<PAGE>   1
                                                                  EXHIBIT 10.12

                               RENAULT & HANDLEY
                       INDUSTRIAL & COMMERCIAL REAL ESTATE

           This LEASE, executed in duplicate at Palo Alto, California, this 5th
PARTIES    day of February, by and between

           Zappettini Investment Co.

           and

           Intuitive Surgical

           hereinafter called respectively Lessor and Lessee, without regard
           to number or gender,

PREMISES   1. WITNESSETH: That Lessor hereby leases to Lessee, and Lessee hires
           from Lessor, those certain premises, hereinafter in this lease
           designated as "the Premises", with the appurtenances, situated in the
           City of Mountain View, County of Santa Clara, State of California,
           and more particularly described as follows, to-wit:

           An approximate 25,000 square foot industrial building commonly
           referred to as 1330 W. Middlefield Road, Mountain View, California,
           together with landscaped areas and parking lot and further described
           in Exhibit A attached hereto.

USE        2. The Premises shall be used and occupied by Lessee for the
           development and technology in the field of minimum evasive surgery
           and for no other purpose without the prior written consent of Lessor.

TERM       3. The term shall be for five (5) years, commencing on 1st day of
           April, 1997, and ending on the 28th day of February 2002.

RENTAL     4. Rent shall be payable to the Lessor without deduction or offset at
           such place or places as may be designated from time to time by the
           Lessor as follows:

           Seventeen Thousand Five Hundred and No/100ths Dollars ($17,500.00)
           shall be due upon the execution of this Lease representing rental due
           April 1, 1997. $17,750.00 shall be due on the 1st day of May 1997 and
           on the 1st day of each and every month including September
          1997. Twenty Two Thousand Five Hundred and No/100ths Dollars
           ($22,500.00) shall be due on October 1, 1997 and on the 1st day of
           each and every month including March 1, 1998. Thirty Two Thousand
           Five Hundred and No/100ths Dollars ($32,500.00) shall be due on April
           1, 1998 and on the 1st day of each and every succeeding month
           including February 1, 2002.




<PAGE>   2



<TABLE>

<S>            <C>
SECURITY       5.   Lessee has deposited with Lessor $ - as security
DEPOSIT        for the full and faithful performance of each and every term,
               provision, covenant and condition of this Lease. In the event Lessee
               defaults in respect of any of the terms, provisions, covenants or
               conditions of this Lease, including, but not limited to the payment of
               rent, Lessor may use, apply or retain the whole or any part of such
               security for the payment of any rent in default or for any other sum
               which Lessor may spend or be required to spend by reason of Lessee's
               default. Should Lessee faithfully and fully comply with all of the
               terms, provisions, covenants and conditions of this Lease, the
               security of any balance thereof shall be returned to Lessee or, at the
               option of Lessor, to the last assignee of Lessee's interest in this
               Lease at the expiration of the term hereof. Lessee shall not be
               entitled to any interest on said security deposit.

POSSESSION     6.  If Lessor, for any reason whatsoever, cannot deliver
               possession of the Premises to Lessee at the commencement of the
               said term, as hereinbefore specified, this Lease shall not be void
               or voidable, nor shall Lessor, or Lessor's agents, be liable to
               Lessee for any loss or damage resulting therefrom; but in that
               event the commencement and termination dates of the Lease and all
               other dates affected thereby shall be revised to conform to the
               date of Lessor's delivery of possession.  The above is, however,
               subject to the provision that the period of delay of delivery of
               the Premises shall not exceed-  days from the commencement date herein.
               If the period of delay of delivery exceeds the foregoing, Lessee,
               at his or its option, may declare this Lease null and void.

ACCEPTANCE     7.  By entry hereunder, the Lessee accepts and Lessor warrants OF the
OF             Premises as being in good and satisfactory working condition, unless
PREMISES       within fifteen (15) days after such entry Lessee shall give Lessor
AND CONSENT    written notice specifying in reasonable detail the respects in which the
TO             Premises were not in satisfactory condition. The Lessee agrees on the last
SURRENDER      day of the term hereof, or on sooner termination of this Lease, to
               surrender the premises, together with all alterations, additions, and
               improvements which may have been made in, to, or on the
               Premises by Lessor or Lessee including all HVAC, electrical
               and mechanical systems, unto Lessor in the same good condition
               as at Lessee's entry into the Premises excepting for such wear
               and tear as would be normal for the period of the Lessee's
               occupancy. The Lessee, on or before the end of the term or
               sooner termination of this Lease, shall remove all Lessee's
               personal property and trade fixtures from the premises and all
               property not so removed shall be deemed to be abandoned by the
               Lessee. If the Premises be not surrendered at the end of the
               term or sooner termination of this Lease, the Lessee shall
               indemnify the Lessor against loss or liability resulting from
               delay by the Lessee in so surrendering the Premises including,
               without limitation, any claims made by any succeeding tenant
               founded on such delay.

