<PAGE>

                                                                 EXHIBIT 10.28

                                 EMPLOYMENT AGREEMENT

BETWEEN:      ATHENA MEDICAL CORPORATION, a Nevada corporation (the "Company");

AND:          JAMES R. WILSON ("Employee").

DATED:        Effective May 1, 1997.

                                    R E C I T A L:

    The Company (dba A FEM Medical Corporation) is engaged in the business of 
developing and marketing feminine hygiene products and diagnostics 
world-wide. Employee is a member of the Company's Board of Directors and was 
appointed by the Board of Directors as the Company's Treasurer on October 22, 
1996.  The parties desire to set forth their agreement as to Employee's 
services as such on and after May 1, 1997.

                                      AGREEMENT:

    In consideration of the foregoing Recital and the terms, conditions and 
covenants set forth below, the parties agree as follows:

SECTION 1.  EMPLOYMENT

    The Company agrees to employ Employee for a term commencing on May 1, 
1997, and continuing until termination in accordance with Section 5.  
Employee accepts employment with the Company on the terms and conditions set 
forth in this Agreement, and agrees to perform the duties of the Company's 
Treasurer as provided in the Company's Bylaws (except as otherwise assigned 
by the Company's Board of Directors to the chief financial officer or other 
officers).  Employee further agrees to perform any specific duties assigned 
to Employee by the Company's Board of Directors.  The parties anticipate that 
Employee will be required to devote at least three days of each week on 
behalf of the Company.

    Employee agrees that in all aspects of his employment, Employee shall 
comply with the policies, standards, rules and regulations of the Company 
from time to time established, and shall perform Employee's duties 
faithfully, intelligently, to the best of Employee's ability and in the best 
interest of the Company.  The devotion of reasonable periods of time by 
Employee for personal purposes, outside non-competitive business activities 
or charitable activities shall not be deemed a 

                                       1


<PAGE>

breach of this Agreement, provided that such purposes or activities do not 
materially interfere with the services required to be rendered to or on 
behalf of the Company.

SECTION 2.  CONFIDENTIALITY

    2.1  Confidential Information

    Employee acknowledges and agrees that all research, product and equipment 
specifications, manufacturing methods, lists of the Company's customers and 
suppliers, marketing and product planning information, and other Company data 
related to its business, as well as information of third parties that the 
Company is required to keep confidential (collectively, the "Confidential 
Information"), are valuable assets of the Company.  Except for disclosures 
reasonably made to advance the business of the Company and information which 
is a matter of public record, Employee shall not, during the term of this 
Agreement or after termination of employment with the Company for any reason, 
disclose any Confidential Information to any person or use any Confidential 
Information (regardless of whether same is considered proprietary or a trade 
secret) for the benefit of Employee or any other person, except with the 
prior written consent of the Company in each instance.

    2.2  Return of Documents and Property

    Employee acknowledges and agrees that all originals and all copies of 
records, reports, files, correspondence, lists, plans, drawings, memoranda, 
notes, sketches, summaries, schedules, codes, tapes and other documentation 
and property related to the business of the Company or containing any 
Confidential Information are and shall be the sole and exclusive property of 
the Company, and shall be returned to the Company upon termination of 
Employee's employment with the Company or upon the written request of an 
authorized representative of the Company at any time.

    2.3  Related Company Policies

    Employee further agrees to comply with all policies, rules and 
regulations adopted by the Company's Board of Directors or shareholders from 
time to time with respect to insider trading and other duties applicable to 
the employees of a publicly-traded corporation.  Employee also agrees, if 
requested, to sign a separate confidentiality agreement applicable to all 
employees.  The terms of such separate agreement will control over any 
conflicting term in this Agreement.

    2.4  Injunction

    Employee agrees that it would be difficult to measure damage to the 
Company from any breach by Employee of Section 2.1, 2.2 or 2.3 and that 
monetary damages

                                       2


<PAGE>

would be an inadequate remedy for any such breach.  Accordingly, Employee 
agrees that if Employee shall breach Section 2.1, 2.2 or 2.3, the Company 
shall be entitled, in addition to any and all other remedies it may have at 
law or in equity, to an injunction or other appropriate order to restrain any 
such breach, without showing or proving any actual damage sustained by the 
Company, and without posting bond or other undertaking.

