Document:

<PAGE>

                                                                    Exhibit 10.2

                           Data Critical Corporation
                      19820 North Creek Parkway, Suite 100
                               Bothell, WA  98011

                                 March 7, 2001

Bradley R. Harlow
225 4th Avenue, #B402
Kirkland, WA  98033

Dear Brad:

     It is my pleasure to offer you the following terms and conditions in
consideration of your continued service as an employee of Data Critical
Corporation (the "Company").  References to "you" and "Executive" mean Bradley
R. Harlow.

     1.   Position.  Executive's position shall be Senior Vice President for the
Company with primary responsibility in business development, as well as sales
and marketing.

     2.   Compensation and Benefits.  Your compensation shall consist of the
following:

     .  An increase in your monthly salary to $15,625 (equating to $187,500 per
        year) from $12,500 (equating to $150,000 per year), subject to customary
        withholding.

     .  Forgiveness of all outstanding principal and accrued and unpaid interest
        on the Promissory Note in the original principal amount of forty-three
        thousand, five hundred thirty-six dollars and sixty-two cents
        ($43,536.62), dated as of July 18, 1997 and executed by you in favor of
        the Company, such forgiveness to be governed by the terms and conditions
        set forth in the letter agreement, dated December 8, 2000, between you
        and the Company.

     .  You will be entitled to payment of a one time cash bonus in the amount
        of $20,000 (subject to customary withholding) in the event (and solely
        in the event) that and upon (i) the Company consummates the proposed
        acquisition as contemplated by Project Viper currently underway and (ii)
        following such acquisition, completion under your oversight of a new
        revenue-bearing integration, license or OEM relationship that includes
        contractual minimum revenues on a quarterly basis with a Data Critical
        Partner such as Philips or GE ("Partner") on such terms and conditions
        that are at least as beneficial to the Company as the terms and
        conditions of the Company's current license agreement with Agilent.

     .  You will be entitled to a minimum year-end bonus of $30,000 (assuming
        you are an employee through December 31, 2001), payable in cash no later
        than January 2002. The Company's Compensation Committee will direct any
        bonus in excess of this amount.

     .  You shall receive a grant of options to purchase 20,000 shares of the
        Company's common stock (the "Option"). The Option shall be granted on
        the standard terms and
<PAGE>

        conditions of the Company's 1999 Stock Option Plan, except that the
        Option will vest in equal monthly installments over a 12-month period
        commencing on the date of grant.

     You will continue to be eligible to participate in our employee benefits
program. The Company currently pays all premiums for its employees and their
dependents' medical, dental, vision, prescription drug card coverage and
employee assistance program through group plans. In addition, the Company pays
for basic life, accidental death and dismemberment and long-term disability
insurance for its employees. Pursuant to our current plan, you will continue to
be eligible for these group benefits. All group insurance benefits arc subject
to change.

     The Company offers a 401(k) plan to all eligible employees. This is an
employee-contribution-only plan provided as a retirement vehicle and as means of
deferring federal income taxes. You may continue making contributions through
payroll deduction.

     3.   Term of Agreement; At-Will Employment.

          (a)  This letter agreement shall commence on the date a countersigned
copy of this letter is received by the Company and shall be in effect for a
period of one year, subject to earlier termination as set forth below (the
"Original Term").

          (b)  The Company and Executive acknowledge that Executive's employment
is and shall continue to be at-will, as defined under applicable law, and that
Executive's employment with the Company may be terminated by either party at any
time for any or no reason, subject to the terms of this letter agreement. If
Executive's employment terminates for any reason, Executive shall not be
entitled to any payments, benefits, damages, award or compensation other than as
provided in this letter agreement or as otherwise required by law. Any payments,
benefits, damages, awards, or other compensation provided for hereunder upon any
termination hereof shall be inclusive of (and not additive to) any such amounts
required pursuant to any applicable law. The rights and duties created by this
Section 3 may not be modified in any way except by a written agreement executed
by the Board of Directors of the Company.