               8. Lessee shall not commit, or suffer to be committed, any
               USES PROHIBITED waste upon the Premises, or any nuisance, or other
               act or thing which may disturb the quiet enjoyment of any other
               tenant in oraround the buildings in which the Premises may be
               located, or allow any sale by auction upon the Premises, or
               allow the Premises to be used for any improper, immoral,
               unlawful or objectionable purpose, or place any loads upon the
               floor, walls, or roof which endanger the structure, or place
               any harmful liquids in the drainage system of the building. No
               waste materials or refuse shall be dumped upon or permitted to
               remain upon any part of the Premises outside of the building
               proper. No materials, supplies, equipment, finished products
               or semi-finished products, raw materials or articles of any
               nature shall be stored upon or permitted to remain on any
               portion of the Premises outside of the buildings proper.
               unless they are in approved enclosures.

</TABLE>


<PAGE>   3

<TABLE>

<S>            <C>

ALTERATIONS    9. The lessee shall make no alterations, additions or
AND            improvements in excess of $10,000 to the Premises or any part thereof
ADDITIONS      without first obtaining the prior written consent of the
               Lessor. The Lessor may impose as a condition to the aforesaid
               consent such requirements as Lessor may deem necessary in
               Lessor's sole discretion, including without limitation thereto,
               the manner in which the work is done, a right of approval of the
               contractor by whom the work is to be performed, the times during
               which it is to be accomplished, and the requirements that upon
               written request of Lessor prior to the expiration or earlier
               termination of the Lease, Lessee will remove any or all
               improvements or additions to the Premises installed at Lessee's
               expense. All such alterations, additions or improvements not
               specified to be removed shall at the expiration of earlier
               termination of the lease become the property of the Lessor and
               remain upon and be surrendered with the Premises. All movable
               furniture, business and trade fixtures, and machinery equipment
               and all special electrical, mechanical or HVAC systems installed
               by Lessee and used solely for the purpose of Lessee's
               manufacturing process, shall remain the property of the Lessee
               and may be removed by the Lessee at any time during the Lease
               term when Lessee is not in default hereunder. Items which are not
               to be deemed as movable furniture, business and trade fixtures,
               or machinery and equipment shall include heating, lighting,
               electrical systems, air conditioning, partitioning, carpeting, or
               any other installation which as become an integral part of the
               Premises. The Lessee will at all times permit notices of
               non-responsibility to be posted and to remain posted until the
               completion of alterations or additions which have been approved
               by the Lessor.

MAINTE-        10. Lessee shall, at Lessee's sole cost, keep and maintain the
NANCE OF       Premises and appurtenances and every part thereof, including but not
PREMISES       limited to, glazing, sidewalks, parking areas including resealing
               when necessary, plumbing, electrical systems, heating and air
               conditioning installations, any store front, roof covering-unless it
               is not feasible to repair the existing roof covering and a new roof
               covering is required, and the interior of the Premises in good order,
               condition, and repair. Lessor at Lessor's sole cost and expense
               shall maintain the exterior of the walls, and structural portions of
               the roof, foundations, walls, and floors except for any repairs
               caused by the wrongful act of the Lessee and Lessee's agents. The
               Lessor will replace the roof covering if repairs to said covering are
               no longer economically feasible in the judgment of roofing experts,
               and provided that said replacement is not made necessary by acts of
               the Lessee and Lessee's agents. The Lessee shall water, maintain and
               replace, when necessary, any shrubbery and landscaping provided by
               the Lessor on the Premises. The Lessee expressly waives the benefits
               of any statute now or hereafter in effect which would otherwise
               afford the Lessee the right to make repairs at Lessor's expense or to
               terminate this lease because of Lessor's failure to keep the Premises
               in good order, conditions or repair.
</TABLE>

<PAGE>   4

        SEE REVISED INSURANCE CLAUSE ATTACHED

<TABLE>
<S>            <C>
ABANDON-       12.   Lessee shall not vacate or abandon the Premises at
MENT           any time during the term; and if Lessee shall abandon, vacate
               or surrender the premises, or be dispossessed by process of law,
               or otherwise, any personal property belonging to Lessee and left
               on the Premises shall be deemed to be abandoned, at the option
               of Lessor, except such property as may be mortgaged to Lessor.
               Abandonment shall be defined as outlined in Section 1951.3 of
               the California Civil Code.

