<PAGE>

EXHIBIT 10.16


                  AGREEMENT Ingen Technologies, Inc. and Vertex Diagnostic, Inc.


[INGEN LOGO]
TECHNOLOGIES, INC.
285 E. County Line Road, Calimesa California 92320
(800) 259-9622 FAX: (800) 777-1186


                              CONSULTING AGREEMENT

         This Agreement made effective as of this 1st day of September, 2004, by
and between Vertex Diagnostics, Inc., a California Corporation doing business in
the State of California, further referred to as the ("Consultant"), whose
principal corporate offices are located at 3151 Cahuenga Blvd. West, Suite 100,
Los Angeles, CA 90068; and INGEN TECHNOLOGIES, INC., A Nevada Corporation and
Public Company, further referred to as the ("Company"), whose principal address
is 285 E. County Line Road, Calimesa, California 92320, and is made with
reference to the following.

                                    RECITALS

A.       The Company is a Medical Device Manufacturer, and in the business of
         providing medical products and services on a Global basis. Said
         products and services are inclusive of, but not limited to, vestibular
         function testing and balance testing.

B.       The Company desires to exclusively engage the services of the
         Contractor to market physicians within the domestic United States to
         sell VNG programs as described in Schedule-A. The Contractor also
         agrees to develop various markets for services for all of North
         America, as well as any future services that the Company deems
         authorized. The Company will use the Contractor as its' exclusive agent
         to provide those services described in Schedule-A.

C.       The Contractor has the expertise, knowledge and resources for
         development and implementation of the services described in Schedule-A.

D.       The Company will provide product, installation, training, market
         assistance, promotional materials and other developmental documentation
         used to promote said products and services in accordance to all laws of
         which govern the Company in this type of industry. If the customer
         decides to purchase the products sold by the Company, those items and
         pricing are listed in Exhibit-B. The company agrees to sell the same
         products to the Contractor at a discounted price of $ 27,000 for the
         VNG and $12,000 for the SportKat.

E.       The Company desires to utilize the Contractor's expertise, knowledge
         and other resources for developing and promoting said services as
         described in the above Recitals for the purpose of establishing sales
         of vestibular testing products for the Contractor's client base, and as
         such, the Contractor desires to use the Company's client base for
         delivering the services as described in Schedule-A.


                                  Page 1 of 8
<PAGE>

NOW, THEREFORE, the Parties mutually agree as follows:

1.       In consideration of the Contractor furnishing the expertise, knowledge
         and other resources in providing said services and market assistance as
         set forth in the above Recitals hereof, the Company agrees to issue
         500,000 Shares as Restricted Rule-144 common stock, in addition the
         Company will provide equipment to the Contractor for each VNG product
         sale that includes a signed Acceptance Agreement from the customer.
         Such acceptance will be in the form of a signed agreement between the
         customer and the Company. The said transaction will be verification of
         acceptance and submitted to the Contractor. If the customer decides to
         purchase a system, the Company agrees to pay a commission of 15% of the
         total sale to the Contractor.

2.       The Company authorizes the Contractor to market, promote and sell the
         products and services of the Company as described in Exhibit-B. Any
         other products and services offered by the Company are not a part of
         this Agreement and may not be sold and/or marketed by the Contractor
         without the written permission or authorization from the Company.

3.       As a part of the services specified herein, the Contractor accepts the
         above considerations and understands his/her rights to sell said
         services within the United States. The Contractor agrees to provide
         his/her "best efforts" to deliver those services as described in
         Schedule-A.

4.       The Contractor agrees to provide the services as described in
         Schedule-A. The Contractor is not obligated to any exclusive
         arrangements with the Company. The Company is not obligated to provide
         a minimum or maximum quota of customers to commit for the Contractor.
         The Contractor agrees to provide the services to the customer within 30
         days after the customer has received the merchandise as described in
         Exhibit-B and the Company has submitted the signed Acceptance
         Agreement, with full payment, to the Contractor .

5.       Except for the amounts paid to the Contractor as stated in paragraph-1
         and within the Recitals herein, the Contractor shall not be entitled to
         other payment and/or reimbursement for expenses incurred pursuant to
         this Agreement. All costs and expenses incurred by the Contractor in
         rendering said services shall be reimbursed or advanced by the Company
         only upon written authorization to the Contractor by the Company.

6.       The Company agrees to provide full and proper assistance to the
         Contractor inclusive of administrative support, technical support, and
         professional support on a best efforts basis and within regulatory
         guidelines and laws set forth for providing said services and without
         penalty to the Contractor.


                                  Page 2 of 8
<PAGE>

7.       The Contractor agrees to provide the Company with proper tax
         documentation and identification upon the signing of this Agreement in
         accordance to State and Federal tax laws.

8.       The relationship between both parties created by this Agreement is that
         of principal ("the Company") and Outside Contractor ("the Contractor")
         in that the time spent and the professional manner in which the
         services are performed shall solely be the responsibility of the
         Contractor. However, the Contractor agrees to use their best and most
         diligent efforts, within all laws, to provide the resources and
         expertise under the terms and conditions setforth herein.

