Abstract: A finger sensor for a pulse oximetry system is provided having a body of flexible, resilient polymeric material formed as a pocket. On the inside walls of the pocket toward the closed end are a LED light source and an opposing photodetector. The space within the pocket transverse to the longitudinal dimension of the pocket exhibits a relatively smaller width and a relatively greater width. As a finger is inserted into the pocket with the fingertip between the LED and the photodetector, the relatively smaller width of the pocket expands and the relatively greater width of the pocket decreases. This expansion and decrease of the pocket dimensions are resisted by the resilient polymeric material, causing the walls of the pocket containing the LED and the photodetector to securely contact and retain the finger within the pocket.

Abstract: A pulse oximetry system is provided in which LEDs of two different wavelengths illuminate tissue containing arterial blood flow. A photodiode receives light from the LEDs and produces electrical signals containing pulsatile components. The components of the two wavelengths are separated and the pulsatile waveforms are monitored until signal peaks are detected at the end of diastole. The waveforms are then integrated over the systolic interval, and the integrals are combined with the signal peak values to determine an index value. The index value is used to select a value representative of oxygen saturation from a look-up table.

Abstract: A communication protocol is provided to enable one of a number of transmitters using a common transmission line to independently gain exclusive use of the line. Before transmitting data, a transmitter first monitors the line to establish that it is idle. If it is, the transmitter then asserts the line for an interval unique to that given device. Thereafter the transmitter monitors the device momentarily to determine that no other transmitter is asserting the line and, if so, the transmitter may then gain exclusive control of the line.

Abstract: A back pressure sensor for a positive displacement pump comprises at least one flexible beam having a pivot end and a drive connector end, and a pump actuator mounted between the pivot end and the drive connector end. The pump actuator connects with a positive displacement member of a pump. At least one sensor beam is connected to the flexible beam at a mounting position between the distal end and vibration damping end thereof. A first capacitor plate is mounted on the flexible beam at a position adjacent to the pivot end thereof, and a second capacitor plate is mounted adjacent the distal end of the sensor beam in a position facing the first capacitor plate at a distance which permits a capacitance coupling between the capacitor plates. A vibration damping mass is secured to the vibration damping end of the sensor beam for damping drive motion vibrations in the sensor beam.

Abstract: A back pressure sensor comprising a flexible beam having a pivot end with a pivot pin and a drive connector end with a means for engaging a pump drive. A pump actuator is connected to the flexible beam at a position intermediate the ends and connects with a positive displacement pumping member. A sensor beam is attached to the flexible beam at a connecting point spaced from said pivot end. A first capacitor plate is mounted on the flexible beam at a point which is spaced from the connecting point. A second capacitor plate is mounted on the sensor beam in a position facing and spaced apart from the first capacitor plate at a distance therefrom which permits formation of a capacitance coupling therebetween.

Abstract: A disposable diaphragm pump cassette comprises a flexible diaphragm member comprising hinged, rigid plates hingingly mounted on an inflexible plate and opposed to a pumping chamber surface to form a pumping chamber. The pump includes check valve means comprising movable circular plates integrally connected with the inflexible plate by flexible, extendable webs. The flexible diaphragm member comprises at least three inflexible diaphragm plates with edges in a common plane, each diaphragm plate having at least two straight diaphragm plate hinge edges. Each diaphragm plate hinge edge is adjacent to and aligned with a second diaphragm plate hinge edge of an adjacent diaphragm plate. The adjacent edges of each diaphragm plate hinge edge and second diaphragm plate hinge edge are attached together by a flexible hinge strip.

Abstract: A hinged plate diaphragm pump comprising a pumping chamber defined by an inflexible member and a flexible member opposed thereto. The flexible member has at least three inflexible plates with edges in a common plane. Each plate has at least two straight plate hinge edges, each plate hinge edge being adjacent to and aligned with a second plate hinge edge of an adjacent plate, the adjacent edges of each plate hinge edge and second plate hinge edge is attached together by a flexible hinge strip. Preferably, the plates comprise at least one array of plates positioned about an axial center of symmetry perpendicular to the common plane. The hinged plates can be hingedly connected to a surrounding support plate and an axially central plate positioned at the axis of symmetry.

Abstract: A blood pressure cuff is applied about a subject's artery, and inflated above the systolic level thus fully occluding the artery for a full heart cycle. The cuff pressure is thereafter reduced to permit an increasing flow through the progressively less occluded artery, and a measure of the peak amplitudes of the successively encountered blood flow (oscillatory complex) pulses stored in memory. Also retained is the cuff pressure obtaining for each stored complex peak. In accordance with varying aspects of the present invention, the stored complex peak-representing data ensemble is corrected for aberrations; and improved data processing operates on the stored (and advantageously corrected) pulse peak data and the corresponding cuff pressure information to determine the subject's mean arterial blood pressure.

