AGREEMENT OF LIMITED PARTNERSHIP


                                       OF

                BIG SKY UROLOGICAL SERVICES LIMITED PARTNERSHIP



<PAGE>

                                    AGREEMENT
                             OF LIMITED PARTNERSHIP
                                       OF
                 BIG SKY UROLOGICAL SERVICES LIMITED PARTNERSHIP


                                TABLE OF CONTENTS

                                                                    Page

         1.       FORMATION...........................................1

         2.       NAME................................................1

         3.       OFFICES.............................................1

         4.       PURPOSE.............................................2

         5.       TERM................................................2

         6.       CERTAIN DEFINED TERMS...............................2

         7.       CAPITAL CONTRIBUTIONS AND DILUTION OFFERINGS........6

         8.       GUARANTIES..........................................7

         9.       CONDITIONS TO THE CAPITAL CONTRIBUTIONS OF CERTAIN LIMITED
                  PARTNERS............................................7

         10.      REPRESENTATIONS, WARRANTIES AND COVENANTS OF THE GENERAL
                  PARTNER.............................................7

         11.      ADMISSION OF LIMITED PARTNERS.......................8

         12.      CAPITAL ACCOUNTS....................................9

         13.      ALLOCATIONS........................................10

         14.      DISTRIBUTIONS......................................11

         l5.      RIGHTS AND OBLIGATIONS OF LIMITED PARTNERS.........11

         16.      LIMITED LIABILITY..................................13

         17.      TRANSFER OF INTERESTS AND ADMISSION OF PARTNERS....14


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         18.      OPTIONAL PURCHASE OF LIMITED PARTNERSHIP INTERESTS ON CERTAIN
                  EVENTS....................................................18

         19.      SALE, ASSIGNMENT OR OTHER TRANSFER OF THE GENERAL PARTNER'S
                  INTEREST..................................................22

         20.      TERMINATION OF THE SERVICES OF THE GENERAL PARTNER........23

         21.      MANAGEMENT AND OPERATION OF BUSINESS......................23

         22.      RESERVES..................................................26

         23.      INDEMNIFICATION AND EXCULPATION OF THE GENERAL PARTNER....27

         24.      DISSOLUTION OF THE PARTNERSHIP............................27

         25.      DISTRIBUTION UPON DISSOLUTION.............................28

         26.      BOOKS OF ACCOUNT, RECORDS AND REPORTS.....................29

         27.      NOTICES...................................................30

         28.      AMENDMENTS................................................30

         29.      LIMITATIONS ON AMENDMENTS.................................31

         30.      MEETINGS, CONSENTS AND VOTING.............................31

         31.      SUBMISSIONS TO THE LIMITED PARTNERS.......................32

         32.      ADDITIONAL DOCUMENTS......................................32

         33.      SURVIVAL OF RIGHTS........................................32

         34.      INTERPRETATION AND GOVERNING LAW..........................32

         35.      SEVERABILITY..............................................32

         36.      AGREEMENT IN COUNTERPARTS.................................32

         37.      THIRD PARTIES.............................................33

         38.      POWER OF ATTORNEY.........................................33


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         39.      ARBITRATION...............................................33

         40.      CREDITORS.................................................34


                                    SCHEDULES

Schedule A  -  Schedule of Partnership Interests


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<PAGE>

THE LIMITED PARTNERSHIP INTERESTS REPRESENTED BY THIS LIMITED
PARTNERSHIP AGREEMENT HAVE NOT BEEN REGISTERED WITH THE
SECURITIES AND EXCHANGE COMMISSION UNDER THE SECURITIES ACT OF
1933, AS AMENDED, UNDER THE SECURITIES ACT OF MONTANA, AS AMENDED,
OR UNDER SIMILAR LAWS OR ACTS OF OTHER STATES IN RELIANCE UPON
EXEMPTIONS UNDER SUCH LAWS.  IN ADDITION, NO TRANSFERS OF LIMITED
PARTNERSHIP INTERESTS MAY BE MADE WITHOUT COMPLIANCE WITH THE
RESTRICTIONS SET FORTH IN ARTICLE 17 BELOW.

                                    AGREEMENT
                             OF LIMITED PARTNERSHIP
                                       OF
                           BIG SKY UROLOGICAL SERVICES
                               LIMITED PARTNERSHIP


     THIS  AGREEMENT  OF LIMITED  PARTNERSHIP  (the  "Agreement")  is made as of
December 2, 1998,  by and among SUN MEDICAL  TECHNOLOGIES,  INC.,  a  California
corporation  and a wholly-owned  subsidiary of Prime Medical  Services,  Inc., a
Delaware  corporation (the "General Partner"),  and persons listed on Schedule A
attached hereto as the Limited Partners.
 
1. FORMATION.

     The  Partnership  was  formed  pursuant  to the filing in the Office of the
Secretary  of State of Montana on or about August 31, 1998 of a  Certificate  of
Limited Partnership in accordance with the provisions of the Act.

2. NAME.

     2.1 The name of the  Partnership  is "Big Sky Urological  Services  Limited
Partnership."

     2.2 The  Partnership  business  shall be conducted  under such names as the
General Partner may from time to time deem necessary or advisable, provided that
appropriate  amendments  to this  Agreement  and  all  necessary  filings  under
applicable assumed or fictitious name statutes or the Act are first obtained.

3. OFFICES.

     3.1 The  principal  office of the  Partnership  shall be at 1301 Capital of
Texas Highway,  Suite C-300,  Austin, Texas 78746, or at such other place as the
General  Partner  may,  from time to time,  designate  by notice to the  Limited
Partners (the "Records Office").



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<PAGE>

     3.2 The Partnership may have such additional offices as the General Partner
may, from time to time, deem necessary or advisable.

4. PURPOSE.

     The purpose and  business of the  Partnership  shall be: (i) to acquire and
operate  one or more  transportable  lithotripters  (or any  other  renal  stone
treatment equipment) for the treatment of renal stones primarily in the areas of
Great Falls, Helena, Butte, Bozeman, Missoula and Kalispell, Montana, or in such
other location(s) as the General Partner may determine,  in its sole discretion,
to be in the best interests of the  Partnership;  (ii) to acquire and operate in
the  future  any other  urological  device  or  equipment;  provided,  that such
equipment  as of the date of  acquisition  by the  Partnership  has received FDA
premarket  approval;  (iii) to  acquire  an  interest  in any  business  entity,
including, without limitation, a limited partnership,  limited liability company
or corporation,  that engages in any business activity described in this Article
4; and (iv) to engage in any and all  activities  incidental  or  related to the
foregoing, upon and subject to the terms and conditions of this Agreement.

5. TERM.

     The  Partnership  shall  terminate  on  December 31,  2048,  unless  sooner
terminated as herein provided.

6. CERTAIN DEFINED TERMS.

     Certain terms used in this Agreement shall have the following meanings:

     Act. The Act means the Montana Uniform Limited  Partnership Act, as then in
effect.

     Affiliate.  An  Affiliate  is  (i) any  person,  partnership,  corporation,
association or other legal entity ("person") directly or indirectly controlling,
controlled  by or under  common  control with another  person;  (ii) any  person
owning or controlling  10% or more of the  outstanding  voting  interest of such
other person; (iii) any officer, director or partner of such person; and (iv) if
such other person is an officer,  director or partner, any entity for which such
person acts in such capacity.

     Agreement.  This  Agreement  of  Limited  Partnership,  as the  same may be
amended from time to time.

     Bank. First Citizens Bank & Trust Company.

     Capital Account.  The Partnership  capital account of a Partner as computed
pursuant to Article 12 of this Agreement.



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<PAGE>

     Capital  Contributions.  All capital contributions made by a Partner or his
or  her  predecessor  in  interest  which  shall  include,  without  limitation,
contributions made pursuant to Article 7 of this Agreement.

     Capital  Transaction.  Any transaction which, were it to generate proceeds,
would produce Partnership Sales Proceeds or Partnership Refinancing Proceeds.

     Code.  The Internal  Revenue  Code of 1986,  as amended,  or  corresponding
provisions of subsequent, superseding revenue laws.

     Dilution Offering. As provided in Article 7.4 of this Agreement, the future
offering of  additional  limited  partnership  interests in the  Partnership  as
determined by the General Partner.  Except as otherwise provided in Article 7.4,
any  successful  Dilution  Offering will  proportionately  reduce the Percentage
Interests of the then current Partners in the Partnership.

     Domestic Proceeding. Any divorce, annulment, separation or similar domestic
proceeding between a married couple.

     Equipment.  The equipment used in the operation of the Lithotripter System,
including the mobile  transport  vehicle,  the  transportable  lithotripter  and
miscellaneous  medical  equipment  and  supplies,  and  any  similar  additional
equipment acquired by the Partnership in the future.

     FDA. The United States Food and Drug Administration.

     General  Partner.  The  general  partner of the  Partnership,  Sun  Medical
Technologies,  Inc., a California  corporation and a wholly-owned  subsidiary of
Prime Medical Services, Inc., a Delaware corporation.

     Guaranty.  The Guaranty  Agreement  pursuant to which each Limited  Partner
will guarantee a portion of the Partnership's  obligations to the Bank under the
Loan. The form of the Guaranty Agreement is included in the Subscription  Packet
accompanying the Memorandum.

     Initial  Limited  Partner.  Stan  Johnson,  a resident  of  Arizona  and an
Affiliate of the General Partner.  The Initial Limited Partner is to be the only
limited partner of the Partnership  until such time as the new Limited  Partners
are admitted to the Partnership, at which time the Initial Limited Partner shall
withdraw from the Partnership.
 
     Limited  Partners.  The Limited  Partners are those  investors in the Units
admitted to the  Partnership  and any person  admitted  as a Limited  Partner in
accordance with the provisions of this Agreement.



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<PAGE>

     Lithotripter.  The extracorporeal shock-wave lithotripter to be acquired by
the Partnership and any replacements therefor or additional  lithotripters to be
purchased by the Partnership.

     Lithotripter   System.   The  mobile  transport   vehicle  and  operational
Lithotripter.

     Loan.  The loan of up to $450,000  from the Bank to the  Partnership.  Loan
proceeds  will be used  by the  Partnership  to (i)  acquire  an  extracorporeal
shockwave lithotripter with options (up to $400,000), and (ii) acquire and upfit
a mobile van to transport the lithotripter (up to $50,000).

     Losses.  The net loss (including Net Losses from Capital  Transactions)  of
the  Partnership  for each Year of the  Partnership  as  determined  for federal
income tax purposes.

     Majority in Interest of the Limited Partners. The Limited Partners who hold
more than 50% of the Percentage Interests in the Partnership held by the Limited
Partners.

     Memorandum.   The  Confidential   Private   Placement   Memorandum  of  the
Partnership dated October 5, 1998, as amended or as supplemented.

     Mobile Kidney Stone.  Mobile  Kidney Stone Centers of  California,  Ltd., a
California limited partnership and an Affiliate of the General Partner.

     Net Gains from Capital Transactions.  The gains realized by the Partnership
as a result of or upon any sale, exchange,  condemnation or other disposition of
the  capital  assets  of  the  Partnership  (which  assets  shall  include  Code
Section 1231 assets) or as a result of or upon the damage or destruction of such
capital assets.