     4.   Severance.  In the event that the Company terminates you at any point
in time without cause at any time during the Original Term of this letter
agreement, the Company will continue to pay your monthly salary of $15,625 per
month, and subject to customary withholding) for a period of six months after
such termination in accordance with its standard payroll procedures. Employee
will continue to receive health benefits over the six-month severance period.
For purposes of this letter, "cause" shall mean, the commission of an act of
fraud or dishonesty in the course of your employment with the Company;
conviction of a crime constituting a felony or in respect of any act of fraud,
dishonesty or moral turpitude; failure to perform the duties assigned to you
material to the business conduct of the Company under circumstances in which you
knew or should have reasonably known that such failure would be detrimental to
the Company, unless you remedy such failure not later than 30 days following
delivery to you of a written notice from the Company describing such failure in
reasonable detail.

     5.   Noncompetition Covenant.  Executive hereby agrees that he shall not,
during the term of his employment pursuant to this letter agreement and for a
period of one year after termination of his employment with the Company and/or
any of its affiliates for any reason, do any

                                       2
<PAGE>

of the following without the prior written consent of the Board of Directors of
the Company (for purposes of this Section, the term "Company" shall mean the
Company and each of its subsidiaries):

          (a)  Compete.  Carry on any business or activity (whether directly or
indirectly, as a partner, stockholder, principal, agent, director, affiliate,
employee, advisor or consultant) for any company or other enterprise carrying on
or proposing to carry on any business or having any product line related to the
business of the Company, including, without limitation, wireless devices,
products, hardware of software for the healthcare industry, remote monitoring
of, or transmission of, ECGs or other patient medical information, any pacemaker
software or hardware products or technology, cardiology-related software,
physician charting products, electronic charge capture or any current or
currently planned (at the time of Executive's termination) products or
businesses by the Company, or that are otherwise competitive with the business
conducted by or planned to conducted by the Company, nor engage in any other
activities that conflict with Executive's obligations to the Company (any such
company or enterprise, being a "Competitor").

          (b)  Solicit Business.  Solicit or influence or attempt to influence
any client, customer or other person either directly or indirectly, to direct
his or its purchase of the Company's products and/or services to any Competitor.

          (c)  No-Hire.  Solicit or influence or attempt to influence, directly
or indirectly, any person employed by the Company or any of its affiliates to
terminate or otherwise cease his employment with the Company or hire any such
person within G months after such person's leaving the Company's employ.

          (d)  Equitable Remedies.  Executive acknowledges and agrees that
Executive's breach of this letter agreement will cause irreparable injury to the
Company for which money damages and other remedies at law would be inadequate,
and as such that the Company and/or its affiliates shall be entitled to
equitable remedies, including, without limitation, specific performance and/or
temporary or permanent injunctive relief.

          (e)  Scope.  Executive acknowledges and agrees that the Company has
relied and is relying on the covenants contained herein in their decision to
enter into this letter agreement and that in light of such reliance the
covenants contained herein are fair and reasonable.

     6.   Effect on other Agreements.  Executive acknowledges and agrees that
all other agreements executed by Executive with or on behalf of the Company,
including without limitation, any confidentiality agreement and any assignment
of inventions agreement, shall remain in full force and effect without
modification; provided, however that in the event (and solely to the extent) the
terms of this letter agreement and any other such agreement conflict, the terms
of this letter agreement shall be deemed to govern.

     7.   Miscellaneous Provisions.

          (a)  Amendments and Waivers.  The terms of this letter agreement may
only be amended or waived only with the written consent of the parties.

          (b)  Sole Agreement.  Subject to Section 6 above, this letter
agreement, including any Exhibits hereto, constitutes the sole agreement of the
parties and supersedes all oral negotiations and prior writings with respect to
the subject matter hereof.

                                       3
<PAGE>

          (c)  Notices.  Any notice required or permitted by thus letter
agreement shall be in writing and shall be deemed sufficient upon receipt, when
delivered personally or by a nationally-recognized delivery service (such as
Federal Express or UPS), or 48 hours after being deposited in the U.S. mail as
certified or registered mail with postage prepaid, if such notice is addressed
to the party to be notified at such party's address as set forth below or as
subsequently modified by written notice.

