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                                                                    EXHIBIT 10.9

                              THIRD AMENDMENT TO
                    TECHNOLOGY TRANSFER AND LICENSE AGREEMENT

     This Third Amendment to Technology Transfer and License Agreement (this
"Amendment") is entered into as of March 10, 2000, by and between SonoSite, Inc.
("SonoSite" or "SONO") and ATL Ultrasound, Inc. ("ATL).

                                    RECITALS

     A.   ATL and SonoSite are parties to that certain Technology Transfer and
License Agreement, dated as of April 2, 1998, as previously amended (the
"License Agreement"), which provides for the allocation of certain rights to
technology as between ATL and SonoSite; and

     B.   ATL and SonoSite desire to amend the License Agreement as set forth in
this Amendment to provide for the respective rights of the parties to products
and joint inventions in their respective markets.

                                    AGREEMENT

     In consideration of the terms and conditions provided below and for other
good and valuable consideration the receipt and sufficiency of which is hereby
acknowledged, the parties hereto agree to amend the License Agreement as
follows:

Section 1.0  Definitions

     Paragraph (b) of Section 1.0 of the License Agreement is amended by adding
a second paragraph as follows:

               Notwithstanding the generality of the foregoing, "ATL Technology"
          shall not include detailed specification documents, software or
          records that are used solely to reduce to practice, in current or
          future commercially-released ATL ultrasound products, the ATL
          Technology described in the preceding paragraph ("ATL Product-Specific
          Data"). ATL Product-Specific Data may include, without limitation,
          component part and assembly specification drawings or computer aided
          design data files, as well as manufacturing fabrication, assembly, and
          test procedures, to the extent any of the foregoing are associated
          with a specific current or future commercially-released ATL product or
          ATL product component. While excluded from the definition of ATL
          Technology, such ATL Product-Specific Data may be selected and made
          available to SonoSite at ATL's sole discretion to describe ATL
          Technology for the purposes of this Agreement.

     Paragraph (c) of Section 1.0 of the License Agreement is amended by adding
a second paragraph as follows:

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               Notwithstanding the generality of the foregoing, "SONO
          Technology" shall not include detailed specification documents,
          software or records that are used solely to reduce to practice, in
          current or future commercially-released SonoSite ultrasound products,
          the SONO Technology described in the preceding paragraph ("SonoSite
          Product-Specific Data"). SonoSite Product-Specific Data may include,
          without limitation, component part and assembly specification drawings
          or computer aided design data files, as well as manufacturing
          fabrication, assembly, and test procedures, to the extent any of the
          foregoing are associated with a specific current or future
          commercially-released SonoSite product or SonoSite product component.
          While excluded from the definition of SONO Technology, such SonoSite
          Product-Specific Data may be selected and made available to ATL at
          SonoSite's sole discretion to describe SONO Technology for the
          purposes of this Agreement.

     Paragraph (d) of Section 1.0 of the License Agreement is deleted in its
entirety and replaced with the following paragraph (d):

               (d) "Handheld Ultrasound Devices" shall mean an ultrasound system
          including a scanhead, a display device (or a data transmitter in lieu
          of a display device), and all intermediate components, together with
          all housings, controls, power sources, and output interfaces connected
          thereto, which do not weigh in the aggregate more than ten pounds.
          Handheld Ultrasound Devices shall include additional or substitute
          components intended for use with and attachment to such an ultrasound
          system which, together with such system, meet the aggregate ten pound
          limitation. The weights of any peripheral devices (specifically
          excluding the components referred to in the immediately preceding
          sentence) which may be connectable to such an ultrasound system, such
          as printers, VCRs, auxiliary monitors, battery chargers, and support
          structures such as brackets, and mobile or immobile stands (so long as
          the Handheld Ultrasound Device is not designed solely for use in
          conjunction with such support structures) shall not be included in
          such weight computation. Handheld Ultrasound Devices may be used with
          a cart that has no ultrasound signal path between the Handheld
          Ultrasound Device and the cart and its components except for a video
          output or summed digital signal output, and that may utilize a
          bidirectional communication protocol (for example, and without
          limitation, a video or summed digital signal) to exchange data or
          images with off-line review stations, archiving stations or non
          real-time image or data processing devices. This Section shall not
          prevent ATL from using wireless ultrasound probes with its
          over-fifteen-pound ultrasound systems.


