SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                         ------------------------------
                                  SCHEDULE TO
                                 (Rule 14d-100)

           TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1)
                     OF THE SECURITIES EXCHANGE ACT OF 1934


                             Protocol Systems, Inc.
     ----------------------------------------------------------------------
                       (Name of Subject Company (Issuer))

                       Welch Allyn Acquisition Corporation
                               Welch Allyn, Inc.
     ----------------------------------------------------------------------
                      (Names of Filing Persons (Offerors))

                     Common Stock, par value $0.01 per share
     ----------------------------------------------------------------------
                         (Title of Class of Securities)

                                    74371R106
     ----------------------------------------------------------------------
                      (CUSIP Number of Class of Securities)

                             M. Jack Rudnick, Esq.,
                       Vice President and General Counsel
                               Welch Allyn, Inc.
                             4341 State Street Road
                       Skaneateles Falls, New York 13153
                                 (315) 685-2500

                                 With Copy To:

                             Ronald C. Berger, Esq.
                Bond, Schoeneck & King, LLP, One Lincoln Center
                         Syracuse,  New York 13202-1355
                                 (315) 422-0121
                 (Name, Address and Telephone Numbers of Person
 Authorized to Receive Notices and Communications on Behalf of Filing Persons)

                                  May 25, 2000

                            CALCULATION OF FILING FEE
- --------------------------------------------------------------------------------
     Transaction
     Valuation*                                         Amount of Filing Fee

        N/A                                                      N/A
- --------------------------------------------------------------------------------
 *Set forth the amount on which the filing fee is calculated and state how it
  was determined.


[   ]  Check the box if any part of the fee is offset as provided by Rule
       0-11(a)(2) and identify the filing with which the offsetting fee was
       previously paid. Identify the previous filing by registration statement
       number, or the Form or Schedule and the date of its filing.


Amount Previously Paid: ________________     Filing Party: _________________
Form or Registration No.: ______________     Date Filed: ___________________

[ X ]  Check the box if the filing relates solely to preliminary communications
       made before the commencement of a tender offer.

       Check the appropriate boxes below to designate any transactions to which
       the statement relates:

[ X ]  third-party tender offer subject to Rule 14d-1.

[   ]  issuer tender offer subject to Rule 13e-4.

[   ]  going-private transaction subject to Rule 13e-3.

[   ]  amendment to Schedule 13D under Rule 13d-2.

       Check the following box if the filing is a final amendment reporting the
       results of the tender offer: [ ]


For more information contact:

Welch Allyn, Inc.                                      For Immediate Release
4341 State Street Road
Skaneateles Falls, NY 13153
Jean Vincent, (315) 685-3696
Vincentjg@mail.welchallyn.com

Protocol Systems, Inc.
8500 S.W. Creekside Place
Beaverton, OR  97008-7107
Grant Gibson, (503) 526-8500
Grantg@protocol.com

              Welch Allyn, Inc. to Acquire Protocol Systems, Inc.

     Skaneateles Falls, NY and Portland, OR, USA -- May 25, 2000 -- Welch Allyn,
Inc., a privately-held company, and Protocol Systems, Inc. (NASDAQ: PCOL) today
jointly announced that their boards of directors have approved and the companies
have signed a definitive merger agreement pursuant to which Welch Allyn will
acquire all of the outstanding stock of Protocol Systems for $16.00 per share in
cash.

     The offer price represents a 47 percent premium to the $10.88 closing price
of Protocol's common stock on April 17, 2000, the last trading day prior to the
date of Protocol's announcement that it had engaged SG Cowen Securities
Corporation to assist Protocol's board of directors in the process of exploring
Protocol's strategic alternatives, including a potential strategic business
combination or sale of the company.

