<PAGE>   1
                               FOURTH AMENDMENT TO
                       AMENDED AND RESTATED LOAN AGREEMENT


         THIS FOURTH AMENDMENT TO AMENDED AND RESTATED LOAN AGREEMENT (the
"Amendment") is made this 27th day of August, 1999, by and among BANK OF
AMERICA, N.A. doing business in Washington as Seafirst Bank, a national banking
association ("Seafirst"), U.S. BANK NATIONAL ASSOCIATION, a national banking
association ("U.S. Bank")(each individually a"Lender" and collectively the
"Lenders"), BANK OF AMERICA, N.A. doing business in Washington as Seafirst Bank,
as agent for Lenders (the "Agent"), SPACELABS MEDICAL, INC., a California
corporation (the "Borrower") and SPACELABS MEDICAL, INC., a Delaware corporation
(the "Guarantor").

                                    RECITALS

         A. Lenders, Borrower, Guarantor and Agent are parties to that certain
Amended and Restated Loan Agreement dated as of July 16, 1997, as amended by
that certain First Amendment to Amended and Restated Loan Agreement dated as of
October 16, 1997, as amended by that certain Second Amendment to Amended and
Restated Loan Agreement dated as of October 15, 1998 and as amended by that
certain Third Amendment to Amended and Restated Loan Agreement dated as of March
15, 1999 (as the same has been and may hereafter be amended, modified or
extended from time to time the "Loan Agreement") and the related Loan Documents
described therein. Capitalized terms used herein and not otherwise defined shall
have the meanings given in the Loan Agreement.

         B. Borrower and Guarantor have requested that the Loan Agreement be
amended to increase the Total Revolving Commitment to $45,000,000. Lenders and
Agent are prepared to amend the Loan Agreement to increase the Total Revolving
Commitment on the terms and conditions set forth below.

         NOW, THEREFORE, the parties agree as follows:

                                    AGREEMENT

         1. DEFINITIONS. Capitalized terms used herein and not otherwise defined
shall have the meaning given in the Loan Agreement. All references in the Loan
Documents to Bank of America National Trust and Savings Association or Bank of
America NT&SA shall mean Bank of America, N.A., formerly known as Bank of
America National Trust and Savings Association.

         2. AMENDMENTS TO LOAN AGREEMENT. The Loan Agreement is amended as
follows:

          (a) AMENDMENT TO DEFINITIONS. In Section 1.1, amendments are made to
the definitions, as follows:

               (1) APPLICABLE REVOLVING INTEREST RATE. The definition of
"Applicable Revolving Interest Rate" is hereby amended and restated to
read as follows:

                           "Applicable Revolving Interest Rate" means (i) in
          respect of the aggregate principal amount Revolving Loans (or portion
          of thereof) up to a maximum of $35,000,000 at any one time
          outstanding, (A) in the case of any Revolving Loan denominated in
          Dollars, the Overnight Rate, the Revolving IBOR Rate, the Revolving
          LIBOR Rate or the Base Rate or (B) in the case of any Revolving Loan
          denominated in an Applicable Currency other than Dollars, the
          Revolving IBOR Rate or the Revolving
<PAGE>   2
          LIBOR Rate, in each case as designated by Borrower in an Interest Rate
          Notice given with respect to such Revolving Loan (or portion thereof)
          or (ii) in respect of the aggregate principal amount Revolving Loans
          (or portion of thereof) in excess of $35,000,000 at any one time
          outstanding, (A) in the case of any Revolving Loan denominated in
          Dollars, the Special Overnight Rate, the Special IBOR Rate, the
          Special LIBOR Rate or the Base Rate or (B) in the case of any
          Revolving Loan denominated in an Applicable Currency other than
          Dollars, the Special IBOR Rate or the Special LIBOR Rate, in each case
          as designated by Borrower in an Interest Rate Notice given with
          respect to such Revolving Loan (or portion thereof) or, in all cases,
          as otherwise determined pursuant to Section 2.8(c).

               (2) MAJORITY LENDERS. The definition of "Majority Lenders" is
hereby amended and restated to read as follows:

               "Majority Lenders" means two (2) or more Lenders holding not less
     than fifty-one (51%) percent of the aggregate pro rata interests in all
     Loans or such greater percentage of the aggregate pro rata interests in all
     Loans as shall be agreed to by all Lenders and Agent.