Abstract: A disposable crimping valve assembly for parenteral solution delivery systems comprises a two-piece tubing receptor housing hingedly connected and with an irreversible snap connection which will not permit removal of the device from parenteral tubing after assembly. A back section has an integral movable pressure plate attached to the housing by integral flexible web connectors. When the movable plate is actuated toward the stationary press surface, tubing is bent over a sharp ridge element until the wall thereof contacting the sharp ridge collapses in a crimping action. The motor drive assembly provides rotational pressure to a threaded actuator engaging the back section without applying axial pressure thereto. The clamp permits manual adjustment to set flow rates when it is separated from the control housing.

Abstract: Catheters formed from polyurethanes containing sufficient halogenated moieties in the polymer structure to make the polyurethanes radiopaque are disclosed. Such polyurethanes can be prepared by employing halogenated diols and/or halogenated diisocyanate reactants. In preferred cases, the catheters are optically transparent in addition to being radiopaque.

Abstract: A mounting clamp particularly suited for mounting medical accessories on support poles comprises a stationary clamping surface which can be attached to an accessory housing. A cam is pivotly mounted on a trunnion connected to the stationary clamping surface has a spiral clamping surface, the stationary clamping surface and spiral clamping surface being positioned to constitute a clamping means when the clamp is in a clamping position. A spring means having one end connected to the trunnion and the other end connected to the cam is provided for biasing the cam to the clamping position. A lever pivotly mounted on the trunnion has a projection which engages the cam and causing it to pivot with the lever when the lever is pivoted to a clamp releasing position. The cam preferably has two spiral surfaces, one generated by a line parallel to the axis of rotation of the cam and the second cam surface by a line forming an angle with the axis of rotation of the cam.

Abstract: A blood pressure cuff is applied about a subject's artery, and inflated above the systolic level thus fully occluding the artery for a full heart cycle. The cuff pressure is thereafter reduced to permit an increasing flow through the progressively less occluded artery, and a measure of the peak amplitudes of the successively encountered blood flow (oscillatory complex) pulses stored in memory. Also retained is the cuff pressure obtaining for each stored complex peak. In accordance with varying aspects of the present invention, the stored complex peak-representing data ensemble is corrected for aberrations; and improved data processing operates on the stored (and advantageously corrected) pulse peak data and the corresponding cuff pressure information to determine the subject's diastolic arterial blood pressure.

Abstract: An inflatable, deflatable cuff, worn by the subject, is coupled to an air reservoir which is at a predetermined pressure which is above systolic pressure. The pressure head is established by a pump mechanism preferably located within the reservoir. When the reservoir is operatively coupled to the cuff, the cuff quickly inflates to a desired artery-occluding initial pressure preparatory to a following blood pressure measuring cycle of operation. The air pump resumes air flow into the reservoir when pressure within the reservoir falls below a predetermined threshold in preparation for a subsequent measurement cycle. The pump also supplies air directly to the cuff should the reservoir contents ever be inadequate to inflate fully the occluding cuff.

Abstract: A disposable pinch valve assembly for parenteral solution delivery systems comprises a two-piece tubing receptor housing hingedly connected and with an irreversible snap connection which will not permit removal of the device from parenteral tubing after assembly. A back section has an integral movable pressure plate attached to the housing by integral flexible web connectors. When the movable plate is actuated toward the stationary press surface, tubing is pinched or crimped therebetween and the cross-section area of the flow passage through the tubing is reduced. The movable pressure plate is designed to engage a actuator connector which engages the device by turning the actuator by hand or by the use of a motor-driven actuator in an axially sliding engagement.

Abstract: A blood pressure cuff is applied to the patient, pumped to a pressure above systolic, and then is reduced in pressure decrements. At each decrement, complexes are detected by investigating the signal slope, and peaks of the complexes are measured and compared. During the complex detection process, the signal slope is measured periodically at a rapid rate, and unless the slope meets predetermined criteria, the input filters are clamped to a baseline, and the process is repeated.

Abstract: A system for monitoring patient respiration include a disposable, convenient moisture detection device. The device is minimally intrusive to the laminar flow of gases and has minimal liquid collection volumes. It is characterized by high sensitivity at rapid response rates.

Abstract: A pressure cuff on the patient is inflated to a predetermined pressure above systolic, and then is deflated incrementally. At each decrement, oscillatory complexes are detected, and respective peaks are compared and evaluated as "true" complexes if they are within certain size matching criteria. After such "true" complexes are identified at a predetermined number of levels (e.g. 2 or 3), only a single complex is investigated at subsequent levels, provided specified size and timing criteria are met.

Abstract: Automated blood pressure monitors utilizing a pressurized cuff are adapted automatically to work with a variety of cuff sizes, including neonatal. An acoustical pressure pulse is generated at the monitor, propagated to and through the cuff, and back to a pressure transducer in the monitor. The total time of propagation is indicative of the cuff size being utilized.