Abstract: In accordance with the present invention, an apparatus and method are described which in general provide for an extended dynamic range in light sensitivity for an imaging device. This extended dynamic range is achieved primarily through control of the light intensity level in a image on a pixel by pixel basis.In one aspect, a multi-faceted light controller is used like a variable iris camera, but on a pixel by pixel basis; thereby achieving a wider range of intensity control.In another aspect, this system is enhanced by adding another controller outside the feedback loop, before an added output image detector.In yet another aspect, some or most of the elements of the controlling and detecting system may be integrated into a composite monolithic structure.

Abstract: A sensor that utilizes strips of piezoelectric material to noninvasively measure the surface force/displacement resulting from a blood pressure wave traveling through an artery and transmitted through the arterial wall and overlying tissue, while canceling noise artifact signals is disclosed. Piezoelectric elements create an electrical signal when pressure is applied to their surface. In the preferred embodiment, the sensor is constructed so that there are three sensing elements--a signal sensing element in the center and one noise sensing element on each side of the center element. The center element is placed over an individuals artery, e.g., the radial artery in a persons wrist. When positioned this way, the two noise sensing elements are positioned on each side of the artery.The center element generates a signal that is a function of the pressure wave in the artery, whereas this signal is highly attenuated in the noise sensing elements.

Abstract: An inexpensive, disposable heating element is prepared for medical applications using layers of biologically-compatible materials disposed about a heating element that is formed of an electrically conductive material which exhibits positive temperature coefficient of resistance and that is then operated by a power controller which responds to the resistance of the heating element or to other electrical indication of operating temperature in order to control the level of power supplied to the heating element. A fuse is distributed about the periphery of the heating element to disconnect electrical power from the heating element in response to excessive heating of the element attributable to a portion of the heating element, usually including the periphery, not being immersed in liquid being warmed.