9.       During the term of this Agreement the Contractor has the right to
         promote services, either directly and/or indirectly, to any entity that
         has a similar products as provided by the Company for the duration of
         this Agreement.

10.      In consideration of the importance of confidentiality, non-disclosure
         and trade secrets, the Contractor acknowledges that during the course
         of this Agreement between the Company and the Contractor, the
         Contractor has had access to and will continue to have access to
         various confidential information and trade secrets consisting of
         compilations of information, records, specifications and trade lists,
         which are owned by the Company and which are regularly used in the
         operation of the Company's business. The Contractor specifically agrees
         to NOT distribute the product pricing of the Company, nor use the brand
         name of EDI and/or Eye Dynamics, Inc. on any of their pricing to their
         clients. Further, the Contractor will agree to keep confidential all
         material related to or made a part of this Agreement from any Medtrak
         Technologies, Inc. client, employee, associate and/or the like.

         In consideration of continued engagement through this Agreement during
         the period of the Agreement by the Company, the Contractor shall not
         disclose any of the aforesaid confidential information or trade
         secrets, directly or indirectly, nor use them in any way, either during
         the term of this Agreement or at any time thereafter, except as
         required in the Contractor's engagement with the Company, but does not
         include information already within the public domain at the time the
         information is acquired by the Contractor, or information that
         subsequently becomes public through no act or omission of the
         Contractor.

          In further consideration of continued engagement and during the period
         of the Agreement, all files, records, documents, drawings,
         specifications, equipment and similar items relating to the business of
         the Company, whether prepared by the Contractors or otherwise, coming
         into the Contractor's possession shall remain the exclusive property of
         the Company and shall not be removed from the Company's premises under
         any circumstances whatsoever without prior written consent of the
         Company.

11.      This Agreement shall continue in effect for a period of two years
         (2-yrs), and may be continued thereafter only by the express mutual
         agreement of both parties. This agreement may be terminated only for
         cause or breech of any terms and conditions setforth herein.

12.      This document contains the entire Agreement of the parties relating to
         this Agreement and correctly sets forth the rights, duties and
         obligations of all parties hereto. Any prior agreements, promises,
         negotiations and/or representations not expressly set forth in this
         Agreement is of no force and effect.


                                  Page 3 of 8
<PAGE>

13.      No waiver of any term or condition of this Agreement shall be deemed or
         construed to be a waiver of such term or condition in the future, or of
         any preceding or subsequent breach of the same or any other term or
         condition of this or any other agreement. All remedies, rights,
         undertakings, obligations and agreements contained in this Agreement
         shall be cumulative and none of them shall be in limitation of any
         other remedy, right, undertaking, obligation or agreement of either
         party hereto.

14.      No amendment or modification of this Agreement or of any covenant,
         condition or limitation herein contained shall be valid unless in
         writing and duly executed by the party to be charged therewith. Unless
         otherwise specifically set forth under a particular provision, any
         amendment or modification shall require the overall consent of both
         parties.

15.      Nothing contained in this Agreement shall be construed so as to require
         the commission of any act contrary to law, and whenever there is a
         conflict between any provision of this Agreement and any statute, law,
         ordinance, rule, order or regulation, the later shall prevail, but in
         such event any such provision of this Agreement shall be curtailed and
         limited only to the extent necessary to bring it within the legal
         requirements.

16.      This Agreement, and all rights and obligations contained herein shall
         be binding on and inure to the benefit of the parties hereto and their
         respective heirs, executors, legal and personal representatives,
         successors and assigns. It is also specifically agreed and understood
         that this Agreement shall be binding upon any successor-in-interest to
         the Company by way of merger, consolidation or otherwise.

17.      Any controversy arising out of or in connection with this Agreement, or
         any amendment thereof, shall be determined and settled by arbitration
         in accordance with the rules of the American Arbitration Association.
         The venue for such arbitration shall be exclusively San Bernardino
         County, the State of California, and any award rendered shall be final
         and binding on each and all of the parties thereto and their
         successor-in-interest, and judgment may be entered thereon in any court
         having jurisdiction thereon. In any such proceeding, the Arbitrator
         shall be and hereby is empowered to render an award directing specific
         performance. Each individual party shall take responsibility for
         obligations pertaining to costs associated with their own legal
         representation.

18.      All notices among the parties hereto shall be in writing and shall be
         deemed duly served when personally delivered to another party or, in
         lieu of such personal service, when deposited in the United States
         mail, certified and return receipt requested, with first class postage
         prepaid thereon, addressed as set forth above, or in such other place
         as may be specified in any written notice given pursuant to this
         paragraph as the address for service of notice. All notices shall be
         delivered to the parties addresses as witnessed below.

                           Company:        Scott Sand, CEO & Chairman
                                           Ingen Technologies, Inc.