    2.5  No Release

    Employee agrees that termination of employment with the Company shall not 
release Employee from any of Employee's obligations under Section 2.1, 2.2 or 
2.3.

SECTION 3. COMPENSATION

    3.1  Amount

    In consideration of all services to be rendered by Employee to the 
Company under this Agreement, the Company shall pay to Employee compensation 
of $5,000.00 per month for a period commencing May 1, 1997, payable monthly 
in arrears or on the same dates as other management personnel are paid. 
Compensation shall be subject to the customary withholding of income taxes 
and to other employment taxes required with respect to compensation paid by 
an employer to an employee.

    3.2  Other Benefits

    Employee's services will be as a part-time employee.  Accordingly, 
neither Employee or Employee's spouse and dependents are or will be entitled 
to coverage and participation with respect to profit-sharing plan, retirement 
plan, accident and health insurance, life insurance or other employment 
benefits, unless Employee meets the respective eligibility conditions 
(including minimum hours-of-service) of each such benefit.

    3.3  Income From Employee's Efforts

    All income generated by Employee for Employee's services to the Company, 
and all activities related to such services, shall belong to the Company, 
whether paid directly to the Company or to Employee.  Employee agrees to, 
upon request by the Company from time to time, render a detailed accounting 
of all transactions during the course of Employee's employment.

                                       3


<PAGE>

    3.4  Work Made for Hire

    All techniques, processes, products, manuals, documents, materials, ideas 
and Confidential Information developed by Employee while employed by the 
Company shall be considered work made for hire and shall, unless specifically 
otherwise agreed in writing by the Company prior to such development, become 
the sole and exclusive property of the Company.

SECTION 4. EXPENSES

    The compensation provided under Section 3.1 above is intended to 
compensate Employee for normal travel expenses (such as those between 
Employer's home or office and the Company's principal office) and incidental 
expenses.  However, Employee shall be entitled to reimbursement from the 
Company for other non-ordinary reasonable expenses necessarily incurred by 
Employee in the performance of Employee's duties under this Agreement (such 
as out-of-state travel), upon presentation of vouchers detailing the amount, 
date and business purpose of each such expense.  All expenses in excess of 
$200.00 must be approved in advance by another officer of the Company, and 
all travel and related expenses and reimbursements will be governed by the 
travel policies and procedures adopted by the Company.

SECTION 5. TERMINATION

    5.1  Termination by Prior Notice or Agreement

    The employment of Employee by the Company may be terminated by either the 
Company or Employee upon the giving of 30 days' prior written notice to the 
other party.  This Agreement may be terminated at any earlier time upon the 
mutual written agreement of the Company and Employee.

    5.2  Immediate Termination

     The employment of Employee by the Company may be terminated immediately 
in the sole discretion of the Board of Directors of the Company upon the 
occurrence of any one of the following events:

    5.2.1     If Employee shall willfully and continuously fail or refuse to 
comply with any of the policies, standards, rules and regulations established 
by the Company's Board of Directors or shareholders from time to time.

    5.2.2     If Employee shall be guilty of fraud, dishonesty or any other 
act of misconduct in the performance of Employee's duties on behalf of the 
Company.

                                       4


<PAGE>

    5.2.3     If Employee shall fail or refuse to perform any provision of 
this Agreement to be performed by Employee.

    5.2.4     Upon the sale, transfer or other disposition of all or 
substantially all the assets of the Company, the distribution of the 
Company's assets to its shareholders in liquidation, or the discontinuance of 
the Company's conduct of the business described in the Recital.

    5.2.5     If Employee shall suffer a permanent disability.  For purposes 
of this Agreement, "permanent disability" shall be defined in accordance with 
the terms of any disability income policy insuring Employee which may be 
purchased by the Company, as determined by the company issuing such policy.  
But if such a policy is not in force, "permanent disability" shall be defined 
as Employee's inability due to physical or mental illness, or other cause, to 
perform the majority of Employee's usual duties for a period of three months 
or more, as determined by a physician licensed to practice medicine in Oregon 
and chosen by the Company.

    5.3  Death

    In the event Employee dies during the term of this Agreement, this 
Agreement shall automatically terminate, and the Company shall pay to 
Employee's estate the compensation which would be otherwise payable to 
Employee through the last day of the month in which Employee's death occurs.