                (3) SPECIAL IBOR RATE. The definition of "Special IBOR Rate"
is hereby added to read as follows:

               "Special IBOR Rate" means, for any Applicable Interest
     Period, an interest rate per annum equal to the Revolving IBOR Rate for
     such Applicable Interest Period plus seventy (70) basis points.

                (4) SPECIAL LIBOR RATE. The definition of "Special LIBOR Rate"
is hereby added to read as follows:

                    "Special LIBOR Rate" means, for any Applicable Interest
     Period, an interest rate per annum equal to the Revolving LIBOR Rate for
     such Applicable Interest Period plus seventy (70) basis points.

                (5)  SPECIAL OVERNIGHT RATE.  The definition of "Special
Overnight Rate" is hereby added to read as follows:

                    "Special Overnight Rate" means, for any Applicable Interest
     Period, an interest rate per annum equal to the Overnight Rate that has
     been or would be quoted to Borrower with respect to Revolving Loans up to a
     maximum of $35,000,000 at any one time outstanding for such Applicable
     Interest Period plus seventy (70) basis points.

     (b) AMENDMENT TO SECTION 2.3. In Section 2.3, amendments are made to the
definitions, as follows:

               (1) EACH LENDER'S REVOLVING COMMITMENT. The table that sets forth
each Lender's "Revolving Commitment" is hereby amended and restated as follows:


                                       2
<PAGE>   3

<TABLE>
<CAPTION>

           Lender                                       Commitment
           ------                                       ----------
           <S>                                          <C>
           Seafirst Bank                                $29,000,000
           U.S. Bank                                    $16,000,000
                                                        -----------
                                            Total       $45,000,000
</TABLE>

                           (2)   TOTAL REVOLVING COMMITMENT.  The reference to
the amount of Thirty-five Million Dollars ($35,000,000) in the sentence that
contains the definition of the Total Revolving Commitment is hereby amended to
refer to the amount of Forty-five Million Dollars ($45,000,000).

         3. AMENDMENT TO BURDICK NOTES. In the first numbered paragraph of each
of the Burdick Notes, the phrase "and ending on the earlier of (a) the date
which is three (3) years after the date hereof, or (b) October 31, 2000" is
hereby deleted and the phrase "and ending on July 16, 2000" is substituted in
its stead.

         4. CONDITIONS TO EFFECTIVENESS. Notwithstanding anything contained
herein to the contrary, this Amendment shall not become effective until each of
the following conditions is fully and simultaneously satisfied:

               (a) DELIVERY OF AMENDMENT. Borrower, Guarantor, each Lender and
Agent shall have executed and delivered counterparts of this Amendment to Agent;

               (b) DELIVERY OF NOTES. Borrower shall have executed and
delivered to Seafirst and U.S. Bank promissory notes substantially in the form
of Exhibits A-1 and A-2 attached hereto (the "Notes");

               (c) CORPORATE AUTHORITY. Agent shall have received in form and
substance reasonably satisfactory to it (1) a copy of a resolution adopted by
the Board of Directors of Borrower authorizing the execution, delivery and
performance of this Amendment and the Notes (collectively, the "Amendment
Documents") certified by the Secretary of Borrower; (2) a copy of a resolution
adopted by the Board of Directors of Guarantor authorizing the execution,
delivery and performance of this Amendment and the subjoined Guarantor's Consent
certified by the Secretary of Guarantor; (3) evidence of the authority of the
persons who have signed the Amendment Documents on behalf of Borrower and this
Amendment and the subjoined Guarantor's Consent on behalf of Guarantor; and (4)
such other evidence of corporate authority as Agent or any Lender shall request;

               (d) OPINION OF COUNSEL. Agent shall have received the written
legal opinion of Clay West, in-house counsel for Borrower and Guarantor
addressed to Agent and Lenders dated as of the date hereof substantially in the
form of Exhibit B attached hereto;

               (e) CONSENT OF GUARANTOR. Guarantor shall have executed the
subjoined Guarantor's Consent;

               (f) REPRESENTATIONS TRUE; NO DEFAULT. The representations of
Borrower as set forth in Article 4 of the Loan Agreement shall be true on and as
of the date of this Amendment with the same force and effect as if made on and
as of this date. No Event of Default and no event which, with notice or lapse of
time or both, would constitute an Event of Default, shall have occurred and be
continuing or will occur as a result of the execution of the Amendment
Documents; and

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<PAGE>   4

                  (g) OTHER DOCUMENTS. Agent and Lenders shall have received
such other documents, instruments, and undertakings as Agent and such Lender may
reasonably request.