          (d)  Choice of Law.  The validity, interpretation, construction and
performance of this letter agreement shall be governed by the laws of the State
of Washington, without giving effect to the principles of conflict of laws.

          (e)  Severability.  If one or more provisions of this letter agreement
are held to be unenforceable under applicable law, the parties agree to
renegotiate such provision in good faith. In the event that the parties cannot
reach a mutually agreeable and enforceable replacement for such provision, then
(i) such provision shall be excluded from this letter agreement, (ii) the
balance of the Agreement shall be interpreted as if such provision were so
excluded and (iii) the balance of the Agreement shall be enforceable in
accordance with its terms.

          (f)  Counterparts.  This letter agreement 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.

          (g)  Arbitration.  Any dispute or claim arising out of or in
connection with this letter agreement will be finally settled by binding
arbitration in Seattle, Washington in accordance with the rules of the American
Arbitration Association by one arbitrator appointed in accordance with said
rules. Judgment on the award rendered by the arbitrator may be entered in any
court having jurisdiction thereof. Notwithstanding the foregoing, the parties
may apply to any court of competent jurisdiction for preliminary or interim
equitable relief, or to compel arbitration in accordance with this paragraph,
without breach of this arbitration provision.

          (h)  Survival.  The provision of Sections 4, 5 and 6(g) shall survive
both the termination of this letter agreement and/or the termination of the
Executive's employment with the Company and/or its affiliates.

          (i)  Advice of Counsel.  EACH PARTY TO THIS LETTER AGREEMENT
ACKNOWLEDGES THAT, IN EXECUTING THIS LETTER AGREEMENT, 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 LETTER AGREEMENT. THIS LETTER
AGREEMENT SHALL NOT BE CONSTRUED AGAINST ANY PARTY BY REASON OF THE DRAFTING OR
PREPARATION HEREOF.

                           [Signature Page Follows]

                                       4
<PAGE>

     The parties have executed this letter agreement the date first written
above.

                                       DATA CRITICAL CORPORATION:

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

                                       Title:  EVP, CFO
                                             ----------------------------

                                       19820 North Creek Parkway
                                       Suite 100
                                       Bothell, WA  98011

                                       BRADLEY R. HARLOW

                                       Signature:  /s/ Bradley R. Harlow
                                                 ------------------------

                                       225 4th Avenue, #B402
                                       Kirkland, WA  98033

                                       5<PAGE>

                                                                    Exhibit 10.3

                   SECOND AMENDMENT TO EMPLOYMENT AGREEMENT

     This Second Amendment to Employment Agreement (the "Second Amendment") is
made as of March 11, 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") (the Original Employment Agreement, as amended by the First
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.   All capitalized terms used herein but not defined herein shall have
the meanings ascribed thereto in the Employment Agreement.

     2.   The following shall be added as a preamble to the Employment Agreement
immediately prior to Section 1 thereof:

     "For purposes of this Agreement, the team "Target Date" shall mean August
     24, 2001. For clarity purposes, references in this Agreement to the
     termination or continuation of Employee's employment with the Company are
     intended to refer to his termination or continuation as an officer and/or
     employee of the Company, whether or not he continues to serve as a director
     of, or consultant to, the Company."

     3.   Section 1 of the Employment Agreement is hereby amended to delete the
reference therein to the date "January 1, 2001" and to substitute therefor the
date "August 24, 2001."

     4.   Section 4(b) of the Employment Agreement is hereby amended to:

          (a)  add the following sentence to Section 4(b)(ii) thereof.

               "Employee shall not be entitled to any bonus pursuant to this
               Section in respect of the 2001 calendar year."; and

          (b)  add the following as a new Section 4(b)(iii) thereto:

                    "(iii)  Provided that the Company enters into a definitive
               agreement in respect of Project Viper while Employee continues to
               be employed with the Company and notwithstanding whether or when
               such project is
<PAGE>

               consummated, then the Company shall pay to Employee a bonus in
               the aggregate amount of $275,000 payable in equal monthly
               installments commencing on the last day of the month in which
               Project Viper closes and continuing on the last day of each month
               thereafter through and until December 31, 2001; provided that if
               Employee's employment with the Company is terminated for any
               reason after such bonus has accrued, the remaining unpaid portion
               of such bonus shall be payable on the last day of Employee's
               employment with the Company."

