<PAGE>   1
EXHIBIT 10.2


                              CONSULTING AGREEMENT

     CONSULTING AGREEMENT, dated as of this first day of January, 1997, between
VITALCOM INC., a Delaware corporation ("VitalCom") and David L. Schlotterbeck
("Schlotterbeck").

                                    RECITALS

     WHEREAS, VitalCom will require the consulting services of a senior level
executive on an interim, part-time basis for assistance with special projects
and management in manufacturing, operations, research and development and
certain sales opportunities;

     WHEREAS, VitalCom desires to obtain consulting services and Schlotterbeck
has indicated his willingness to provide services, on the terms and conditions
set forth herein;

     NOW THEREFORE, on the basis of the foregoing premises and in consideration
of the mutual covenants and agreements herein, the parties hereto agree as
follows:

     Section 1. CONSULTING. VitalCom hereby agrees to contract for the personal
services of Schlotterbeck and Schlotterbeck hereby accepts consulting work from
VitalCom, on the terms and subject to the conditions hereinafter set forth.
Donald W. Judson, VitalCom's President & CEO ("Judson"), shall periodically
authorize Schlotterbeck to perform personal services and complete special
projects in manufacturing, operations, research and development, sales and other
areas designated by Judson . The principal location that such services shall be
rendered shall be at VitalCom's principal offices located in Tustin, California,
although Schlotterbeck understands and agrees that he may be required to travel
from time to time to accomplish assignments.

     Section 2. TERM. This consulting agreement shall commence on the date
hereof and shall continue until June 30, 1997.

     Section 3. COMPENSATION. Schlotterbeck will be paid $850 per day for
services rendered. Schlotterbeck will be remunerated for reasonable travel,
entertainment, and other expenses, such as telephone calls, incurred on behalf
of VitalCom in authorized work. Schlotterbeck will submit an itemized bill for
services rendered and expenses incurred at least one time per month. All
invoices will be submitted to Judson for approval. Payment will be made on all
invoices within 10 days after approval by Judson.



                                       24
<PAGE>   2
     Section 4. WORK AUTHORIZATION. Judson will authorize projects and work on a
weekly basis by a verbal authorization to Schlotterbeck. However, it is
anticipated that projects and services to be performed by Schlotterbeck will not
exceed one to two days work per week. Work authorization in excess of three days
per week will require a written authorization by Judson.

     Section 5. INDEPENDENT CONTRACTOR. Schlotterbeck is an independent
contractor to VitalCom. Schlotterbeck shall be responsible for any income,
employment, franchise, or any other taxes on remuneration paid by VitalCom.
Pursuant to this consulting agreement Schlotterbeck shall not be entitled to any
VitalCom fringe benefits, including but not limited to employer payroll taxes,
insurance, paid time off or pension plans.

     Section 6. SECRECY AND NON-COMPETITION. Schlotterbeck acknowledges that
during consulting assignments he will obtain and be exposed for confidential and
proprietary material, knowledge, contacts and know-how of VitalCom's which could
be used to the substantial advantage of a competitor of VitalCom and to
VitalCom's substantial detriment. During the term of this consulting agreement
and for period of two years after Schlotterbeck shall not participate or engage,
directly or indirectly, for himself on or behalf of or in conjunction with any
person, partnership, corporation or other entity, whether as an employee, agent,
officer, director, shareholder, partner, joint venturer, investor (other than
owning or holding not greater than a two percent (2%) interest in a publicly
held entity), or otherwise, in any business activities if such activity consists
of any activity undertaken or expressly contemplated to be undertaken by
VitalCom or any of its subsidiaries.

     In addition, Schlotterbeck hereby ratifies and confirms all of the terms,
provisions, and obligations set forth in that certain Proprietary Information
and Inventions Agreement entered into by Schlotterbeck and VitalCom dated August
23, 1995, and all of the terms and provisions of Section 7 of the Employment
Agreement dated August 29, 1995 by and between Schlotterbeck and VitalCom, as
amended January 5, 1996 and January 1, 1997.

Section 7. SEVERABILITY AND GOVERNING LAW. Schlotterbeck acknowledges and agrees
that the covenants set forth in Section 6 are reasonable. If any of such
covenants or such other provisions of this Agreement are found to invalid or
unenforceable by a final determination of a court of competent jurisdiction the
remaining terms and provisions hereof shall be unimpaired and the invalid or
unenforceable term shall be replaced with a valid and enforceable provision that
expresses the intent of the parties. This agreement shall be governed by and
construed in accordance with the laws of the State of California.

Section 8. TERMINATION. Either party may terminate this Agreement, except for
the provisions of Section 6, upon 15 days written notice.


                                       25
<PAGE>   3
Section 9. NOTICES. Notice, by hand delivery or mailed by overnight courier or
by registered or certified mail, postage prepaid shall be:

     (i) if to Schlotterbeck, at 57 Poppy Hill Rd., Laguna Niguel, CA 92677 
     (ii) if to VitalCom, at 15222 Del Amo Avenue, Tustin, CA 92780, Attn.:
     Donald W. Judson.

Section 10. ENTIRE AGREEMENT. This Agreement constitutes the entire
understanding and agreement of the parties hereto regarding consulting services
to be provided by Schlotterbeck. This Agreement supersedes all prior
negotiations, discussions, and understandings between the parties relating to
the subject matter of this Agreement.

     IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of
the date first above written.



                            /s/ David L. Schlotterbeck
                            ------------------------------------------
                            Consultant: David L. Schlotterbeck



                            VITALCOM INC.



                            /s/ Donald W. Judson
                            ------------------------------------------
                            Donald W. Judson
                            Its President & CEO, Chairman of the Board



                                       26