Bio-logic Announces Special Meeting of Stockholders.

MUNDELEIN, Ill. -- 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.