FREE FROM      13.   Lessee shall keep the Premises and the property in
LIENS          which the Premises are situated, free from any liens arising
               out of any work performed, materials furnished, or
               obligations incurred by Lessee.

COMPLIANCE     14.   Lessee shall, at his sole cost and expense, comply
WITH           with all of the requirements of all Municipal, State and
GOVERN-        Federal authorities now in force, or which may hereafter be
MENTAL         in force, pertaining to Lessee's specific use the Premises,
REGULATIONS    and shall faithfully observe in the use of the Premises all
               Municipal ordinances and State and Federal statutes now in force
               or which may hereafter be in force. The judgment of any court of
               competent jurisdiction, or the admission of Lessee in any action
               or proceeding against Lessee, whether Lessor be a party thereto
               or not, that Lessee has violated any such ordinance or statute in
               the use of the Premises, shall be conclusive of that fact as
               between Lessor and Lessee.

INDEMNI-       15.   The Lessee, as a material part of the consideration to be
FICATION OF    rendered to the Lessor, hereby waives all claims against the
LESSOR AND     Lessor for damages to goods, wares and merchandise, and all other
LESSEE'S       personal property in, upon, or about the Premises and for
LIABILITY      injuries to persons in or about the Premises, from any cause
INSURANCE      arising at any time, excepting claims arising from the Lessor's
               negligence, and the Lessee will hold the Lessor exempt and
               harmless from any damage or injury to any person, or to the
               goods, wares and merchandise and all other personal property of
               any person, arising from the use of the Premises by the Lessee,
               or from the failure of the Lessee to keep the Premises in good
               condition and repair, as herein provided.

                      SEE REVISED INSURANCE CLAUSE ATTACHED

ADVERTISE-     16.   Lessee will not place or permit to be placed, in, upon or
MENTS AND      about the Premises any unusual or extraordinary signs, or any
SIGNS          signs not approved by the city or other governing authority. The
               Lessee will not   place, or permit to be placed, upon the
               Premises, any signs, advertisements or notices without the
               written consent of the Lessor first had and obtained. Any sign so
               placed upon the Premises shall be so placed upon the
               understanding and agreement that Lessee will remove same at the
               termination of the tenancy herein created and repair any damage
               or injury to the Premises caused thereby, and if not so removed
               by Lessee then Lessor may have same so removed at Lessee's
               expense.

UTILITIES      17. Lessee shall pay for all water, gas, heat, light, power,
               telephone service and all other service supplied to the Premises.
               If the premises are not served by a separate water meter, the
               Lessee shall pay to the Lessor 100 percent of the water bill for
               the entire property covered by said bill and of which the
               Premises are a part.

ATTORNEY'S     18.   In case suit should be brought for the possession of the
FEES           Premises, for the recovery of any sum due hereunder, or because
               of the breach of any other covenant herein, the losing party
               shall pay to the prevailing party a reasonable
</TABLE>
<PAGE>   5

<TABLE>
<S>               <C>
                  attorney's fee, which shall be deemed to have accrued on the
                  commencement of such action and shall be enforceable whether
                  or not such action is prosecuted to judgment.

DEFAULT           19.   In the event of any breach of this Lease by the
                  Lessee, or an abandonment of the Premises by the Lessee, the
                  Lessor has the option of 1) removing all persons and property
                  from the Premises and repossessing the Premises in which case
                  any of the Lessee's property which the Lessor removes from the
                  Premises may be stored in a public warehouse or elsewhere at
                  the cost of, and for the account of Lessee, or 2) allowing the
                  Lessee to remain in full possession and control of the
                  Premises. If the Lessor chooses to repossess the Premises, the
                  Lease will automatically terminate in accordance with
                  provisions of the California Civil Code, Section 1951.2. In
                  the event of such termination of the Lease, the Lessor may
                  recover from the Lessee: 1) the worth at the time of award of
                  the unpaid rent which had been earned at the time of
                  termination including interest at 7% per annum; 2) the worth
                  at the time of award of the amount by which the unpaid rent
                  which would have been earned after termination until the time
                  of award exceeds the amount of such rental loss that the
                  Lessee proves could have been reasonably avoided including
                  interest at 7% per annum; 3) the worth at the time of award of
                  the amount by which the unpaid rent for the balance
                  of the term after the time of award exceeds the amount of such
                  rental loss that the Lessee proves could be reasonably
                  avoided; and 4) any other amount necessary to compensate the
                  Lessor for all the detriment proximately caused by the
                  Lessee's failure to perform his obligations under the Lease or
                  which in the ordinary course of things would be likely to
                  result therefrom. If the Lessor chooses not to repossess the
                  premises, but allows the Lessee to remain in full possession
                  and control of the Premises, then in accordance with
                  provisions of the California Civil Code, Section 1951.4, the
                  Lessor may treat the Lease as being in full force and effect,
                  and may collect from the Lessee all rents as they become due
                  through the termination date of the lease as specified in the
                  lease. For the purposes of this paragraph, the following do
                  not constitute a termination of Lessee's right to possession:
                  a) Acts of maintenance or preservation or efforts to relet the
                  property.
                  b) The appointment of a receiver on the initiative of the
                  Lessor to protect his interest under this Lease.

