Abstract: A control system for a blood pressure monitor having a blood pressure cuff, an air pump for inflating the cuff, a pressure transducer measuring the air pressure in the cuff, and a bleed valve for selectively venting the blood pressure cuff to reduce the cuff pressure. The air pump leaks air when it is de-energized, thereby inadvertently leaking air from the blood pressure cuff when the air pressure in the cuff is to be maintained constant as an attempt is made to detect blood flow beneath the cuff. A two-way valve is placed in series with the air pump to isolate the air pump from the cuff when the pressure in the cuff is to be maintained constant. The two-way valve allows air to leak from the blood pressure cuff through the air pump when the cuff is to be vented. The two-way valve and the bleed valve thus provide redundant venting of the blood pressure cuff.

Abstract: An electro-optical connector having a plug containing a center light emitter or detector and an interconnected pair of light detectors or emitters symmetrically positioned with respect to the center light emitter or detector. A socket, also containing a center light detector or emitter and an interconnected pair of symmetrically positioned outer light emitters or detectors, is adapted to receive the plug. The plug may thus be inserted into the socket with a plurality of angular orientations. The plug is retained in the socket by a pair of resilient tabs extending into respective recesses in the socket. The tabs may be removed from the recesses by exerting an outward force on the tabs, either directly or by exerting a transverse force on the plug thereby generating a rotational moment on the plug that exerts an outwardly directed force on the tab. As a result, the plug may be removed from the socket by exerting side forces on the plug without damaging the plug or socket.

Abstract: An optical data link for transferring data between a pair of connectors and for activating an electrical device to which one of the connectors is attached. A light-emitting diode (LED) and a phototransistor are mounted in each of the connectors, with the LED of each connector visible to the phototransistor of the other connector when the connectors engage each other. The LEDs and phototransistors are connected to respective interface circuits. The interface circuits for at least one of the LEDs limits the current through the LED regardless of the amplitude of a driving signal. The interface circuits for the phototransistors maintain a relatively constant voltage across the phototransistors so that the phototransistors function as current switches. The electrical device is activated in response to closure of a magnetically sensitive reed switch mounted in the connector attached to the electrical device.

Abstract: A blood pressure cuff having an internal acoustic pickup cup. In one embodiment, the cup communicates with the interior of the blood pressure cuff bladder through an aperture that is sufficiently large to allow pressure equalization between the interior of the bladder and the cup and sufficiently small to prevent Karotkoff sounds from being coupled from the cup to the interior of the bladder. A single pneumatic tube extends from the cup and through the wall of the bladder to a first enclosure that is coupled to a second enclosure through a conduit. The first enclosure contains a microphone for converting the acoustic signals picked up by the cup into a corresponding electrical signal. The second enclosure contains a pressure transducer for providing an electrical signal indicative of the pressure in the bladder. In a second embodiment, the cup and bladder are isolated from each other and separate tubes extend from the bladder and the cup to separate enclosures.

Abstract: An ambulatory blood pressure monitor comprises a cuff coupled by a single fluid passageway to a manifold which in turn is coupled to a pump, valve and pressure transducer. The manifold comprises a larger main chamber in fluid communication with a smaller secondary chamber through a small channel in a wall separating the chambers. The pump, cuff and valve are in fluid communication with one another directly through the main chamber while the pressure transducer is coupled to the cuff through the secondary chamber.

Abstract: A non-fade display for a CRT which includes a brightened dot, or "bouncing ball", is described. The refreshed display makes use of relatively short persistence phosphors, together with a digital controller to momentarily stop a trace at a predetermined point corresponding to the newest data sample point, increase its intensity to form the brightened dot, follow the brightened dot with a blanked zone, and then continue with the older part of the trace.BACKGROUND OF THE INVENTIONThe present invention relates to a display system utilized in conjunction with a cathode ray tube (CRT). In particular, the invention is used in conjunction with CRTs designed to display data including a periodically updated trace.In various types of apparatus, including oscilloscopes and monitoring devices, such as patient monitors, a CRT is used to display a trace representative of the data being monitored.