EXHIBIT 10.9
                SECOND LEASE MODIFICATION AND EXTENSION AGREEMENT
      THIS SECOND LEASE MODIFICATION AND EXTENSION AGREEMENT is made and entered
into this 12th day of April, 2004, by and between AMB PROPERTY, L.P., a Delaware
limited partnership (hereinafter referred to as "Lessor"), and MEDWAVE, INC., a
Minnesota corporation (hereinafter referred to as "Lessee").
WITNESSETH:
      WHEREAS, Lessor and Lessee have entered into a lease agreement dated the
10th day of April, 1997, (hereinafter referred to as "Lease"), and the Lease was
amended on November 30, 1999, and on March 29, 2002, wherein Lessor leased to
Lessee and Lessee rented from Lessor ▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇ West ("Premises")
consisting of approximately 5,964 square feet of net rentable area in the
Building commonly known as Round Lake Business Center;
WHEREAS, the Term of the Lease as set forth in the Lease was to expire May 31,
2004; and
      WHEREAS, at the special insistence and request of Lessee, Lessor has
agreed to extend the Term of the Lease, and make such other amendments to the
Lease as provided below.
      NOW, THEREFORE, in consideration of the mutual promises of the parties
hereto and other good and valuable consideration, the receipt and sufficiency of
which are hereby acknowledged, the Lease shall be amended as follows:
      1.    Recitals. The above recitals shall constitute an integral pact of
            this Amendment.
      2.    Capitalized Terms. Capitalized terms set forth in this Amendment
            shall have the same meaning as in the Lease, unless specifically
            modified and amended herein.
      3.    Term of Lease. The Term of the Lease shall be extended for an
            additional three (3) years commencing June 1, 2004, and terminating
            May 31, 2007, unless earlier terminated, as provided in the Lease
            (the "Extended Term").
      4.    Monthly Base Rent. During the Extended Term, Lessee shall pay to
            Lessor as Monthly Base Rent on or before the fret day of each month
            per the terms and conditions set forth in the Lease as follows:
            (a)   June 1, 2004, through May 31, 2005: Two Thousand Eight Hundred
                  Fifty-Seven and 75/100 Dollars ($2,857.75).
            (b)   June 1, 2005, through May 31, 2006: Two Thousand Nine Hundred
                  Thirty-Two and 30/100 Dollars ($2,932.30).
            (c)   June 1, 2006, through May 31, 2007: Two Thousand Nine Hundred
                  Seventy-Two and 06/100 Dollars ($2,972.06).
      5.    Tenant Improvements: Lessor shall, at Lessor's expense, replace one
            HVAC unit on the westerly portion of the Premises. The work will be
            performed during regular business hours.
      6.    Notices. All bills, statements or notices of communications which
            Lessor may desire or be required to give to Lessee shall be deemed
            sufficiently given or rendered if in writing and either delivered to
            Lessee personally or sent by registered or certified mail addressed
            to Lessee at the Demised Premises, and at the time of the rendition
            thereof of such notice or communication shall be deemed to be the
            time when the same is delivered to Lessee or deposited in the mail
            as herein
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provided. Any notice by Lessee or Lessor must be served by registered or
certified mail addressed to Lessor at the following address:
AMB Property, L.P.                           WITH A COPY TO:
c/o CB ▇▇▇▇▇▇▇ ▇▇▇▇▇, Inc.                   AMB Property Corporation
770 Minnesota Center                         Asset Manager - Minneapolis
▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇ South                     ▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇▇
▇▇▇▇▇▇▇▇▇▇▇, ▇▇  ▇▇▇▇▇-▇▇▇▇                  ▇▇▇▇▇▇, ▇▇  ▇▇▇▇▇
      7.    Headings. Paragraph headings used in this Amendment are for
            convenience only, and shall not affect the construction of this
            Amendment.
      8.    Construction. This Amendment shall be construed under the laws of
            the State of Minnesota. Whenever possible, each provision of this
            Amendment shall be interpreted in such manner as to be effective and
            valid under applicable law. If any term or provision of this
            Amendment shall to any extent be held invalid or unenforceable, the
            remainder shall not be affected thereby, and each other term or
            provision of this Amendment shall be valid and be enforced to the
            fullest extent permitted by law.
      9.    Survival of Other Terms and Conditions. Except as modified herein,
            all other terms and conditions of the Lease shall remain in full
            force and effect, and nothing herein shall be construed to relieve
            either Lessor or Lessee of any obligations as set forth herein.
      10.   Entire Agreement. This Least Modification and Extension Agreement,
            the Lease and Exhibits thereto set forth all covenants, promises,
            agreements, conditions and understandings between Lessor and Lessee
            concerning the Leased Premises. No representations, warranties,
            undertakings or promises, whether oral, implicated, written or
            otherwise, have been made by either party hereto to the other unless
            expressly stated in this Lease Modification and Extension Agreement
            or unless mutually agreed to in writing between the parties hereto
            after the date hereof, and neither party has relied upon any verbal
            representations, agreements, or understandings not expressly set
            forth herein. Except as herein otherwise provided, no subsequent
            alteration, amendment, change or addition to this Lease shall be
            binding upon Lessor or Lessee unless reduced to writing and signed
            by them. All other tears and conditions as stated in the Lease
            remain in full force and effect.
      11.   Option Rights. Any option rights which may have existed under the
            terms of the Lease shall terminate as of the date of the execution
            of this Amendment.
      12.   Submission of Amendment. The submission of this Amendment to Lease
            Agreement for examination does not constitute a reservation of or
            option for the Leased Premises, and this Amendment shall become
            effectively only upon execution and delivery thereof by Lessor and
            Lessee.
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      IN WITNESS WHEREOF, the parties hereto have executed this Amendment as of
the day and year first above written.
LESSEE:                                    LESSOR:
Medwave, Inc.,                             AMB PROPERTY, L.P.,
a Minnesota corporation                    a Delaware limited partnership
                                           By: AMB Property Corporation
                                               a Maryland corporation
                                               Its general partner
By: _________________________________      By: _________________________________
Its: ________________________________      Its:_________________________________
Medwave
Attn:  ▇▇▇ ▇'▇▇▇▇▇▇
▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇
▇▇▇▇▇▇▇, ▇▇  ▇▇▇▇▇
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