multiple
applications.

OUR STRATEGY

Our goal is to lead in the design, development and commercialization of high
performance, highly miniaturized, hand-carried, all-digital ultrasound imaging
devices. Our strategy to reach that goal consists of the following key elements:

..  Maximize the productivity of our US sales force by increasing our sales
   training and support and focusing on specific clinical markets and
   geographic regions;

..  Raise market awareness of the SonoSite platform and brand name by increasing
   our marketing efforts to both traditional users of ultrasound as well as
   potential new users;

..  Maintain product and technology leadership by continuing to enhance our
   existing products and creating new products;

..  Increase our direct sales force in key European markets by increasing our
   European sales staff and expanding to additional European countries; and

..  Expand into new ultrasound markets by leveraging the portability, high
   quality and cost effectiveness of our products in new applications.

                               -----------------

We were formerly the handheld ultrasound device division of ATL Ultrasound,
Inc., or ATL. On April 6, 1998, we were spun off as a publicly owned
corporation. ATL retained no ownership in us following the spin-off. We sold
our first products in September 1999 and have sold over 6,000 units to date.
Our executive offices are located at 21919 30th Drive SE, Bothell, Washington
98021-3904, and our telephone number is (425) 951-1200. Our website is
www.sonosite.com. The information contained on our website is not incorporated
by reference into, and does not form any part of, this prospectus.

2



The offering



                                       
Common stock offered by us............... 2,700,000 shares

Common stock to be outstanding after this
  offering............................... 14,076,789 shares

Use of proceeds.......................... Working capital and general corporate purposes,
                                          potentially including increased funding of sales
                                          and marketing activities, acceleration of our
                                          product development efforts, protection of our
                                          intellectual property and expansion of our
                                          manufacturing capacity, as well the possible
                                          acquisition of complementary technologies and
                                          businesses.

Nasdaq National Market symbol............ SONO



Unless we specifically state otherwise, the information in this prospectus
assumes that the underwriters do not exercise their option to purchase up to
405,000 shares of common stock to cover over-allotments.


The number of shares of common stock outstanding after this offering is based
on shares outstanding as of May 10, 2002, and excludes:



..  2,897,335 shares of common stock issuable upon exercise of options
   outstanding as of May 10, 2002 at a weighted average exercise price of
   $15.07 per share, of which options to purchase 1,243,959 shares were
   exercisable; and



..  579,362 shares available for future grant under our equity incentive plans
   as of May 10, 2002.


Recent developments


On April 22, 2002, we announced our financial results for the first quarter of
2002. We reported revenues of $12.8 million for the quarter ended March 31,
2002, as compared to revenues of $8.2 million for the quarter ended March 31,
2001, an increase of 57%. Gross margins were 58.0% as compared to 40.4% for the
quarter ended March 31, 2001. We reported a quarterly net loss of $3.7 million,
or $0.32 per share for the quarter ended March 31, 2002, as compared to a
quarterly net loss of $6.7 million, or $0.70 per share for the quarter ended
March 31, 2001. The weighted average shares outstanding used to calculate the
net loss per share for the quarter ended March 31, 2002 was approximately
11,372,000, as compared to approximately 9,567,000 for the quarter ended March
31, 2001. The foregoing information for the first quarter of 2002 is unaudited.


                                                                              3



Summary consolidated financial data


The as adjusted balance sheet data gives effect to the sale of 2,700,000 shares
of our common stock in this offering at an assumed public offering price of
$16.48 per share, after deducting underwriting discounts and commissions and
estimated offering expenses. The following data should be read together with
the consolidated financial statements, the related notes and other financial
information included in this prospectus and incorporated into this prospectus
by reference.




                                                                       Year ended December 31,
                                                                ------------------------------------
Statement of operations data                                           1999          2000       2001
----------------------------------------------------------------------------------------------------
                                                                (in thousands, except per share data
                                                                                 
Sales revenue.................................................. $ 10,185      $ 32,037    $ 45,695
Cost of sales revenue..........................................    6,498        18,649      21,861
                                                                --------      --------    --------
Gross margin on sales revenue..................................    3,687        13,388      23,834

Grant revenue..................................................      125            --          --

Operating expenses:
   Research and development....................................   14,533        11,835      12,715
   Sales and marketing.........................................    9,767        17,371      22,312
   General and administrative..................................    2,637         4,647       5,198
                                                                --------      --------    --------
Total operating expenses.......................................   26,937        33,853      40,225

Total other income (loss)......................................    1,513         1,493         (18)
                                                                --------      --------    --------

Net loss....................................................... $(21,612)     $(18,972)   $(16,409)
                                                                ========      ========    ========

Basic and diluted net loss per share........................... $  (3.08)     $  (2.01)   $  (1.59)
                                                                ========      ========    ========

Weighted average shares of common stock used in computing basic
  and diluted net loss per share...............................    7,025         9,418      10,300
                                                                ========      ========    ========





                                                      As of December 31, 2001
                                                      -----------------------
    Balance sheet data                                   Actual   As adjusted
    -------------------------------------------------------------------------
                                                          (in thousands)
                                                            
    Cash, cash equivalents and short-term investments $ 33,116    $ 74,217
    Working capital..................................   49,326      90,427
    Total assets.....................................   63,178     104,279
    Long-term obligations, less current portion......      185         185
    Accumulated deficit..............................  (77,901)    (77,901)
    Shareholders' equity.............................   55,683      96,784



4



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Risk factors

Investing in our common stock involves a high degree of risk. In addition to
the other information in this prospectus, you should carefully consider the
risks described below before purchasing our common stock. If any of the
following risks actually occur, our business could be materially harmed, and
our financial condition and results of operations could be materially and
adversely affected. As a result, the trading price of our common stock could
decline, and you might lose all or part of your investment.

RISKS RELATED TO OUR BUSINESS

If our products do not gain market acceptance, we will fail to generate
sufficient revenue to maintain our business.

The market for hand-carried, high performance ultrasound devices is new and
largely undeveloped. Our products represent a new technological alternative to
traditional ultrasound examinations. We seek to sell our products to current
users of ultrasound, as well as to physicians and other healthcare providers
who do not currently use ultrasound, and our success will depend on the
acceptance of our products by the medical community, patients and third-party
payors as medically useful, safe and cost-effective. Competing hand-carried or
traditional cart-based ultrasound devices may be more cost-effective than our
products. Physicians and other healthcare providers may adopt our products at a
slow rate, if at all. If the market fails to accept our products, we will be
unable to generate sufficient sales revenue to maintain our business.

If we are unable to compete effectively, we will fail to generate sufficient
revenue to maintain our business.

We currently face competition from companies that manufacture cart-based and
portable ultrasound devices. The dominant competitors in this industry are GE
Medical Systems, a unit of General Electric Company, Siemens AG and Philips
Medical Systems, a unit of Koninklijke Philips Electronics, N.V. that recently
purchased two other competitors, Agilent Healthcare Solutions Group and ATL,
our former parent company. These competitors are very large, global
organizations and have the following advantages over us:

..  greater financial and infrastructure resources;

..  larger research and development staffs;

..  greater experience in product manufacturing, marketing and distribution;

..  greater brand name recognition; and

..  long-standing relationships with many of our potential customers.

These manufacturers of cart-based and portable ultrasound devices could use
their greater resources to increase and withstand competition through various
means, including price and payment terms, product quality, market penetration,
employee compensation, hospital systems integration and complementary services
such as warranty protection, maintenance and product training. Existing product
supply relationships between these companies and our potential customers could
discourage widespread adoption of our products due to brand loyalty or
preferred customer discounts. Competition from these companies could result in
higher turnover of our employees. If we are unable to respond to competitive
pressures from the cart-based and portable ultrasound markets, we could
experience delayed or reduced market acceptance of our products, higher
expenses and lower sales revenue.

--------------------------------------------------------------------------------
                                                                              5



Risk factors
--------------------------------------------------------------------------------


In addition, as the market for hand-carried, high performance ultrasound
devices develops, we expect competition to increase as potential and existing
competitors enter the hand-carried market or modify their existing products to
more closely approximate the combined portability, quality, performance and
cost or our products. Our current competitors in the hand-carried market
include GE Medical Systems, Agilent/Philips Medical Systems, Biosound Esaote,
Inc., Medison America Inc., a subsidiary of Medison Company, Ltd., and Terason,
a division of TeraTech Corporation. Other potential entrants to the
hand-carried market include Novasonics, Inc. These competitors may develop
highly portable or hand-carried ultrasound devices that offer the same or
greater reliability and quality, perform greater or more useful functions, or
are more cost-effective than our products. If we are unable to compete
effectively with new entrants to the hand-carried, high performance ultrasound
market, we will be unable to generate sufficient sales revenue to maintain our
business.