                                  Page 4 of 8
<PAGE>

                                           285 E. County Line Rd.
                                           Calimesa, CA 92320
                                           (800) 259-9622
                                           Tax ID No. 88-0429044

                           Contractor:     Ashot Tadevosyan
                                           Vertex Diagnostics, Inc.
                                           3151 Cahuenga Blvd. West, Suite 100
                                           Los Angeles, CA 90068

19. This Agreement shall be governed and construed in accordance with laws of
the State of California.

         IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
         of the date first set forth above and agree to all of the terms and
         conditions of this Agreement setforth herein.




         The Contractor:
                         ---------------------------------  -----------------
                         Ashot Tadevosyan, Principal              Date




         The Company:    /s/ Scott Sand                     September 1, 2004
                         ---------------------------------  -----------------
                         Scott Sand                               Date


                                  Page 5 of 8
<PAGE>

                                   SCHEDULE-A

   SERVICES PROVIDED BY INGEN TECHNOLOGIES, INC. AND PRECISE DIAGNOSTIC, INC.
   --------------------------------------------------------------------------


1.       Preferred Provider Care will provide a 2-day balance medicine training
         program (focused on test reading) here in Jacksonville for all of your
         physicians and technician customers who require training and assistance
         for their new VNG private-label equipment. This seminar will include
         all training manuals, as well as the opportunity for hands on training
         for physicians and technicians and the opportunity for question and
         answer sessions with staff (underwritten by Preferred Provider Care.)

2.       Attendees are responsible for their own travel arrangements, all travel
         costs and incidentals.

3.       Ingen Technologies, Inc. will refer physicians to Precise Diagnostic,
         Inc., and Precise Diagnostic, Inc. will provide equipment, technician
         and clinical support to the physician.

4.       Precise Diagnostic, Inc. will provide a contract agreement with the
         Physician regarding considerations for providing equipment, technician
         and clinical support.


Contract will be valid for two years.


-----------------------------------
Scott Sand, CEO & Chairman


                                  Page 6 of 8
<PAGE>

                                    EXHIBIT-A

                         PHYSICIAN ACCEPTANCE AGREEMENT

         THE PURCHASING PHYSICIAN AND/OR INSTITUTION HAS AGREED TO ACCEPT
         SERVICES FROM PRECISE DIAGNOSTIC, INC. FOR EQUIPMENT, TRAINING AND
         CLINICAL SUPPORT. THAT SUPPORT INCLUDES THE FOLLOWING:


1.       Preferred Provider Care will provide a 2-day balance medicine training
         program (focused on test reading) here in Jacksonville for all of your
         physicians and technician customers who require training and assistance
         for their new VNG private-label equipment. This seminar will include
         all training manuals, as well as the opportunity for hands on training
         for physicians and technicians and the opportunity for question and
         answer sessions with staff (underwritten by Preferred Provider Care.)

2.       Attendees are responsible for their own travel arrangements, all travel
         costs and incidentals.

3.       Ingen Technologies, Inc. will refer physicians to Precise Diagnostic,
         Inc., and Precise Diagnostic, Inc. will provide equipment, technician
         and clinical support to the physician.

4.       Precise Diagnostic, Inc. will provide a contract agreement with the
         Physician regarding considerations for providing equipment, technician
         and clinical support.



         Accepted By: ______________________________ __________________
                           Physician Name                  Date


                                  Page 7 of 8
<PAGE>

                                    EXHIBIT-B

                          PRODUCT LIST SOLD TO CUSTOMER

ITI INGEN TECHNOLOGIES, INC.                         PROFORMA INVOICE
285 E. COUNTY LINE ROAD
CALIMESA CA 92320
(800) 259-9622

Date: OPEN

SOLD TO: Client                                                 SHIP TO: Client

ITEM QTY  PART NO.         DESCRIPTION                                  PRICE
--------------------------------------------------------------------------------

1  1ea.  Model-2000  Secure Balance 2 Channel VNG                     $38,000.00
                     Complete with computer system,
                     1-Camera Goggle,Oculomotor Full-Field Projector
                     Secure Balance(TM) Full Clinical VNG Software version 1.00
                     Atmos Air Irrigator and Scope
                     Installation and training (On-Site).
                     2-Day Physician Interpretation Workshop
                     Tower Computer or Laptop Notebook
                     HP Color Printer

2  1ea.  Model-4000  SPORTKAT Balance System                          $15,000.00
                     Balance Therapy & Posturograhy Platform
                     VVP Computer Data System Assessment
                     & Treatment Software 3.02 Flat Panel
                     Display Computer System Base Unit
                     360 Degree Platform w/Tilt Sensor
                     Handrails with Gauge Readout PSI
                     DC-Power Supply Installation and
                     Training (On-Site)

                     Full Warranty 1-Year
                     Software Upgrades - No Charge


Grand Total                                                           $53,000.00

                          TAX and FREIGHT NOT INCLUDED
--------------------------------------------------------------------------------
         NET 30 DAYS       FOB: OCEANSIDE CA          DELIVERY: 2-4 WEEKS ARO
--------------------------------------------------------------------------------


                                  Page 8 of 8