LATE              20.   Lessee hereby acknowledges that late payment by
CHARGES           Lessee to Lessor of rent and other sums due hereunder will
                  cause Lessor to incur costs not contemplated by this lease,
                  the exact amount of which will be extremely difficult to
                  ascertain. Such costs include, but are not limited to,
                  processing and accounting charges, and late charges which may
                  be imposed on Lessor by the terms of any mortgage or trust
                  deed covering the Premises. Accordingly, if any installment of
                  rent or any other sum due from Lessee shall not be received by
                  Lessor or Lessor's designee within ten (10) days after such
                  amount shall be due, Lessee shall pay to Lessor a late charge
                  equal to ten percent (10%) of such overdue amount. The parties
                  hereby agree that such late charge represents a fair and
                  reasonable estimate of the costs Lessor will incur by reason
                  of late payment by Lessee. Acceptance of such late charge by
                  Lessor shall in no event constitute a waiver of
</TABLE>


<PAGE>   6


               REVISED INSURANCE CLAUSE

<TABLE>
<S>               <C>
                        This Lease Clause replaces the Insurance clause (11.) in the
                                     Renault & Handley Net Lease Form.

                  11. Lessee shall not use, or permit the Premises, or any part
                  thereof, to be used, for any purposes other than that for
                  which the Premises are hereby leased; and no use shall be made
                  or permitted to be made on the Premises, nor acts done, which
                  will cause a cancellation of any insurance policy covering
                  said building, or any part thereof, nor shall Lessee sell or
                  permit to be kept, used or sold, in or about the premises, any
                  article which may be prohibited by the standard form of fire
                  insurance policies. Lessee shall, at his sole cost and
                  expense, comply with any and all requirements, pertaining to
                  the Lessee's use and occupancy of the Premises, of any
                  insurance organization or company, necessary for the
                  maintenance of reasonable fire and public liability insurance,
                  covering said building and appurtenances.

                  11.1 Lessee shall, at its expense, obtain and keep in force
                  during the term of this Lease a policy of comprehensive public
                  liability insurance insuring Lessee, Lessor agents, invitees
                  and contractors including, Lessor's lender, against any
                  liability arising out of the Lessee's use, occupancy or
                  maintenance of the Premises. Such insurance policy shall have
                  a combined single limit for both bodily injury and property
                  damage in an amount not less than ONE MILLION Dollars
                  ($1,000,000.00). The limits of said insurance shall not limit
                  the liability of Lessee hereunder.

INSURANCE         11.2 Lessee shall, at its expense, keep in force during the
                  term of this Lease, a policy of fire and property damage
                  insurance in an "all risk" form with a sprinkler leakage
                  endorsement, insuring Lessee's inventory, fixtures, equipment
                  and personal property within the Premises for the full
                  replacement value thereof.

                  11.3 Lessor shall maintain a policy or policies of fire and
                  property damage insurance in an "all risk" form, with
                  sprinkler and, at the option of the Lessor, earthquake
                  endorsements, covering loss or damage to the building,
                  including Lessee's leasehold improvements installed with the
                  written consent of the Lessor, in such amounts and with such
                  coverage as Lessor deems advisable.

                  11.4 Lessee shall pay to Lessor as additional rent, during the
                  term hereof within 10 days after receipt of an invoice
                  therefore, 100 percent of the premiums for any insurance
                  obtained by Lessor pursuant to 11.3 above. Lessor may obtain
                  such insurance for the Building separately, or together with
                  other buildings and improvements which Lessor elects to insure
                  together under blanket policies of insurance. In such case
                  Lessee shall be liable for only such portion of the premiums
                  for such blanket policies as are allocable to the Premises. It
                  is understood and agreed that Lessee's obligation under this
                  paragraph shall be prorated to reflect the Commencement Date
                  and Expiration Date of the Lease.

