Abstract: A calibration boot for use with an optical catheter includes a plurality of materials, each having a different reflectivity characteristic with respect to known wavelengths of light. The boot is positioned over the distal end of the optical catheter and light is emitted from the distal end of the optical catheter into one of the materials at a time. At each emission, the reflected or backscattered light is measured by a detector and a plurality of signals are obtained. The plurality of readings are used to calibrate the overall optical catheter and system. The use of a plurality of calibration signals improves the overall system accuracy, particularly where two or more variables are present in the measured parameter. In the preferred system, the parameter being sensed in the oxygenatin of blood invasively.

Abstract: A rotary type of flowmeter having an orifice directing the flow toward a moveable needle. The needle moves within a channel that has a varying cross-sectional area in a plane transverse to the needle movement such that the effect of the velocity of the fluid impinging on the needle to cause its movement is controlled.

Abstract: A circuit for monitoring the program flow of a computerized or microprocessed system, includes a comparator for matching a uniquely assigned address for entering a given mode of operation, with an address presented by the system controller for entering the operating mode. If the addresses do not match, in response to the detected illegal mode entry attempt, a reset signal is generated for resetting the controller to reinitiate the programmed flow of operation.

Abstract: A system for controlling the amount of light radiation directed upon an infant from a fiberoptic phototherapy pad by feedback from a light detector that itself is a fiberoptic pad. The fiberoptic detecting pad receives and detects the light density radiation over an area and is located intermediate the normal fiberoptic phototherapy pad and the infant and therefore is in the best position to detect accurately, the light impinging upon the infant. In some embodiments, the light detector pad is manufactured as part of the fiberoptic phototherapy pad itself as a unitary construction. Light readily travels through the light detector to the infant, yet the light detector senses the light intensity and density of the light passing therethrough.

Abstract: The nasal septum probe of the present invention mounts the optical devices of a photoplethysmographic probe in a housing that clips onto the patient's nasal septum. The septum provides an arterial bed for monitoring purposes and this locus is not subject to significant patient motion or peripheral shutdown of arteriolar blood flow. Furthermore, one embodiment of the invention shows a combination of the photoplethysmographic apparatus with a nasal cannula to provide dual purpose apparatus to minimize the sensor and cable proliferation.

Abstract: This arterial blood monitoring system takes advantage of the basic statistical property that arterial blood contains a plurality of dominant absorbers, whose measured light absorption spectra appear as a constant over a short interval of time. By measuring the transmitted light as it varies with arterial pulsation at selected wavelengths of light, over a common light path, the relative amount of these dominant absorbers in the arterial blood can noninvasively be determined. To ensure the common light path, a sandwich construction light detector is used.