If our competitors develop and market medical imaging devices that render our
products obsolete or noncompetitive, we will be unable to compete.

The life cycles of our products are difficult to estimate. Our products could
become obsolete or unmarketable if:

..  our competitors introduce ultrasound devices that are superior to ours;

..  other products using new technologies emerge; or

..  industry standards exceed our products' capabilities.

If we fail to enhance our existing products or develop and market new products,
our products will become obsolete and we will be unable to compete.

Our single technological platform renders us less able to withstand adverse
changes in the market.

Although we market our products for use in a variety of clinical applications
and settings, we have only a single technological platform upon which all our
ultrasound devices are based. Any attempt to design a new platform for
ultrasound imaging will require substantial amounts of time and money, and may
not be successful. If our platform becomes obsolete, unmarketable or unaccepted
by the market for any reason, and we are unable or slow to develop a new
platform to replace it, we will be unable to generate sufficient sales revenue
to maintain our business.

If traditional providers of ultrasound examinations discourage potential new
users from adopting our products, we could experience limited demand for our
products.

In traditional ultrasound practice, physicians and other healthcare providers
typically refer patients to centralized locations where radiologists and other
specialized personnel provide ultrasound examinations. Although our products
are currently used by radiologists, our products also enable the delivery of
ultrasound examinations at the primary point of care by the examining physician
or healthcare provider. Radiologists and other ultrasound specialists have a
professional and financial interest in maintaining traditional ultrasound
practice. If these traditional providers of ultrasound examinations discourage
other healthcare providers from adopting our products, we could experience
limited demand for our products.

If the training and education necessary to conduct ultrasound examinations
discourage new users from adopting our products, we could experience limited
demand for our products.

We seek to sell our products to customers already experienced in ultrasound
procedures, as well as to physicians and other healthcare providers who do not
currently use ultrasound imaging devices or administer ultrasound examinations.
Although customers who are experienced in ultrasound procedures will need
little, if any, specialized training to use our products, any new users of
ultrasound will require

--------------------------------------------------------------------------------
6



Risk factors
--------------------------------------------------------------------------------

training and education to properly administer ultrasound examinations. If these
potential customers are unable or unwilling to be trained due to cost, time
constraints, unavailability of courses or other reasons, we could experience
limited demand for our products.

If our suppliers, including our single-source suppliers, fail to supply us with
the components that we need to manufacture our products on a timely basis, we
could experience production delays, cost increases and lost sales.

We depend on suppliers, including some single-source suppliers, to provide
highly specialized parts, such as custom-designed integrated circuits, cable
assemblies and transducer components. We also depend on single-source suppliers
to provide other components, such as image displays, batteries, capacitors and
cables. We do not maintain significant inventories of components, and may
experience an interruption of supply if a supplier is unable or unwilling to
meet our time, quantity and quality requirements. There are relatively few
alternative sources of supply for some of these components. An increase in
demand for some parts by other companies could also interrupt our supply of
components. We have in the past experienced supply problems in timeliness and
quality, but to date these problems have not resulted in lost sales or lower
demand. Nevertheless, if we experience an interruption of supply or are
required to switch suppliers, the manufacture and delivery of our products
could be interrupted, our manufacturing costs could substantially increase and
we could lose substantial amounts of product sales.

If we or our suppliers fail to comply with regulations governing our
manufacturing practices, we could experience production delays, cost increases
and lost sales.

The US Food and Drug Administration, or FDA, requires us and our key suppliers
to demonstrate and maintain compliance with the FDA's Quality System
Regulation, or QSR, which covers the methods and documentation of the design,
testing, production, control, quality assurance, labeling, packaging and
shipping of our products. The FDA enforces the QSR through periodic,
unannounced inspections. We or any of our key component suppliers may fail to
comply with regulatory requirements. Failure to take corrective action in
response to a QSR inspection could force a shutdown of our manufacturing
operations and a recall of, or field action relating to, our products. Such
failure may prevent us from meeting production schedules, minimizing
manufacturing costs, maintaining quality requirements or completing product
sales.

For example, the FDA inspected our manufacturing facility in August 2001. In
addition, the British Standards Institution performed a management systems
assessment of our manufacturing processes in May 2000, February 2001 and June
2001. These inspections resulted in observations to which we submitted
responses, and we believe these responses have been accepted by those agencies.
Also, in August 2001 the FDA classified as a class II field action a May 2000
software upgrade we issued to correct an error in an algorithm contained in one
of our products. If our appeal of this classification is unsuccessful, we will
be required to take additional steps in an effort to ensure that all affected
purchasers receive the upgrade. If required to take action, we do not believe
the associated costs will be significant. Although to date these actions by
regulatory bodies have not required us to incur substantial costs or delay
product shipments, we expect to experience further inspections and incur
additional costs as a result of governmental regulation.

Our limited manufacturing experience and the complexity of our products may
impair our ability to respond effectively to manufacturing problems, manage our
inventory and avoid excessive warranty costs.

Prior to the fourth quarter of 2000, we had outsourced the manufacture of our
products to ATL. In the fourth quarter of 2000, we transitioned product
manufacturing to our own facility under the control of

--------------------------------------------------------------------------------
                                                                             7



Risk factors
--------------------------------------------------------------------------------

our employees. In order to make this transition, we built a series of
manufacturing lines and developed our own manufacturing processes and
procedures. We have limited experience in managing manufacturing problems and
risks, such as line shutdowns, product procurement issues, regulatory
compliance, rework, quality system issues or yield issues. We manufacture our
products and determine product mix based on forecasts of sales in future
periods. Incorrect forecasts and long order lead-times could lead to shortages
or surpluses of product inventory. If we experience any manufacturing problems,
we may experience delays in shipping our products. Our failure to effectively
manage our manufacturing process may prevent us from meeting production
schedules, minimizing manufacturing costs, maintaining quality requirements or
completing product sales.

In addition, our products are intricate and technically complex. As a result,
deficiencies in our design and manufacturing process may result in significant
warranty exposure. Our products generally carry a one-year warranty against
defects in materials and workmanship. We will be responsible for all claims,
actions, damages, liens, liabilities and costs for all product field actions,
returns and defects attributable to manufacturing. Although we have established
accruals for the liability associated with product warranties, any unforeseen
warranty exposure could increase our expenses and impair our operating results.

Our reliance on a single manufacturing facility may impair our ability to
respond to natural disasters or other unforeseen catastrophic events.

Our sole manufacturing facility is located in a single building in Bothell,
Washington. Despite precautions taken by us, a natural disaster such as an
earthquake or other unanticipated catastrophic events at this building could
significantly impair our ability to manufacture our products and operate our
business. Our facility and certain manufacturing equipment would be difficult
to replace and could require substantial replacement lead-time. Such
catastrophic events may also destroy any inventory of product or components.
While we carry insurance for natural disasters and business interruption, the
occurrence of such event could result in losses that exceed the amount of our
insurance coverage, which would impair our financial results.

If our products do not perform as expected, we could experience lost revenue,
delayed or reduced market acceptance of our products, increased costs and
damage to our reputation.

Our success depends on the market's confidence that we can provide reliable,
high quality medical devices. Our customers are particularly sensitive to
product defects and errors because of the use of our products in medical
practice. Our reputation and the public image of our products may be impaired
for any of the following reasons:

..  failure of products to perform as expected;

..  a perception that our products are difficult to use; and

..  litigation concerning the performance of our products or our technology.

Even after any underlying problems are resolved, any manufacturing defects or
performance errors in our products could result in lost revenue, delay in
market acceptance, damage to our reputation, increased service and warranty
costs and claims against us.

We have a history of losses, we expect future losses and we may never be
profitable.