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Section 2.5  Disclosure of Technology

     Section 2.5 of the License Agreement is deleted in its entirety and
replaced with the following Section 2.5:

          2.5. Disclosure of Technology. At reasonable intervals during the
          three-year-period following the Effective Date, the parties shall meet
          to disclose technology developed by the parties that is included
          within the scope of the license each party granted to the other party
          under the terms of this Agreement. Any technology that is disclosed,
          including any material and information disclosed during the meetings,
          shall be subject to the provisions in this Agreement. If SonoSite
          requests additional engineering support from ATL regarding ATL
          Technology, beyond these periodic meetings, such support will be
          provided and charged separately as an engineering service pursuant to
          the rates and terms of the relevant service agreement between the
          parties. If ATL requests additional engineering support from SonoSite
          regarding SonoSite Technology, beyond these periodic meetings, such
          support will be provided and charged separately as an engineering
          service pursuant to SonoSite's then-current rates and terms for such
          services.

          In addition, not less often than once during each six month period
          during the three-year period following the Effective Date, ATL shall
          provide SonoSite a report concerning ATL Technology developed or
          discovered during the previous six-month period, and SonoSite shall
          provide ATL a report concerning SONO Technology developed or
          discovered during the previous six-month period. Such reports shall
          include, at a minimum, a list of all patents issued and all patent
          applications filed during the six-month period covered by the report.

          ATL shall disclose to SonoSite the detailed specifications of all
          SonoSite products developed by ATL for SonoSite, including all
          information needed to manufacture and test the products (to include
          manufacturing process and procedure documentation, test software and
          source code).

Section 3.0  Royalty Payments

     The phrase "SONO and its distributors, licensee, and agents" in the first
paragraph of Section 3.0 is deleted and replaced with the word "SONO".

Section 3.1  Defined Terms

     The second and third paragraphs of Section 3.1 are deleted in their
entirety and replaced with the following paragraph:


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          For the purposes of this Section the term "net revenues" shall mean
          the gross revenues from the sale, licensing, and/or billable parts and
          labor resulting from after-the-sale service of Embedded Ultrasound
          Devices, Handheld Ultrasound Devices or Highly Portable Ultrasound
          Devices actually received by SONO (including its subsidiary companies
          and any other entities at least 50% owned by SONO or controlled by
          SONO), less any taxes (except income taxes) on the Devices, credits
          for returned Devices, quantity discounts actually given by SONO or its
          licensees, freight allowances, cash discounts actually given by SONO,
          and any agent's commissions actually paid by SONO. No royalty shall be
          payable to ATL by SONO with respect to accessories to Embedded
          Ultrasound Devices, Handheld Ultrasound Devices or Highly Portable
          Ultrasound Devices that are manufactured to SONO's functional design
          specifications, but which are developed or manufactured by a third
          party using only such third party's technology.

Section 8.0  Joint Inventions

     The License Agreement is amended by adding a new Article VIII as follows:

                             VIII. JOINT INVENTIONS

          8.0 Any patent applications (including, without limitation, any
          provisional application) filed by either party after April 6, 1998,
          claiming inventions made jointly by employees of SonoSite and ATL
          after such date ("Joint Patents") shall give rise to the rights of
          SonoSite and ATL set forth in this Section 8.

          8.1 SonoSite shall have the exclusive right under all Joint Patents to
          import, make, sell and use Handheld Ultrasound Devices and Highly
          Portable Ultrasound Devices from the Effective Date until April 6,
          2003 (the "Exclusivity Period"). Such right includes the exclusive
          right to sublicense others under all Joint Patents to import, make,
          sell and use Handheld Ultrasound Devices and Highly Portable
          Ultrasound Devices during the Exclusivity Period. During the
          Exclusivity Period, ATL shall not import, make, sell, or use, or
          license, sublicense, or otherwise grant or transfer to any third party
          the right to import, make, sell or use, any Handheld Ultrasound Device
          or Highly Portable Ultrasound Device under any Joint Patent.

