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                                    EXHIBIT 4


                 SECOND AMENDMENT TO RIGHTS AGREEMENT (REFORMED)

     This Second Amendment (this "AMENDMENT") to Rights Agreement (the "RIGHTS
AGREEMENT") is effective as of May 29, 2001, by and between MiniMed Inc., a
Delaware corporation (the "COMPANY") and Computershare Investor Services LLC,
(the "RIGHTS AGENT").

                                   BACKGROUND

     A. The Company and Harris Trust Company of California entered into a Rights
Agreement effective as of July 24, 1995 and an Amendment thereto effective as of
May 1, 1999 (collectively the "Rights Agreement"). The Rights Agent has
succeeded to all of the rights and obligations of its Harris Trust Company of
California.

     B. The parties now desire to further amend the Rights Agreement on the
terms set forth below.

                                    AMENDMENT

     NOW, THEREFORE, the parties hereby agree as follows:

     1. All capitalized terms not otherwise defined in this Amendment shall have
the meanings set forth in the Rights Agreement.

     2. Section 1(b) of the Rights Agreement is amended by adding at the end
thereof the following paragraph:

          "Also notwithstanding anything to the contrary in this Section 1(b),
     for all purposes of this Agreement (including without limitation Section
     3(h) and 7(d) but not including the proviso to Section 1(z)(iv)) Medtronic,
     Inc. ("Medtronic") shall not be deemed to Beneficially Own securities of
     the Company (including without limitation any shares of Common Stock of the
     Company or Rights with respect thereto) that are (x) subject to the
     Agreements to Facilitate Merger (the "Support Agreements") to be entered
     into between Medtronic and certain stockholders of the Company in
     connection with the Medtronic Merger Agreement before, concurrently with or
     after the execution and delivery of the Medtronic Merger Agreement or (y)
     Beneficially Owned directly or indirectly by any of the parties (other than
     Medtronic) to the Agreements to Facilitate Merger nor shall the execution
     and delivery the Support Agreements or the Medtronic Merger Agreement or
     the consummation of the transactions contemplated thereby be deemed to
     result in any Person becoming a 15% Stockholder. "Medtronic Merger
     Agreement" is defined as the Agreement and Plan of Merger among Medtronic,
     the Company and MMI Merger Corp., a wholly-owned subsidiary of Medtronic,
     which the parties propose to enter into at or about the time this



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     Amendment is entered into and providing for the merger of MMI Merger
     Corp. into the Company as a result of which the Company will become a
     wholly-owned subsidiary of Medtronic".

     3. Section 1(k) of the Rights Agreement is amended to read in full as
follows:

          "'Expiration Date' shall mean the earlier of the Effective Time (as
     defined in the Medtronic Merger Agreement) of the merger contemplated by
     the Medtronic Merger Agreement or May 23, 2005."

     4. Section 1(z) of the Rights Agreement is hereby deleted in its entirety
and the following is inserted in lieu thereof:

     "(z) "15% Stockholder" shall mean any Person that, together with all
Affiliates and Associates of such Person, hereafter acquires Beneficial
Ownership of, in the aggregate, a number of Voting Shares of the Company equal
to 1% or more of the Voting Shares then outstanding and thereupon or thereafter
Beneficially Owns 15% or more of the Voting Shares of the Company then
outstanding; provided, however, that the term "15% Stockholder" shall not
include:

               (i) any Person who is the Beneficial Owner of at least 15% of the
          outstanding Common Shares both on the date of this Agreement and at
          the completion of the Company's initial public offering of Common
          Shares,

               (ii) the Company, any wholly owned Subsidiary of the Company, any
          employee benefit plan of the Company or of a Subsidiary of the
          Company, or any Person holding Voting Shares for or pursuant to the
          terms of any such employee benefit plan;

