Document:

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                                                                    Exhibit 10.8

                              THIRD AMENDMENT TO
                             EMPLOYMENT AGREEMENT
                           Dated as of July 2, 2001

     THIS THIRD AMENDMENT TO EMPLOYMENT AGREEMENT (this "Amendment") is entered
into as of July 2, 2001 (the "Effective Date") between Data Critical Corporation
("Data Critical" or the "Company") and Michael E. Singer ("you" or the
"Executive").

                                  WITNESSETH:

     WHEREAS, the Company and the Executive have entered into a certain
employment agreement dated as of June 14, 1999, an Amendment of Employment
Agreement dated as of February 24, 2000 and a Second Amendment to Employment
Agreement dated as of March 11, 2001 (collectively, the "Original Employment
Agreement") setting forth certain agreements with respect to terms of the
Executive's employment with the Company; and

     WHEREAS, in connection with the Company's acquisition of VitalCom, Inc. and
as a result of the related consolidation and move of the Company's operations to
Tustin, California, the parties hereto wish to amend the terms of the Original
Employment Agreement as hereinafter set forth (the Original Employment
Agreement, as amended by this Amendment, being collectively, the "Employment
Agreement");

     NOW THEREFORE, in consideration of the mutual premises set forth herein and
for other good and valuable consideration, the receipt and sufficiency of which
are hereby acknowledged, the parties hereto hereby agree as follows:

     SECTION 1.  Amendments.  The Original Employment Agreement is hereby
amended as follows:

          Section 5(b)(ii) of the Original Employment Agreement is hereby
     amended and restated in its entirety to read as follows:

               "(ii) Termination Without Cause.  Based on overall Company policy
          and as an Officer of the Company and pursuant to Section 1, after
          August 24, 2001, the Company may not terminate Employee's employment
          with the Company without cause unless it provides Employee at least
          thirty (30) days' advance written notice of such termination.  In
          addition, in the event that at any time prior to December 30, 2001:

                    (a) the Company terminates your employment at any point in
               time without cause, or

                    (b) as a requirement of your continued employment with the
               Company, the Company requires you to permanently relocate to
               Tustin, California and rather than relocate, you elect to
               voluntarily terminate your employment with the Company (which
               event shall be deemed a termination without cause),

          then in either such case as an Officer of the Company and based on
          stated company policy, the Company will pay you $19,000 per month
          (subject to customary withholding) for a period of two months after
          such termination in accordance with the Company's standard payroll
          procedures.

     SECTION 2.  Effect on Original Employment Agreement.  This Amendment amends
the Original Employment Agreement and all terms of this Amendment shall be
deemed incorporated
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into and made a part of the Original Employment Agreement. Except as and to the
extent specifically modified by the terms of this Amendment, all terms of the
Original Employment Agreement shall remain in full force and effect. All
references to the Employment Agreement in any other agreement or document, and
all references in the Employment Agreement to "this Agreement," "hereof,"
"hereunder," or "hereto" or words of similar import shall be deemed to be
references to the Original Employment Agreement as amended hereby.

     SECTION 3.  Miscellaneous Provisions.

     3.1  Choice of Law.  The validity, interpretation, construction and
performance of this Amendment shall be governed by the laws of the State of
Washington, without giving effect to the principles of conflict of laws.

     3.2  Counterparts.  This Amendment may be executed in counterparts, each of
which shall be deemed an original, but all of which together will constitute one
and the same instrument.

     3.3  Advice of Counsel.  EACH PARTY TO THIS AMENDMENT ACKNOWLEDGES THAT, IN
EXECUTING THIS AMENDMENT, SUCH PARTY HAS HAD THE OPPORTUNITY TO SEEK THE ADVICE
OF INDEPENDENT LEGAL COUNSEL, AND HAS READ AND UNDERSTOOD ALL OF THE TERMS AND
PROVISIONS OF THIS AMENDMENT.  NEITHER THE ORIGINAL EMPLOYMENT AGREEMENT NOR
THIS AMENDMENT SHALL BE CONSTRUED AGAINST ANY PARTY BY REASON OF THE DRAFTING OR
PREPARATION HEREOF.

                           [Signature Page Follows]

                                       2
<PAGE>

     The parties have executed this Amendment on the date first written above.