     Net  Losses  from  Capital   Transactions.   The  losses  realized  by  the
Partnership  as a result of or upon any sale,  exchange,  condemnation  or other
disposition of the capital assets of the  Partnership  (which shall include Code
Section 1231 assets) or as a result of or upon the damage or destruction of such
capital assets.

     Offering.  The offer to  potential  investors  of 99 Units  pursuant to the
Memorandum.

     Partners. The General Partner and the Limited Partners, collectively, where
no distinction is required by the context in which the term is used herein.

     Partnership.  Big Sky Urological  Services Limited  Partnership,  a Montana
limited partnership.

     Partnership Cash Flow. For the applicable  period,  the excess,  if any, of
(A) the sum of (i) all  gross  receipts  from any source for such period,  other
than from Partnership loans, Capital Transactions and Capital Contributions, and
(ii) any funds released by the Partnership from


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<PAGE>

     previously established reserves,  over (B) the sum of (i) all cash expenses
paid by the  Partnership  for such  period;  (ii) the  amount of all payments of
principal  on  loans  to  the  Partnership;  (iii) capital  expenditures  of the
Partnership; and (iv) such reasonable reserves as the General Partner shall deem
necessary or prudent to set aside for future repairs,  improvements or equipment
replacement or additions, or to meet working capital requirements or foreseen or
unforeseen future  liabilities and  contingencies of the Partnership;  provided,
however,  that the amounts referred to in (B)(i),  (ii) and (iii) above shall be
taken into account only to the extent not funded by Capital Contributions, loans
or paid out of previously established reserves. Such term shall also include all
other funds deemed  available for  distribution  and designated as  "Partnership
Cash Flow" by the General Partner.

     Partnership  Interest.  The  interest  of a Partner in the  Partnership  as
defined by the Act and this Agreement.

     Partnership Refinancing Proceeds. The cash realized from the refinancing of
Partnership assets after retirement of any secured loans and less (i) payment of
all  expenses  relating  to  the  transaction  and  (ii) establishment  of  such
reasonable  reserves as the General  Partner shall deem  necessary or prudent to
set  aside  for  future  repairs,  improvements,  or  equipment  replacement  or
additions,  or to meet working  capital  requirements  or foreseen or unforeseen
future liabilities or contingencies of the Partnership.

     Partnership  Sales  Proceeds.  The cash realized  from the sale,  exchange,
casualty or other  disposition of all or a portion of  Partnership  assets after
the  retirement  of all secured  loans and less (i) the  payment of all expenses
related to the transaction and (ii) establishment of such reasonable reserves as
the  General  Partner  shall deem  necessary  or prudent to set aside for future
repairs, improvements, or equipment replacement or additions, or to meet working
capital   requirements   or  foreseen  or  unforeseen   future   liabilities  or
contingencies of the Partnership.

     Percentage Interest. The interest of each Partner in the Partnership, to be
determined initially in the case of a Limited Partner by reference to his or her
Unit  ownership  based  upon the  Limited  Partners  holding  an  aggregate  99%
Percentage Interest in the Partnership, with each initial Unit sold representing
an initial 1% interest.  The General  Partner will initially own a 1% Percentage
Interest in the Partnership. A Partner's Percentage Interest may be reduced by a
future Dilution Offering.  The Partners' Percentage Interests in the Partnership
as of the date hereof are as set forth in Schedule A attached hereto. Any future
adjustments  in the  Partners'  Percentage  Interests,  due to  future  Dilution
Offerings or otherwise, will also be reflected by amendments to Schedule A.

     Profit. The net income of the Partnership (including Net Gains from Capital
Transactions)  for each Year of the Partnership as determined for federal income
tax purposes.

     Pro Rata Basis.  In  connection  with an  allocation  or  distribution,  an
allocation or distribution in proportion to the respective  Percentage Interests
of the class of Partners to which reference is made.



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<PAGE>

     Sales Agency  Agreement.  The sales agency agreement  through which MedTech
Investments,  Inc.,  an  Affiliate  of the General  Partner and a  broker-dealer
company  registered with the Securities and Exchange  commission and a member of
the National  Association of Securities  Dealers,  Inc. shall offer and sell the
limited partnership interest of the Partnership pursuant to the Memorandum.

     Sales  Commission.  The $100 sales commission paid to MedTech  Investments,
Inc. for each Unit sold.

     Service. The Internal Revenue Service.

     Units.  The 99 equal limited partner  interests in the Partnership  offered
pursuant  to the  Memorandum  for a price  per Unit of  $1,500  in cash,  plus a
personal guaranty of 1% of the  Partnership's  obligations under the Loan (up to
$4,500 principal guaranty obligation).

     Year. An annual accounting period ending on December 31 of each year during
the term of the Partnership.

7. CAPITAL CONTRIBUTIONS AND DILUTION OFFERINGS.

     7.1 General Partner Contribution.  On or before the date of this Agreement,
the General Partner will  contribute to the capital of the  Partnership  cash in
the  amount  equal to 1% (up to $1,500)  of the total  cash  contributed  to the
Partnership by the Partners in the offering made pursuant to the Memorandum.

     7.2 Limited  Partner  Contribution.  Each Limited  Partner hereby agrees to
contribute and shall contribute to the capital of the Partnership on the date of
his or her admission to the  Partnership  the cash amount set forth opposite his
or her name on Schedule A attached hereto.

     7.3 No Interest.  Except as otherwise provided herein, no interest shall be
paid on any contribution to the capital of the Partnership.

     7.4 Dilution  Offerings.  If the General  Partner,  in its sole discretion,
determines  that it is in the best  interest  of the  Partnership,  the  General
Partner may, from time to time,  offer, sell and issue, for and on behalf of the
Partnership,  additional  limited  partnership  interests in the  Partnership (a
"Dilution   Offering")  to  investors  who  are  not  already  Limited  Partners
("Qualified  Investors").  The primary purpose of any Dilution Offering would be
to raise additional capital for any legitimate  Partnership purpose as set forth
in Article 4. Any limited partnership  interests offered by the Partnership in a
Dilution  Offering  shall  be sold in the  manner  and  according  to the  terms
prescribed in the sole  discretion of the General  Partner;  provided,  however,
that any additional limited partnership interests offered in a Dilution Offering
will be sold for a price no lower than the highest price for which proportionate
limited  partnership  interests in the Partnership  have been previously sold by
the Partnership unless otherwise determined by a vote of the General Partner and


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<PAGE>

a Majority in Interest of the Limited Partners.  Any sale of additional  limited
partnership  interests  will  result  in  the  proportionate   dilution  of  the
Percentage Interests of the existing Partners. Notwithstanding the above, in the
event of a  Dilution  Offering,  the  General  Partner  may  elect,  in its sole
discretion,   to  prevent   dilution  of  its  Percentage   Interest  by  either
contributing  additional  capital to the  Partnership  or purchasing  additional
limited  partnership  interest in any Dilution Offering.  Limited Partners shall
have no right to purchase  additional  limited partner interests in any Dilution
Offering.  Any investor acquiring a limited  partnership  interest in a Dilution
Offering  shall agree to be bound by the terms of this  Agreement,  and shall be
automatically  admitted as a Limited Partner of the Partnership.  Any adjustment
in the Partners'  Percentage  Interests resulting from a Dilution Offering shall
be set forth on an amended Schedule A to be attached hereto.

8. GUARANTIES.

     Each Partner  agrees to execute and deliver to the  Partnership on the date
of his or her  admission to the  Partnership  a Guaranty in the amount set forth
opposite his or her name on Schedule A attached hereto.

9. CONDITIONS TO THE CAPITAL CONTRIBUTIONS OF CERTAIN LIMITED PARTNERS.

     The  obligations  of  any  Limited  Partners  acquiring  their  Partnership
Interests  in  the  Offering  or  a  Dilution  Offering  to  make  cash  Capital
Contributions  hereunder are subject to the condition that the  representations,
warranties,  agreements  and  covenants  of the  General  Partner  set  forth in
Article 10 of this  Agreement are and shall be true and correct or have been and
will have been complied  with in all material  respects on the date such Capital
Contributions  are  required  to be made,  except  to the  extent  that any such
representation or warranty expressly pertains to an earlier date.

10. REPRESENTATIONS, WARRANTIES AND COVENANTS OF THE GENERAL PARTNER.

     10.1 The General  Partner  hereby  represents  and  warrants to the Limited
Partners that:

     (a) The Partnership is a limited  partnership formed in accordance with and
validly  existing  under the Act and the other  applicable  laws of the State of
Montana;

     (b) The General Partner is duly qualified to transact business in the State
of Montana;

     (c) The interests in the Partnership of the Limited Partners will have been
duly  authorized or created and validly  issued and the Limited  Partners  shall
have no


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<PAGE>

personal liability to contribute money to the Partnership other than the amounts
agreed to be  contributed  by them in the  manner  and on the terms set forth in
this Agreement,  subject,  however,  to such limitations as may be imposed under
the Act;

     (d) Except as  disclosed in the  Memorandum  or  documentation  prepared in
connection  with a Dilution  Offering,  no material breach or default adverse to
the Partnership exists under the terms of any other material agreement affecting
the Partnership; and

     (e) The General  Partner is a  California  corporation  formed and existing
under the laws of the State of California.

     10.2 The General Partner hereby covenants to the Limited Partners that:

     (a) It will at all times act in a  fiduciary  manner  with  respect  to the
Partnership and the Limited Partners;

     (b) Except as provided in Article 19, it will serve as the General  Partner
of the Partnership until the Partnership is terminated  without  reconstitution;
and

     (c) It will  cause the  Partnership  to carry  adequate  public  liability,
property  damage and other  insurance  as is  customary  in the  business  to be
engaged in by the Partnership.

11. ADMISSION OF LIMITED PARTNERS.

     The General  Partner  may permit the offer and sale of limited  partnership
interests  on the terms and  conditions  provided  in the  Memorandum  or future
Dilution  Offerings and may admit persons  subscribing  for interests as Limited
Partners  in the  Partnership  on the  terms  and  conditions  set forth in this
Article 11.

     (a) The General Partner shall have approved of the admission of said person
in writing on such terms and conditions as the General Partner shall determine;

     (b) Said person shall have executed such  documents or  instruments  as the
General  Partner may deem  necessary or desirable to effect his or her admission
as a Limited Partner;

     (c) Said  person  shall  have  accepted  and  adopted  all of the terms and
provisions of this Agreement, as then amended;



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<PAGE>

     (d) Said person (if a corporation)  shall deliver to the General  Partner a
certified  copy of a  resolution  of its Board of  Directors  authorizing  it to
become a Limited Partner under the terms and conditions of this Agreement; and

     (e) Said  person,  upon  request  by the  General  Partner,  shall pay such
reasonable  expenses as may be incurred in  connection  with its  admission as a
Limited Partner.

12. CAPITAL ACCOUNTS.

     A Capital  Account shall be  established  for each Partner and shall at all
times be  determined  and  maintained  in  accordance  with the  Final  Treasury
Regulations  under  Section 704(b)  of the Code,  as the same may be amended.  A
Partner shall not be entitled to withdraw any part of his or her Capital Account
or to receive  any  distribution  from the  Partnership,  except as  provided in
Articles 14 and 25.

     (a) Each Partners' Capital Account shall be increased by:

     (i) The amount of his or her Capital  Contribution  pursuant to  Article 7;
and

     (ii) The amount of Profits  allocated to him or her pursuant to Article 13;
and

     (iii) The Partner's pro rata share  (determined  in the same manner as such
Partner's share of Profits and Losses allocated  pursuant to Article 13  hereof)
of any income or gain exempt from tax.

