The FORE-SIGHT™ Cerebral Oximeter was designed to give health care providers information to guard against neurological injuries due to compromised cerebral tissue oxygenation. Cerebral tissue oxygen saturation values are important to clinicians because cerebral hypoxia (lack of oxygen supply to brain tissue) is one of the leading causes of brain injuries that occur in many surgical and clinical situations. The FORE-SIGHT™ Cerebral Oximeter utilizes the Company's patented, optically-based Near Infra-Red Spectroscopy (NIRS) technology to monitor absolute cerebral tissue oxygen saturation levels.

The non-invasive FORE-SIGHT™ Cerebral Oximeter offers clinicians several advantages:

ABSOLUTE CEREBRAL OXYGEN SATURATION VALUES
The FORE-SIGHT™ Cerebral Oximeter provides clinicians with an absolute indication of cerebral tissue oxygen saturation. This absolute value, displayed on the monitor and updated every few seconds, gives clinicians an immediate, clear indication of a patient's cerebral oxygen saturation status.

The ability to view absolute cerebral tissue oxygen saturation (SctO2) values has several advantages. Clinically relevant data regarding the status of the patient is available to the user within a few seconds of applying the sensor. Absolute readings also provide the clinician with flexibility in initiating SctO2 monitoring - monitoring can begin before or during a procedure, with either situation giving the user reliable, relevant results. With the ability to view absolute values, the patient's status can be assessed pre-operatively and decisions regarding clinical interventions can be made from the start of the procedure. Absolute values also allow the clinician to assess the patient's saturation values simply by viewing a single, accurate measurement on the monitor.

EXCEPTIONAL ACCURACY
The FORE-SIGHT™ Cerebral Oximeter system design incorporates several features for outstanding data accuracy.

• Advanced Optics - utilizes LASER-SIGHT™ technology for increased light source precision and superb data accuracy.
• Innovative, Patented Data Analysis Algorithm – accounts for optical characteristics of background tissue in determining cerebral tissue oxygen saturation values to minimize patient dependent variables.
• Novel Patient Sensor Design –minimizes interference from tissues outside the brain, when combined with our patented data analysis algorithm, resulting in exceptional measurement accuracy.

Absolute measurements obtained using the FORE-SIGHT™ Cerebral Oximeter have been confirmed via comparisons with invasive "gold standard" (co-oximetry of arterial and jugular bulb blood samples) measurements. In our most recent validation study conducted at Duke University, the CAS cerebral oximeter determined SctO2, showed a strong correlation with the gold standard SctO2 over a wide spectrum of SctO2 values (50-100%). The bias and precision (1 standard deviation) for the CAS cerebral oximeter SctO2, compared to gold standard SctO2, was 0.07 ± 3.69. This result demonstrates a very high level of accuracy when compared with "gold standard" results across a very wide spectrum of SctO2 values.

REAL-TIME DATA DISPLAY
Data is updated both graphically and numerically every few seconds, providing the clinician with immediate information regarding the patient's status, and allowing the clinician to quickly react to changes in saturation values.

Approximately 17-23% of people undergoing cardiopulmonary bypass surgery suffer from cerebral venous oxygen desaturation, resulting in compromised cognitive outcomes.1 Continuous oxygen delivery is critical for the brain, which is among the most susceptible organs to oxygen deprivation.5 After about ten seconds of brain ischemia, loss of consciousness will occur. After about 20 seconds, electrical activity in the brain will stop. In just a few minutes, a person experiencing brain ischemia will begin to sustain irreversible brain damage.2 If cerebral tissue oxygen de-saturation can be detected before it reaches a critical point, there is an opportunity for interventions to occur to minimize or prevent permanent damage.

The FORE-SIGHT™ Cerebral Oximeter was designed to monitor cerebral tissue oxygen saturation values and give clinicians an opportunity to intervene before damage to the brain occurs.

The FORE-SIGHT™ Cerebral Oximeter works by projecting harmless near infra-red light through the scalp and skull and into the brain via a disposable sensor on the patient's forehead. The device measures the light that is returned to detectors on the sensor and analyzes this information utilizing patented algorithms to determine absolute cerebral tissue oxygen saturation levels.

The FORE-SIGHT™ Cerebral Oximeter operates based on the principle that blood contains hemoglobin in two primary forms, oxygenated hemoglobin (HbO2) and de-oxygenated hemoglobin (Hb). These two forms of hemoglobin absorb light in different, measurable ways. Oxygen saturation levels are found by determining the ratio of oxygenated hemoglobin to total hemoglobin at the microvascular level (arterioles, venules and capillaries) interrogated by light from the oximeter sensor. Cerebral tissue oxygen saturation is a mixed oxygen saturation parameter and reflects a proportional mix of arterial (~30%) and venous (~70%) blood in brain tissue. This proportional mix was based on results reported from Positron Emission Tomography (PET) scan studies on the brain. 3

ADVANCED OPTICS AND INNOVATIVE DATA ANALYSIS ALGORITHM
The FORE-SIGHT™ Cerebral Oximeter utilizes advanced optics and an innovative data analysis algorithm for superb data accuracy. The FORE-SIGHT™ Cerebral Oximeter incorporates CAS Medical's unique LASER-SIGHT technology consisting of a laser system that produces four specific wavelengths of light each having a very narrow spectral bandwidth of approximately one nanometer. These four highly precise wavelengths, when utilized in conjunction with our patented data analysis algorithm, resolve for oxy- and de-oxy hemoglobin levels to calculate SctO2, while accounting for background tissue light absorption and scattering interference. The net effect is minimized patient-dependent variability resulting in exceptional data accuracy and absolute data measurements.

REFERENCES:

1. Croughwell., et al. Jugular bulb saturation and cognitive dysfunction after cardiopulmonary bypass. Annals of Thoracic Surgery, Vol 58 1994
2. Notle, John. The Human Brain: An Introduction to Its Function Anatomy. Fifth edition. Mosby, 2002. p119
3. Schmidt, Michael., et al. Xenon Attenurates Cerebral Damage after Ischemia in Pigs. Anesthesiology. 102(5): 929-936, May 2005
4. MacLeod., et al. IARS conference March 2006 Anesth Analg; 102; S-162.
5. Nollert G., et al. Postoperative neuropsychological dysfunction and cerebral oxygenation during cardiac surgery. Thorac Cardiovasc Surg. 1996 Jun;44(3): 158-60.