                  11.5 Lessee and Lessor each hereby waives any and all rights
                  of recovery against the other, or against the officers,
                  directors, employees, partners, agents and representatives of
                  the other, for loss of or damage to the property of the
                  waiving party or the property of others under its control, to
                  the extent such loss or damage is insured against under any
                  insurance policy carried by Lessor or Lessee hereunder. Each
                  party shall notify their respective insurance carriers of this
                  waiver, and obtain from the respective insurer a waiver by
                  such insurer of all rights of subrogation or assignment of
                  claims in connection with a claim against Lessor or Lessee, as
                  the case may be, covered by such insurance.


</TABLE>

<PAGE>   7




                   <TABLE>
<S>           <C>
                   Lessee's default with respect to such overdue amount, nor
                   prevent Lessor from exercising any of the other rights and
                   remedies granted hereunder.

SURRENDER OF       21. The voluntary or other surrender of this Lease by
LEASE              Lessee, or a mutual cancellation thereof, shall not work a
                   merger, and shall, at the option of Lessor, terminate all or
                   any existing subleases or subtenancies, or may, at the option
                   of Lessor, operate as an assignment to him of any or all such
                   subleases or subtenancies.

TAXES              22. The Lessee shall be liable for all taxes levied
                   against personal property and trade or business fixtures.
                   The Lessee also agrees to pay, as additional rental,
                   during the term of this Lease and any extensions thereof,
                   all real estate taxes plus the yearly installments of any
                   special assessments which are of record or which may
                   become of record during the term of this lease. If said
                   taxes and assessments are assessed against the entire
                   building and building site, and this Lease does not cover
                   the entire building or building site, the taxes and
                   assessment installments allocated to the Premises shall be
                   prorated on a square footage or other equitable basis, as
                   calculated by the Lessor. It is understood and agreed
                   that the Lessee's obligation under this paragraph will be
                   pro-rated to reflect the commencement and termination
                   dates of this Lease.

NOTICES            23. All notices to be given to Lessee may be given in writing
                   personally or by depositing the same in the United States
                   mail, postage prepaid, and addressed to Lessee at the said
                   Premises, whether or not Lessee has departed from, abandoned
                   or vacated the Premises.

ENTRY BY           24. Lessee shall permit Lessor and his agents to enter
LESSOR             into and upon and with prior written notice the Premises
                   at all reasonable times for the purpose of inspecting the
                   same or for the purpose of maintaining the building in which
                   the Premises are situated, or for the purpose of making
                   repairs, alterations or additions to any other portion of
                   said building, including the erection and maintenance of such
                   scaffolding, canopies, fences and props as may be required
                   without any rebate of rent and without any liability to
                   Lessee for any loss of occupation or quiet enjoyment of the
                   Premises thereby occasioned; and shall permit Lessor and his
                   agents, at any time within ninety days prior to the
                   expiration of this Lease, to place upon the Premises any
                   usual or ordinary "For Sale" or "To Lease" signs and exhibit
                   the Premises to prospective tenants at reasonable hours.

DESTRUCTION        25. In the event of a partial destruction of the Premises
OF                 during the said term from any cause, Lessor shall forthwith
PREMISES           repair the same, provided such repairs can be made within
                   ninety (90) days from date of destruction under the laws and
                   regulations of State, Federal, County or Municipal
                   authorities, but such partial destruction shall in no way
                   annul or void this Lease, except that Lessee shall be
                   entitled to a proportionate reduction of rent while such
                   repairs are being made, such proportionate reduction to be
                   based upon the extent to which the making of such repairs
                   shall interfere with the business carried on by Lessee in the
                   Premises. If such repairs cannot be made in ninety (90) days
                   from date of destruction Lessor may, at his option, make same
                   within a reasonable time, this Lease continuing in full force
                   and effect and the rent to be proportionately reduced as
                   aforesaid in this paragraph provided. In the event that
                   Lessor does not so elect to make such repairs which cannot be
                   made in ninety (90) days, or such repairs cannot be made
                   under such laws and