     (b) Each Partner's Capital Account shall be decreased by:

     (i) The amount of Losses  allocated to him or her  pursuant to  Article 13;
and

     (ii) The amount of Partnership  Cash Flow,  Partnership  Sales Proceeds and
Partnership  Refinancing  Proceeds distributed to him or her pursuant to Article
14; and

     (iii)  The  Partner's  pro rata  share  of any  other  expenditures  of the
Partnership which are not deductible in computing  Partnership Profits or Losses
and which are not added to the tax basis of any Partnership property, including,
without limitation,  expenditures described in Section 705(a)(2)(B) of the Code.
The  Partner's  pro rata share of such  expenditures  shall be determined in the
same manner as


                                       -9-
<PAGE>

such Partner's share of Profits and Losses allocated pursuant to Article 13.

13. ALLOCATIONS

     (a) Profits and Losses.  The Profits and Losses of the Partnership shall be
allocated  among the Partners in  accordance  with their  respective  Percentage
Interests.  In allocating  Profits and Losses, Net Gains and Losses from Capital
Transactions (a part of Profits and Losses), if any, shall be allocated first.

     (b)  Qualified  Income  Offset.  If any Partner  unexpectedly  receives any
adjustment, allocation or distribution described in Treasury Regulations Section
1.704-1(b)(2)(ii)(d)(4)  through (6) which causes or increases a deficit balance
in such  Partner's  Capital  Account  (adjusted  for this  purpose in the manner
provided  in  Treasury  Regulations  Section  1.704-1(b)(2)(ii)(d)),   items  of
Partnership income and gain shall be specially allocated to each such Partner in
an amount and manner  sufficient  to  eliminate,  to the extent  required by the
Regulations, the deficit Capital Account of such Partner as quickly as possible,
provided that an allocation  pursuant to this Article 13(b) shall be made if and
only to the extent that such Partner would have a deficit  Capital Account after
all other allocations provided for in this Article 13 have been tentatively made
as if this Article 13(b) were not in the  Agreement.  This provision is intended
to be a "qualified  income offset," as defined in Treasury  Regulations  Section
1.704-1(b)(2)(ii)(d),  such Regulation being specifically incorporated herein by
reference.

     (c) Sales Commission.  The Sales Commission shall be allocated to the Units
which are not held by the General Partner and its Affiliates and are acquired in
the Offering in proportion to the respective capital  contributions  represented
by such Units (i.e.,  $100 in Sales Commissions per each such Unit). The purpose
of this Article 13(c) is to allocate the Sales  Commission to those Partners who
actually bore the burden of paying the Sales Commission.

     (d)  Allocations  Between  Transferor and  Transferee.  In the event of the
transfer (other than the pledges of the General Partner's  interest permitted by
Article 19 or Permitted Pledges described in Article 17.2(b)) of all or any part
of a Partner's interest (in accordance with the provisions of this Agreement) in
the Partnership at any time other than at the end of a Year, or the admission of
a new Partner (in accordance with the terms of this Agreement), the transferring
Partner  or  new  Partner's  share  of the  Partnership's  income,  gain,  loss,
deductions and credits, as computed both for accounting purposes and for federal
income tax purposes,  shall be allocated between the transferor  Partner and the
transferee Partner (or Partners),  or the new Partner and the other Partners, as
the case may be, in the same ratio as the number of days in such Year before and
after the date of the transfer or admission;

  
                                      -10-
<PAGE>

provided,  however,  that if there has been a sale or other  disposition  of the
assets of the  Partnership  (or any part  thereof)  during  such Year,  then the
General Partner may elect, in its sole  discretion,  to treat the periods before
and after the date of the transfer or  admission as separate  Years and allocate
the Partnership's net income, gain, net loss, deductions and credits for each of
such deemed separate Years.  Notwithstanding  the foregoing,  the  Partnership's
"allocable  cash basis items," as that term is used in Section  706(d)(2)(B)  of
the Code,  shall be allocated  as required by Section  706(d)(2) of the Code and
the regulations thereunder.

     (e) Tax Withholding.  The Partnership shall be authorized to pay, on behalf
of any Partner, any amounts to any federal, state or local taxing authority,  as
may be necessary for the Partnership to comply with tax  withholding  provisions
of the Code or the other income tax or revenue laws of any taxing authority.  To
the extent the Partnership  pays any such amounts that it may be required to pay
on behalf of a Partner,  such amounts shall be treated as a cash distribution to
such  Partner  and shall  reduce  the  amount  otherwise  distributable  to such
Partner.

14. DISTRIBUTIONS.

     (a) Distribution of Partnership  Cash Flow.  Partnership Cash Flow shall be
distributed  to the  Partners  within  60 days  after the end of each  Year,  or
earlier  in the  discretion  of the  General  Partner,  in  proportion  to their
respective Percentage Interests at the time of distribution.
 
     (b) Distribution of Partnership  Refinancing Proceeds and Partnership Sales
Proceeds.  Partnership Refinancing Proceeds and Partnership Sales Proceeds shall
be distributed to the Partners within 60 days of the Capital  Transaction giving
rise to such proceeds,  or earlier in the discretion of the General Partner,  in
proportion to their respective Percentage Interests at the time of distribution.

     (c) Distribution in Liquidation.  Upon liquidation of the Partnership,  all
of the  Partnership's  property  shall be sold and Profits and Losses  allocated
accordingly.   Proceeds  from  the  liquidation  of  the  Partnership  shall  be
distributed in accordance with Article 25.

l5. RIGHTS AND OBLIGATIONS OF LIMITED PARTNERS.

     15.1 Management. The Limited Partners shall not take part in the management
of the business,  nor transact any business for the Partnership,  nor shall they
have power to sign for or to bind the Partnership. The Partnership may, however,
contract  with  one or  more  Limited  Partners  to act  as  the  local  medical
director(s) of the Lithotripter System. No Limited Partner may withdraw from the
Partnership except as expressly permitted herein.



                                      -11-
<PAGE>

     15.2  Operation of  Lithotripter  System.  The Limited  Partners  shall not
operate or utilize  the  Partnership  Lithotripter  System or other  Partnership
equipment except pursuant to (i) an agreement with the Partnership;  or (ii) any
other arrangement specifically approved by the General Partner.

     15.3 Outside Activities. The Limited Partners agree that they owe fiduciary
duties to the Partnership  and, as a consequence,  each Limited Partner (that is
not the General  Partner or an  Affiliate  of the General  Partner)  agrees that
(s)he shall not engage in "Outside Activities" (as defined below) in the "Market
Area" (as defined below)  while(s)he is a Limited Partner in the Partnership and
shall  otherwise be subject to the  provisions of this Article 15.3.  The phrase
"Outside Activities" means directly or indirectly owning,  leasing or subleasing
a lithotripter (or any similar  equipment or competing devices used for treating
renal or biliary stone disease) or any other therapeutic  equipment  acquired by
the Partnership.  Prohibited indirect ownership shall include without limitation
the direct or indirect  ownership of any interest in a business venture (through
stock ownership, partnership interest ownership, ownership by or through a close
family member, or as otherwise  determined in good faith by the General Partner)
involving the ownership,  purchase,  lease, sublease,  promotion,  management or
operation of a lithotripter (or similar  equipment or competing devices used for
treating renal or biliary stone disease) or other competing device or equipment,
unless the General Partner determines that such activity by the Limited Partners
is not  detrimental to the best interests of the  Partnership.  The ownership of
less than 1% of the capital stock  (calculated  on a fully  diluted  basis) of a
corporation  whose stock is  publicly  owned or  regularly  traded on any public
exchange shall not constitute an Outside Activity.

     Upon the  termination  or transfer of a Limited  Partner's  interest in the
Partnership  for any  reason,  including  a transfer  pursuant  to Article  18.3
hereof, the withdrawing Limited Partner shall not, for a period of two (2) years
following  the date of  withdrawal,  engage  in any  Outside  Activities  in any
"Market Area" in which the  Partnership  is  transacting  business or within the
prior twelve months has transacted business (the "Restricted  Facilities").  For
the purposes of this  Article 15.3,  the term  "Market  Area" shall mean (i) the
area within a fifty (50) mile  radius of any  Restricted  Facility,  but if such
area is determined by a court of competent jurisdiction to be too broad, then it
shall  mean (ii) the area  within a thirty  (30) mile  radius of any  Restricted
Facility, but if such area is determined by a court of competent jurisdiction to
be too broad then it shall mean (iii) the area within a fifteen (15) mile radius
of any Restricted Facility.

     In the event a Limited  Partner  wishes and intends to engage in an Outside
Activity in a Market Area, he or she must provide  written notice of such intent
to the General  Partner prior to engaging in the Outside  Activity.  The written
notice shall be deemed an election by the Limited  Partner to withdraw  from the
Partnership (the "Notice of Withdrawal"), and shall give the General Partner the
purchase  rights as  provided  in  Article  18.3  hereof.  After  the  Notice of
Withdrawal,  the former Limited Partner may engage in an Outside Activity in the
Market Area only after waiting the period of two years specified in this Article
15.3. In the event of breach of the waiting  period,  the  Partnership  shall be
entitled to any remedy at law or equity with respect to such  breach,  including
without limitation an injunction or suit for damages.


                                      -12-

<PAGE>


     If a Limited  Partner during his or her  participation  in the  Partnership
engages in an Outside  Activity in a Market Area  without  first  notifying  the
General  Partner in violation of this Article 15.3, the Limited Partner shall be
deemed to have  given a Notice of  Withdrawal  on the date the  General  Partner
first  becomes  aware of the Limited  Partner's  Outside  Activity in the Market
Area.  Upon  receiving a Limited  Partner's  Notice of  Withdrawal or equivalent
thereof, the Partnership may invoke the purchase rights provided in Article 18.3
and shall be entitled  to any other  remedy at law or equity  including  without
limitation an injunction or suit for damages.
 
     15.4   Disclosure  of  Confidential   Information.   Each  Limited  Partner
acknowledges and agrees that his or her  participation in the Partnership  under
this Agreement  necessarily  involves his or her  understanding of and access to
certain  trade  secrets and other  confidential  information  pertaining  to the
business of the Partnership.  Accordingly,  each Limited Partner (other than the
General   Partner  and  its  Affiliates  that  may  also  hold  Limited  Partner
Partnership  Interests) agrees that at all times during his or her participation
in the Partnership as a Limited Partner and thereafter, (s)he will not, directly
or indirectly, without the express written authority of the Partnership,  unless
required by law or directed by a applicable legal authority having  jurisdiction
over  the  Limited  Partner,  disclose  or use for the  benefit  of any  person,
corporation  or other  entity  (other  than  the  Partnership),  or the  Limited
Partner, (i) any trade, technical, operational, management or other secrets, any
patient or customer  lists or other  confidential  or secret data,  or any other
proprietary,  confidential or secret  information of the Partnership or (ii) any
confidential information concerning any of the financial arrangements, financial
condition,  hospital or  physician  contracts,  third party payor  arrangements,
quality assurance and outcome analysis programs, competitive status, customer or
supplier matters, internal organizational matters, technical abilities, or other
business affairs of or relating to the Partnership.  The Limited Partners (other
than the General  Partner and its Affiliates  that may also hold Limited Partner
Partnership  Interests)  acknowledge  that  all  of  the  foregoing  constitutes
proprietary information,  which is the exclusive property of the Partnership. In
the event of breach of this Article 15.4 as determined  by the General  Partner,
the Partnership shall be entitled to any remedy at law or equity with respect to
such breach, including without limitation, an injunction or suit for damages.