                                 DATA CRITICAL CORPORATION

                                 By:     /s/ Richard L. Earnest
                                    ----------------------------------
                                 Name:  Richard L. Earnest
                                 Title: Chief Executive Officer

                                 MICHAEL E. SINGER

                                 Signature:   /s/ Michael E. Singer
                                           ---------------------------

                                       3<PAGE>
                                                                    Exhibit 10.9

                              FOURTH AMENDMENT TO
                              EMPLOYMENT AGREEMENT

          This Fourth Amendment to Employment Agreement (the "Fourth Amendment")
is made as of July 18, 2001 by and between Michael Singer ("Employee") and Data
Critical Corporation, a Delaware corporation (the "Company").

                                  WITNESSETH

          WHEREAS, Employee and the Company are parties to an Employment
Agreement dated as of June 14, 1999 (the "Original Employment Agreement") and to
an Amendment of Employment Agreement dated as of February 24, 2000 (the "First
Amendment") and to a Second Amendment to Employment Agreement dated as of March
11, 2001 (the "Second Amendment") and to a Third Amendment to Employment
Agreement dated as of July 2, 2001 (the "Third Amendment") (the Original
Employment Agreement, as amended by the First Amendment, Second Amendment and
Third Amendment, is herein referred to as the "Employment Agreement");

          WHEREAS, Employee and the Company wish to amend the Employment
Agreement as set forth in this Amendment;

          NOW, THEREFORE, in consideration of the mutual consideration,
promises, representations and covenants set forth herein, the receipt and
sufficiency of which are hereby acknowledged, Employee and the Company agree as
follows:

                                   AGREEMENT

          1.   Section 4(c)(v) of the Employment Agreement hereby is deleted in
its entirety.

          2.   The first sentence of Section 5(b)(i) of the Employment Agreement
hereby is amended by the deletion of the reference to Section 4(c)(v) therein.

          3.   This Fourth Amendment may be executed in one or more
counterparts, all of which shall be considered one and the same agreement.
<PAGE>

          IN WITNESS WHEREOF, the parties hereto have executed this FOURTH
AMENDMENT TO EMPLOYMENT AGREEMENT as of the date and year first above written.

                                 DATA CRITICAL CORPORATION

                                 By:     /s/ Richard L. Earnest
                                     --------------------------------
                                 Name:  Richard L. Earnest
                                 Title: Chief Executive Officer

                                 Address:  19820 North Creek Parkway
                                           Suite 100
                                           Bothell, WA  98011

                                 MICHAEL E. SINGER

                                         /s/ Michael E. Singer
                                     --------------------------------

                                 Address:  2404 86th Avenue NE
                                           Bellevue, WA  98004

                                       2<PAGE>
                                                                   Exhibit 10.10

                           Data Critical Corporation
                     19820 North Creek Parkway, Suite 100
                               Bothell, WA 98011
                 phone (425) 482-7000/facsimile (425) 482-7010

July 18, 2001

Michael E. Singer
Executive Vice President, Corporate Development
and Chief Financial Officer

Dear Michael:

     In appreciation of your contributions to the Company, I would like to offer
you a cash bonus of $200,000 that will vest and be payable immediately upon the
closing of our merger with and into a General Electric Company affiliate.  This
amount will be in addition to any other payments and benefits to which you are
entitled under your other agreements with the Company.

                                    Very truly yours,

                                    DATA CRITICAL CORPORATION

                                         /s/ Richard L. Earnest
                                    ---------------------------------
                                    By:  Richard L. Earnest
                                    Title:  Chief Executive Officer

ACCEPTED AND AGREED:

MICHAEL E. SINGER

   /s/ Michael E. Singer
---------------------------

ACKNOWLEDGED:

GENERAL ELECTRIC COMPANY

By:    /s/ Pamela Krop
   ------------------------
Name:  Pamela Krop
Title: Vice President and General Counsel<PAGE>
                                                                   Exhibit 10.11

             FIRST AMENDMENT TO LICENSE AND DISTRIBUTION AGREEMENT

     This FIRST AMENDMENT TO LICENSE AND DISTRIBUTION AGREEMENT ("First
Amendment") is made this 30th day of June, 2001 by and between AGILENT
TECHNOLOGIES, INC, a Delaware corporation (together with its subsidiaries and
successors, being collectively, "Agilent"), and DATA CRITICAL CORPORATION, a
Delaware corporation (together with its subsidiaries and successors, being
collectively, "Data Critical" and together with Agilent being collectively, the
"Parties" and each individually, a "Party"). The Parties agree as follows:

     WHEREAS, Agilent and Data Critical are parties to that certain Distribution
and License Agreement dated as of November 22, 2000 (the "Agreement").   Any
capitalized terms not specifically defined herein shall have the meanings
ascribed to them in the Agreement.