We have incurred net losses in each quarter since we commenced operations. As
of March 31, 2002, we had an accumulated deficit of approximately $81.6
million. Although we will continue to incur additional losses in the near term,
we expect to achieve one or more profitable quarters within the next several
quarters. Even if we do achieve one or more profitable quarters, however, we
may be unable to sustain or increase future profitability on a quarterly or
annual basis. Additionally, our losses may


--------------------------------------------------------------------------------
8



Risk factors
--------------------------------------------------------------------------------

increase if we cannot increase or sustain our revenue. Our revenue from product
sales has been insufficient to cover our expenses, and we expect that our
operating expenses will substantially increase in the foreseeable future as we
expand our sales and marketing infrastructure, our manufacturing capability and
possibly our product development activities. Our expansion efforts, to be
successful, may require more funding than we currently anticipate. Accordingly,
we will need to generate significant additional sales revenue in the future
before we will be able to sustain or increase profitability. If we cannot
generate such revenue, we may never be profitable. If we fail to achieve or
sustain profitability, the market price for our common stock will likely fall.

A failure to manage our growth could impair our ability to achieve our business
objectives.

We have experienced rapid growth since our inception as a stand-alone company.
Our sales revenue increased from $10.2 million in 1999 to $32.0 million in 2000
and $45.7 million in 2001. During 2001, we increased the number of our sales
representatives in the United States from 26 to 51, introduced two new products
to the market and began expanding our operations in Europe. We expect continued
significant growth in all areas of operations as we continue to develop,
manufacture, market and sell our products. Our growth could strain our existing
management, operational and financial resources. In order to manage our growth
effectively, we will need to expand our manufacturing and quality assurance
staff, our sales staff and our manufacturing capabilities. In addition, we will
need to improve the productivity and efficiency of our existing operational,
financial and management resources and
information systems. We may be unable to hire and retain the personnel
necessary to operate and expand our business. We also may be unable to increase
the productivity and efficiency of our existing resources. If we fail to timely
improve or augment our existing resources in response to our growth, we may be
unable to effectively manage our business and achieve our objectives.

Our strategy of expanding and maintaining our domestic sales force may fail to
generate a substantial increase in sales.

We began direct sales of our products in the United States in February 2000
with a sales force comprised of sonographers with little direct sales
experience. Since then, we have nearly doubled the size of our direct sales
force in the United States by supplementing our sonographers with trained
professional sales people. We expect to continue expanding our domestic sales
force to add clinical application specialists, including cardiology product
specialists, in an effort to improve our sales efficiency and reach new
markets. This expansion will require extensive training efforts, substantial
management attention and a substantial increase in sales and marketing
expenses. Despite our expenditures and efforts, we may not successfully expand
our market penetration or generate a substantial increase in sales.

Our limited financial resources may impair our ability to market our products
effectively and may limit our product sales.

Marketing is critical to generate awareness of our products and promote the new
uses of ultrasound that our products enable. Our marketing efforts must
overcome the marketing efforts of our competitors, as well as the resistance
that may be shown by both existing and new ultrasound users. We have incurred
and will continue to incur significant expenditures for a range of marketing
efforts, including attendance at trade shows, direct mail solicitations and
print advertising. If our limited financial resources impair our marketing
budget, we may be unable to generate sufficient brand awareness to positively
impact product sales. This lack of brand awareness may result in delayed or
reduced market acceptance of our products and may limit our product sales.

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                                                                             9



Risk factors
--------------------------------------------------------------------------------


If our operating results fluctuate and fall below expectations of securities
analysts and investors, our stock price may decline and you may lose some or
all of your investment.

Our operating results have fluctuated in the past, and we expect these
fluctuations to continue in the foreseeable future. Many factors affecting our
quarterly operating results are outside our control, including:

..  product and price competition;

..  global economic conditions;

..  performance of our third-party distributors;

..  year-end customer budget constraints and other customer buying patterns; and

..  changes in component cost and availability.

Other factors are difficult to control, including:

..  demand for our products;

..  estimating appropriate manufacturing levels for forecasted sales;

..  inventory management and obsolescence;

..  performance of our direct sales and distribution channels;

..  development of new and enhanced products;

..  product introductions and commercializations; and

..  timing and magnitude of our expenses.

A negative fluctuation of our operating results could run contrary to the
expectations of securities analysts or investors, which may reduce the market
price of our stock and cause a loss of some or all of your investment.

Our creation, maintenance and expansion of direct sales and distribution
operations in Europe will burden our resources and may fail to generate a
substantial increase in sales.

We have historically relied on third-party distributors to sell our products in
Europe. We recently commenced operations in the United Kingdom, France and
Germany to sell our products directly in each of those countries. We expect to
expand our European direct sales operations in the future. Establishing,
maintaining and expanding these operations will require us to:

..  substantially increase our costs of operations;

..  temporarily divert existing management resources;

..  establish an efficient and self-reliant local infrastructure;

..  attract, hire and train qualified local sales and administrative personnel;

..  comply with additional local regulatory requirements; and

..  expand our information, financial, distribution and control systems to
   manage expanded global operations.

--------------------------------------------------------------------------------
10



Risk factors
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Our movement into Europe will require substantial financial and management
resources. The costs of this expansion are unpredictable, difficult to control
and may exceed budgeted amounts. Despite our expenditures and efforts, we may
not generate a substantial increase in European sales revenue, which would
impair our operating results.

Our foreign sales revenue is subject to currency fluctuation and other risks
associated with doing business outside the United States.

The percentage of our sales revenue originating outside the United States
equaled 48% in 2001 and 53% in 2000. Of this foreign sales revenue,
approximately 35% originated in Japan in 2001 and 49% in 2000. Our revenue from
international sales may be adversely affected by any of the following risks:

..  currency rate fluctuations;

..  reduced protection for intellectual property rights;

..  longer receivables collection periods and greater difficulty in receivables
   collection;

..  localizing products for foreign markets; and

..  compliance with export laws, including license requirements, trade
   restrictions and tariff increases.


As of March 31, 2002, 61% of our outstanding accounts receivable balance was
from international customers. Our distributor in Japan was indebted to us for
approximately $1.4 million, representing 11% of our outstanding accounts
receivable balance. In addition, approximately 5% of our outstanding
receivables was from a single customer in Argentina who was indebted to us for
$603,000. We regularly review our receivable position in foreign countries for
any indication that collection may be at risk. For example, due to current
economic events in Argentina, including the decision to allow the Argentine
peso to float against the US dollar, we recorded an additional allowance of
$102,000 on an account in Argentina during the first quarter of 2002, and we
may be required to write off some or all of our Argentine receivables.


Our foreign distributors may be unwilling or unable to devote sufficient
resources to market and sell our products, which could delay or reduce market
acceptance and sales of our products outside the United States.


We currently depend on foreign distributors to help promote market acceptance
and demand for our products in countries in which we do not have a direct sales
force. For example, sales to our distributor in Japan, Olympus, represented 17%
of our revenue in 2001 and 11% of our revenue in the quarter ended March 31,
2002. Foreign distributors that are in the business of distributing other
medical products may not devote the resources and support required within these
countries to generate awareness of our products and grow or maintain product
sales. If these distributors are unwilling or unable to market and sell our
products, we could experience delayed or reduced market acceptance and sales of
our products outside the United States.


The loss of any principal member of our management team or scientific staff, on
whom we rely heavily, could impair our ability to compete.

Our success depends heavily on our ability to retain the services of the
principal members of our management team and scientific staff. Competition
among medical device companies for qualified employees is intense. We may fail
to retain these key employees, and we may fail to attract qualified
replacements if they do leave. We do not maintain key-person insurance on any
of our employees. We do not have employment agreements with any of our
employees. The loss of any of our key employees could significantly delay or
prevent the achievement of our scientific or business objectives.

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                                                                             11



Risk factors
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RISKS RELATED TO OUR INTELLECTUAL PROPERTY

If we are unable to protect and enforce our intellectual property rights, we
may be unable to compete effectively.

Much of our value arises out of our proprietary technology and intellectual
property for the design, manufacture and use of hand-carried ultrasound imaging
devices. Our success and ability to compete effectively depend on our ability
to protect our proprietary information. We rely on patent, copyright, trade
secret and trademark laws to protect our proprietary technology and limit the
ability of others to compete with us using the same or similar technology.

We currently hold five patents relating to the weight of digital beamformers,
beamforming capabilities, digital conversion circuitry, transceiver circuitry
and circuit integration. Additionally, we have a license from our former
parent, ATL, to use certain ATL technology and ATL technological developments
in our hand-carried products. This license is exclusive through April 5, 2003,
and nonexclusive after that date. We also enter into confidentiality or license
agreements with our employees, consultants and corporate partners, and
generally control access to, and the distribution of, our product designs,
documentation and other proprietary information, as well as the designs,
documentation and other information that we license from others.