16. LIMITED LIABILITY.

     No  Limited  Partner  shall be  required  to make any  contribution  to the
capital  of the  Partnership  except  as set forth in  Article  7, nor shall any
Limited  Partner  in his or her  capacity  as such,  be bound by, or  personally
liable for, any expense,  liability or obligation of the  Partnership  except to
the extent of his or her (i) interest in the  Partnership;  (ii)  Guaranties  of
Partnership  obligations;  and (iii) obligation to return  distributions made to
him or her under certain circumstances as required by the Act.



                                      -13-
<PAGE>

17. TRANSFER OF INTERESTS AND ADMISSION OF PARTNERS.

     17.1 Transferability.

     (a) The term  "transfer"  when used in this  Agreement  with  respect  to a
Partnership Interest includes a sale, assignment,  gift, pledge, exchange or any
other  disposition  (but  does  not  include  the  issuance  of new  Partnership
Interests pursuant to a Dilution Offering);

     (b) Except as otherwise  provided herein,  the General Partner shall not at
any time transfer or assign its interest or obligation as General Partner;

     (c)  The  Partnership   Interest  of  any  Limited  Partner  shall  not  be
transferred,  in whole or in part,  except in accordance with the conditions and
limitations set forth in Articles 17.2 or 18;

     (d) The transferee of a Partnership  Interest by  assignment,  operation of
law or otherwise,  shall have only the rights,  powers and privileges enumerated
in Article  17.3 or  otherwise  provided  by law and may not be  admitted to the
Partnership  as a Limited  Partner  except as provided  in Article  17.4 or as a
General Partner except as provided in Article 17.5;

     (e) Notwithstanding  any provision herein to the contrary,  the Partnership
Agreement  shall in no way  restrict  the  issuance or transfers of stock of the
General Partner; and

     (f) Notwithstanding  any provision herein to the contrary,  the issuance of
Partnership  Interests  pursuant to a Dilution Offering and the admission of new
Limited  Partners  pursuant  to a Dilution  Offering  shall be  governed  by the
provisions of Article 7.4 of this Agreement.

     17.2 Restrictions on Transfers by Limited Partners.

     (a) All or part of a Partnership  Interest may be  transferred by a Limited
Partner  only with the prior  written  approval  of the General  Partner,  which
approval may be granted or denied in the sole discretion of the General Partner.

     (b) The General  Partner  shall not approve any  transfer of a  Partnership
Interest,  except a pledge of any Partnership Interest by the General Partner to
any bank, insurance company or other financial  institution to secure payment of
indebtedness (a "Permitted Pledge"), or otherwise unless the proposed transferee
shall have furnished the General Partner with a sworn statement that:



                                      -14-
<PAGE>

     (i) The  proposed  transferee  proposes to acquire  his or her  Partnership
Interest  as a  principal,  for  investment  and not  with a view to  resale  or
distribution;

     (ii)  The   proposed   transferee   meets   such   requirements   regarding
sophistication, income and net worth as required by applicable state and federal
securities laws;

     (iii) The proposed transferee has met such net worth and income suitability
standards as have been established by the General Partner;

     (iv) The proposed transferee  recognizes that investment in the Partnership
involves  certain risks and has taken full  cognizance of and understands all of
the risk factors related to the purchase of a Partnership Interest; and

     (v) The proposed  transferee has met all other  requirements of the General
Partner for the proposed transfer.

     (c)  Other  than  in the  case  of a  Permitted  Pledge,  a  transfer  of a
Partnership  Interest  may be made  only  if,  prior to the  date  thereof,  the
Partnership  upon request  receives an opinion of counsel,  satisfactory in form
and substance to the General Partner, that neither the offering nor the proposed
transfer will require  registration under federal or applicable state securities
laws or regulations.

     17.3 Rights of Transferee. Unless admitted to the Partnership in accordance
with Article 17.4, the transferee of a Partnership Interest or a part thereof or
any right, title or interest therein shall not be entitled to any of the rights,
powers,  or privileges of his or her predecessor in interest,  except that (s)he
shall  be  entitled  to  receive  and be  credited  or  debited  with his or her
proportionate share of Partnership income, gains, Profits,  Losses,  deductions,
credits or distributions.

     17.4 Admission of Limited Partners. Except as otherwise provided in Article
18, the General  Partner,  or the  transferee of all or part of the  Partnership
Interest of either a General  Partner or a Limited  Partner,  may be admitted to
the  Partnership as a Limited Partner upon furnishing to the General Partner all
of the following:

     (a) The  written  approval  of a Majority in Interest of all of the Limited
Partners (except the assignor  Partner),  or the assignor  Partner alone,  which
approval  may be granted or denied in the sole  discretion  of such  Partners or
Partner (as the case may be);



                                      -15-
<PAGE>

     (b) The written  approval of the General  Partner,  which  approval  may be
granted or denied in the sole discretion of the General Partner;

     (c) Acceptance,  in a form satisfactory to the General Partner,  of all the
terms and  conditions  of this  Agreement  and any other  documents  required in
connection with the operation of the  Partnership  pursuant to the terms of this
Agreement;

     (d) A properly executed power of attorney  substantially  identical to that
contained in Article 38;

     (e) Such other  documents  or  instruments  as may be  required in order to
effect his or her admission as a Limited Partner; and

     (f) Payment of such  reasonable  expenses as may be incurred in  connection
with his or her admission as a Limited Partner.

     17.5 Admission of General Partners. A Limited Partner, or the transferee of
all or part of the Partnership  Interest of the General Partner, may be admitted
to the  Partnership as a general  partner upon furnishing to the General Partner
all of the following:

     (a) The  written  consent of both the  General  Partner  and a Majority  in
Interest of the Limited Partners,  which consent may be granted or denied in the
sole discretion of the Partners;

     (b)  Such  financial  statements,  guarantees  or other  assurances  as the
General  Partner may require with regard to the ability of the proposed  general
partner to fulfill the financial obligations of a general partner hereunder;

     (c) Acceptance,  in form  satisfactory to the General  Partner,  of all the
terms and  provisions  of this  Agreement  and any other  documents  required in
connection with the operation of the  Partnership  pursuant to the terms of this
Agreement; 

     (d) A certified  copy of a resolution of its Board of Directors (if it is a
corporation)  authorizing  it to  become a general  partner  under the terms and
conditions of this Agreement;

     (e) A power  of  attorney  substantially  identical  to that  contained  in
Article 38;

     (f) Such other  documents  or  instruments  as may be  required in order to
effect its admission as a general partner; and


                                      -16-
<PAGE>

     (g) Payment of such  reasonable  expenses as may be incurred in  connection
with its admission as a general partner.

     Notwithstanding  the above, a transferee  that controls or is controlled by
the General  Partner or one or more of its Affiliates  that receives all or part
of the  Partnership  Interest  of the  General  Partner  may be  admitted to the
Partnership  as a general  partner upon  complying  with all the  provisions  of
Article 17.5 except for subparagraph  17.5(a).  As long as the transferee either
controls  or is  controlled  by  the  General  Partner  or one  or  more  of its
Affiliates,  no  Limited  Partner  consents  will  be  required  to  admit  such
transferee as a general partner to the Partnership.

     17.6 Amendment of Certificate of Limited Partnership and Qualification. The
General  Partner shall take all steps  necessary and  appropriate to prepare and
record any  amendments  to the  Certificate  of Limited  Partnership,  as may be
necessary or appropriate  from time to time to comply with the  requirements  of
the Act, including, without limitation, upon the admission to the Partnership of
any general partner pursuant to the provisions of Article 17.5, and may for this
purpose exercise the power of attorney delivered to the General Partner pursuant
to Article 17.5 or 38. In  addition,  the General  Partner  shall take all steps
necessary and appropriate to prepare and record any and all documents  necessary
to qualify the Partnership to do business in jurisdictions where the Partnership
is doing  business,  and may for this  purpose  exercise  the power of  attorney
delivered to the General Partner pursuant to Articles 17.4, 17.5 or 38.

     17.7  Fundamental  Changes.  In the event a plan is approved by the General
Partner  providing  for the  merger or  consolidation  of the  Partnership  with
another  person  or  entity,  or the  sale  of all or  substantially  all of the
Partnership Interests,  including without limitation the exchange of Partnership
Interests for equity  interests in another person or entity or for cash or other
consideration  or  combination  thereof,  then and in such  event,  the  Limited
Partners shall be obligated to take or refrain from taking,  as the case may be,
such actions as the plan may provide, including,  without limitation,  executing
such  instruments,  and providing such  information as the General Partner shall
reasonably  request.  Any plan described in this Article 17.7 may also effect an
amendment to the  Partnership  Agreement  or the  adoption of a new  partnership
agreement in connection with the merger of the  Partnership  with another person
or entity. The plan may also provide that the General Partner and its Affiliates
shall receive fees for services rendered in connection with the operation of the
Partnership  or  any  successor   entity   following  the  consummation  of  the
transactions described in the plan, and neither the Partnership nor the Partners
shall  have  any  right  by  virtue  of this  Agreement  in the  income  derived
therefrom.  Any  securities  or other  consideration  to be  distributed  to the
Partners  pursuant to the plan shall be  distributed  in the manner set forth in
Article 25(c) as though the Partnership were being liquidated.  For this purpose
only,  the fair market  value of the  securities  or other  consideration  to be
received  pursuant  to the plan shall be treated as  "Profits"  and the  capital
accounts of the Partners  shall be  increased in the manner  provided in Article
12(a)(ii).  No Partner  shall be entitled to any  dissent,  appraisal or similar
rights in connection with a plan contemplated by this Article 17.7.



                                      -17-
<PAGE>

     17.8 Withdrawal of Initial Limited Partner. Upon the date the first Limited
Partner is admitted to the  Partnership  in  accordance  with Article 11 of this
Agreement, the Initial Limited Partner shall withdraw from the Partnership,  and
thereupon  his  Capital  Contribution  shall  be  returned  and his  Partnership
Interest canceled and reallocated to the Limited Partners.

18. OPTIONAL PURCHASE OF LIMITED PARTNERSHIP INTERESTS ON CERTAIN EVENTS.

     18.1  Death.  Upon the death of a Limited  Partner,  the  deceased  Limited
Partner's  executor,  administrator,  or other legal or personal  representative
shall give written notice of that fact to the General  Partner.  The Partnership
shall  have the  option to  purchase  at the  Closing  (as  defined  below)  the
Partnership   Interest  of  the  deceased   Limited  Partner  (whose   executor,
administrator  or other  legal or  personal  representative  shall  then  become
obligated  to sell such  Partnership  Interest) at the price  determined  in the
manner  provided  in  Article 18.6  of  this  Agreement  and  on the  terms  and
conditions  provided in Article 18.7 of this  Agreement.  The Partnership  shall
have a period of thirty (30) days  following  the date of notice of the death of
the Limited Partner (the "Option  Period") within which to notify in writing the
deceased Limited  Partner's  executor,  administrator or other legal or personal
representative,  whether the Partnership  wishes to purchase all or a portion of
the Partnership  Interest of the deceased  Limited  Partner.  If the Partnership
does not elect to  purchase  the entire  Partnership  Interest  of the  deceased
Limited  Partner  before the  expiration  of the Option Period and in the manner
provided  herein,  the portion of the Partnership  Interest not purchased by the
Partnership  shall  be  held  by  the  deceased  Limited   Partner's   executor,
administrator  or  other  legal  representative  pursuant  to the  terms of this
Agreement.