     5.   Section 4(c) of the Employment Agreement is hereby amended by
renumbering existing Section 4(c)(iii) as Section 4(c)(vi) and inserting new
Sections 4(c)(iii), 4(c)(iv) and 4(c)(v) as follows:

          "(iii)  The Board of Directors shall also grant to Employee on March
     12, 2001 an option to purchase 75,000 shares of the Company's Common Stock,
     which shares will have an exercise price equal to the fair market value per
     share (equal to the per share price of such shares at the close of regular
     trading) on March 9, 2001. Provided Employee continues to be employed by
     the Company on the Target Date, this option shall become exercisable, and
     shall vest in full, on the Target Date. If Employee's employment with the
     Company is terminated in accordance with Sections 5(a)(i), (iii) or (v) of
     this Agreement prior to the Target Date, the options described in this
     Section shall automatically expire and be terminated.

          (iv)    Upon the termination of the Employee's employment with the
     Company for any reason and notwithstanding anything contained in any
     applicable Stock Option Plan of the Company or any Stock Option Agreement
     relating thereto, Employee hereby agrees that the unvested portion of all
     options for the purchase of the Company's common stock previously granted
     to Employee up to such time shall automatically expire and be immediately
     terminated.

          (v)     Provided Employee continues to be employed by the Company
     through the Target Date and notwithstanding anything contained in any
     applicable Stock Option Plan of the Company or any Stock Option Agreement
     relating thereto, all options for the purchase of the Company's stock
     previously granted to the Employee through the Target Date (including
     pursuant to Sections 4(c)(iii) above) shall be and remain exercisable and
     non-terminable until the earlier of (1) the fourth anniversary of the date
     on which Employee ceased to be an "Employee" or a "Consultant" under (and
     as such terms are defined in) the Company's 1999 Stock Option Plan or (2)
     the expiration date of such options. The Board of Directors of the Company
     and the Company shall take such actions as shall be required to effect such
     provision."

     6.   The first sentence of Section 5(b)(i) of the Employment Agreement is
hereby deleted and the following shall be substituted therefor:

          "If Employee's employment terminates by Voluntary Termination prior to
     the Target Date, then Employee shall not be entitled to receive payment of
     any severance benefits, payment or other entitlement pursuant hereto other
     than as set forth in this Section 5(b)(i). If the Employee's employment
     terminates by Voluntary Termination after

                                       2
<PAGE>

     the Target Date, Employee shall continue to be entitled to the compensation
     and benefits set forth in Sections 4(b)(iii), 4(c)(iii), 4(c)(iv), 4(c)(v),
     5(c), 5(d) and 5(e), and to the payment set forth in this Section 5(b)(i),
     but shall not otherwise be entitled to payment of any severance benefits or
     other amounts pursuant hereto."

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

          "(ii)  Termination Without Cause.  Pursuant to Section 1, Employee may
     not be Terminated Without Cause on or prior to die Target Date. If
     Employee's employment with the Company is terminated pursuant to Section
     5(a)(ii) or 5(a)(iv) after the Target Date, then Employee shall be entitled
     solely to payment of amounts as specified in Section 5(b)(i) above, with no
     rights to receive any other severance benefits, payments or other
     entitlements other than as specified in such Section."

     8.   Section 5(b)(iii) of the Employment Agreement is hereby amended (x) to
add the following immediately after the section heading "Termination for Cause":

          "(1)   Termination On or Prior to the Target Date"; and

(y) to add the following at the conclusion of the Section:

          "(2)   Termination After the Target Date.  In the event the Employee
     is terminated by way of Termination for Cause after the Target Date, the
     Employee shall be entitled to all amounts payable to him pursuant to
     Section 5(b)(iii)(1) above, and shall otherwise be entitled to all other
     rights and benefits which pursuant to the terms hereof have accrued to the
     Employee as a result of his employment by the Company through the Target
     Date. The Employee shall not be entitled to any other payments, rights or
     entitlements.

