Abstract: A small battery-operated oximeter noninvasively measures tissue oxygenation. This oximeter employs a high intensity, very short duration light pulse that penetrates clothing of a patient. A photodetector assembly of the oximeter is responsive to light reflected through clothing of the patient. The oximeter optically filters the reflected light. A ratio of the intensity of reflected red light to the intensity of reflected infrared light indicates tissue oxygenation of the patient.

Abstract: A noise-immune blood pressure measurement system filters out high frequency noise and blood pulses. The system also recognizes and filters out slow, large noise signals in the range of 0.5 Hz. Such noise signals result when a patient wearing the system makes slow, large finger movements, or is slowly transported by a vehicle over a large bump, for instance. The system accurately derives systolic, mean arterial, and diastolic pressures even when used in a noisy emergency vehicle or battlefield situation.

Abstract: An apparatus and method for non-invasive, noise insensitive blood pressure determination which is useful in a battlefield or emergency vehicle environment. The system features an occlusion bladder and a sensing bladder both adapted to fit over the limb of a patient. The pressure in the occlusion bladder is raised to a value which prevents flow and is then gradually decreased. The pressure in both bladders is monitored. When the pressure in the sensing bladder reaches a minimum value, the pressure in the occlusion bladder is equal to the systolic pressure. The first, second, and third time derivatives of the pressure in the sensing bladder are monitored. The first derivative is useful in identifying the minimum in the pressure in the sensing bladder. When the third time derivative of the pressure in the sensing bladder passes through zero, the pressure in the occlusion bladder is equivalent to the mean arterial pressure.