Abstract: Low-cost tourniquet cuff apparatus includes: an inflatable bladder formed of flexible material having a bladder width dimension when the bladder is uninflated and a having a bladder length dimension sufficient for encircling a limb of a surgical patient at a desired location on the limb and for overlapping upon itself, wherein the bladder includes a bladder first inner surface facing a bladder second inner surface along the bladder length dimension and across the bladder width dimension when the bladder is uninflated; securing means for securing the overlapping bladder around the limb at the desired location; port means communicating pneumatically with the inflatable bladder and releasably connectable to a tourniquet instrument for supplying the bladder with pressurized gas; and stiffener means having a predetermined stiffness and having a stiffener width dimension less than the bladder width dimension, wherein the stiffener means is non-releasably attached to the bladder first inner surface within the inflat

Abstract: A low-cost disposable tourniquet cuff includes: a first sheet formed of flexible material that is impermeable to gas; a second sheet facing the first sheet and formed of flexible material impermeable to gas; a bladder seal joining the first sheet to the second sheet around a perimeter to form an inflatable bladder within the perimeter; port means communicating pneumatically with the bladder and releasably connectable to a tourniquet instrument; stiffener means contained within the inflatable bladder and formed of gas-impermeable material less flexible than the first sheet, wherein the stiffener means has a stiffener width dimension less than the bladder width dimension and is joined to the first sheet to form a non-inflatable portion of the first sheet; and securing means attached to the non-inflatable portion of the first sheet and adapted to allow a surgical user to releasably secure the cuff around the limb at the desired location so that the bladder overlaps upon itself.

Abstract: A surgical tourniquet cuff for limiting usage to improve safety, comprises: an inflatable portion having a length sufficient for encircling a patient's limb at a desired location; cuff connector means communicating pneumatically with the inflatable portion and adapted near an end for connecting to a tourniquet instrument to establish a releasable pneumatic connection; and a cuff usage register located at a predetermined distance from the end of the cuff connector means and adapted for containing a usage amount record indicative of an amount of a predetermined usage of the cuff. The cuff usage register may further contain a usage limit record indicative of a predetermined limit of the predetermined usage of the cuff. The cuff usage register may be further adapted for enabling the cuff usage record and the usage limit record to be read by a tourniquet instrument that is pneumatically connected to the inflatable portion through the cuff connector means.

Abstract: A surgical tourniquet cuff system includes a tourniquet cuff with a cuff connector for communicating pneumatically with the cuff and for releasably connecting to a tourniquet instrument connector to establish a pneumatic passageway between the cuff connector and the tourniquet instrument connector. A tourniquet instrument supplies pressurized gas through the pneumatic passageway to the cuff. The tourniquet instrument connector includes a cuff pressure transducer for producing a cuff pressure signal indicative of the pressure of gas within the gas passageway near the connection. The cuff may include a cuff usage register for containing a cuff usage record and the tourniquet instrument connector may include a cuff usage register interface for reading the record. The tourniquet cuff may further include a cuff sheath forming a flexible conduit containing the cuff connector and sized to allow the connection of the cuff connector to the tourniquet instrument connector within the sheath.

Abstract: A tourniquet cuff has minimal flow restrictions within its pneumatic passageway under normal operating conditions, has a substantially reduced likelihood of partial or complete obstructions or interruptions of the pneumatic passageway under foreseeable operating conditions, can indicate exposure of the cuff to external agents that are capable of affecting the integrity of the pneumatic passageway before use, and can be manufactured economically.

Abstract: Tourniquet apparatus for rapidly and accurately measuring a patient's limb occlusion pressure comprises: an inflatable tourniquet cuff for encircling a limb at a location; a tourniquet instrument releasably connectable to the cuff that includes: pressure sensing means for producing a cuff pressure signal indicative of the level of pressure in the cuff; pressure regulation means communicating with the cuff and responsive to the cuff pressure signal for regulating the pressure in the cuff near a reference pressure level; blood flow transducing means adapted for applying to a portion of the limb distal to the cuff to produce a blood flow signal indicative of blood flow in the portion; and limb occlusion pressure means responsive to the blood flow signal and the cuff pressure signal and operable for detecting arterial pulsations of blood flow, for increasing the reference pressure level in synchrony with the arterial pulsations and for producing a limb occlusion pressure value indicative of the lowest cuff pressu

