Instrumentarium's Datex-Ohmeda Division Presents Award-Winning Depth of Anesthesia Research at World Congress.

Business/Health Editors & Medical Writers

MONTREAL--(BW HealthWire)--June 5, 2000

Instrumentarium's (Nasdaq: INMRY; Helsinki: INS1V.HE) Datex-Ohmeda division is presenting groundbreaking research at the World Congress of Anaesthesiologists (WCA) conference in Montreal this week.

"Advances in Measuring Depth of Anesthesia," a series of three breakfast seminars on June 6-8 sponsored by Datex-Ohmeda, features presentations by leading researchers. Dr. Hanna Viertio-Oja, principal mathematician at the Datex-Ohmeda Research Unit in Helsinki, is presenting her team's award-winning research: "Entropy of the EEG: A robust index for depth of hypnosis," on Thursday, June 8.

Dr. Viertio-Oja's abstract on the topic, "New method to determine depth of anesthesia from EEG measurements," was awarded Best Abstract in the Clinical Application of Technology category at the Society of Technology in Anesthesia annual meeting in Orlando, Fla., earlier this year. The work of Dr. Viertio-Oja and her colleagues on entropy as one of the most promising new potential electroencephalogram (EEG) correlates of depth of anesthesia is quickly gaining worldwide recognition. In an article published in Anesthesiology News (Vol 26, Number 4, p.1 (2000)), Dr. Kirk Shelley, session moderator at the annual meeting and Associate Professor of Anesthesiology, Yale University School of Medicine, is quoted as saying "The science and the research are impressive."

Dr. Viertio-Oja's results on entropy as the fundamental characteristic of hypnotic depth are supported by recent results on a thermodynamic model of the neural system (Steyn-Ross et al., Phys Rev E 60 (1999)), which indicate that loss of consciousness with anesthesia is analogous to a state change of matter, such as the one that takes place in water when it freezes. When water freezes, the decrease in entropy is equivalent to the latent heat that is removed. This same removal of latent heat has been observed in anesthetized patients. "The alert mind is in a mess, but when a patient loses consciousness as a result of anesthesia, the amount of disorder is reduced and, consequently, the entropy of EEG decreases," said Dr. Viertio-Oja. (Note: Dr. Moira Steyn-Ross, University of Waikato in Hamilton, New Zealand, will also speak at the June 8 breakfast seminar on the topic, "Theory of consciousness based on a microscopic model of the neural system.")

Based on a study of 105 patients who were undergoing routine general anesthesia, Dr. Viertio-Oja said, "Entropy nicely follows the assessment of anesthesia state as evaluated by the anesthesiologist and is a natural and robust characteristic of hypnotic depth. Loss of consciousness occurred at a universal critical value of entropy, which is independent of the patient. Recovery of consciousness was also clearly indicated by entropy." The abstract is available on the company's web site: www.datex-ohmeda.com/news.htm.

Datex-Ohmeda has a long history of involvement in clinical research in EEG monitoring, having introduced the world's first commercially successful EEG monitor for anesthesia in 1982, the Datex ABM Anesthesia and Brain Monitor. Datex-Ohmeda is committed to continuing development of clinical parameters that may have potential use in clinically relevant monitoring of the depth of anesthesia. Current parameters include EEG (also featuring Auditory Evoked Potential monitoring), neuromuscular transmission (NMT) for monitoring of neuromuscular blockade as well as electromyogram (EMG) and electrocardiogram (ECG) derivatives for monitoring of analgesia. Some of these features are pending U.S. Food and Drug Administration (FDA) clearance for marketing in the United States and approved medical device licenses in Canada.

Datex-Ohmeda is the world's leading supplier of anesthesia equipment and services and an emerging leader in critical care. The company's wide range of products includes patient monitoring systems, clinical information systems, anesthesia machines and ventilators. Datex-Ohmeda had sales of $580 million in 1999 and employed approximately 3,500 professionals worldwide. (See also www.datex-ohmeda.com)

Instrumentarium Corporation is a leading international medical technology company, operating in Anesthesia and Critical Care (Datex-Ohmeda) and Medical Equipment, as well as in Optical Retail. Instrumentarium had sales in 1999 of $824 million and employed approximately 5,100 professionals worldwide. Instrumentarium is listed on the Helsinki Exchanges (INS1V.HE) with ADRs listed on the Nasdaq (INMRY). (See also www.intrumentarium.com)