     18.2  Bankruptcy,  Insolvency or  Assignment  for Benefit of Creditors of a
Limited Partner. In the event that an involuntary or voluntary  proceeding under
the Federal  Bankruptcy  Code,  as amended,  is filed for or against any Limited
Partner,  or if any Limited  Partner shall make an assignment for the benefit of
his creditors,  or if any Limited Partner has a receiver or custodian  appointed
for his assets,  or any Limited  Partner  generally  fails to pay his debts when
due, the insolvent  Limited  Partner  shall give written  notice (the "Notice of
Insolvency") to the General  Partner of the  commencement of any such proceeding
or the  occurrence  of such event within five days of the first notice to him of
such  commencement or occurrence of such event.  The Partnership  shall have the
option to purchase at the Closing (as defined below) the Partnership Interest of
the  insolvent  Limited  Partner  (which the  insolvent  Limited  Partner or his
trustee, custodian,  receiver or other personal or legal representative,  as the
case may be, shall then become obligated to sell) at the price determined in the
manner  provided  in  Article 18.6  of  this  Agreement  and  on the  terms  and
conditions  provided in Article 18.7 of this  Agreement.  The Partnership  shall
have a period of thirty (30) days following the date of the Notice of Insolvency
(the "Option  Period")  within which to notify in writing the insolvent  Limited
Partner  or his  trustee,  custodian,  receiver,  or  other  legal  or  personal
representative,  whether the Partnership  wishes to purchase all or a portion of
the Partnership  Interest of the insolvent  Limited Partner.  If the Partnership
does not elect to purchase  the entire  Partnership  Interest  of the  insolvent
Limited  Partner  before the  expiration  of the Option Period and in the manner
provided  herein,  the portion of the Partnership  Interest not purchased by the
Partnership shall be held


                                      -18-
<PAGE>

by the insolvent  Partner,  his trustee,  custodian,  receiver or other legal or
personal representative pursuant to the terms of this Agreement.

     18.3  Breach of  Article  15.3.  In the event the  General  Partner  either
receives a Notice of Withdrawal  as provided in Article 15.3 or receives  notice
of a breach  of  Article  15.3 by or with  respect  to a  Limited  Partner  (the
"Defaulting  Limited  Partner"),  the  General  Partner  may elect,  in its sole
discretion,  to treat such event as a default  under this  Agreement and enforce
the  provisions of this Article 18.3. If the General  Partner  elects to enforce
the  provisions  of this Article  18.3,  the General  Partner shall give written
notice of such  election  (the "Notice of Default")  to the  Defaulting  Limited
Partner  within 180 days of the date the  General  Partner  first  received  the
Notice of Withdrawal or notice of the defaulting  event.  The Partnership  shall
have the option to purchase at the  Closing (as defined  below) the  Partnership
Interest of the Defaulting Limited Partner (which the Defaulting Limited Partner
shall  then  become  obligated  to sell) at the price  determined  in the manner
provided  in  Article  18.6 of this  Agreement  and on the terms and  conditions
provided in Article 18.7 of this Agreement.  The Partnership shall have a period
of thirty  (30) days  following  the date it sends the  Notice of  Default  (the
"Option  Period")  within  which to notify in  writing  the  Defaulting  Limited
Partner,  whether the  Partnership  wishes to  purchase  all or a portion of the
Partnership  Interest of the Defaulting Limited Partner. If the Partnership does
not elect to purchase the entire Partnership  Interest of the Defaulting Limited
Partner  before the  expiration of the Option Period and in the manner  provided
herein, the portion of the Partnership Interest not purchased by the Partnership
shall be held by the Defaulting  Limited  Partner  pursuant to the terms of this
Agreement.

     18.4 Domestic  Proceeding.  In the event that a spouse of a Limited Partner
commences  against  a  Limited  Partner,  or a  Limited  Partner  is named in, a
Domestic Proceeding,  the Limited Partner shall give written notice (the "Notice
of Domestic  Proceeding") to the General Partner of the commencement of any such
proceeding within five days of the first notice to him of such commencement. The
Partnership  shall have the option to purchase at the Closing (as defined below)
the  Partnership  Interest  of the  Limited  Partner  involved  in the  Domestic
Proceeding  (which the Limited Partner shall then become  obligated to sell), at
the price  determined in the manner  provided in Article 18.6 of this  Agreement
and on the terms and conditions provided in Article 18.7 of this Agreement.  The
Partnership  shall have a period of thirty (30) days  following  the date of the
Notice of Domestic  Proceeding  (the "Option  Period") within which to notify in
writing the Limited  Partner  involved in the Domestic  Proceeding,  whether the
Partnership  wishes to purchase all or a portion of the Partnership  Interest of
such  Limited  Partner.  If the  Partnership  does  not  elect to  purchase  the
Partnership  Interest of the Limited Partner involved in the Domestic Proceeding
before the  expiration of the Option Period and in the manner  provided  herein,
the portion of the Partnership  Interest not purchased by the Partnership  shall
be held by such Limited Partner pursuant to the terms of this Agreement.

     18.5  Divestiture  Option.  If state  or  federal  regulations  or laws are
enacted or applied,  or if any other legal  developments  occur,  which,  in the
opinion  of the  General  Partner  adversely  affect (or  potentially  adversely
affect) the operation of the Partnership (e.g., the enactment


                                      -19-
<PAGE>

or application of prohibitory  physician  self-referral  legislation against the
Partnership or its Partners),  the General Partner shall promptly either, in its
sole discretion,  (i) take the steps outlined in this Article 18.5 to divest the
Limited  Partners  of  their  Partnership   Interests,   or  (ii)  dissolve  the
Partnership  as provided in Article  24.1(f).  If the  General  Partner  chooses
option (i),  it shall  deliver a written  notice to all of the Limited  Partners
(the "Notice of Election") and purchase such  Partnership  Interests for its own
account.  The purchase price to be paid for each  Partnership  Interest shall be
determined  in the manner as provided in Article  18.6 and shall be on the terms
and  conditions  as provided in Article  18.7.  The transfer of the  Partnership
Interests  and the payment of the purchase  price (as provided in Article  18.6)
shall be made at such time as  determined  by the  General  Partner to be in the
best interests of the Partnership and its Limited Partners. Each Limited Partner
hereby makes,  constitutes and appoints the General Partner,  with full power of
substitution,  his true and lawful  attorney-in-fact,  to take such  actions and
execute such  documents on his behalf to effect the transfer of his  Partnership
Interest as provided in this Article 18.5. The foregoing power of attorney shall
not be affected  by the  subsequent  incapacity  or mental  incompetence  of any
Limited Partner.

     18.6  Purchase  Price.  The purchase  price to be paid for the  Partnership
Interest of any Limited  Partner whose interest is being  purchased  pursuant to
the provisions of  Article 18.1,  18.2, 18.3, 18.4 or 18.5 (the "Selling Limited
Partner")  shall be determined in the manner  provided in this Article 18.6. The
purchase price for a Partnership  Interest  purchased pursuant to the provisions
of Article 18.1, 18.2, 18.3, 18.4 or 18.5 shall be an amount equal to the lesser
of (i) the  fair  market  value of the  Selling  Limited  Partner's  Partnership
Interest on the Valuation Date (prorated in the event that only a portion of his
or her  Partnership  Interest is being  purchased) as determined by an Appraiser
(as defined below) selected by the General Partner,  or (ii) the Selling Limited
Partner's share of the  Partnership's  book value, if any (prorated in the event
that only a portion of his or her  Partnership  Interest is being  purchased) as
reflected by the Capital Account of the Selling Limited Partner  (unadjusted for
any appreciation in Partnership assets and as reduced by depreciation deductions
claimed  by the  Partnership  for tax  purposes)  as of the  Valuation  Date (as
defined below). The General Partner, in its sole discretion,  may pursue both of
the above valuation  methods and choose the lesser value of the two as indicated
above,  or may designate and follow only one of the methods in  calculating  the
purchase price.  For purposes of this Article 18.6, the term  "Appraiser"  shall
mean an independent appraiser who is qualified in appraising limited partnership
interests and who has at least five years experience. In determining fair market
value, the Appraiser shall take into consideration any outstanding indebtedness,
liabilities,   liens  and  obligations  of  the  Partnership  and  the  relative
Partnership  Interests and capital accounts of all Partners, as well as applying
any customary discounts for lack of liquidity and control.  Such appraisal shall
be conducted in accordance with professional appraisal standards.  The valuation
of the  Appraiser  shall be  conclusive  and binding upon the  Partnership,  the
purchaser and the Selling  Limited Partner and his or her  representatives.  The
determination  of the Selling  Limited  Partner's  Capital  Account or aggregate
distributable  amount on the Valuation  Date (as defined below) shall be made by
the  Partnership's  internal  accountant (the  "Partnership  Accountant") upon a
review of the  Partnership  books of account,  and a formal  audit is  expressly
waived. The statement of the Partnership  Accountant with respect to the Capital
Account or aggregate distributable amount of the Selling


                                      -20-
<PAGE>

Limited  Partner on the Valuation Date shall be binding and conclusive  upon the
Partnership,   the   purchaser   and  the  Selling   Limited   Partner  and  his
representative.  The  Valuation  Date  shall  be  the  last  day  of  the  month
immediately  preceding  the  month in which  occurs:  (i) the death of a Selling
Limited  Partner,  in the  case of a  purchase  by  reason  of  death;  (ii) the
bankruptcy or insolvency of a Selling Limited Partner, in the case of a purchase
by reason of such  bankruptcy or  insolvency;  (iii) the Notice of Withdrawal or
breach of Article  15.3 as provided in Article 18.3 in the case of a purchase by
reason thereof; (iv) the commencement of the Domestic Proceeding, in the case of
a purchase  by reason  thereof;  or (v) the Notice of  Election  as  provided in
Article 18.5, in the case of a purchase by reason  thereof.  Any Limited Partner
whose  Partnership   Interest  is  purchased   pursuant  to  the  provisions  of
Article 18.1,  18.2,  18.3,  18.4 or 18.5 shall be entitled only to the purchase
price which shall be paid at the Closing in cash (or by  certified  or cashier's
check) and shall not be entitled to any Partnership distributions made after the
Valuation  Date.  The transfer of a  Partnership  Interest of a Selling  Limited
Partner  shall  be  deemed  to occur as of the  Valuation  Date and the  Selling
Limited  Partner shall have no voting or other rights as a Limited Partner after
such date. The purchaser shall be entitled to any distributions  attributable to
the transferred interest after the Valuation Date and the Partnership shall have
the right to deduct the  amount of any such  distributions  made to the  Selling
Limited Partner after the Valuation Date from the purchase price.