Our efforts afford only limited protection and may not adequately protect our
rights to the extent necessary to sustain any competitive advantage we may
have. Despite our efforts to protect our intellectual property, we may
experience:

..  unauthorized use of our technology by competitors;

..  independent development of the same or similar technology by a competitor,
   coupled with a lack of enforceable patents on our part;

..  failure of our pending patent applications to result in issued patents;

..  successful interference actions to our patents or successful oppositions to
   our patents and patent applications;

..  unauthorized disclosure or use of our proprietary information by former
   employees or affiliates; and

..  failure by our commercial partners to comply with their obligations to share
   technology or use our technology in a limited manner.

Policing unauthorized use of our intellectual property will be difficult and
may be cost-prohibitive. We may fail to prevent misappropriation of our
technology, particularly in countries where the laws may not protect our
proprietary rights to the same extent as do the laws of the United States. If
we cannot prevent other companies from using our proprietary technology or if
our patents are found invalid or otherwise unenforceable, we may be unable to
compete effectively against other manufacturers of ultrasound devices, which
could decrease our market share.

If we are involved in intellectual property claims and litigation, the
proceedings may divert our resources and subject us to significant liability
for damages, substantial litigation expense and the loss of our proprietary
rights.

In order to protect or enforce our patent rights, we may initiate patent
litigation. In addition, others may initiate patent litigation against us. We
may become subject to interference proceedings conducted in patent and
trademark offices to determine the priority of inventions. There are numerous
issued and pending patents in the medical device field. The validity and
breadth of medical technology patents may

--------------------------------------------------------------------------------
12



Risk factors
--------------------------------------------------------------------------------

involve complex legal and factual questions for which important legal
principles may remain unresolved. In addition, because patent applications can
take many years to result in issued patents and are maintained in confidence by
the US Patent and Trademark Office while pending, there may be currently
pending applications of which we are unaware, which may later result in issued
patents that our products may infringe. There could also be existing patents of
which we are not aware that one or more of our products may infringe.
Litigation may be necessary to:

..  assert or defend against claims of infringement;

..  enforce our issued and licensed patents;

..  protect our trade secrets or know-how; or

..  determine the enforceability, scope and validity of the proprietary rights
   of others.


We may become involved in the defense and prosecution, if necessary, of
intellectual property suits, patent interferences, opposition proceedings and
other administrative proceedings. For example, on July 24, 2001, Neutrino
Development Corporation filed a complaint against us, which alleged that our
sale and manufacture of our hand-carried ultrasound devices infringed upon a
patent held by Neutrino. We responded to the claim, asserting alternative
defenses of noninfringement and patent invalidity. In addition, we filed a
counterclaim seeking a declaratory judgment of noninfringement and invalidity
regarding Neutrino's patent. We also defeated Neutrino's request for a
preliminary injunction preventing us from manufacturing and selling our
products for the duration of the litigation. On February 20, 2002, in what is
known as a "Markman" hearing, the parties presented their arguments regarding
the proper construction of Neutrino's patent claims. The court has not yet
ruled on the issues presented in that hearing, and may issue a ruling at any
time. Although we continue to vigorously defend ourselves against this claim,
this litigation may result in an adverse judgment against us. Sales of the
allegedly infringing products represented virtually all of our revenue for the
quarter ended March 31, 2002 and the years ended December 31, 2001, 2000 and
1999. Through March 31, 2002, we had incurred approximately $900,000 in defense
of this claim, and we expect to incur additional substantial litigation
expenses until the claim is resolved.


Our involvement in intellectual property claims and litigation could:

..  divert existing management, scientific and financial resources;

..  subject us to significant liabilities;

..  allow our competitors to market competitive products without obtaining a
   license from us;

..  cause product shipment delays and lost sales;

..  require us to enter into royalty or licensing agreements, which may not be
   available on terms acceptable to us, if at all; or

..  force us to discontinue selling or modify our products, or to develop new
   products.

The termination or other loss of our license to use certain ATL technology
would significantly impair our ability to manufacture, market and sell our
products.

We license certain technology from ATL that is incorporated into our single
technology platform, and we use this ATL technology in all of our hand-carried
ultrasound imaging devices. Virtually all of our revenue is attributable to
products incorporating this ATL technology.

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                                                                             13



Risk factors
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ATL may terminate our license in the event of an uncured material default by us
in our obligations under the license agreement. Although many key aspects of
our technology platform--including the high level of miniaturization that
allows us to manufacture high performance, hand-carried, all-digital ultrasound
imaging devices--are independently owned by us under the terms of our spin-off
from ATL, the termination or other loss of our license to use ATL technology
would significantly impair our ability to manufacture, market and sell our
products. If this happens, we may be unable to generate sufficient revenues to
maintain our business.

RISKS RELATED TO OUR INDUSTRY

If healthcare reimbursement practices or reform restricts coverage available to
our customers for the use of our products, we may experience limited market
acceptance of our products.

Market acceptance of our products depends in part on the extent to which our
customers will receive reimbursement for the use of our products from
governmental authorities, private health insurers and other third-party payors.
Our customers currently receive reimbursement for ultrasound procedures
performed using our products consistent with reimbursement criteria applicable
to ultrasound procedures generally. The continuing efforts of governmental
authorities, private health insurers and other third-party payors to contain or
reduce the costs of healthcare through various means may, however, limit market
acceptance of our products. Increasing efforts by governmental and third-party
payors, such as Medicare, private insurance plans and managed care
organizations, to contain or reduce healthcare costs may affect our ability to
market our current products, commercialize our potential products and become
profitable. Reimbursement coverage, to the extent available, may not be
adequate to enable us to achieve market acceptance of our products. In
addition, we believe that third-party payors will attempt to reduce healthcare
costs by limiting both coverage and level of reimbursement for new products
cleared by the FDA or comparable foreign agencies. Our products enable new
kinds of medical procedures involving novel ultrasound applications for which
there is no reimbursement history. The efforts of government and third-party
payors to contain or reduce the cost of healthcare could restrict physicians'
and other healthcare providers' willingness to select our products and
implement new ultrasound procedures, which could delay or reduce market
acceptance of our products.

Additionally, there has been and will continue to be a number of federal and
state proposals to implement government controls on pricing. The existence and
adoption of these proposals could affect our ability to successfully market our
current products and commercialize new products.

Compliance with governmental regulation of our business could be costly and
time-consuming, and could prevent us from introducing new products in a timely
manner.

Our products, our manufacturing activities and the manufacturing activities of
our third-party medical device manufacturers are subject to extensive
regulation by a number of governmental agencies, including the FDA and
comparable international agencies. Our third-party manufacturers and we are or
will be required to:

..  obtain prior clearance or approval from these agencies before we can market
   and sell our products;

..  undergo rigorous inspections by domestic and international agencies; and

..  satisfy content requirements for all of our sales and promotional materials.

Compliance with the regulations of these agencies, including the Environmental
Protection Agency and the Occupational Safety and Health Administration, may
require us to incur substantial costs and may delay or prevent the introduction
of new or improved products. We may be subject to fines, sanctions,

--------------------------------------------------------------------------------
14



Risk factors
--------------------------------------------------------------------------------

including the temporary or permanent suspension of operations, product field
actions, criminal prosecution and marketing restrictions, if we fail to comply
with the laws and regulations pertaining to our business. Our third-party
medical device manufacturers may also be subject to the same sanctions and, as
a result, may fail to supply us with components required to manufacture our
products.

Product liability and other claims and product field actions could increase our
costs, delay or reduce our sales and damage our reputation, which could
significantly impair our financial condition.

Our business exposes us to the risk of product liability, malpractice or
warranty claims inherent in the sale and support of medical device products,
including those based on claims that the use or failure of one of our products
resulted in a misdiagnosis or harm to a patient. Such claims may damage our
reputation by raising questions about our products' safety and efficacy, and
could interfere with our efforts to market our products. Although to date we
have not been involved in any medical malpractice or product liability
litigation, we may incur significant liability if such litigation were to
occur. We may also face adverse publicity resulting from product field actions
or regulatory proceedings brought against us. Although we currently maintain
liability insurance in amounts we believe are commercially reasonable, any
product liability we incur may exceed our insurance coverage. Liability
insurance is expensive and may cease to be available on acceptable terms, if at
all. A product liability or other claim or product field action not covered by
our insurance or exceeding our coverage could significantly impair our
financial condition. In addition, a product field action or a liability claim
against us could significantly harm our reputation and make it more difficult
to obtain the funding and commercial relationships necessary to maintain our
business.