     9.   Section 5(b)(iv) is hereby amended and restated in its entirety to
read as follows:

          "(iv)  Constructive Termination.  "Constructive Termination" shall be
     deemed to have occurred if (A)(1) the Employee ceases to report directly to
     the Chief Executive Officer of the Company, (2) a substantial portion of
     the Employee's duties as Chief Financial Officer are assigned to another
     employee of the Company (other than to an employee reporting to the
     Employee) or any other employee shall be designated as the Chief Financial
     Officer of the Company, (3) the Employee is required to, and refuses to,
     relocate to a facility or location more than 30 miles from the Company's
     current location, or (4) there is a reduction in the Employee's base
     compensation; and (B) within the 30 day period following any such event;
     the Employee elects to terminate his employment voluntarily. For all
     purposes of this Agreement, die Constructive Termination of the Employee
     shall be deemed an involuntary Termination Without Cause in accordance with
     Sections 5(a)(ii) and 5(b)(ii) of this Agreement. Notwithstanding anything
     contained herein to the contrary, the Company covenants and agrees not to
     authorize or undertake any of the actions specified in the immediately
     preceding clauses (A)(1) through (A)(4) prior to the Target Date."

     10.  Section 5(b)(v) of the Employment Agreement is hereby amended (x) to
add the following immediately after the section heading "Termination by Reason
of Death or Disability":

                                       3
<PAGE>

          "(1)   Termination Prior to the Target Date"; and

(y) to add the following at the conclusion of the Section:

          "(2)   Termination On or After the Target Date.  In the event the
     Employee is terminated on or after the Target Date as a result of
     Employee's Death or Disability, the Employee shall be entitled to all
     amounts payable to him pursuant to Section 5(b)(v)(1) above, and shall in
     addition be entitled to all other rights and benefits which pursuant to the
     terms hereof have accrued to the Employee as a result of his employment by
     the Company through the Target Date. The Employee shall not be entitled to
     any other payments, rights or entitlements."

     11.  Section 5(b)(vi) of the Agreement is hereby deleted in its entirety.

     12.  Section 5 of the Employment Agreement is hereby further amended by
adding new Sections 5(c), 5(d), 5(e) and (f) as follows:

          "(c)   Health Benefits.  If Employee shall remain employed by the
     Company through the Target Date, Employee shall be entitled to fully-paid
     coverage under the Company's group health plan for one (1) year following
     any termination of Employee's employment for any reason other than a
     Termination for Cause.

          (d)    Board Membership.  In the event that Employee's employment with
     the Company is terminated for any reason whatsoever, Employee. shall,
     promptly upon the request of a majority of the other members of the Board
     of Directors, resign from the Board of Directors. The Company agrees that,
     so long as Employee is either employed by the Company or serving as a
     director of the Company, Employee shall be appointed to any Selection
     Committee of the Board of Directors formed for the purpose of selecting a
     new Chief Executive Officer.

          (e)    Publicity.  Employee and the Company agree that Employee shall
     be given the opportunity to review and approve (such approval not to be
     unreasonably withheld) any press releases or other public announcement of
     the Company in respect of the termination of Employee's employment with the
     Company for any reason.

          (f)    Non-Disparagement.  Each of the Employee and the Company agree
     to refrain from making any disparaging or derogatory comment in the future
     to the press or any individual or entity regarding the other that relates
     to their activities or relationship, which comment would likely cause
     material damage or harm to the business interests or reputation of other."

     13.  The terms and provisions of the Employment Agreement, as amended by
the First Amendment shall remain in full force and effect except to the extent
expressly modified hereby. All references to the "Agreement" contained in the
Employment Agreement shall mean the Employment Agreement, as amended by the
First Amendment and this Second Amendment.

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

                                       4
<PAGE>

     15.  This Second Amendment and the rights and obligations of the parties
hereto shall be governed by, and construed in accordance with, the laws of the
State of Washington, without regard to the conflicts of laws principles thereof.

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

                                       DATA CRITICAL CORPORATION

                                       By:  /s/ Richard Earnest
                                          ------------------------------
                                       Name:
                                       Title:

                                       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

                                       5

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00022-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00022-of-00352.parquet"}]]