     18.7 Closing.

     18.7.1  Closing of Purchase and Sale.  The Closing of any purchase and sale
of a Partnership  Interest pursuant to Article 18.1, 18.2, 18.3, 18.4 or 18.5 of
this Agreement shall take place at the principal office of the  Partnership,  or
such other place  designated by the General  Partner,  on the date determined as
follows (the "Closing"):

     (a) In the case of a purchase and sale  occurring by reason of the death of
a Limited  Partner as provided in Article  18.1 of this  Agreement,  the Closing
shall be held on the thirtieth  day (or if such  thirtieth day is not a business
day, the next business day following the thirtieth  day) next following the last
to occur of:

     (i) Qualification of the executor or personal administrator of the deceased
Limited Partner's estate;

     (ii) The date on which any necessary determination of the purchase price of
the Partnership Interest to be purchased has been made; or

     (iii) The date that coincides with the close of the Option Period.

     (b) In  the  case  of a  purchase  and  sale  occurring  by  reason  of the
occurrence of one of the events described in Article 18.2, 18.3, 18.4 or 18.5 of
this

   
                                      -21-
<PAGE>

Agreement,  the Closing shall be held on the thirtieth day (or if such thirtieth
day is not a business day, the next  business day  following the thirtieth  day)
next following the later to occur of:

     (i) The date on which any necessary  determination of the purchase price of
the Partnership Interest to be purchased has been made; or

     (ii) The date that coincides with the close of the Option Period.

     At the Closing,  although not necessary to effect the transfer, the Selling
Limited  Partner shall  concurrently  with tender and receipt of the  applicable
purchase price,  deliver to the purchaser duly executed  instruments of transfer
and assignment,  assigning good and marketable  title to the portion or portions
of the Selling Limited  Partner's  entire  Partnership  Interest thus purchased,
free and clear from any liens or encumbrances  or rights of others therein.  The
parties acknowledge that occurrence of any of the triggering events described in
Article 18.1,  18.2,  18.3, 18.4 or 18.5 and compliance with all the Articles of
this  Agreement,  except the execution of the transfer  documents by the Selling
Limited  Partner as provided  above in this  Article 18.7.1,  are  sufficient to
effect the  complete  transfer  of the  Selling  Limited  Partner's  Partnership
Interest and the Selling Limited Partner shall be deemed to consent to admission
of the transferee as a substitute Limited Partner.  Notwithstanding  the date of
the  Closing  or whether a Closing  is  successfully  held,  the  transfer  of a
Partnership Interest of a Selling Limited Partner shall be deemed to occur as of
the Valuation Date as defined in Article 18.6. The deemed  transfer is effective
regardless of whether the Selling Limited Partner  performs the duties set forth
in this Article 18.7.1.

     18.7.2 Terms and  Conditions  of Purchase.  The  Partnership  Interest of a
Limited Partner shall not be transferred to any Partner unless the  requirements
of Articles 17.2 and 17.4 (b) through (f) are satisfied  with respect to it. The
purchaser shall be liable for all  obligations  and  liabilities  connected with
that portion of the  Partnership  Interest  transferred  to it unless  otherwise
agreed in writing.

19. SALE, ASSIGNMENT OR OTHER TRANSFER OF THE GENERAL PARTNER'S INTEREST.

     19.1 The General Partner may not mortgage, pledge,  hypothecate,  transfer,
sell,  assign or  otherwise  dispose of all or any part of its  interest  in the
Partnership,  whether  voluntarily,  by  operation  of  law  or  otherwise  (the
foregoing  actions being  hereafter  collectively  referred to as "Transfers" or
singularly as a "Transfer") except as permitted by this Article.



                                      -22-
<PAGE>

     19.2 If the General Partner makes a Transfer (other than a mortgage, pledge
or hypothecation) of its general partner interest in the Partnership pursuant to
this Article, it shall be liable for all obligations and liabilities incurred by
it as the general  partner of the Partnership on or before the effective date of
such Transfer, but shall not be liable for any obligations or liabilities of the
Partnership arising after the effective date of the Transfer.

     19.3 No Transfer by the General Partner shall be permitted unless:

     (a) Counsel for the Partnership shall have rendered an opinion that none of
the actions taken in connection with such Transfer will cause the Partnership to
be  classified  other than as a partnership  for federal  income tax purposes or
will cause the  termination or dissolution of the  Partnership  under state law;
and

     (b) Such documents or  instruments,  in form and substance  satisfactory to
counsel for the  Partnership,  shall have been  executed and delivered as may be
required in the opinion of counsel for the  Partnership to effect fully any such
Transfer.

     Notwithstanding the foregoing  provisions of this Article 19.3, the General
Partner  may pledge  its  interest  in the  Partnership  to any bank,  insurance
company or other financial institution to secure payment of indebtedness.

20. TERMINATION OF THE SERVICES OF THE GENERAL PARTNER.

     If the General  Partner  shall be finally  adjudged by a court of competent
jurisdiction to be liable to the Limited Partners or the Partnership for any act
of gross negligence or willful misconduct in the performance of its duties under
the terms of this  Agreement,  the  General  Partner  may be removed and another
substituted with the consent of all of the Limited Partners.  Such consent shall
be evidenced by a certificate of removal signed by all of the Limited  Partners.
In the event of removal,  the new general  partner  shall  succeed to all of the
powers,  privileges  and  obligations  of the General  Partner,  and the General
Partner's  interest in the Partnership  shall become that of a Limited  Partner,
and the General  Partner  shall  maintain  its same  Percentage  Interest in the
Partnership  notwithstanding  anything contained in the Act to the contrary.  In
addition,  in the event of removal, the new general partner shall take all steps
necessary and  appropriate to prepare and record an amendment to the Certificate
of Limited  Partnership  to reflect the  removal of the General  Partner and the
admission of such new general partner.

21. MANAGEMENT AND OPERATION OF BUSINESS.

     21.1 All  decisions  with  respect to the  management  of the  business and
affairs of the Partnership shall be made by the General Partner.



                                      -23-

<PAGE>

     21.2 The General  Partner  shall be under no duty to devote all of its time
to the business of the Partnership,  but shall devote only such time as it deems
necessary  to conduct  the  Partnership  business  and to operate and manage the
Partnership in an efficient manner.

     21.3 The General  Partner may charge to the  Partnership  all  ordinary and
necessary  costs  and  expenses,  direct  and  indirect,   attributable  to  the
activities, conduct and management of the business of the Partnership. The costs
and expenses to be borne by the Partnership  shall include,  but are not limited
to, all expenditures  incurred in acquiring and financing the Equipment or other
Partnership  property,  legal and  accounting  fees and  expenses,  salaries  of
employees of the  Partnership,  consulting  and quality  assurance  fees paid to
independent contractors, insurance premiums and interest.

     21.4 In  addition  to,  and not in  limitation  of,  any  rights and powers
covenanted by law or other provisions of this Agreement,  and except as limited,
restricted  or  prohibited  by the express  provisions  of this  Agreement,  the
General  Partner  shall have and may exercise on behalf of the  Partnership  all
powers and rights necessary,  proper,  convenient or advisable to effectuate and
carry out the purposes, business and objectives of the Partnership.  Such powers
shall include, without limitation, the following:

     (a) To conduct  the  Offering  and any  Dilution  Offering on behalf of the
Partnership;

     (b) To acquire on behalf of the  Partnership  (i) one or more fixed base of
transportable  lithotripsy systems,  including the Lithotripter System, (ii) any
other assets  related to the  provision of  lithotripsy  services,  or (iii) any
other assets or equipment or an interest in another entity  consistent  with the
purposes  of the  Partnership  as  provided  in  Article  4  (collectively,  the
"Additional  Assets"),  at such times and at such price and upon such terms,  as
the General Partner deems to be in the best interest of the Partnership;

     (c) To purchase,  hold, manage,  lease,  license and dispose of Partnership
assets,  including the purchase,  exchange,  trade or sale of the  Partnership's
assets at such price, or amount, for cash, securities or other property and upon
such  terms,  as the  General  Partner  deems to be in the best  interest of the
Partnership; provided, that should the Partnership assets be exchanged or traded
for  securities  or other  property  (the  "Replacement  Property")  the General
Partner shall have the same powers with regard to the Replacement Property as it
does towards the traded property;

     (d) To  exercise  the  option  of the  Partnership  to  purchase  a Limited
Partner's Partnership Interest pursuant to Article 18;

     (e)  To  determine  the  travel   itinerary  and  site  locations  for  the
Lithotripter System or other Partnership technology;


                                      -24-
<PAGE>

     (f) To borrow money for any Partnership  purpose (including the acquisition
of the Additional Assets) and, if security is required  therefor,  to subject to
any security device any portion of the property for the  Partnership,  to obtain
replacements  of any other  security  device,  to  prepay,  in whole or in part,
refinance,  increase,  modify,  consolidate  or extend any  encumbrance or other
security device;

     (g) To deposit,  withdraw, invest, pay, retain (including the establishment
of reserves  in order to acquire  the  Additional  Assets)  and  distribute  the
Partnership's  funds  in any  manner  consistent  with  the  provisions  of this
Agreement;

     (h) To institute and defend actions at law or in equity;

     (i) To enter into and carry out  contracts  and  agreements  and any or all
documents and  instruments  and to do any and all such other things as may be in
furtherance of  Partnership  purposes or necessary or appropriate to the conduct
of the Partnership activities;

     (j) To execute,  acknowledge and deliver any and all instruments  which may
be deemed necessary or convenient to effect the foregoing;

     (k) To form a new limited  partnership  made up of  qualified  investors to
treat gallstone  patients (if the FDA approves a lithotripter for such purpose),
and to contract on behalf of the  Partnership  with the new limited  partnership
for the use for a fee of a Partnership lithotripter for the treatment of the new
limited partnership's gallstone patients; and

     (l) To engage or retain  one or more  persons  to  perform  acts or provide
materials as may be required by the Partnership,  at the Partnership's  expense,
and to  compensate  such  person or persons  at a rate to be set by the  General
Partner,  provided that the  compensation is at the then prevailing rate for the
type of services and materials provided, or both. Any person, whether a Partner,
an Affiliate of a Partner or otherwise, including without limitation the General
Partner,  may be employed or engaged by the  Partnership to render  services and
provide  materials,   including,   but  not  limited  to,  management  services,
professional services,  accounting services,  quality assessment services, legal
services, marketing services,  maintenance services or provide materials; and if
such person is a Partner or an Affiliate  of a Partner,  (s)he shall be entitled
to, and shall be paid  compensation for said services or materials,  anything in
this Agreement to the contrary  notwithstanding,  provided that the compensation
to be received for such services or materials is  competitive in price and terms
with then prevailing rate for the type of services  and/or  materials  provided.
The Partnership,  pursuant to the terms of a Management Agreement, will contract
with the General Partner with respect to the supervision and coordination of the
management and administration of the day-to-day operations of the Partnership's


                                      -25-
<PAGE>

business for a monthly fee equal to 7.5% of net Partnership Cash Flow per month.
All costs incurred by the General  Partner under the Management  Agreement shall
be paid or reimbursed by the  Partnership  directly.  The  Partnership  may also
contract with healthcare  facilities and/or qualified physicians desiring to use
its Lithotripter System for the treatment of patients. Owning an interest in the
Partnership  shall not be a  condition  to using the  Lithotripter  System.  The
General Partner and its Affiliates may engage in or possess an interest in other
business  ventures of any nature and description  independently  or with others,
including,  but  not  limited  to,  the  operation  of a  fixed-base  or  mobile
lithotripsy  unit,  whether  or not such  business  ventures  are in  direct  or
indirect  competition with the Partnership,  and neither the Partnership nor the
Partners  shall  have  any  right by  virtue  of this  Agreement  in and to said
independent ventures or to the income or profits derived therefrom.