         5. REPRESENTATIONS AND WARRANTIES. Borrower hereby represents and
warrants to Lenders and Agent that each of the representations and warranties
set forth in Article 4 of the Loan Agreement is true and correct in each case as
if made on and as of the date of this Amendment and Borrower expressly agrees
that it shall be an additional Event of Default under the Loan Agreement if any
representation or warranty made hereunder shall prove to have been incorrect in
any material respect when made.

         6. NO FURTHER AMENDMENT. Except as expressly modified by this
Amendment, the Loan Agreement and the other Loan Documents shall remain
unmodified and in full force and effect and the parties hereby ratify their
respective obligations thereunder. Without limiting the foregoing, Borrower
expressly reaffirms and ratifies its obligation to pay or reimburse Agent and
Lenders on request for all reasonable expenses, including legal fees, actually
incurred by Agent or such Lender in connection with the preparation of this
Amendment and the closing of the transactions contemplated hereby.

         7.       MISCELLANEOUS.

                  (a) ENTIRE AGREEMENT. This Amendment comprises the entire
agreement of the parties with respect to the subject matter hereof and
supersedes all prior oral or written agreements, representations or commitments.

                  (b) COUNTERPARTS. This Amendment may be executed in any number
of counterparts and by different parties hereto in separate counterparts, each
of which when so executed shall be deemed to be an original, and all of which
taken together shall constitute one and the same Amendment.

                  (c) GOVERNING LAW. This Amendment and the other agreements
provided for herein and the rights and obligations of the parties hereto and
thereto shall be construed and interpreted in accordance with the laws of the
State of Washington.

                  (d) ORAL AGREEMENTS NOT ENFORCEABLE.

         ORAL AGREEMENTS OR ORAL COMMITMENTS TO LOAN MONEY, EXTEND CREDIT, OR TO
         FOREBEAR FROM ENFORCING REPAYMENT OF A DEBT ARE NOT ENFORCEABLE UNDER
         WASHINGTON LAW.

         EXECUTED AND DELIVERED by the duly authorized officers of the parties
as of the date first above written.


         BORROWER:            SPACELABS MEDICAL, INC., a California corporation



                              By
                                -------------------------------------------

                               Its
                                 -------------------------------------------


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         GUARANTOR:            SPACELABS MEDICAL, INC., a Delaware corporation



                                        By
                                          -------------------------------------

                                          Its
                                             -----------------------------------


         LENDERS:                       BANK OF AMERICA, N.A., a national
                                        banking association



                                        By
                                          -------------------------------------

                                          Its
                                             -----------------------------------


                                        U.S. BANK NATIONAL ASSOCIATION, a
                                       national banking association



                                        By
                                          -------------------------------------

                                          Its
                                             -----------------------------------


         AGENT:                         BANK OF AMERICA, N.A., a national
                                        banking association



                                        By
                                          -------------------------------------

                                          Its
                                             -----------------------------------



                                       5
<PAGE>   6

                               GUARANTOR'S CONSENT


         SPACELABS MEDICAL, INC., a Delaware corporation (the "Guarantor") is a
guarantor of the indebtedness, liabilities and obligations of SPACELABS MEDICAL,
INC., a California corporation (the "Borrower") under the Amended and Restated
Loan Agreement and the other Loan Documents described in the Loan Agreement.
Guarantor hereby acknowledges that it has received a copy of the Fourth
Amendment to Amended and Restated Loan Agreement dated as of August 27, 1999 by
and among Borrower, Bank of America, N.A. doing business in Washington as
Seafirst Bank and U.S. Bank National Association, as lenders, Bank of America,
N.A. doing business in Washington as Seafirst Bank, as agent, and Guarantor (the
"Amendment") and hereby consents to its contents, including all prior and
current amendments to the Loan Agreement and the other Loan Documents described
therein (notwithstanding that such consent is not required). Guarantor hereby
confirms that its guarantee of the obligations of Borrower remains in full force
and effect, and that the obligations of Borrower under the Loan Documents shall
include the obligations of Borrower under the Loan Documents as amended by the
Amendment.


         GUARANTOR:             SPACELABS MEDICAL, INC., a Delaware corporation



                                        By
                                          -------------------------------------

                                          Its
                                             -----------------------------------

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