RISKS RELATED TO THE CAPITAL MARKETS AND DILUTION

If our stock price continues to be volatile, your shares may decline in value.

The market price for our common stock, as well as for securities of emerging
growth companies generally, has been volatile in the past and is likely to
continue to be volatile. If you decide to purchase our shares, you may be
unable to resell them at or above the price you paid due to a number of
factors, many of which are beyond our control, including:

..  the difference between quarterly operating results and those expected by
   investors or securities analysts;

..  changes in earnings estimates by analysts;

..  the loss of significant orders;

..  announcements of technological innovations or new products by our
   competitors;

..  changes in the structure of healthcare financing and payment systems;

..  general conditions in the medical industry or global economy;

..  a lack of liquidity in the market for our stock; and

..  significant sales of our common stock by one or more of our shareholders.

Our future capital-raising activities could involve the issuance of equity
securities, which would dilute your investment and could result in a decline in
the trading price of our common stock.

To meet our long-term funding requirements, we may sell securities in the
public or private equity markets if and when conditions are favorable, even if
we do not have an immediate need for additional

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                                                                             15



Risk factors
--------------------------------------------------------------------------------

capital at that time. Furthermore, we may enter into financing transactions at
prices that represent a substantial discount to market price. Raising funds
through the issuance of equity securities will dilute the ownership of our
existing shareholders. A negative reaction by investors and securities analysts
to any sale of our equity securities could result in a decline in the trading
price of our common stock.

ADDITIONAL RISKS RELATED TO OUR BUSINESS OPERATIONS

If we incur tax liability in connection with our spin-off from ATL, we would be
required to pay a potentially significant expense, which would diminish our
financial resources.

Our spin-off was treated by ATL as a tax-free spin-off under Section 355 of the
Internal Revenue Code of 1986. If ATL were to recognize taxable gain from the
spin-off, the Internal Revenue Service, or IRS, could impose that liability on
any member of the ATL consolidated group as constituted prior to the spin-off,
including us. Generally, the IRS may assert that our spin-off from ATL is a
taxable transaction until the expiration of the statute of limitations
applicable to ATL with respect to the spin-off transaction. The expiration of
the statute of limitations with respect to the spin-off transaction depends
upon the actions and tax filings of ATL and the special rules applicable to
spin-offs in general, which special rules could result in the extension of the
general statute of limitations for an indefinite period of time. In the event
of a tax liability, ATL has agreed to cover 85% of any such liability, unless
the tax is imposed due to our actions solely or by ATL solely, in which case,
we have agreed with ATL that the party who is solely at fault shall bear all of
the tax liability. We are unaware of any actions that would result in a tax
liability to us under the indemnity agreement regarding the spin-off
transaction. We are aware that ATL was acquired in a transaction subsequent to
the spin-off transaction, which could potentially result in the spin-off being
treated as a taxable transaction, but which resulting tax liability in our view
would be the sole responsibility of ATL pursuant to our agreement with ATL. ATL
may refuse, however, to indemnify us for a tax liability arising out of the
spin-off transaction or may argue that it did not cause the tax liability to be
imposed. In such event, we may incur a significant expense for all or a portion
of the taxes related to the spin-off.

If our expenses exceed our revenue and we fail to obtain timely additional
financing, we could experience delays or reductions in our product development
and sales efforts, which would impair our operating results.

To date, our revenue has been insufficient to cover the expenses of our
operations. Our future revenue may continue to be insufficient to support the
expenses of our operations and the expansion of our business. We may therefore
need additional equity or debt capital to finance our operations as we develop
our products and expand our sales. To date, our capital requirements have been
met primarily by the sale of equity, sales revenue and contributions by ATL in
connection with our spin-off. Specifically, in August 2001, we raised net
proceeds of $23.1 million through the sale of 1,666,667 shares of our common
stock, in November 1999, we raised net proceeds of $29.3 million through the
sale of 1,250,000 shares of our common stock and in April 1999, we raised net
proceeds of $35.4 million through the sale of 2,990,000 shares of our common
stock. In connection with the spin-off, we received $30 million in contributed
capital from ATL. ATL has no further obligations to provide us with funding,
and we do not expect any future funding from this source. Therefore, if we
require additional financing, we would need to explore other sources of
financing, including public equity or debt offerings, private placements of
equity or debt and collaborative or other arrangements with corporate partners.
Financing may be unavailable when needed or may be unavailable on acceptable
terms. If we fail to obtain financing, we may be required to delay, reduce or
eliminate some or all of our research and development and sales and marketing
efforts, and our business could fail.

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16



Risk factors
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The concentrated ownership of our common stock could delay or prevent a change
of control, which could cause a decline in the market price of our common stock.

As of December 31, 2001, our executive officers, directors and affiliated
entities together beneficially owned approximately 5% of the outstanding shares
of our common stock. Four other shareholders owned in the aggregate
approximately 42% of the outstanding shares of our common stock. Among these
shareholders, the State of Wisconsin Investment Board, or SWIB, owned
approximately 17.2% of the outstanding shares of our common stock and WM
Advisors owned approximately 11.6%. As a result, these shareholders or any
other concentrated owner may be able to exert significant influence over all
matters requiring shareholder approval, including the election of directors,
matters relating to the attraction and retention of employees, and approval of
significant corporate transactions that could include certain matters relating
to future financing arrangements and unsolicited tender offers. This
concentration of ownership may delay, deter or prevent a third party from
acquiring control over us at a premium over the then-current market price of
our common stock, which could result in a decline in our stock price.

Our restated articles of incorporation, our bylaws, Washington law and some of
our agreements contain provisions that could discourage a takeover and prevent
shareholders from receiving a premium for their shares.

There are provisions in our restated articles of incorporation, our bylaws and
Washington law that make it more difficult for a third party to obtain control
of us, even if doing so would be beneficial to our shareholders. Additionally,
our acquisition may be made more difficult or expensive by the following:

..  change of control provisions in our license agreement with ATL, which
   require us to pay ATL:

 .  $150 million if, prior to April 6, 2003, any single person or entity
    obtains, directly or indirectly, voting control of a majority of our common
    stock or the power to elect our entire board of directors; or

 .  $75 million if, at any time between April 6, 2003 and April 6, 2006, any
    single person or entity engaged in the medical diagnostic imaging business,
    other than through the sale or manufacture of our products, obtains,
    directly or indirectly, voting control of a majority of our common stock or
    the power to elect our entire board of directors;

..  acceleration provisions in benefit plans and change-in-control agreements
   with our employees; and

..  our shareholder rights plan, which is designed to dilute a hostile
   acquiror's interest so that the acquisition becomes prohibitively expensive.
   Under our rights plan, each of our shareholders has one share purchase right
   for each share of common stock held, with each right having an exercise
   price approximating our board of directors' estimate of the long-term value
   of one share of our common stock. The rights are triggered if an acquiror
   acquires, or successfully makes a tender offer for, 15% or more of our
   outstanding common stock. In such event, each shareholder other than the
   acquiror would have the right to purchase, at the exercise price, a number
   of newly issued shares of our capital stock at a 50% discount. If the
   acquiror were to acquire 50% or more of our assets or earning power, each
   shareholder would have the right to purchase, at the exercise price, a
   number of shares of acquiror's stock at a 50% discount. Our board of
   directors may redeem the rights at a nominal cost at any time before a
   person acquires 15% or more of our outstanding common stock, which allows
   board-approved transactions to proceed. In addition, our board of directors
   may exchange all or part of the rights (other than rights held by the
   acquiror) for such number of shares of our common stock equal in value to
   the exercise price. Such an exchange produces the desired dilution without
   actually requiring our shareholders to purchase shares. Our rights plan
   excludes SWIB's ownership of our common stock so long as such ownership does
   not reach 20% of our outstanding common stock.

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                                                                             17



--------------------------------------------------------------------------------


Forward-looking statements

Our disclosure and analysis in this prospectus and the documents incorporated
by reference, including the documents listed below in the section entitled
"Where you can find more information," contain forward-looking statements.
Forward-looking statements provide our current expectations or forecasts of
future events. Forward-looking statements include statements about our plans,
objectives, expectations and intentions and other statements that are not
historical facts. Words such as "believe," "anticipate," "expect" and "intend"
may identify forward-looking statements, but the absence of these words does
not necessarily mean that a statement is not forward-looking. Forward-looking
statements are subject to known and unknown risks and uncertainties, and are
based on potentially inaccurate assumptions that could cause actual results to
differ materially from those expected or implied by the forward-looking
statements. Our actual results could differ materially from those anticipated
in the forward-looking statements for many reasons, including the factors
described in the section entitled "Risk factors" in this prospectus.