     21.5 In addition to other acts  expressly  prohibited or restricted by this
Agreement  or by law,  the General  Partner  shall have no  authority  to act on
behalf of the Partnership in:

     (a) Doing any act in contravention  of this Agreement or the  Partnership's
Certificate of Limited Partnership;

     (b) Doing any act which would make it  impossible  to carry on the ordinary
business of the Partnership;

     (c) Possessing or in any manner dealing with the Partnership's  property or
assigning the rights of the Partnership in the Partnership's  property for other
than Partnership purposes;

     (d) Admitting a person as a Limited  Partner or a General Partner except as
provided in this Agreement; or

     (e) Performing any act (other than an act required by this Agreement or any
act taken in good faith  reliance upon counsel's  opinion)  which would,  at the
time such act  occurred,  subject any Limited  Partner to liability as a general
partner in any jurisdiction.
 
22. RESERVES.

     The General  Partner may cause the  Partnership to create a reserve account
to be used exclusively for repairs and acquisition of Additional  Assets and for
any other valid  Partnership  purpose.  The General  Partner shall,  in its sole
discretion, determine the amount of payments to such reserve.



                                      -26-
<PAGE>

23. INDEMNIFICATION AND EXCULPATION OF THE GENERAL PARTNER.

     23.1 The General  Partner is accountable to the  Partnership as a fiduciary
and consequently must exercise good faith and integrity in handling  Partnership
affairs.  The General Partner and its Affiliates  shall have no liability to the
Partnership which arises out of any action or inaction of the General Partner or
its  Affiliates  if the  General  Partner  or its  Affiliates,  in  good  faith,
determined  that  such  course  of  conduct  was in  the  best  interest  of the
Partnership  and such course of conduct did not constitute  gross  negligence or
willful misconduct of the General Partner or its Affiliates. The General Partner
and its Affiliates  shall be indemnified by the Partnership  against any losses,
judgments,  liabilities,  expenses and amounts paid in  settlement of any claims
sustained by them in  connection  with the  Partnership,  provided that the same
were not the result of gross negligence or willful misconduct on the part of the
General Partner or its Affiliates.

     23.2 The General  Partner shall not be liable for the return of the Capital
Contributions of the Limited Partners,  and upon  dissolution,  Limited Partners
shall look solely to the assets of the Partnership.

24. DISSOLUTION OF THE PARTNERSHIP.

     24.1 The  Partnership  shall be dissolved and  terminated  and its business
wound up upon the occurrence of any one of the following events:

     (a) The expiration of its term on December 31, 2048;

     (b) The  filing by, on behalf of, or  against  the  General  Partner of any
petition or pleading,  voluntary or involuntary,  to declare the General Partner
bankrupt under any bankruptcy  law or act, or the  commencement  in any court of
any  proceeding,  voluntary  or  involuntary,  to declare  the  General  Partner
insolvent  or  unable  to pay its  debts,  or the  appointment  by any  court or
supervisory authority of a receiver, trustee or other custodian of the property,
assets or business of the General  Partner or the assignment by it of all or any
part of its  property or assets for the benefit of  creditors,  if said  action,
proceeding or  appointment  is not  dismissed,  vacated or otherwise  terminated
within ninety (90) days of its commencement;

     (c) The determination of the General Partner that the Partnership should be
dissolved;

     (d) The occurrence of an event  described in a plan approved by the General
Partner   pursuant  to  Article  17.7  resulting  in  the   dissolution  of  the
Partnership;



                                      -27-
<PAGE>

     (e) The  election  of the  General  Partner  to  dissolve  the  Partnership
following the occurrence of an event described in Article 18.5;

     (f)  Except as  otherwise  provided  in any plan  approved  by the  General
Partner pursuant to Article 17.7, the sale, exchange or other disposition of all
or substantially all of the property of the Partnership without making provision
for the replacement thereof; and

     (g) The dissolution,  retirement,  resignation,  death, disability or legal
incapacity  of  a  general  partner,  and  any  other  event  resulting  in  the
dissolution  or termination  of the  Partnership  under the laws of the State of
Montana.

     24.2  Notwithstanding the provisions of Article 24.1, the Partnership shall
not be dissolved and terminated  upon the retirement,  resignation,  bankruptcy,
assignment for the benefit of creditors, dissolution, death, disability or legal
incapacity of a general partner, and its business shall continue pursuant to the
terms and  conditions  of this  Agreement,  if any  general  partner  or general
partners  remain  following  such event;  provided that such  remaining  general
partner or general partners are hereby obligated to continue the business of the
Partnership.  If no general  partner remains after the occurrence of such event,
the  business  of the  Partnership  shall  continue  pursuant  to the  terms and
conditions of this  Agreement,  if, within ninety (90) days after the occurrence
of such event,  a Majority in Interest of the Limited  Partners agree in writing
to  continue  the  business  of  the  Partnership,  and,  if  necessary,  to the
appointment  of one or more persons or entities to be substituted as the general
partner.  In the event the Limited  Partners agree as provided above to continue
the business of the  Partnership,  the new general  partner or general  partners
shall succeed to all of the powers,  privileges  and  obligations of the General
Partner,  and the General  Partner's  interest in the Partnership shall become a
Limited  Partner's  interest  hereunder.  Furthermore,  in the event a remaining
general partner or the Limited  Partners,  as the case may be, agree to continue
the  business of the  Partnership  as provided  herein,  the  remaining  general
partner or the newly appointed general partner or general partners,  as the case
may be, shall take all steps  necessary and appropriate to prepare and record an
amendment to the Certificate of Limited  Partnership to reflect the continuation
of the business of the Partnership and the admission of a new general partner or
general partners, if any.

25. DISTRIBUTION UPON DISSOLUTION.

     Upon the  dissolution  and  termination  of the  Partnership,  the  General
Partner or, if there is none, a representative  of the Limited  Partners,  shall
cause the cancellation of the Partnership's  Certificate of Limited Partnership,
shall  liquidate the assets of the  Partnership,  and shall apply and distribute
the proceeds of such liquidation in the following order of priority:

     (a) First, to the payment of the debts and liabilities of the  Partnership,
and the expenses of liquidation;



                                      -28-
<PAGE>

     (b) Second,  to the creation of any reserves which the General  Partner (or
such  representatives of the Limited Partners) may deem reasonably necessary for
the payment of any  contingent or unforeseen  liabilities  or obligations of the
Partnership or of the General  Partner  arising out of or in connection with the
business and operation of the Partnership; and

     (c) Third,  the balance,  if any,  shall be  distributed to the Partners in
accordance  with the Partners'  positive  Capital  Account  balances  after such
Capital  Accounts  are  adjusted  as  provided  by  Article 13,  and  any  other
adjustments  required by the Final Treasury  Regulations under Section 704(b) of
the Code.  Any general  partner with a negative  Capital  Account  following the
distribution  of  liquidation  proceeds or the  liquidation of its interest must
contribute to the  Partnership an amount equal to such negative  Capital Account
on or before the end of the  Partnership's  taxable  year (or, if later,  within
ninety days after the date of liquidation).  Any capital so contributed shall be
(i)  distributed  to those  Partners with positive  Capital  Accounts until such
Capital  Accounts are reduced to zero,  and/or (ii) used to  discharge  recourse
liabilities.

26. BOOKS OF ACCOUNT, RECORDS AND REPORTS.

     26.1 Proper and complete  records and books of account shall be kept by the
General Partner in which shall be entered fully and accurately all  transactions
and such other  matters  relating to the  Partnership's  business as are usually
entered  into  records  and books of account  maintained  by persons  engaged in
businesses of a like character.  The books and records of the Partnership  shall
be  prepared  according  to the  accounting  method  determined  by the  General
Partner. The Partnership's fiscal year shall be the calendar year. The books and
records shall at all times be maintained at the Partnership's Records Office and
shall be open to the reasonable  inspection  and  examination of the Partners or
their duly authorized representatives during reasonable business hours.

     26.2  Within  ninety  (90) days  after the end of each  Year,  the  General
Partner  shall send to each person who was a Limited  Partner at any time during
such year such tax  information,  including,  without  limitation,  Federal  tax
Schedule  K-1, as shall be  reasonably  necessary  for the  preparation  by such
person of his federal  income tax return.  The  General  Partner  will also make
available to the Limited Partners any other information required by the Act.

     26.3 The General Partner shall maintain at the Partnership's Records Office
copies of the Partnership's  original Certificate of Limited Partnership and any
certificate of amendment,  restated  certificate or certificate of  cancellation
with  respect  thereto and such other  documents as the Act shall  require.  The
General Partner will furnish to any Limited Partner upon request or as otherwise
required  by law a copy of the  Partnership's  original  Certificate  of Limited
Partnership  and  any  certificate  of  amendment,   restated  certificate,   or
certificate of cancellation, if any.




<PAGE>

                                      -29-
     26.4  The  General  Partner  shall,  in its sole  discretion,  make for the
Partnership  any and all  elections  for  federal,  state and local tax purposes
including,  without limitation, any election, if permitted by applicable law, to
adjust the basis of the  Partnership's  property  pursuant to Code Sections 754,
734(b) and 743(b), or comparable provisions of state or local law, in connection
with transfers of interests in the Partnership and Partnership Distributions.

     26.5 The  General  Partner is  designated  as the Tax  Matters  Partner (as
defined in Section  6231 of the Code) and to act in any similar  capacity  under
state or local law, and is authorized  (at the  Partnership's  expense):  (i) to
represent the Partnership  and Partners  before taxing  authorities or courts of
competent  jurisdiction in tax matters  affecting the Partnership or Partners in
their  capacity  as  Partners;  (ii) to extend the  statute of  limitations  for
assessment of tax  deficiencies  against Partners with respect to adjustments to
the  Partnership's  federal,  state or local tax  returns;  (iii) to execute any
agreements  or other  documents  relating  to or  affecting  such  tax  matters,
including  agreements or other  documents that bind the Partners with respect to
such tax matters or otherwise affect the rights of the Partnership and Partners;
and (iv) to  expend  Partnership  funds  for  professional  services  and  costs
associated  therewith.  The General Partner is authorized and required to notify
the federal,  state or local tax authorities of the appointment of a Tax Matters
Partner in the manner provided in Treasury Regulations Section 301.6231(a)(7)-1,
as modified  from time to time.  In its  capacity as Tax  Matters  Partner,  the
General Partner shall oversee the Partnership's tax affairs in the manner which,
in its best judgment, is in the interests of the Partners.

27. NOTICES.

     All notices under this Agreement shall be in writing and shall be deemed to
have been given when delivered personally,  or mailed by certified or registered
mail, postage prepaid, return receipt requested.  Notices to the General Partner
shall be  delivered  at, or mailed  to,  its  principal  office.  Notices to the
Partnership  shall be delivered  at, or mailed to, its  principal  office with a
copy to each of its  business  offices.  Notice  to a Limited  Partner  shall be
delivered to such Limited  Partner,  or mailed to the last address  furnished by
him for such purposes to the General Partner. Limited Partners shall give notice
of a change of address to the  General  Partner in the manner  provided  in this
Article.

