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                                                                   EXHIBIT 10.13

                                 PROMISSORY NOTE

                                       [To be dated as of the distribution date]

$[33,300,000]                                             Waltham, Massachusetts


         FOR VALUE RECEIVED, Viasys Healthcare Inc. (the "Maker"), promises to
pay to [Thermo Finance Corporation BV ("Thermo Finance")], its successors in
interest and assigns or the holder of this Note, at the offices of Thermo
Finance or such other place as the holder of this Note may from time to time
designate in writing, in lawful money of _____ and in immediately available
funds, the principal sum of $[33,300,000], together with interest on the unpaid
principal balance of this promissory note (the "Note") from time to time
outstanding at the rate of [_____]% per year until paid in full.

         Principal and interest shall be paid as follows:

         A. Interest shall accrue on the unpaid principal balance of this Note
from the date hereof through and including the date on which the unpaid
principal balance of this Note is paid in full, computed on the basis of a year
of 365 days for the actual number of days elapsed. The accrued interest on the
unpaid principal balance of this Note shall be payable quarterly.

         B. The entire unpaid principal amount of this Note, and all unpaid
Interest due hereunder, will be payable on [the date that is 12 months from the
date hereof].

         Notwithstanding anything set forth above, this Note shall be due and
payable as follows:

         On the date of receipt by the Maker or any majority-owned subsidiary of
the Maker of any cash proceeds from the sale of any equity securities (other
than upon option exercise) or the incurrence of indebtedness in respect of
borrowed money (any such event, a "Financing"), the Maker shall prepay the Note
in an aggregate amount equal to 100% of such proceeds, net of underwriting
discounts and commissions and other reasonable costs and expenses associated
therewith, including reasonable legal fees and expenses.

         This Note shall become immediately due and payable without notice or
demand upon the occurrence at any time of any of the following events of
default:

         (1)  default in the payment or performance of this or any other
              liability or obligation of the Maker to the holder, including the
              payment when due of any principal or interest under this Note
              (whether at the stated due date or maturity date thereof or in
              the event of a Financing as contemplated by the preceding
              paragraph);

         (2)  the liquidation, termination of existence, dissolution, insolvency
              or business failure of the Maker, or the appointment of a receiver
              or custodian for the Maker or any part of its property;

         (3)  the institution by or against the Maker or any indorser of
              this Note of any proceedings under the United States
              Bankruptcy Code or any other federal or state


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              bankruptcy, reorganization, receivership, insolvency or other
              similar law affecting the rights of creditors generally or the
              making by the Maker or any indorser or guarantor of this Note of
              a composition or an assignment or trust mortgage for the benefit
              of creditors; or

         (4)  determination by the holder that it is insecure with respect to
              the payment of any obligation of the Maker to the holder.

         Upon the occurrence of any such event of default, the holder shall have
then, or at any time thereafter, all of the rights and remedies afforded by the
Uniform Commercial Code as from time to time in effect in the Commonwealth of
Massachusetts or afforded by other applicable law.

         Every amount overdue under this Note shall bear interest from and after
the date on which such amount first became overdue at an annual rate of ___%.
Such interest on overdue amounts under this Note shall be payable on demand and
shall accrue and be compounded monthly until the obligation of the Maker with
respect to the payment of such interest has been discharged (whether before or
after judgment).

         In no event shall any interest charged, collected or reserved under
this Note exceed the maximum rate then permitted by applicable law and if any
such payment is paid by the Maker, then such excess sum shall be credited by the
holder as a payment of principal.

         All payments by the Maker under this Note shall be made without set-off
or counterclaim and be free and clear and without any deduction or withholding
for any taxes or fees of any nature whatever, unless the obligation to make such
deduction or withholding is imposed by law. The Maker shall pay and save the
holder harmless from all liabilities with respect to or resulting from any delay
or omission to make any such deduction or withholding required by law.

         Whenever any amount is paid under this Note prior to its stated
maturity or due date, the payments shall be allocated between outstanding
principal and accrued interest as shall be determined by the holder in its
discretion.

         The Maker agrees to pay on demand all costs of collection, including
reasonable attorneys' fees, incurred by the holder in enforcing the obligations
of the Maker under this Note.

         No delay or omission on the part of the holder in exercising any right
under this Note shall operate as a waiver of such right or of any other right of
such holder, nor shall any delay, omission or waiver on any one occasion be
deemed a bar to or waiver of the same or any other right on any future occasion.
The Maker and every indorser of this Note regardless of the time, order or place
of signing waives presentment, demand, protest and notices of every kind and
assents to any extension or postponement of the time of payment or any other
indulgence, to any substitution, exchange or release of collateral, and to the
addition or release of any other party or person primarily or secondarily
liable.

         This Note may be prepaid in whole or in part at any time or from time
to time without premium or penalty.

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         None of the terms or provisions of this Note may be excluded, modified
or amended except by a written instrument duly executed on behalf of the holder
expressly referring to this Note and setting forth the provision so excluded,
modified or amended.

         All rights and obligations hereunder shall be governed by the laws of
the Commonwealth of Massachusetts and this Note is executed as an instrument
under seal.

ATTEST:                                    Viasys Healthcare Inc.


By:  ____________________________          By: _________________________________
     Name:  _____________________              Name:  Randy H. Thurman
     Title:  ____________________              Title: President and Chief
                                                      Executive Officer



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