     The total value of the transaction is approximately $145 million. Under the
terms of the agreement, Welch Allyn will commence a tender offer to purchase all
outstanding shares of Protocol common stock within ten business days.
Protocol's board of directors will recommend that Protocol shareholders tender
their shares.  Following completion of the tender offer, Welch Allyn intends to
consummate a cash merger to acquire any shares not previously tendered and
purchased in the tender offer, and all outstanding options to acquire Protocol
shares will be cashed-out at that time.

     "In recent years, we have been able to serve our front-line clinical
customers more completely by successfully expanding into new product areas such
as patient monitoring," said Peter H. Soderberg, president and chief executive
officer of Welch Allyn, Inc. "This transaction furthers Welch Allyn's interest


in advancing its worldwide patient monitoring market presence and obtaining core
competencies and technologies to enhance the quality and accessibility of
patient data in highly cost effective ways."

     Soderberg further added, "It is our intent to combine our rapidly growing
patient monitoring business with Protocol, forming Welch Allyn Protocol, Inc., a
wholly-owned subsidiary of Welch Allyn, Inc. This new business will be
headquartered in Beaverton, Oregon, and it will direct our interests in the
patient monitoring, multiparameter electronic vital signs, and networked
clinical data communications markets."

     Robert F. Adrion, Protocol's current president and chief executive officer,
will become president and chief executive officer of Welch Allyn Protocol, Inc.
Expressing support for the merger, Adrion said,  "The Protocol Systems team is
excited about joining Welch Allyn.  Our companies have complementary products
and markets, a reputation for high quality, and a history of successful
collaboration.  Together we will be able to provide more solutions to more
customers globally, share technology and capabilities, and further accelerate
growth.  Protocol's board is pleased that our strategic exploration process has
led to a transaction that delivers good value to our shareholders."

     Welch Allyn's acquisition of Protocol Systems' stock is subject to
clearance under the Hart-Scott-Rodino Antitrust Improvements Act as well as
other customary conditions.

     Protocol Systems, Inc. designs, manufactures and markets mission-critical
flexible monitoring solutions that improve patient care and lower healthcare
operating costs.  Protocol uses innovative computer and software technologies to
provide vital patient data and connect clinicians with mobile patients via
workstations, wireless devices and the Internet.  Protocol is based in
Beaverton, Ore. and its products are available in more than 90 countries around
the world.

     Welch Allyn, Inc. was founded in 1915 and is today a leading manufacturer
and marketer of innovative medical and dental diagnostic equipment and miniature
precision lamps.  Headquartered in Skaneateles Falls, New York, USA, Welch
Allyn, Inc. has more than 1,800 employees and numerous manufacturing, sales, and
distribution facilities located throughout the world.

                                      ###


This press release contains forward-looking statements that involve risks and
uncertainties, including but not limited to those regarding the companies Welch
Allyn, Inc. and Protocol Systems, Inc. and the definitive agreement pursuant to
which Welch Allyn will acquire all of the outstanding shares of Protocol
Systems.  Actual results could vary materially from the description contained
herein due to many factors, including but not limited to, the risk that the
acquisition is not completed because one or more of the conditions to the tender
offer or the merger cannot be satisfied or for any other reason the merger
agreement is terminated.

The tender offer for the outstanding shares of Protocol Systems, Inc. common
stock described in this announcement has not yet commenced.  At the time the
tender offer is commenced, Welch Allyn will file a tender offer statement
(including an offer to purchase, a related letter of transmittal and other offer
documents) with the Securities and Exchange Commission (SEC), and Protocol will
file a solicitation/recommendation statement with the SEC.  Investors and
security holders are strongly advised to read both the tender offer statement
and the solicitation/recommendation statement regarding the tender offer, when
they become available, because they will contain important information.  The
offer to purchase, the related letter of transmittal and certain other offer
documents, as well as the solicitation/recommendation statement, will be made
available to all shareholders of Protocol Systems at no expense to them.  In
addition, investors and security holders may obtain a free copy of these
statements (when available) and other documents filed by Welch Allyn and
Protocol Systems at the SEC's website at www.sec.gov.