Bio-logic Announces Special Meeting of Stockholders

Bio-logic Systems Corp. (Nasdaq:BLSC) today announced
that it will hold a special meeting of stockholders on Wednesday,
January 4, 2006, at 10:00 a.m., Central Standard Time, at One
Bio-logic Plaza, Mundelein, Illinois 60060, for the purpose of voting
upon a proposal to approve the previously announced merger agreement
dated as of October 16, 2005, among Bio-logic, Natus Medical
Incorporated ("Natus") and a wholly-owned subsidiary of Natus, and the
merger of that subsidiary into Bio-logic, as contemplated by the
merger agreement. Stockholders of record of Bio-logic at the close of
business on November 14, 2005 will receive notice of, and are entitled
to vote at, the special meeting. For the proposed merger to proceed,
the holders of a majority of Bio-logic's outstanding common stock as
of such record date must vote to approve and adopt the merger
agreement and to approve the proposed merger. Under the terms, and
subject to the conditions, of the merger agreement, Natus will pay
$8.77 in cash for each outstanding share of Bio-logic common stock.
   Bio-logic and Natus are working toward completing the merger as
quickly as possible after the special meeting.

   Where To Find Additional Information About The Merger

   On November 15, 2005, Bio-logic filed with the Securities and
Exchange Commission a definitive proxy statement, and has filed and
will file other relevant materials, in connection with the merger.
Before making any decision with respect to the merger, stockholders of
Bio-logic are urged to read the definitive proxy statement and the
other relevant materials filed with the SEC because they contain
important information about the merger. The proxy statement and other
relevant materials may be obtained free of charge at the SEC's web
site at (www.sec.gov). In addition, stockholders of Bio-logic may
obtain free copies of the documents filed with the SEC by contacting
our solicitation agent, Morrow & Co., Inc., at [phone] or email
to [e-mail]. Stockholders may also read and copy any
reports, statements and other information filed by Bio-logic at the
SEC public reference room at 450 Fifth Street, N.W., Washington, D.C.
20549 or call the SEC at 1-800-SEC-0330 for further information on
public reference rooms.
   Bio-logic and Natus and their respective executive officers and
directors may be deemed to be participants in the solicitation of
proxies from Bio-logic's stockholders in favor of the merger agreement
and the merger. Certain executive officers and directors of Bio-logic
have interests in the merger, including severance arrangements and
their ownership of Bio-logic's common stock and options to acquire
common stock (including acceleration of restricted stock and options),
and their interests are described in the definitive proxy statement.

   Cautionary Note Regarding Forward-Looking Statements

   This press release contains forward-looking statements that are
based on the beliefs of the management of Bio-logic, as well as
assumptions made by, and information currently available to,
Bio-logic's management. The forward-looking statements are subject to
certain risks, uncertainties and other factors that could cause actual
results to differ materially from those expressed in or implied by the
forward looking statements, including the risk that Bio-logic's merger
with Natus will not be consummated on a timely basis or at all and
other risks related to the pendency of the merger. Except as expressly
required by the federal securities laws, Bio-logic undertakes no
obligation to update or revise these forward-looking statements or
forecasts to reflect new events or changed circumstances or for any
other reason.