You should not unduly rely on these forward-looking statements, which speak
only as of the date of this prospectus. We undertake no obligation to publicly
revise any forward-looking statement to reflect circumstances or events after
the date of this prospectus or to reflect the occurrence of unanticipated
events. You should, however, review the factors and risks we describe in the
reports we file from time to time with the SEC after the date of this
prospectus.

Use of proceeds


We estimate that the net proceeds to us from this offering will be
approximately $41.1 million, assuming a public offering price of $16.48 per
share and after deducting underwriting discounts and commissions and the
estimated expenses of this offering. If the underwriters exercise their
overallotment option in full, the net proceeds to us will be approximately
$47.4 million. We have no specific plans for the use of proceeds. We are
conducting this offering to ensure we will have sufficient cash to achieve our
business objectives. We intend to use the proceeds for working capital and
general corporate purposes. These general corporate purposes include
expenditures that we will incur to execute our strategy, and may include:


..  increased spending on specific marketing efforts to expand physicians'
   awareness of our products as well as the new uses of ultrasound that our
   products enable;

..  increased spending on our general sales and marketing activities in response
   to new or increased competition in the hand-carried ultrasound device market;

..  efforts to accelerate our existing product development, either in response
   to increased competition or for other reasons;

..  protection of our intellectual property, including enforcement of our
   patents and defense of patent litigation brought against us;

..  expansion of our manufacturing capacity in response to any increased demand
   for our products or a desire to bring component manufacture in-house; and

..  potential acquisitions of complementary technologies and businesses.

Pending any of these uses, we intend to invest the net proceeds of this
offering in short-term, interest-bearing, investment-grade securities. We will
retain broad discretion in allocating the net proceeds of this offering.

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18



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Capitalization

The following table sets forth our capitalization as of December 31, 2001:

..  on an actual basis; and


..  on an as adjusted basis to give effect to the sale of the 2,700,000 shares
   of common stock offered by us, at the assumed public offering price of
   $16.48 per share and after deducting underwriting discounts and commissions
   and estimated offering expenses to be paid by us.





                                                             As of December 31, 2001
                                                             -----------------------
                                                                Actual  As adjusted
------------------------------------------------------------------------------------
                                                                 (in thousands)
                                                                  
Cash and cash equivalents...................................  $ 33,116     $ 74,217
                                                              ========     ========
Long-term obligations, net of current portion...............  $    185     $    185
                                                              --------     --------
Shareholders' equity
  Preferred stock, $1.00 par value; 6,000,000 shares
   authorized; none issued and outstanding..................         -            -
  Common stock, $0.01 par value; 50,000,000 shares
   authorized; 11,363,231 issued and outstanding,
   actual; 14,063,231 issued and outstanding, as adjusted...       114          141
Additional paid-in capital..................................   133,470      174,544
Accumulated deficit.........................................   (77,901)     (77,901)
Accumulated other comprehensive loss........................         -            -
                                                              --------     --------
   Total shareholders' equity...............................    55,683       96,784
                                                              --------     --------
   Total capitalization.....................................  $ 55,868     $ 96,969
                                                              ========     ========



The table above should be read in conjunction with our consolidated financial
statements and the related notes appearing elsewhere in this prospectus and
excludes:

..  2,621,188 shares of common stock issuable upon exercise of options
   outstanding as of December 31, 2001, at a weighted average exercise price of
   $14.49 per share, of which options to purchase 1,025,956 shares were
   exercisable; and

..  369,662 shares available for future grant under our equity incentive plans
   as of December 31, 2001.

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                                                                             19



--------------------------------------------------------------------------------


Market price of common stock

Our common stock is traded publicly through the Nasdaq National Market under
the symbol "SONO." The following table presents quarterly information on the
price range of our common stock. This information indicates the high and low
sales prices reported by the Nasdaq National Market. These prices do not
include retail markups, markdowns or commissions.




                                                        Common stock price
                                                        ------------------
                                                             High      Low
      --------------------------------------------------------------------
                                                            
      Fiscal year ended December 31, 2000
        First quarter.................................. $37.25    $21.88
        Second quarter.................................  35.13     18.63
        Third quarter..................................  35.13     17.00
        Fourth quarter.................................  21.06     12.00

      Fiscal year ended December 31, 2001
        First quarter..................................  17.38      8.38
        Second quarter.................................  20.00     10.50
        Third quarter..................................  27.85     14.65
        Fourth quarter.................................  27.50     17.99

      Fiscal year ended December 31, 2002
        First quarter..................................  28.01     18.20
        Second quarter (through May 10, 2002)..........  19.68     15.92




On May 10, 2002, the last reported sales price of our common stock was $16.48
per share, and there were approximately 3,617 shareholders of record of our
common stock.


--------------------------------------------------------------------------------
20



--------------------------------------------------------------------------------


Dilution


If you invest in our common stock, your interest will be diluted to the extent
of the difference between the public offering price per share you pay in this
offering and the net tangible book value per share of our common stock
immediately after this offering. Our net tangible book value at March 31, 2002
was approximately $51.6 million, or $4.53 per share of common stock. Net
tangible book value per share is equal to our total tangible assets minus total
liabilities divided by the number of shares of common stock outstanding at
March 31, 2002. Assuming a public offering price of $16.48 per share, after
giving effect to the sale of the 2,700,000 shares of common stock offered by
this prospectus and deducting underwriting discounts and commissions and our
estimated offering expenses, our pro forma net tangible book value would have
been approximately $92.7 million, or $6.58 per share of common stock. This
represents an immediate increase in net tangible book value of $2.05 per share
to existing shareholders and an immediate dilution of $9.90 per share to new
investors. The following table illustrates this calculation on a per share
basis:




                                                                      
Assumed public offering price per share........................             $16.48
 Net tangible book value per share at March 31, 2002........... $   4.53
 Increase per share attributable to new investors..............     2.05
                                                                --------
Pro forma net tangible book value per share after this offering               6.58
                                                                            ------
Dilution per share to new investors............................             $ 9.90
                                                                            ======




If the underwriters exercise their over-allotment option in full, there will be
an increase in pro forma net tangible book value to $6.83 per share to existing
shareholders and an immediate dilution in pro forma net tangible book value of
$9.65 per share to new investors.



The number of shares of common stock outstanding used for existing shareholders
in the table above is based on shares outstanding as of March 31, 2002, and
excludes:



..  2,715,718 shares of common stock issuable upon exercise of options
   outstanding as of March 31, 2002, at a weighted average exercise price of
   $14.83 per share, of which options to purchase 1,079,804 shares were
   exercisable; and



..  262,862 shares available for future grant under our equity incentive plans
   as of March 31, 2002 and an additional 500,000 shares available for future
   grant under our equity incentive plans approved by our shareholders on April
   30, 2002.


--------------------------------------------------------------------------------
                                                                             21



--------------------------------------------------------------------------------


Underwriting

We and the underwriters for this offering named below have entered into an
underwriting agreement concerning the shares being offered. Subject to
conditions, each underwriter has severally agreed to purchase the number of
shares indicated in the following table. UBS Warburg LLC and Deutsche Bank
Securities Inc. are the representatives of the underwriters.



                                                                   Number of
   Underwriters                                                       Shares
   ----------------------------------------------------------------------------
                                                                
   UBS Warburg LLC................................................
   Deutsche Bank Securities Inc...................................
                                                                   ---------
      Total....................................................... 2,700,000
                                                                   =========


If the underwriters sell more shares than the total number set forth in the
table above, the underwriters have a 30-day option to purchase up to an
additional 405,000 shares from us at the public offering price less the
underwriting discounts and commissions to cover these sales. If any shares are
purchased under this option, the underwriters will severally purchase shares in
approximately the same proportion as set forth in the table above.

The following table shows the per share and total underwriting discounts and
commissions we will pay to the underwriters. These amounts are shown assuming
both no exercise and full exercise of the underwriters' option to purchase up
to 405,000 additional shares.