          8.2 ATL shall have the exclusive right under all Joint Patents to
          import, make, sell and use ultrasound products that are not Handheld
          Ultrasound Devices or Highly Portable Ultrasound Devices during the
          Exclusivity Period. Such right includes the


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          exclusive right to sublicense others under all Joint Patents to
          import, make, sell and use ultrasound products which are not Handheld
          Ultrasound Devices or Highly Portable Ultrasound Devices during the
          Exclusivity Period. During the Exclusivity Period, SonoSite shall not
          import, make, sell or use, or license, sublicense or otherwise grant
          or transfer to any third party the right to import, make, sell or use
          any ultrasound product that is not a Handheld Ultrasound Device or
          Highly Portable Ultrasound Device under any Joint Patent.

          8.3 After April 6, 2003, SonoSite shall have the nonexclusive right
          under all Joint Patents to import, make, sell and use any and all
          ultrasound products, without the right to sublicense. SonoSite shall
          continue to have the exclusive right to sublicense others under all
          Joint Patents to import, make, sell, and use Handheld Ultrasound
          Devices and Highly Portable Ultrasound Devices, and ATL shall not
          sublicense or otherwise grant or transfer to any third party the right
          to import, make, sell, or use any Handheld Ultrasound Device or Highly
          Portable Ultrasound Device under any Joint Patent.

          8.4 After April 6, 2003, ATL shall have the nonexclusive right under
          all Joint Patents to import, make, sell and use any and all ultrasound
          products, without the right to sublicense. ATL shall continue to have
          the exclusive right to sublicense others under all Joint Patents to
          import, make, sell and use ultrasound products which are not Handheld
          Ultrasound Devices or Highly Portable Ultrasound Devices, and SonoSite
          shall not sublicense or otherwise grant or transfer to any third party
          the right to import, make, sell or use, any ultrasound product that is
          not a Handheld Ultrasound Device or Highly Portable Ultrasound Device
          under any Joint Patent.

          8.5 Attachment 8.5 lists all patents and applications identified as of
          the date of this Third Amendment for filing as Joint Patents. As other
          Joint Patents are identified they will be added to Attachment 8.5 by
          mutual agreement of the parties. Ownership of the presently identified
          registrations for Joint Patents will be assigned as indicated in
          Attachment 8.5. The assignment of ownership for future Joint Patents
          will be determined by the parties with consideration to relationships
          with previously filed applications and to assignment which will result
          in the best protection under the patent laws. If none of these
          considerations apply, ownership of each Joint Patent application will
          be to assigned to SonoSite.


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          8.6 The legal work on all Joint Patents, and all legal and filing fees
          associated therewith, will be the responsibility of the assignee
          company, unless the parties agree otherwise in a particular situation.
          Each of SonoSite and ATL release each other and the attorneys and
          agents of the other party from any and all claims which they may have
          concerning the performance of legal work on Joint Patents and the
          validity and scope of any Joint Patent.

     Except as amended by this Agreement, the License Agreement and the First
and Second Amendments are unchanged and continue in full force and effect.

     The parties hereto have caused this Agreement to be executed by their
authorized representatives as of the date first indicated above.

ATL:                                          SonoSite:

ATL Ultrasound, Inc.                          SonoSite, Inc.

By   /s/ Timothy C. Mickelson                 By   /s/ Kevin M. Goodwin
   ---------------------------------             -------------------------------
Its  President                               Its   President, CEO
    --------------------------------              ------------------------------


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                         Attachment 8.5 - Joint Patents

     1.   "Cordless Scanheads," by JJ Hwang, Lauren Pflugrath, Leo Catallo and
William Picatti, assigned to ATL and presently filed in the U.S. as application
serial numbers 09/197,398, 09/197,196, 09/197,186 and 09/196,852.

     2.   Matrix Filters," by JJ Hwang and Roy Peterson, assigned to SonoSite.

     3.   "High Frame Rate Pulse Inversion and RF Interpolation Imaging," by JJ
Hwang and Brent Robinson, assigned to ATL and presently filed in the U.S. as
application serial numbers 09/252,053 and 09/251,563.

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