Aspect Medical Systems Further Demonstrates Commitment to Critical Care Market At American Association of Critical Care Nurses National Teaching Institute Exposition.

Business/Technology Editors and Health/Medical Writers

NEWTON, Mass.--(BW HealthWire)--May 9, 2002

-Critical Care Nurses Show Strong Interest in BIS Technology-

Aspect Medical Systems (NASDAQ: ASPM), the global leader in clinically proven technology that measures the effects of anesthetics and sedatives on the brain, is demonstrating BIS(R) (Bispectral Index(R)) technology at the American

Association of Critical Care Nurses (AACN) National Teaching Institute (NTI(TM)) and Critical Care Exposition in Atlanta, from May 6th to 9th.

The critical care nursing community has expressed significant interest in BIS technology at the meeting as evidenced by overflowing attendance at 18 in-booth continuing education (CE) sessions as well as a CE breakfast symposium lead by Richard Riker, MD, from Maine Medical Center, and Karen Lafleur, CCRN, from Massachusetts-based Baystate Medical Center. More than 300 critical care nurses attended the breakfast session to learn how innovations in sedation assessment improve patient care.

"Critical care nurses are at the heart of providing comfort and care for critically ill patients and are an essential customer to facilitate widespread adoption of BIS in the ICU," said Patricia McGaffigan, MS, RN, critical care marketing director for Aspect. "There has been high demand for BIS in the ICU community and many nurses at this meeting have indicated that they would like to add it to their practice." The largest meeting in the critical care field, this year's NTI brought together more than 6,000 acute and critical care professionals from all over the world to learn about the latest advances in practice and technology.

BIS technology provides critical care clinicians with a means to objectively and reliably assess sedation in critically ill patients. Over- and under-sedation of patients is a widely recognized challenge in the ICU where sedation assessment has been guided primarily by vital signs or subjective sedation assessment scales - approaches that may not be sufficient to achieve optimal patient assessment.

"Oversedation can lead to a cascade of events that can negatively affect nearly every system in the body, ultimately increasing the risk of complications, time on the ventilator, and length of stay in the ICU. On the other end of the spectrum, undersedation can have negative implications on patient safety, patient comfort, and the nurse's ability to achieve set medical goals," said DaiWai Olson, critical care nurse at Duke University Hospital. "Critical care nurses see the BIS as a powerful new tool in the ICU. It provides objective information about patient needs that enables us to make better, more informed decisions." He continued, "In addition to these clinical benefits, we've been able to document significant cost savings when BIS is used to guide sedation management at our institution."

BIS technology is also being displayed on the show floor as an integrated module solution at the Datex-Ohmeda, GE Medical Systems Information Technologies, Philips and Spacelabs Medical exhibits.

About BIS Monitoring

BIS monitoring provides direct information about the effects of anesthetics and sedatives on the brain. The technology works by placing a BIS sensor on a patient's forehead to obtain information from electrical brain activity, or EEG. The BIS monitor then translates this information into a single number from 100 (indicating an awake patient) to zero (indicating the absence of brain electrical activity) that objectively represents each patient's level of consciousness. BIS monitoring thereby enables clinicians to minimize the risk of under- and over- dosing of anesthetics and sedatives. Other vital signs, such as heart rate and blood pressure, do not correlate with depth of consciousness and are unreliable measures of adequate anesthesia and sedation.

About Aspect Medical Systems, Inc.

Aspect Medical Systems (NASDAQ: ASPM) is a global market leader in brain monitoring technology. To date, the company's Bispectral Index (BIS) technology has been used to assess more than five million patients and has been the subject of more than 900 published articles and abstracts. BIS is currently in use in the ORs and ICUs of more than 60 percent of the best-ranked hospitals with operating rooms in the U.S. (based on a U.S. News & World Report ranking of best hospitals) and is available in more than 160 countries. Aspect has secured OEM agreements with the six largest manufacturers of patient monitoring systems and partnerships with six of the largest group purchasing organizations in the United States. Based in Newton, Mass., Aspect employs more than 220 people worldwide. For more information, visit the company's web site at http://www.aspectms.com.

Certain statements about Aspect in this release and on Aspect's Web site are forward-looking and may involve risk and uncertainties, including statements with respect to the benefits of, and demand and market acceptance for Aspect's products, Aspect's competitive position and success of Aspect's marketing strategies. Among the important factors that could cause actual results to differ materially from those indicated by such forward-looking statements are the results of clinical trials, market acceptance of products and products under development, regulatory approval of products under development, regulatory approval of requests for reimbursement, the scope of Aspect's patent protection and other risks included under the heading, "Factors Affecting Future Operating Results," in Aspect's Annual Report on Form 10-K for the year ended December 31, 2001 filed on March 29, 2002, with the Securities and Exchange Commission. In addition, the statements in this press release represent Aspect's expectations and beliefs as of the date of this press release. Aspect anticipates that subsequent events and developments may cause these expectations and beliefs to change. However, while Aspect may elect to update these forward-looking statements at some point in the future, it specifically disclaims any obligation to do so. These forward-looking statements should not be relied upon as representing the Company's expectations or beliefs as of any date subsequent to the date of this press release.

Bispectral Index and BIS are registered trademarks of Aspect Medical Systems, Inc. A-2000 is a trademark of Aspect Medical Systems, Inc.