Abstract: Air emboli detection method and apparatus for use in cardiopulmonary bypass surgery or the like comprising modular sensor, control and power units. The sensor unit is adapted to releasably clamp a blood flow tubing or conduit in a vertical orientation below a blood deaerator, and includes an LED infrared source and a phototransistor detector. The control unit applies pulsed power to the light source only at preselected periodic intervals, and monitors for an output from the detector only at times corresponding to the preselected intervals to achieve an enhanced signal-to-noise ratio. The power unit includes a solid state relay responsive to detection of emboli for removing power from a blood pump or the like.

Abstract: A multispectral data classification system has an improved apparatus for the identification of training samples of multispectral image data useful in the computation of spectral signatures.A set of multispectral image data is displayed on a user-interactive device in a two-dimensional ordered array. The training sample is defined by the sequential definition of the vertices of a polygon representing the training sample. A rectangle is closely superscribed about the polygon. The data elements within the rectangle are examined to determine if they are within the polygon.The apparatus includes a multispectral data classification system incorporating a color, CRT display for displaying the set of data; a manually-operable trackball cursor interactive with the color, CRT display for defining the polygon and rectangle; an alphanumeric keyboard and monochrome CRT for providing communication between the operator and system; and a random access memory device.