                                                       No exercise Full exercise
--------------------------------------------------------------------------------
                                                             
Per share............................................. $           $
   Total.............................................. $           $



We estimate that the total expenses of the offering payable by us, excluding
underwriting discounts and commissions, will be approximately $725,000.


Shares sold by the underwriters to the public will initially be offered at the
public offering price set forth on the cover of this prospectus. Any shares
sold by the underwriters to securities dealers may be sold at a discount of up
to $      per share from the public offering price. Any of these securities
dealers may resell any shares purchased from the underwriters to other brokers
or dealers at a discount of up to $      per share from the public offering
price. If all the shares are not sold at the public offering price, the
representatives may change the offering price and the other selling terms.

We and each of our directors and executive officers have agreed with the
underwriters not to offer, sell, contract to sell, hedge or otherwise dispose
of, directly or indirectly, any of our common stock or securities convertible
into or exchangeable for shares of our common stock during the period from the
date of this prospectus continuing through the date 90 days after the date of
this prospectus, subject to certain exceptions, without the prior written
consent of UBS Warburg LLC.

In connection with this offering, the underwriters may purchase and sell shares
of common stock in the open market. These transactions may include stabilizing
transactions, short sales and purchases to cover positions created by short
sales. Stabilizing transactions consist of bids or purchases made for the
purpose of preventing or retarding a decline in the market price of the common
stock while the offering is in progress. These transactions may also include
short sales and purchases to cover positions created by short sales. Short
sales involve the sale by the underwriters of a greater number of shares than
they are required to purchase in the offering. Short sales may be either
"covered short sales" or "naked short

--------------------------------------------------------------------------------
22



Underwriting
--------------------------------------------------------------------------------

sales." Covered short sales are sales made in an amount not greater than the
underwriters' over-allotment option to purchase additional shares in the
offering. The underwriters may close out any covered short position by either
exercising their over-allotment option or purchasing shares in the open market.
In determining the source of shares to close out the covered short position,
the underwriters will consider, among other things, the price of shares
available for purchase in the open market as compared to the price at which
they may purchase shares through the over-allotment option. Naked short sales
are sales in excess of the over-allotment option. The underwriters must close
out any naked short position by purchasing shares in the open market. A naked
short position is more likely to be created if the underwriters are concerned
that there may be downward pressure on the price of the shares in the open
market after pricing that could adversely affect investors who purchase in the
offering.

The underwriters also may impose a penalty bid. This occurs when a particular
underwriter repays to the underwriters a portion of the underwriting discount
received by it because the representatives have repurchased shares sold by or
for the account of that underwriter in stabilizing or short covering
transactions.

These activities by the underwriters may stabilize, maintain or otherwise
affect the market price of our common stock. As a result, the price of our
common stock may be higher than the price that otherwise might exist in the
open market. If these activities are commenced, they may be discontinued by the
underwriters at any time. These transactions may be effected on the Nasdaq
National Market or otherwise.

In addition, in connection with this offering certain of the underwriters (and
selling group members) may engage in passive market making transactions in our
common stock on the Nasdaq National Market prior to the pricing and completion
of this offering. Passive market making consists of displaying bids on the
Nasdaq National Market no higher than the bid prices of independent market
makers and making purchases at prices no higher than these independent bids and
effected in response to order flow. Net purchases by a passive market maker on
each day are limited to a specified percentage of the passive market maker's
average daily trading volume in the common stock during a specified period and
must be discontinued when such limit is reached. Passive market making may
cause the price of our common stock to be higher than the price that otherwise
would exist in the open market in the absence of such transactions. If passive
market making is commenced, it may be discontinued at any time.

We have agreed to indemnify the several underwriters against some liabilities,
including liabilities under the Securities Act of 1933, and to contribute to
payments that the underwriters may be required to make in respect of the
Securities Act.

UBS Warburg LLC, an underwriter in this offering, has in the past provided and
may in the future from time to time provide investment banking and other
services to us, including the provision of certain advisory services.

--------------------------------------------------------------------------------
                                                                             23



--------------------------------------------------------------------------------


Where you can find more information

We file annual, quarterly and special reports, proxy statements and other
information with the SEC. Our SEC filings are available to the public over the
Internet at the SEC's website at http://www.sec.gov. The SEC's website contains
reports, proxy statements and other information regarding issuers, such as
SonoSite, that file electronically with the SEC. You may also read and copy any
document we file with the SEC at the SEC's Public Reference Room at 450 Fifth
Street, N.W., Washington, D.C. 20549. You may also obtain copies of the
documents at prescribed rates by writing to the SEC's Public Reference Section
at 450 Fifth Street, N.W., Washington, D.C. 20549. Please call the SEC at
1-800-SEC-0330 for further information on the operation of its Public Reference
Room.

Incorporation of certain documents by reference

The SEC allows us to "incorporate by reference" into this prospectus the
information we have filed with the SEC. Any information that we file
subsequently with the SEC will automatically update this prospectus. We
incorporate by reference into this prospectus the information contained in
documents listed below, which is considered to be a part of this prospectus:

..  Our annual report on Form 10-K/A for the year ended December 31, 2001, which
   contains audited consolidated financial statements for the most recent
   fiscal year for which we have filed audited consolidated financial
   statements;

..  The description of our common stock contained in our registration statement
   on Form 10 filed on February 13, 1998, and two amendments to such Form 10
   filed on March 19, 1998 and March 31, 1998, under Section 12(g) of the
   Securities Exchange Act of 1934, or Exchange Act;


..  Our definitive proxy statement dated March 25, 2002, relating to our April
   30, 2002 annual meeting of shareholders;



..  Our quarterly report on Form 10-Q for the quarter ended March 31, 2002,
   filed on May 13, 2002; and


..  All other reports filed by us pursuant to Section 13(a) or 15(d) of the
   Exchange Act since December 31, 2001.

We also incorporate by reference all documents we file under Section 13(a),
13(c), 14 or 15(d) of the Exchange Act after the date of this prospectus and
before the filing of a post-effective amendment that indicates that the
securities offered by this prospectus have been sold or that deregisters the
securities covered by this prospectus then remaining unsold. The information
contained in any such filings will be deemed to be a part of this prospectus,
commencing on the dates on which the documents are filed.

You may request a copy of these filings, at no cost, by writing or telephoning
us at the following address.

                                SonoSite, Inc.
                               Michael J. Schuh
                              21919 30th Drive SE
                        Bothell, Washington 98021-3904
                                (425) 951-1200

--------------------------------------------------------------------------------
24



--------------------------------------------------------------------------------


Legal matters

Various legal matters with respect to the validity of the shares of common
stock offered by this prospectus will be passed upon for us by Orrick,
Herrington & Sutcliffe LLP, Seattle, Washington. Dewey Ballantine LLP, New
York, New York, is counsel for the underwriters in connection with this
offering.

Experts

Our consolidated financial statements and schedule as of December 31, 2001 and
2000, and for each of the years in the three-year period ended December 31,
2001, have been incorporated by reference into this prospectus and in the
registration statement in reliance upon the report of KPMG LLP, independent
auditors, which is also incorporated by reference into this prospectus, and
upon their authority as experts in accounting and auditing.

--------------------------------------------------------------------------------
                                                                             25



                             [LOGO] SONOSITE, INC.





--------------------------------------------------------------------------------


PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14.  Other Expenses of Issuance and Distribution

The following table lists the costs and expenses payable by the registrant in
connection with the sale of the common stock covered by this registration
statement. All amounts are estimates except for the SEC registration fee, the
Nasdaq additional listing fee and the NASD fee.



                                                            
        SEC registration fee.................................. $  6,596
        Nasdaq additional listing fee.........................   22,500
        NASD fee..............................................    7,669
        Printing and engraving expenses.......................   72,000
        Legal fees and expenses...............................  450,000
        Accounting fees and expenses..........................  150,000
        Miscellaneous fees and expenses.......................   16,235
                                                               --------
           Total.............................................. $725,000
                                                               ========



Item 15.  Indemnification of Directors and Officers

Article VI of the registrant's Restated Articles of Incorporation provides that
the registrant may indemnify and hold harmless to the fullest extent provided
by the Washington Business Corporation Act, or the WBCA, or other applicable
law, each person who was or is made a party to or is threatened to be made a
party to or is involved (including, without limitation, as a witness) in any
actual or threatened action, suit or other proceeding, whether civil, criminal,
derivative, administrative or investigative, by reason of the fact that he or
she is or was a director, officer, employee or agent of the registrant or,
being or having been such a director, officer, employee or agent, he or she is
or was serving at the request of the registrant as a director, officer,
employee, agent, trustee or in any other capacity of another corporation or of
a partnership, joint venture, trust or other enterprise, including service with
respect to employee benefit plans, whether the basis of such proceeding is
alleged action or omission in an official capacity or in any other capacity
while serving as a director, officer, employee, agent, trustee or in any other
capacity, against all expense, liability and loss (including, without
limitation, attorneys' fees, judgments, fines, Employee Retirement Income
Security Act of 1974 excise taxes or penalties and amounts to be paid in
settlement) actually or reasonably incurred or suffered by such person in
connection therewith. Such indemnification may continue as to a person who has
ceased to be a director, officer, employee or agent of the registrant and shall
inure to the benefit of his or her heirs and personal representatives.