    5.4  Proration of Compensation

    Except as otherwise provided in Section 5.3, upon termination of 
employment, the compensation payable to Employee pursuant to Section 3.1 
shall be prorated to the date of such termination and shall be payable on the 
first day of the month following such termination date.

    5.5  At-Will Employment

    The employment by Employee by the Company is "at-will".  Employee may 
terminate employment at any time, for any reason or for no reason. 
Correspondingly, the Company may terminate Employee's employment at any time, 
for any reason or for no reason.

SECTION 6. MISCELLANEOUS

    6.1  Representation by Employee

    Employee represents and warrants to the Company that there is no 
employment contract or any other contractual obligation to which Employee is 
subject which

                                       5


<PAGE>

prevents Employee from entering into this Agreement or from performing fully 
Employee's duties under this Agreement.

    6.2  Notices

    Any notice or consent required or permitted to be given under this 
Agreement shall be in writing and shall be deemed to have been given when 
personally delivered to a party or 24 hours after deposit in the United 
States Mail, first class postage prepaid by both first class and certified 
mail, return receipt requested, or 24 hours after delivery to a recognized 
national overnight carrier, with overnight shipping charges paid, and 
addressed to such party as follows:

                If to Employee:     James R. Wilson
                                    3198 Powder River Drive
                                    Eugene, OR 97408

                If to the Company:  Athena Medical Corporation
                                    10180 SW Nimbus Avenue, Suite J-5
                                    Portland, OR 97223
                                    Attn: President

or such other address as a party may specify by a notice in writing, given in 
the same manner.

    6.3  Attorneys' Fees

    If any action or other proceeding shall be instituted relating to any 
term or condition of this Agreement or relating to any of the rights, duties 
or obligations arising under it (including without limitation a proceeding 
for injunction as provided by Section 2.4), the prevailing party shall be 
entitled to recover from the other party, and the other party agrees to pay 
to the prevailing party, whether or not the matter proceeds to final judgment 
or decree, in addition to costs and disbursements allowed by law, such sum as 
the trial and each appellate court may adjudge reasonable as attorneys' fees 
in such action or other proceeding, and in any appeal of it.

    6.4  Interpretation

    The waiver by either party of a breach of any term or provision of this 
Agreement shall not be construed as a waiver of any subsequent breach of the 
same or any other term or provision by either party.  Time is of the essence 
of this Agreement in all particulars.  The term "days" means calendar days.  
This Agreement may not be amended or modified except by written agreement 
executed by the parties.  The captions heading the sections and subsections 
of this Agreement are inserted for 

                                       6


<PAGE>

convenience of reference only, and are not to be used to define, limit, 
construe or describe the scope or intent of any term, provision or section of 
this Agreement.  This Agreement may be executed in several counterparts, each 
of which shall be deemed an original but all of which taken together shall 
constitute one and the same instrument.

    6.5  Integration

    This Agreement has been approved by the Company's Board of 
Directors pursuant to Nevada Revised Statutes 78.140(3) and Article III, 
Section 13 of the Company's Bylaws.  THIS AGREEMENT CONTAINS THE FINAL AND 
CONCLUSIVE AGREEMENT AND UNDERSTANDING OF THE PARTIES WITH RESPECT TO THE 
SUBJECT MATTER OF IT, AND SUPERSEDES ALL PRIOR AND CONTEMPORANEOUS 
AGREEMENTS, ORAL OR WRITTEN, INCLUDING WITHOUT LIMITATION THE PARTIES' 
CONSULTANT AGREEMENT OF DECEMBER 1, 1996 . EXCEPT AS SET FORTH IN THIS 
AGREEMENT, THERE ARE NO PROMISES, REPRESENTATIONS, AGREEMENTS OR 
UNDERSTANDINGS, ORAL OR WRITTEN, BETWEEN THE PARTIES RELATING TO THE SUBJECT 
MATTER OF THIS AGREEMENT.

           EXECUTED as of the date first set forth above.
           

                                     COMPANY:

                                     Athena Medical Corporation
           

                                    By: ---------------------------
                                         Its President
           

                                     EMPLOYEE:
           

                                     -------------------------------
                                         James R. Wilson


                                       7