</TABLE>


<PAGE>   8




<TABLE>
<S>                <C>

                   regulations, this Lease may be terminated at the option of
                   either party. In respect to any partial destruction which
                   Lessor is obligated to repair or may elect to repair under
                   the terms of this paragraph, the provision of Section 1932,
                   Subdivision 2, and of Section 1933, Subdivision 4, of the
                   Civil Code of the State of California are waived by Lessee.
                   In the event that the building in which the Premises may be
                   situated be destroyed to the extent of not less than 33-1/3%
                   of the replacement cost thereof, Lessor may elect to
                   terminate this Lease, whether the Premises be injured or not.
                   A total destruction of the building in which the Premises may
                   be situated shall terminate this Lease. In the event of any
                   dispute between Lessor and Lessee relative to the provisions
                   of this paragraph, they shall each select an arbitrator, the
                   two arbitrators so selected shall select a third arbitrator
                   and the three arbitrators so selected shall hear and
                   determine the controversy and their decision thereon shall be
                   final and binding upon both Lessor and Lessee, who shall bear
                   the cost of such arbitration equally between them.

ASSIGNMENT         26. The Lessee shall not assign, transfer, or
AND SUBLET-        hypothecate the leasehold estate under this Lease, or any
TING               interest therein, and shall not sublet the Premises, or
                   any part thereof, or any right or privilege appurtenant
                   thereto, or suffer any other person or entity to occupy or
                   use the Premises, or any portion thereof, without, in each
                   case, the prior written consent of the Lessor. Lessor agrees
                   not to unreasonably withhold consent to sublet or assign. As
                   a condition for granting its consent to any subletting the
                   Lessor may require the Lessee to agree to pay to the Lessor,
                   as additional rental, all rents received by the Lessee from
                   its Sublessee which are in excess of the amount payable by
                   the Lessee to the Lessor hereunder. The Lessee shall, by
                   sixty (60) days written notice, advise the Lessor of its
                   intent to sublet the Premises or any portion thereof for any
                   part of the term hereof. Within thirty (30) days after
                   receipt of Lessee's notice, Lessor shall either give approval
                   to Lessee to sublease the portion of the Premises described
                   in Lessee's notice, or Lessor shall terminate this Lease as
                   to the portion of the Premises described in Lessee's notice
                   on the date specified in Lessee's notice. If Lessee intends
                   to sublet the entire Premises and Lessor elects to terminate
                   this Lease, this Lease shall be terminated on the date
                   specified in Lessee's notice. If, however, this Lease shall
                   terminate pursuant to the foregoing with respect to less than
                   all the Premises, the rent, as defined and reserved
                   hereinabove shall be adjusted on a prorata basis to the
                   number of square feet retained by Lessee, and this Lease as
                   so amended shall continue in full force and effect. If the
                   Lessor approves a subletting, the Lessee may sublet
                   immediately after receipt of the Lessor's written approval.
                   In the event Lessee is allowed to assign, transfer or sublet
                   the whole or any part of the Premises, with the prior written
                   consent of Lessor, no assignee, transferee or sublessee shall
                   assign or transfer this Lease, either in whole or in part, or
                   sublet the whole or any part of the Premises, without also
                   having obtained the prior written consent of the Lessor. A
                   consent of Lessor to one assignment, transfer, hypothecation,
                   subletting, occupation or use by any other person shall not
                   release Lessee from any of Lessee's obligations hereunder or
                   be deemed to be a consent to any subsequent similar or
                   dissimilar assignment, transfer, hypothecation, subletting,
                   occupation or use by any other person. Any such assignment,
                   transfer, hypothecation, subletting, occupation or use
                   without such consent shall be void and

</TABLE>


<PAGE>   9




<TABLE>
<S>                <C>

                   shall constitute a breach of this Lease by Lessee and shall,
                   at the option of Lessor exercised by written notice to
                   Lessee, terminate this Lease. The leasehold estate under this
                   Lease shall not, nor shall any interest therein, be
                   assignable for any purpose by operation of law without the
                   written consent of Lessor. As a condition to its consent,
                   Lessor may require Lessee to pay all expense in connection
                   with the assignment, and Lessor may require Lessee's assignee
                   or transferee (or other assignees or transferees) to assume
                   in writing all of the obligations under this Lease.

CONDEM-            27. If any part of the premises shall be taken for any
NATION             public or quasi-public use, under any statute or by right
                   of eminent domain or private purchase in lieu thereof, and a
                   part thereof remains which is susceptible of occupation
                   hereunder, this Lease shall, as to the part so taken,
                   terminate as of the date title shall vest in the condemnor or
                   purchaser, and the rent payable hereunder shall be adjusted
                   so that the Lessee shall be required to pay for the remainder
                   of the term only such portion of such rent as the value of
                   the part remaining after such taking bears to the value of
                   the entire

</TABLE>


<PAGE>   10




<TABLE>
<S>                <C>

                  Premises prior to such taking; but in such event Lessor shall
                  have the option to terminate this Lease as of the date when
                  title to the part so taken vests in the condemnor or
                  purchaser. If all of the premises, or such part thereof be
                  taken so that there does not remain a portion susceptible for
                  occupation hereunder, this Lease shall thereupon terminate. If
                  a part or all of the Premises be taken, all compensation
                  awarded upon such taking shall go to the Lessor and the Lessee
                  shall have no claim thereto.