Abstract: A occlusion detector for a dual-port surgical tourniquet system comprises: a tourniquet cuff for encircling a patient's limb and including an inflatable portion that communicates pneumatically with a first cuff port and that communicates pneumatically with a second cuff port independently of the first cuff port; a tourniquet instrument that is releasably connectable to the first and second cuff ports to establish first and second pneumatic passageways between the tourniquet cuff and the tourniquet instrument, wherein the tourniquet instrument includes pressure sensing means communicating with the first pneumatic passageway for producing an indication of the pressure in the cuff over a time period suitably long for the performance of a surgical procedure, pressure regulation means communicating with the second pneumatic passageway for regulating the pressure in the cuff near a reference pressure level, and an occlusion detector for introducing a pneumatic pressure pulse into the first pneumatic passageway duri

Abstract: This invention relates to an actuator assembly for a turbocharger pressure control valve assembly and a method of assembling a pressure control assembly of a turbocharger. The assembly comprises an actuator coupled to an actuator rod which in use is coupled to the valve assembly to control the position thereof. The actuator rod comprises an elongate member at least a portion of which is flexible. The actuator rod may be a resilient member which may be substantially straight when stressed. In use the actuator rod may extend in a substantially straight line between the actuator and the valve assembly.

Abstract: An adaptive tourniquet cuff system comprises: a tourniquet cuff having a physical characteristic and including an inflatable bladder of a length greater than the circumference of a limb at a selected location; a cuff connector carried on the cuff and communicating pneumatically with the bladder for releasably connecting to a tourniquet instrument to establish a gas-tight passageway between the bladder and the tourniquet instrument; and an identifying collar including identification means indicative of the physical characteristic and detectable by the tourniquet instrument upon establishment of the gas-tight passageway. The tourniquet instrument may supply gas to the bladder through the gas-tight passageway at a pressure sufficient to stop arterial blood flow into the limb distal to the cuff at the selected location, and may adapt its operation in response to the detected physical characteristic of the cuff.

Abstract: A hazard monitor for surgical tourniquet systems comprises: pressure transducing means for detecting a pressure in a pneumatic tourniquet cuff; power switch means for enabling an operator in initiate an interruption in the supply of electrical power required by pressure regulator means, wherein the tourniquet instrument is connectable pneumatically to the tourniquet cuff to supply pressurized gas to the cuff, thereby producing a pressure in the cuff; pneumatic connector means for enabling an operator to connect an inflatable cuff to the pressure regulator means, and hazard detection means communicating pneumatically with the pneumatic connector means for detecting pressurized gas having a pressure greater than a predetermined pressure level when an interruption in the supply of electrical power is initiated by the operator.

Abstract: An oil control device for incorporation in a system for sealing the passage of a rotating shaft (3) through an opening. The oil control device comprises an annular member (10) for rotation with said shaft (3) and provided with a circumferentially spaced array of passages (24, 18) for centrifugally displacing fluid away from said shaft (3) as it rotates. The passages (24, 18) comprise channels which are open along their length.

Abstract: Apparatus for applying an adaptable pressure waveform to a patient's limb for augmenting venous blood flow in the limb comprises: an inflatable sleeve for positioning onto a limb to apply a pressure to the limb beneath the sleeve when inflated with gas; pressure transducing means for sensing the pressure of gas in the sleeve and for producing a sleeve pressure signal indicative of the sensed pressure; pressure waveform application means responsive to the sleeve pressure signal and a reference pressure waveform signal for controlling the supply of pressurized gas to the sleeve so that the sensed pressure in the sleeve is maintained near a varying pressure indicated by the reference pressure waveform signal; and waveform register means for producing the reference pressure waveform signal indicative of a reference pressure waveform during a cycle time period wherein the reference pressure waveform includes a maximum pressure at a time within the cycle time period and a rate of pressure increase in an interval le

Abstract: A method of monitoring the patency of an inflated tube in a pneumatic medical device. The method includes inflating the tubing of the device, generating a pneumatic pulse at one part of the tubing by varying pressure in the tubing, sensing at another part of the tubing the variation of the pressure, determining the time between the generated and sensed pressure, and producing a human-perceptible signal when the time between the generated and sensed pressure exceeds a reference level.