               (iii) any Person if such Person would not otherwise be a 15%
          Stockholder but for a reduction in the number of outstanding Voting
          Shares resulting from a stock repurchase program or other similar plan
          of the Company or from a self tender offer of the Company, which plan
          or tender offer commenced on or after the date hereof, provided,
          however, that the term "15% Stockholder" shall include such Person
          from and after the first date upon which (A) such Person and or its
          Affiliates and Associates (taken collectively), since the date of the
          commencement of such plan or tender offer, shall have acquired
          Beneficial Ownership of, in the aggregate, a number of Voting Shares
          of the Company equal to 1% or more of the Voting Shares of the Company
          then outstanding and (B) such Person, together with all Affiliates and
          Associates of such Person, shall Beneficially Own 15% or more of the
          Voting Shares of the Company then outstanding, or

               (iv) Medtronic, but only to the extent that it acquires or is
          deemed to acquire Beneficial Ownership of any Voting Shares by
          entering into the Medtronic Merger Agreement or by consummating the
          transactions contemplated thereby or by entering into the Support
          Agreements or by consummating the transactions contemplated thereby,
          provided, however, that the term "15% Stockholder" shall include
          Medtronic from and after the first date after entering into the
          Medtronic Merger Agreement or the Support Agreements upon which (A)
          Medtronic and/or its Affiliates and Associates (taken collectively)
          shall have acquired Beneficial Ownership of, in the aggregate, a
          number of

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          Voting Shares of the Company equal to 1% or more of the
          Voting Shares of the Company then outstanding and (B) Medtronic,
          together with all of its Affiliates and Associates, shall Beneficially
          Own 15% or more of the Voting Shares of the Company then outstanding.

In no event shall the execution and delivery of the Medtronic Merger Agreement
or the Support Agreements or the consummation of the transactions contemplated
thereby result in a Distribution Date, a Section 3(a) Event, an 11(a)(ii) Event
or a 13(a) Event, with or without the passage of time, or otherwise cause any
distribution of the Rights or any right to exercise the Rights.

Solely for purposes of the proviso to Section 1(z)(iv), Medtronic shall be
deemed to Beneficially Own securities of the Company that are subject to the
Support Agreements or Beneficially Owned directly or indirectly by any of the
parties (other than Medtronic) to the Support Agreements. In calculating the
percentage of the outstanding Voting Shares that are Beneficially Owned by a
Person for purposes of this subsection (z), Voting Shares that are Beneficially
Owned by such Person shall be deemed outstanding, and Voting Shares that are not
Beneficially Owned by such Person and that are subject to issuance upon the
exercise or conversion of outstanding conversion rights, exchange rights, rights
(other than Rights), warrants or options shall not be deemed outstanding. Any
determination made by the Board of Directors as to whether any Person is or is
not a 15% Stockholder shall be conclusive and binding upon all holders of
Rights."

     5. There is hereby added to the Rights Agreement a new Section 35 which
will read in full as follows:

          "Notwithstanding anything else in this Agreement to the contrary, on
     the Expiration Date all Rights shall, without any payment by the Company or
     Medtronic, expire with neither the Company nor Medtronic having any
     obligations under, and no persons having any rights under, this Agreement
     except for the payment of fees and expenses and indemnification, if any, to
     which the Rights Agent is entitled under this Agreement".

     6. The Summary of Rights referred to in Section 3(d) of the Rights
Agreement shall be revised by the Company to reflect the changes made by this
Amendment prior to its being sent out as required by Section 3(d).

     7. This Amendment shall be governed by and construed in accordance with the
laws of the State of Delaware applicable to contracts made and to be performed
entirely within such State.

     8. This Amendment may be executed in any number of counterparts and each of
such counterparts shall for all purposes be deemed to be an original, and all
such counterparts shall together constitute but one and the same instrument.


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     IN WITNESS WHEREOF, the Corporation and the Rights Agent have executed this
Amendment effective as of the date first above written.

                                       THE CORPORATION:

                                       MINIMED INC.


                                       By:      /s/ Terrance H. Gregg
                                                ---------------------
                                       Name:    Terrance H. Gregg
                                                ---------------------
                                       Title:   President
                                                ---------------------


                                       THE RIGHTS AGENT:

                                       COMPUTERSHARE INVESTOR SERVICES LLC.


                                       By:      /s/ Kenneth J. Vlk
                                                ---------------------
                                       Name:    Kenneth J. Vlk
                                                ---------------------
                                       Title:   Relationship Manager
                                                ---------------------








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