EFFECT OF         28.  The term "Lessor" as used in this Lease, means only the
CONVEYANCE        owner for the time being of the land and building containing the
                  Premises, so that, in the event of any sale of said land or
                  building, or in the event of a lease of said building, the
                  Lessor shall be and hereby is entirely freed and relieved of
                  all covenants and obligations of the Lessor hereunder, and it
                  shall be deemed and construed, without further agreement
                  between the parties and the purchaser at any such sale, or the
                  Lessee of the building, that the purchaser or lessee of the
                  building has assumed and agreed to carry out any and all
                  covenants and obligations of the Lessor hereunder. If any
                  security be given by the Lessee to secure the faithful
                  performance of all or any of the covenants of this Lease on
                  the part of the Lessee, the Lessor may transfer and deliver
                  the security, as such, to the purchaser at any such sale or
                  the lessee of the building, and thereupon the Lessor shall be
                  discharged from any further liability in reference thereto.

SUBORDI-          29.   Lessee agrees that this Lease may, at the option of
NATION            Lessor, be subject and subordinate to any mortgage, deed of trust
                  or other instrument of security which has been or shall be
                  placed on the land and building or land or building of which
                  the Premises form a part, and this subordination is hereby
                  made effective without any further act of Lessee. The Lessee
                  shall, at any time hereinafter, on demand, execute any
                  instruments, releases, or other documents that may be required
                  by any mortgagee, mortgagor, or trustor or beneficiary under
                  any deed of trust for the purpose of subjecting and
                  subordinating this Lease to the lien of any such mortgage,
                  deed of trust or other instrument of security.

WAIVER            30.   The waiver by Lessor of any breach of any term, covenant
                  or condition, herein contained shall not be deemed to be a
                  waiver of such term, covenant or condition or any subsequent
                  breach of the same or any other term, covenant or condition
                  therein contained. The subsequent acceptance of rent hereunder
                  by Lessor shall not be deemed to be a waiver of any preceding
                  breach by Lessee of any term, covenant or condition of this
                  Lease, other than the failure of Lessee to pay the particular
                  rental so accepted, regardless of Lessor's knowledge of such
                  preceding breach at the time of acceptance of such rent.

HOLDING           31.   Any holding over after the expiration of the said term,
OVER              with the consent of Lessor, shall be construed to be a tenancy
                  from month to month, at a rental to be negotiated by Lessor
                  and Lessee prior to the expiration of said term, and shall
                  otherwise be on the terms and conditions herein specified, so
                  far as applicable.

SUCCESSORS        32.   The covenants and conditions herein contained shall,
AND               subject to the provisions as to assignment, apply to and bind the
ASSIGNS           heirs, successors, executors, administrators and assigns of all of
                  the parties hereto; and all of the parties hereto shall be jointly
                  and severally liable hereunder.

TIME              33.   Time is of the essence of this Lease.

MARGINAL          34.  The marginal headings or titles to the paragraphs of this
CAPTIONS          Lease are not a part of this Lease and shall have no effect upon
                  the construction or interpretation of any part thereof. This
                  instrument contains all of the agreements and conditions made
                  between the parties hereto and may not be modified orally or
                  in any other manner than by an agreement in writing signed by
                  all of the parties hereto or their respective successors in
                  interest.


</TABLE>


<PAGE>   11




<TABLE>
<S>                <C>
                  PARAGRAPHS #35, 36 AND 37 ATTACHED HERETO ARE HEREBY MADE A PART OF
                  THIS LEASE.
</TABLE>

           THIS LEASE HAS BEEN PREPARED FOR SUBMISSION TO YOUR ATTORNEY WHO WILL
           REVIEW THE DOCUMENT AND ASSIST YOU TO DETERMINE WHETHER YOUR LEGAL
           RIGHTS ARE ADEQUATELY PROTECTED. RENAULT & HANDLEY IS NOT AUTHORIZED
           TO GIVE LEGAL AND TAX ADVICE. NO REPRESENTATION OR RECOMMENDATION IS
           MADE BY RENAULT & HANDLEY OR ITS AGENTS OR EMPLOYEES AS TO THE LEGAL
           SUFFICIENCY, LEGAL EFFECT OR TAX CONSEQUENCES OF THIS DOCUMENT OR ANY
           TRANSACTION RELATING THERETO. THESE ARE QUESTIONS FOR YOUR ATTORNEY
           WITH WHOM YOU SHOULD CONSULT BEFORE SIGNING THIS DOCUMENT.