     WHEREAS, the parties wish to amend the Agreement and agree to certain other
terms as provided herein.

     NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, the parties hereto agree as
follows:

     1.   Section 4.5 of the Agreement is hereby amended by deleting the
amount "$750" therein and replacing the same with the amount "$650".

     2.   Section 5.1 of the Agreement is hereby amended by deleting the first
sentence thereof in its entirety and replacing the same with the following:
"Data Critical shall offer factory-only repair/replacement services, solely at
its own or licensed service facilities and solely on the terms and conditions
set forth herein (a) for the Data Critical proprietary receivers, at any time
after their initial delivery to Agilent or the end user, and (b) for the
transmitters sold by Data Critical for use with the Integrated StatView Product
after the expiration of the warranty thereon."

     3.   Section 5.2 of the Agreement is hereby amended by deleting such
section in its entirety and replacing the same with the following:

     "(a) Subject to the foregoing, Data Critical will offer Agilent
     repair/replacement services for the transmitters sold by Data Critical for
     use in connection with the Integrated StatView Product based upon the
     following pricing schedule (all hardware repair/replacement payment terms
     are net 30 from the date of invoice to Agilent) (in each case, plus
     applicable taxes and duties):

          Transmitters:  $300.00 per unit after the 14 month warranty period
     therefor..

     (b)  Subject to the foregoing, Data Critical will at no charge replace
     receivers sold by Data Critical to Agilent with new receivers (i) when
     found to be defective upon initial receipt by Agilent, or (ii) when found
     to be defective upon initial delivery to an end user. In addition for all
     other failures by receivers, Data Critical will offer Agilent
     repair/replacement services for the receivers sold by Data

<PAGE>

     Critical for use in connection with the Integrated StatView Product based
     upon the following pricing schedule (all hardware repair/replacement
     payment terms are net 30 from the date of invoice to Agilent) (in each
     case, plus applicable taxes and duties):

          Receivers: $200.00 per unit if failure not due to misuse or abuse; and
                     $100.00 per unit if returned but no failure found.

     Data Critical and Agilent agree that Data Critical will have sole
     discretion to determine whether receivers returned by Agilent are to be
     repaired/replaced or have failed due to misuse or abuse. Misuse or abuse
     will include, but will not be limited to, water damage, severe shock or
     substantial case damage." For the first twelve months that Agilent ships
     receivers to end customers, findings of misuse or abuse will not constitute
     more than 5% of the total repair returns. Further limits on this percentage
     deemed abused will be determined at the annual contract reviews.

     4.   Section 9.2 of the Agreement is hereby amended (a) by deleting the
phrase "its proprietary receivers and" from the first sentence thereof, (b) by
deleting the phrase ", in each case," from the first sentence thereof, and (c)
by deleting the phrase "receiver or" from the last sentence thereof.

     5.   After Agilent has been shipping receivers to end customers for at
least six months, Data Critical agrees to meet with Agilent to review the
performance of the receivers.

     6.   Each Party represents and warrants to the other Party that it has full
corporate power and authority to execute and deliver this First Amendment and to
perform the transactions contemplated hereunder.

     7.   The terms and provisions of the Agreement, as amended hereby, shall
remain in full force and effect.  All references to the "Agreement" contained
therein shall mean the Agreement, as amended by this First Amendment.

     8.   The execution, delivery and effectiveness of this First Amendment
shall not operate as a waiver of any right, power or remedy of the either Party
under the Agreement or any of the other instruments, documents or agreements
related thereto, if any, nor constitute a waiver of any provision contained
therein, except as specifically set forth herein.

     9.   This First Amendment shall be governed by, and construed and enforced
in accordance with, the laws of the State of New York.

     10.  This First Amendment may be executed in one or more counterparts, all
of which shall be considered one and the same agreement.

                           [Signature page follows.]

                                       2
<PAGE>

     IN WITNESS WHEREOF, each of Agilent and Data Critical has caused this First
Amendment to be signed by their respective officers duly authorized as of the
date first written above.

Agreed To:

Agilent Technologies, Inc.

By:     /s/ Anthony S. Ecock                     6/26/01
    ------------------------------          -----------------
Name:  Anthony S. Ecock                     Date
Title: General Manager

Data Critical Corporation

By:    /s/ Michael E. Singer                     6/30/01
    ------------------------------          -----------------
Name:  Michael E. Singer                    Date
Title: Executive Vice President,
       Corporate Development,
       Chief Financial Officer

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