Abstract: A configuration register is incorporated into an electrically powered tourniquet apparatus for enabling an operator to change the values of parameters initially employed at the time of the next use of the apparatus, such as the initial pressure settings and elapsed time limits. These changed initial values of parameters are stored in memory and remain there despite inadvertent or intentional interruption of electrical power to the apparatus. An event register provides capability for recording the occurrence of events (cuff inflation, cuff deflation, etc.) and for relating the occurrence of the events to hazards and undesirable outcomes such as nerve damage associated with tourniquet usage. A safety circuit is included to detect and respond safely to certain failures which are possible within the tourniquet apparatus.

Abstract: Apparatus for evaluating the stability of the shoulder joint of a human subject includes a rotatable, elbow-holding assembly that has sensors and associated processing components for producing an indication of the rotational angle of the long axis of the humerus of the subject relative to a reference. Sensors measure muscle activity as the humerus is rotated. Changes in the muscle activity measurement are processed to produce an indication of the changes in the subject's apprehension as the humerus is moved. The apparatus may include a clock that indicates the times when muscle activity occurs. The levels of muscle activity may be recorded at different times and indicated to the operator. Pressure can be applied in a direction normal to the long axis of the humerus, and sensors produce an indication of the level of the applied pressure and corresponding apprehension of the subject. Also available is an indication of the level of muscle activity that occurs when such pressure is applied.

Abstract: A configuration register is incorporated into an electrically powered tourniquet apparatus for enabling an operator to change the values of parameters initially employed at the time of the next use of the apparatus, such as the initial pressure settings and elapsed time limits. These changed initial values of parameters are stored in memory and remain there despite inadvertent or intentional interruption of electrical power to the apparatus. An event register provides capability for recording the occurrence of events (cuff inflation, cuff deflation, etc.) and for relating the occurrence of the events to hazards and undesirable outcomes such as nerve damage associated with tourniquet usage.

Abstract: A physiologic tourniquet includes a safety interlock system for detecting any potentially hazardous attempt to change tourniquet cuff pressure during a procedure involving the use of two cuffs for intravenous regional anesthesia. The attempt to change pressure is prevented until the operator provides a timely and separate confirmation action.

Abstract: An overlapping tourniquet cuff system for improved application of pressure to the limb, including an inflatable bladder; a sheath for containing the inflatable bladder wherein the sheath has a length sufficient to encircle the limb and overlap on itself in a substantially circumferential direction around the limb; a mechanism for securing the overlapped sheath around the limb; and a stiffening mechanism for superimposing over a region of the overlapped and secured sheath to constrain the shape of the sheath beneath the region when the bladder is inflated. The stiffening mechanism includes a securing mechanism for securing the overlapping sheath in a substantially circumferential direction around the limb independently of the sheath securing mechanism such that the sheath remains overlapped and secured in a substantially circumferential direction if the sheath securing mechanism is not engaged or becomes ineffective while the bladder is inflated.

Abstract: Apparatus for monitoring the patency of tubing in a pneumatic medical device including: an inflatable appliance for positioning onto the surface of a limb and adapted to apply pressure to the limb beneath the appliance when inflated with gas; tubing for establishing a pneumatic conduit between the inflatable appliance and a pressure control system. The pressure control system for supplies the tubing with gas at a controlled pressure. The pressure control system includes a pulse generating system for generating a pneumatic pulse at a sensing location in the tubing by producing a variation in the pressure of the gas at the sensing location during a finite time interval. A tubing patency monitoring system is adapted to sense the variation of pneumatic pressure at the sensing location and produce a tubing obstruction signal when the variation of pneumatic pressure sensed after the finite time interval exceeds a reference level.

Abstract: A tourniquet cuff provides a convenient and safe mechanism for connecting a sterile cuff that is disposed within a sterile surgical field with a source of pressurized air outside of the sterile field. Also provided is mechanism for connecting the cuff's inflatable bladder to the end of a tube to establish a gas-tight passageway between the tube and the bladder while allowing rotation of the tube end relative to the bladder in clockwise and counterclockwise directions around the cylindrical axis of the tube and maintaining the gas-tight passageway during and after such rotation and while also ensuring that an operator can disconnect the tube from the bladder only by manually applying an unlocking force and by applying a disconnecting force in a direction at a right angle to the unlocking force while the unlocking force remains applied.