March 2009 Nassib Chamoun, President and CEO Neal Armstrong, CFO rev 2.10

2 Safe Harbor Statement Certain statements in this presentation are forward-looking statements for the purposes of Section 21E of the Securities Exchange Act of 1934, and such statements may involve risks and uncertainties, including statements with respect to: the expected increase in sales of BIS sensors, the potential market for our products, short term and long term strategies and objectives, and expected profitability and positive cash flow in future periods. There are a number of important factors that could cause actual results to differ materially from those indicated by these forward-looking statements including: Our ability to achieve widespread market acceptance of our BIS monitoring technology and to compete with new products or alternative techniques that may be developed by others, including third-party anesthesia monitoring products; Competitive and regulatory risks relating to our ability to successfully develop and introduce enhancements and new products; Risks related to our limited worldwide sales and marketing experience and our ability to develop and implement a successful sales and marketing strategy, including with respect to our own sales force, distributors, OEMs and other sales channels in order to generate meaningful product revenue; The risk that we will not remain profitable if hospitals and anesthesia providers do not buy and use our BIS systems and BIS sensors in sufficient quantities; The risk that cases of awareness with recall during monitoring with the BIS system and/or significant product liability claims could limit market acceptance; and Other factors that could cause our actual results to vary from these forward-looking statements, including without limitation those set forth under the heading “Risk Factors” in our Quarterly Report on Form 10-Q for the fiscal quarter ended December 31, 2008 as filed with the SEC. In addition, the statements in this presentation represent our views only as of today and should not be relied upon as representing our views as of any subsequent date. While we may elect to update forward-looking statements at some point in the future, we specifically disclaim any obligation to do so, even if our estimates change and, therefore, you should not rely on these forward-looking statements as representing our views as of any date subsequent to today. This presentation includes non-GAAP financial measures. These non-GAAP measures are not prepared in accordance with U.S. generally accepted accounting principles. A reconciliation of the non-GAAP financial measures to the most directly comparable GAAP measures, and other information regarding these non-GAAP measures, is available in the Investor Relations section of our website at

3 Mission To improve people’s lives by helping medical professionals deliver the best possible patient care through innovative brain monitoring technologies.

4 Background Headquarters in Norwood, MA —International operations in The Netherlands 320 Employees —US field organization: 85 —International field & logistics support: 50 Broad and deep global OEM partnerships Disposables > 80% of Product Revenue Q4 Product Revenue $25M —75% gross margin —4% growth year-over year —Non-GAAP Operating Margin $(1.2)m¹ —Strong balance sheet ¹ Non-GAAP results exclude share-based expense.

5 BIS Technology & Value Proposition ¹ Appropriate range for general anesthesia with adequate analgesia. Optimal Depth of Unconsciousness Underdosing Increased Risk Of Awareness Overdosing Longer Recovery Side-effects Drug Costs Class I Evidence BIS monitoring leads to 5-fold reduction on incidence of awareness Less Drug Use Higher Quality & Faster Recovery Optimal Depth of Unconsciousness¹ Preliminary Studies: Deep anesthesia may be associated with long- term complications, including risk of postoperative mortality Prospective Trials in Progress Awake Flat line EEG BIS Index Range

6 Market Opportunity: Worldwide $ Billion market largely untapped Total SitesAnnual Procedures¹ Operating Room87,00050,000,000 Intensive Care60,00020,000,000 TOTAL147,00070,000,000 Current Market Penetration: BIS Monitoring56,0006,200,000 38% 9% Worldwide patients monitored to date31 Million ¹Includes BIS eligible procedures only

7 U.S. BIS Adoption Estimates ¹ U.S. News & World Report, July ² 20 Million Procedures × $15 US Sensor Price Total installed base through Q ,700 % of all U.S. ORs71% % of largest 1,000 hospitals77% % of “America’s Best Hospitals”¹80% Top 150 Accounts87% Top 600 Accounts57% Active Customers37% Non Customers-— Total Market19% ProcedureSensor Sales (Millions) PenetrationCurrentPotentialTotal A $300 Million Opportunity² in US Operating Rooms Clinician Adoption Institutional Adoption

8 BIS Monitoring System Patient / setting specific Smart-chip enabled >80% gross margin >80% of Product Revenue Range of alternatives Standalone/OEM integration BISx centric platform

9 Quarterly Revenue Growth Trends

10 Reaccelerating Growth Increasing Procedure Penetration —Expanded US field sales force from 40 to 60 representatives —Focus on largest and best customers to advance the standard of care —Target customers with the greatest potential for procedure growth —Deliver effective clinical education programs Enhancing the value proposition for BIS —Evaluate role and impact of BIS on patient outcomes —IDN partnerships to establish effectiveness —Impact of BIS adoption on Medicare population —Pave the way for Pay for Performance (P4P), quality indicators and evidence based guidelines Product Leadership and Expanded Opportunity —Bilateral system & composite Variability Index —Acquire & strategically integrate one or more products with a focus on an enhanced outcomes value proposition

11 BIS Competitive Advantage Safety, quality & cost benefits well established —3,200 published articles and abstracts including a Cochrane Review —BIS is The Only brain monitoring system that is proven in prospective clinical trials to reduce the risk of intraoperative awareness with recall* —BIS is The Only technology with an FDA indication for use that addresses the issue of awareness with recall A standardized platform across the continuum of care Significant installed base & extensive clinical experience —56,000 monitors & modules installed worldwide —31 million patients monitored Partnerships with OEMs ( Access to 90% of global market) Global field organization of 135 – exclusively focused on BIS * Myles PS, Et. al. Bispectral Index Monitoring to Prevent Awareness During Anaesthesia: The B-Aware Randomised Controlled Trial. The Lancet 2004; 363: Ekman A, Et al. Reduction in the Incidence of Awareness Using BIS Monitoring. Acta Anaesthesiologica Scandinavica 2004; 48 (1): 20-6.

12 GAAP Quarterly Financial Performance

13 Non-GAAP Quarterly Financial Performance

14 Highlights A leading brain monitoring company with growth opportunities in the Operating Room and Intensive Care Unit Consciousness monitoring during anesthesia and sedation —$100M annual run rate with significant upside - $1B annual potential —Revenue mix >80% disposable sensors and growing —Gross margin ~75% —Target: Non-GAAP Profitable in Q1 2009

One Upland Road Norwood, MA Tel: Nasdaq: ASPM

Supplemental Material

17 Cumulative Systems in Place

18 Quarterly Shipment Trends