28. AMENDMENTS.

     Subject to the  provisions  of Article  28,  this  Agreement  is subject to
amendment  only by written  consent of the  General  Partner  and a Majority  in
Interest of the Limited Partners;  provided, however, the consent of the Limited
Partners shall not be required if such  amendments are ministerial in nature and
do not  contravene  the provisions of Article 29.  Further,  no Limited  Partner
consent  shall be  required  to amend  Schedule A to reflect  the  admission  of
Partners as contemplated by the Offering,  any Dilution Offering or as otherwise
herein permitted.



                                      -30-
<PAGE>

29. LIMITATIONS ON AMENDMENTS.

     Notwithstanding  the  provisions  of  Article  28,  no  amendment  to  this
Agreement shall:

     (a) Enlarge the  obligations of any Partner under this Agreement or convert
the interest in the  Partnership  of any Limited  Partner into the interest of a
general partner or modify the limited liability of any Limited Partner,  without
the consent of such Partner;

     (b) Amend the  provisions  of Article 13, 14, 16 or 25 without the approval
of the General  Partner  and a Majority  in  Interest  of the Limited  Partners;
provided,  however, that the General Partner may at any time amend such Articles
without the consent of the Limited  Partners in order to permit the  Partnership
allocations  to be sustained for federal  income tax purposes,  but only if such
amendments do not materially  affect adversely the rights and obligations of the
Limited Partners,  in which case such amendments may only be made as provided in
this Article 29(b); or

     (c) Amend this Article 29 without the consent of all Partners.

30. MEETINGS, CONSENTS AND VOTING.

     30.1 A meeting of the  Partnership  to consider  any matter with respect to
which the Partners may vote as set forth in this  Agreement may be called by the
General Partner or by Limited  Partners who hold more than  twenty-five  percent
(25%) of the  aggregate  interests  in the  Partnership  held by all the Limited
Partners.  Upon  receipt of a notice  requesting  a meeting  by such  Partner or
Partners  and stating the purpose of the  meeting,  the General  Partner  shall,
within ten (10) days thereafter, give notice to the Partners of a meeting of the
Partnership to be held at a time and place  generally  convenient to the Limited
Partners  on a date not  earlier  than  fifteen  (15) days after  receipt by the
General  Partner of the notice  requesting a meeting.  The notice of the meeting
shall set forth the time, date, location and purpose of the meeting.

     30.2 Any consent of a Partner  required by this  Agreement  may be given as
follows:

     (a) By a written  consent given by the  consenting  Partner and received by
the  General  Partner at or prior to the doing of the act or thing for which the
consent is solicited, or

     (b) By the affirmative  vote by the consenting  Partner to the doing of the
act or thing for which the consent is solicited at any meeting  called  pursuant
to this Article to consider the doing of such act or thing.


                                      -31-

<PAGE>

     30.3 When exercising  voting rights expressly granted under the Articles of
this Agreement,  each Partner shall have that number of votes as is equal to the
Percentage Interest of such Partner at the time of the vote, multiplied by 100.

31. SUBMISSIONS TO THE LIMITED PARTNERS.

     The General Partner shall give the Limited  Partners notice of any proposal
or other  matter  required by any  provision  of this  Agreement or by law to be
submitted for consideration  and approval of the Limited  Partners.  Such notice
shall include any information required by the relevant provision or by law.

32. ADDITIONAL DOCUMENTS.

     Each party  hereto  agrees to execute and  acknowledge  all  documents  and
writings  which the  General  Partner may deem  necessary  or  expedient  in the
creation of this Partnership and the achievement of its purpose.

33. SURVIVAL OF RIGHTS.

     Except as herein otherwise  provided to the contrary,  this Agreement shall
be binding upon and inure to the benefit of the parties hereto,  their successor
and assigns.

34. INTERPRETATION AND GOVERNING LAW.

     When the context in which words are used in this  Agreement  indicates that
such is the intent,  words in the singular  number shall  include the plural and
vise versa;  in addition,  the  masculine  gender shall include the feminine and
neuter  counterparts.  The Article  headings or titles and the table of contents
shall not define,  limit, extend or interpret the scope of this Agreement or any
particular Article. This Agreement shall be governed and construed in accordance
with the laws of the State of Montana  without giving effect to the conflicts of
laws provisions thereof.

35. SEVERABILITY.

     If any  provision,  sentence,  phrase  or  word of  this  Agreement  or the
application  thereof to any person or  circumstance  shall be held invalid,  the
remainder of this Agreement,  or the  application of such  provision,  sentence,
phrase, or word to persons or circumstances,  other than those as to which it is
held invalid, shall not be affected thereby.

36. AGREEMENT IN COUNTERPARTS.

     This Agreement may be executed in several counterparts, each of which shall
be  deemed  an  original,  but all of which  shall  constitute  one and the same
instrument. In addition, this Agreement may contain more than one counterpart of
the signature page and this Agreement may


                                      -32-
<PAGE>

be executed by the affixing of the  signatures of each of the Partners to one of
such  counterpart  signature pages; all of such signature pages shall be read as
though  one,  and they shall have the same force and effect as though all of the
signers had signed a single signature page.

37. THIRD PARTIES.

     The agreements,  covenants and representations contained herein are for the
benefit of the parties  hereto inter se and are not for the benefit of any third
parties including, without limitation, any creditors of the Partnership.

38. POWER OF ATTORNEY.

     Each Limited  Partner hereby makes,  constitutes  and appoints Stan Johnson
and Cheryl Williams,  severally,  with full power of substitution,  his true and
lawful  attorneys-in-fact,  for him and in his name, place and stead and for his
use and benefit to sign and acknowledge,  file and record, any amendments hereto
among the Partners for the further  purpose of executing and filing on behalf of
each Limited Partner,  any and all certificates of limited  partnership or other
documents  necessary to constitute the Partnership or to effect the continuation
of the  Partnership,  the  admission  or  withdrawal  of a general  partner or a
limited partner,  the qualification of the Partnership in a foreign jurisdiction
(or  amendment  to such  qualification),  the  admission of  substitute  Limited
Partners or the  dissolution or termination  of the  Partnership,  provided such
continuation,   admission,   withdrawal,   qualification,   or  dissolution  and
termination are in accordance with the terms of this Agreement.

     The foregoing power of attorney is a special power of attorney coupled with
an interest,  is irrevocable and shall survive the death or legal  incapacity of
each  Limited  Partner.  It may be  exercised  by any one of said  attorneys  by
listing all of the Limited Partners  executing any instrument over the signature
of the  attorney-in-fact  acting for all of them.  The power of  attorney  shall
survive the delivery of an assignment  by a Limited  Partner of the whole or any
portion of his Unit.  In those cases in which the assignee of, or the  successor
to, a  Limited  Partner  owning a Unit has been  approved  by the  Partners  for
admission to the  Partnership  as a  substitute  Limited  Partner,  the power of
attorney  shall survive for the sole purpose of enabling the General  Partner to
execute,   acknowledge  and  file  any  instrument   necessary  to  effect  such
substitution.

     This power of attorney shall not be affected by the subsequent  bankruptcy,
dissolution, incapacity or mental incompetence of any Limited Partner.

39. ARBITRATION.

     Any dispute  arising out of or in  connection  with this  Agreement  or the
breach thereof shall be decided by  arbitration  in Austin,  Texas in accordance
with the then effective commercial arbitration rules of the American Arbitration
Association,   and  judgment   thereof  may  be  entered  in  any  court  having
jurisdiction thereof.


                                      -33-
<PAGE>

40. CREDITORS.

     None of the  provisions  of this  Agreement  shall be for the benefit of or
enforceable by any creditors of the Partnership.

     IN WITNESS  WHEREOF,  the parties have executed  this  Agreement of Limited
Partnership as of the day and year first above written.

                                            GENERAL PARTNER:

                                            SUN MEDICAL TECHNOLOGIES, INC., 
                                             a California corporation


                                            By:  ______________________________
                                                 Stan Johnson, President

ATTEST:

_________________________                                      [CORPORATE SEAL]
Secretary


                                            INITIAL LIMITED PARTNER:


                                            __________________________________
                                            Stan Johnson




                                      -34-


STATE OF ____________________)
                                            )
COUNTY OF __________________                         )

     On this _______ day of ___________, 1998, before me, the undersigned Notary
Public in and for the  County of  _______________  in the State of  ___________,
personally  came Stan  Johnson,  who,  being by me duly  sworn,  said that he is
President of Sun Medical Technologies, Inc., the sole general partner of Big Sky
Urological Services Limited Partnership,  that the seal affixed to the foregoing
instrument in writing is the corporate  seal of the  corporation,  and that said
writing was signed, sworn to, and sealed by him in behalf of said corporation by
its authority duly given. And the said Stan Johnson,  further certified that the
facts set forth in said  writing are true and  correct,  and  acknowledged  said
instrument to be the act and deed of said corporation.

                  WITNESS my hand and notarial seal.


                                    -------------------------------------------

                                    Notary Public
My commission expires:

___________________________

STATE OF ________________                   )
                                            )
COUNTY OF ______________                    )


     I,  _______________________________,  a notary  public in and for the State
and County set forth  above,  do hereby  certify  that Stan  Johnson  personally
appeared before me this _____ day of _________,  1998 and acknowledged and swore
to the due  execution  of the  foregoing  Limited  Partnership  Agreement in his
capacity as the initial limited partner.




                                    ------------------------------------------

                                    Notary Public

My commission expires:

___________________________





                                      -35-
<PAGE>

                           COUNTERPART SIGNATURE PAGE


     By signing this  Counterpart  Signature Page, the undersigned  acknowledges
his or her  acceptance of that certain  Agreement of Limited  Partnership of Big
Sky  Urological  Services  Limited  Partnership,  and his or her intention to be
legally bound thereby.

                  Dated this _________ day of ___________________, 199__.



                                    -------------------------------------------

                                    Signature



                                    -------------------------------------------

                                    Printed Name




STATE OF _______________                    )
                                            )
COUNTY OF _____________                     )


     BEFORE ME, the  undersigned  Notary  Public in and for the State and County
set forth above,  on the _______ day of  __________________,  199__,  personally
appeared  ___________________,  and,  being by me first duly sworn,  stated that
(s)he signed this Counterpart Signature Page for the purpose set forth above and
that the statements contained therein are true.




                                    -------------------------------------------

                                    Signature of Notary Public


                                    -------------------------------------------

                                    Printed Name of Notary

My Commission Expires:

___________________________
[SEAL]


                                      -36-
<PAGE>

                                   SCHEDULE A

                        Schedule of Partnership Interests

                 BIG SKY UROLOGICAL SERVICES LIMITED PARTNERSHIP

           CONTRIBUTIONS OF CAPITAL TO THE PARTNERSHIP AND PERCENTAGE
                                    INTERESTS

                                          Cash                       Percentage
General Partner                       Contribution   Guaranty(1)      Interest 

Sun Medical Technologies, Inc.            $1,448.48   $ 4,500.00          1%
1301 Capital of Texas Highway
Suite C-300
Austin, Texas 78746

Limited Partners as a whole             $143,400.00   $445,500.00        99%


TOTAL:                                  $144,848.48   $450,000.00       100%


(1)  Represents the principal portion of each Partner's guaranty obligation,  as
     each Partner's  obligation under the Guaranty  includes not only principal,
     but also (as provided in the Guaranty)  accrued and unpaid  interest,  late
     payment  penalties  and all costs  incurred by the Bank in  collecting  any
     defaulted obligations.


                                      -37-