The registrant may pay the expenses of a director, officer, employee or agent
of the registrant incurred in defending any such proceeding in advance of the
final disposition of any such proceeding; provided, however, that the payment
of such expenses in advance of the final disposition of a proceeding shall be
made to or on behalf of a director, officer, employee or agent only upon
delivery to the registrant of (a) an undertaking, by or on behalf of such
director, officer, employee or agent, to repay all amounts so advanced if it
shall ultimately be determined that such director, officer, employee or agent
is not entitled to be indemnified under the registrant's Restated Articles of
Incorporation or otherwise, which undertaking may be unsecured and may be
accepted without reference to financial ability to make repayment and (b) a
written confirmation by such director, officer, employee or agent of his or her
good-faith belief that he or she has met the standard of conduct in the WBCA.

--------------------------------------------------------------------------------
                                                                           II-1



PART II
--------------------------------------------------------------------------------


No indemnification shall be provided under the registrant's Restated Articles
of Incorporation to any such person if the registrant is prohibited by the WBCA
or other applicable law as then in effect from paying such indemnification. The
WBCA (Sections 23B.08.500 through 23B.08.600 of the Revised Code of Washington)
authorizes a court to award, or a corporation's board of directors to grant,
indemnity to directors and officers in terms sufficiently broad to permit such
indemnification under certain circumstances for liabilities arising under the
Securities Act.

The WBCA includes a provision (Section 23B.08.320 of the Revised Code of
Washington) that permits a corporation to limit a director's liability to the
corporation or its shareholders for monetary damages for his or her acts or
omissions as a director, except in certain circumstances involving intentional
misconduct, self-dealing or illegal corporate loans or distributions, or any
transaction from which the director personally benefits. Article V of the
registrant's Restated Article of Incorporation contains provisions
implementing, to the fullest extent permitted by Washington law, such
limitations on a director's liability to the registrant and its shareholders.

In addition, the registrant maintains an insurance policy insuring its
directors and officers for certain acts or omissions while acting in their
official capacities.

Item 16.  Exhibits


   

 1.1+ Form of Underwriting Agreement

 5.1+ Opinion of Orrick, Herrington & Sutcliffe LLP, counsel to the registrant, regarding the legality
        of the common stock being registered

23.1  Consent of KPMG LLP, Independent Auditors

23.2+ Consent of Orrick, Herrington & Sutcliffe LLP (contained in Exhibit 5.1)

24.1+ Power of attorney

--------
+ Previously filed.

Item 17.  Undertakings

    A.  Insofar as indemnification for liabilities arising under the Securities
Act may be permitted to directors, officers and controlling persons of the
registrant pursuant to the foregoing provisions or otherwise, the registrant
has been advised that in the opinion of the SEC such indemnification is against
public policy as expressed in the Securities Act and is therefore
unenforceable. If a claim for indemnification against such liabilities (other
than the payment by the registrant of expenses incurred or paid by a director,
officer or controlling person of the registrant in the successful defense of
any action, suit or proceeding) is asserted by a director, officer or
controlling person in connection with the securities being registered, the
registrant will, unless in the opinion of its counsel the matter has been
settled by controlling precedent, submit to a court of appropriate jurisdiction
the question of whether such indemnification by it is against public policy as
expressed in the Securities Act, and will be governed by the final adjudication
of such issue.

    B.  The undersigned registrant hereby undertakes that:

       (1)  For purposes of determining any liability under the Securities Act,
   the information omitted from the form of prospectus filed as part of this
   registration statement in reliance upon Rule 430A and contained in a form of
   prospectus filed by the registrant pursuant to Rule 424(b)(1) or (4) or
   497(h) under the Securities Act shall be deemed to be part of this
   registration statement as of the time it was declared effective.

--------------------------------------------------------------------------------
II-2



PART II
--------------------------------------------------------------------------------


       (2)  For the purpose of determining any liability under the Securities
   Act, each post-effective amendment that contains a form of prospectus shall
   be deemed to be a new registration statement relating to the securities
   offered therein, and the offering of such securities at that time shall be
   deemed to be the initial bode fide offering thereof.

       (3)  For purposes of determining any liability under the Securities Act,
   each filing of the registrant's annual report pursuant to Section 13(a) or
   15(d) of the Exchange Act (and, where applicable, each filing of an employee
   benefit plan's annual report pursuant to Section 15(d) of the Exchange Act)
   that is incorporated by reference in the registration statement shall be
   deemed to be a new registration statement relating to the securities offered
   therein, and the offering of such securities at that time shall be deemed to
   be the initial bona fide offering thereof.

--------------------------------------------------------------------------------
                                                                           II-3



--------------------------------------------------------------------------------


Signatures


Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-3 and has duly caused this Amendment No. 4 to
registration statement to be signed on its behalf by the undersigned,
thereunder duly authorized, in the city of Seattle, state of Washington, on the
13th day of May, 2002.


                                          SONOSITE, INC.

                                          By /S/  KEVIN M. GOODWIN
                                            -----------------------------------
                                             Kevin M. Goodwin
                                             President and Chief Executive
                                             Officer


Pursuant to the requirements of the Securities Act of 1933, this Amendment No.
4 to registration statement has been signed by the following persons in the
capacities indicated below on the 13th day of May, 2002.




         Signature                                  Title
         ---------                                  -----
                          

   /S/  KEVIN M. GOODWIN     President, Chief Executive Officer and Director
----------------------------   (Principal Executive Officer)
      Kevin M. Goodwin

   /S/  MICHAEL J. SCHUH     Vice President-Finance, Chief Financial Officer and
----------------------------   Secretary (Principal Financial and Accounting
      Michael J. Schuh         Officer)

     *  KIRBY L. CRAMER      Chairman of the Board
----------------------------
      Kirby L. Cramer

    *  EDWARD V. FRITZKY     Director
----------------------------
     Edward V. Fritzky

*  STEVEN R. GOLDSTEIN, M.D. Director
----------------------------
 Steven R. Goldstein, M.D.

   *  ERNEST MARIO, PH.D.    Director
----------------------------
    Ernest Mario, Ph.D.

*  WILLIAM G. PARZYBOK, JR.  Director
----------------------------
  William G. Parzybok, Jr.

 *  JEFFREY PFEFFER, PH.D.   Director
----------------------------
   Jeffrey Pfeffer, Ph.D.


--------------------------------------------------------------------------------
II-4



Signatures
--------------------------------------------------------------------------------



          Signature                                     Title
          ---------                                     -----
                               

  *  JACQUES SOUQUET, PH.D.       Director
------------------------------
    Jacques Souquet, Ph.D.

*  RICHARD S. SCHNEIDER, PH.D.    Director
------------------------------
 Richard S. Schneider, Ph.D.

   *  DENNIS A. SARTI, M.D.       Director
------------------------------
    Dennis A. Sarti, M.D.

    /S/  MICHAEL J. SCHUH
*By:
------------------------------
       Michael J. Schuh
       Attorney-in-fact


--------------------------------------------------------------------------------
                                                                           II-5



--------------------------------------------------------------------------------


Exhibit index



Exhibit
Number
--------------------------------------------------------------------------------------------------------
     

  1.1+  Form of Underwriting Agreement

  5.1+  Opinion of Orrick, Herrington & Sutcliffe LLP, counsel to the registrant, regarding the legality
          of the common stock being registered

 23.1   Consent of KPMG LLP, Independent Auditors

 23.2+  Consent of Orrick, Herrington & Sutcliffe LLP (contained in Exhibit 5.1)

 24.1+  Power of attorney

--------
+ Previously filed.

--------------------------------------------------------------------------------