           IN WITNESS WHEREOF, Lessor and Lessee have executed these presents,
           the day and year first above written.

                     LESSOR                             LESSEE

             ZAPPETTINI INVESTMENT CO.           INTUITIVE SURGICAL

                /s/ G. O. McKee                    /s/ Lonnie M. Smith
                ---------------                    -------------------

               3/4/97                              3/4/97



<PAGE>   12




                              ADDITIONAL PARAGRAPHS

     The following additional paragraphs are hereby made a part of that certain
     Lease dated February 5, 1997, by and between Zappettini Investment Co.,
     Lessor, and Intuitive Surgical, Lessee, covering the Premises located at
     1330 W. Middlefield, Mountain View, California.

     35. Lessor will indemnify Lessee from and against all costs of response,
     corrective action, remedial action, claims, demands, losses and liabilities
     arising from any pre-existing environmental contamination which may have
     occurred prior to the Lessee taking possession of the Premises.

     Lessee will only be responsible for contamination of the Premises or the
     soils or ground water thereon or thereunder in violation of Hazardous
     Materials Laws, that is caused by Lessee or Lessee's agents or contractors
     during the term as may be extended. All hazardous materials and toxic
     wastes that Lessee brings on the Premises shall be stored according to
     Hazardous Materials' Laws.

     All hazardous materials and toxic wastes that Lessee brings on the site
     shall be stored according to all local, state and national government
     regulations. Hazardous Materials shall be defined as those substances that
     are recognized as posing a risk of injury to health or safety by the Santa
     Clara Fire Department, the Santa Clara County Health Department, the
     Regional Water Quality Control Board, the State of California or the
     Federal Government.

     For purposes of this Lease, "Hazardous Materials' Laws" shall mean all
     local, state and federal laws, statutes, ordinances, rules, regulations,
     judgements, injunctions, stipulations, decrees, orders, permits, approvals,
     treaties or protocols now or hereafter enacted, issued or promulgated by
     any governmental authority which relate to any Hazardous Material or the
     use, handling, transportation, production, disposal, discharge, release,
     emission, sale or storage of, or the exposure of any person to, a Hazardous
     Material.

     36. Quiet Enjoyment. Landlord covenants and agrees that Tenant, so long as
     it shall not be in default hereunder, shall and may, at all times during
     the term of this Lease and any extension and renewal hereof, peacefully and
     quietly have, hold, occupy, and enjoy the Premises without any hindrance or
     molestation whatever.

     37. Option. Lessor hereby grants to Lessee the option to renew this Lease
     for 1 (one) additional 3 (three) year term commencing on the termination
     date of the Lease. Said option shall be exercised by letter and no later
     than 60 (sixty) days and no earlier than 120 (one hundred twenty) days
     prior to the termination date of this Lease. All the terms and conditions
     contained in the original Lease shall govern the extension period excepting
     the monthly rental shall be 95% of the then fair market value for similar
     buildings within a one mile radius from the above location.

     38. Lessor recognizes that Lessee intends to sublease some or all of the
     Premises in one or more portions prior to use of the Premises by Lessee for
     research development and manufacturing in connection with minimally
     invasive surgical instrument systems. Lessor therefore agrees not to
     unreasonably withhold consent for Lessee to sublease the Premises in one or
     more portions. Notwithstanding paragraph 26 of this lease, in the event
     that Lessor withholds consent to sublease a portion of the Premises, Lessor
     shall not terminate the lease with respect to the portion of the Premises
     specified in Lessee's notice without the prior written consent of Lessee.

     Lessor recognizes that Sublessees of Lessee will use the Premises for
     purposes other than research and development of minimally invasive surgery
     systems. Lessor therefore agrees not to unreasonably withhold consent for
     use of the Premises for purposes other than research, development and
     manufacturing minimally invasive surgical instrument systems. Lessee
     recognizes that use of the Premises may be reasonably limited to office
     space, research, development, storage and light manufacturing as is typical
     in similar buildings in the immediate vicinity.

                                                      /s/ G. O. McKee