Abstract: A mechanism, such as a motor driving a pump, creates a pulsating fluid flow. There is a control for varying the pulsation frequency independently of the fluid pressure or rate of flow. Another control varies the pressure or rate of fluid flow independently of the frequency of pulsation. Separate pulsatile lavage, irrigation, and aspiration functions are provided. In another aspect, the mechanism for producing the pulsating flow includes a fluid driving means, such as a reciprocating pump, and there is a means for varying the length of stroke of the driving means.

Abstract: A lavage system including a motor having a drive member, a pump housing having a door, a pump having a pump body and a driven member, a means for coupling the motor drive member and the pump driven member, and a means activated by the closing of the housing door for gripping the pump body and securing it within the pump housing. The gripping and securing means includes a pair of fingers which pass through a portion of the pump body, and a wedge on the door which forces the fingers apart and against the pump body when the door is closed. The means for coupling the drive member and the driven member and the gripping and securing means are engageable by the pump along the same direction for ease of insertion of the pump in the housing.

Abstract: This invention relates to an improved tourniquet cuff. The cuff is of the type which includes an inflatable member for wrapping about a body part, such that the inflatable member is secured to the body part, and at least one tube is provided to facilitate inflation of the inflatable member, with the inflatable member having a length dimension, and a width dimension. The inflatable member is formed in a substantially arcuate shape, with the radius of the arc passing along the width dimension. In the preferred embodiment, the inflatable member includes a bladder and a polyester reinforced backing, both of which have the arcuate shape. The invention also provides a set of tourniquet cuffs having the arcuate shape and in which the cuffs of the set nest one within the other. In the preferred embodiment, the inside radius of one cuff is equal to the outside radius of the next smaller size cuff.

Abstract: An electrosurgical unit having a power source, and an amplifier which includes a bipolar transistor and a FET in series with the amplifier load. In cut and blend modes, the power output of the unit is controlled by a variable voltage applied to the base terminal of the bipolar transistor. In coagulation, fulgration, and bipolar modes the power output is controlled by a variable duty cycle voltage applied to the gate terminal of the FET.

Abstract: A compression hip screw comprises a plate with a barrel, a lag screw adapted for fixation to a femoral head, a compression screw engageable with the lag screw to retain the plate and barrel attached with the femur and a locking pin to oppose rotation between the barrel and the lag screw. The locking pin is disposed on one side of the barrel to provide a robust structure for the lag screw and enable the barrel to transmit loads developed during the walking mode for the hip.

Abstract: An electrosurgical unit having feedforward power regulation. In one embodiment there is an amplifier which produces a pulse modulated electrosurgical output signal. A microprocessor calculates an adjusted pulse width (duty cycle) just sufficient to account for the power changes due to voltage fluctuations. The microprocessor controls the pulse width of the gate voltage of a power transistor in the amplifier to regulate the amplifier output. In another embodiment the supply voltage is fed into the base drive circuitry of an amplifier power transistor through the photo-resistor side of an optoisolator. The lamp brightness of the optoisolator and thus the gain of the base drive circuitry is adjusted by the amplifier power level control. The nonlinearity of the optoisolator complements the nonlinearity of the amplifier so that the net gain in the amplifier drive at any power setting is just sufficient to account for the voltage fluctuation.

Abstract: This invention relates to an improved fluid pump. The pump is of the type, wherein a reciprocating motor acts in concert with supply and exhaust valves to pump fluid from a source to its destination. In the preferred embodiment, the motor comprises a reciprocating diaphragm and the supply and exhaust valves comprise a single resilient plate with individual valve members formed as cutouts therein. The valve plate is sandwiched between two plates which form the associated porting. The interaction between the various ports on the valve plates results in improved sealing effect for the valves.

Abstract: An electrosurgical unit including voltage control circuitry which operates to limit the voltage at the electrosurgical electrodes when the unit is not in coagulation mode. The electrosurgical unit includes sensing circuitry for providing a signal representative of the voltage at the electrosurgical electrodes, a mode setting switch or dial for changing between a cut mode setting and a coagulation mode setting, a circuit for producing a mode signal, and an RF power generator responsive to the mode setting switch for providing a cut mode waveform at the electrode outputs when the mode setting switch is in cut mode and a coagulation mode waveform when the mode setting switch is in the coagulation mode setting. A voltage limiting circuit is responsive to the signal from the sensing circuitry and limits the voltage at the outputs when the electrosurgical unit in cut mode. Suppression circuitry responsive to the mode signal prevents the voltage limiting circuitry from operating in coagulation mode.

Abstract: A linear motor drives a reciprocating pump to produce a flow of lavage fluid. In the preferred embodiment the motor is a moving coil linear motor and the coil is attached to one plate of a drive member comprising a pair of circular plates connected by three shafts that slide in bearings passing through the motor core. Springs having varying coil spacing are seated between the plates and motor core to variably damp the motor's motion, with the strongest damping at the ends of its reciprocating stroke.

Abstract: A linear motor comprising a moveable coil, a stationary core in which the coil moves, and a drive member including a shaft and a bearing, the shaft moveable in the bearing and passing through the core. In the preferred embodiment, the drive member includes a pair of circular plates connected by three shafts that slide in bearings passing through the motor core, with the coil attached to the periphery of one of the plates. Springs having varying coil spacing are seated between the plates and the motor core to damp the motor's motion, with the strongest damping at the ends of its reciprocating stroke.

Abstract: An automatic tourniquet with an improved occlusion detector. A pump and valve for inflating and deflating a tourniquet cuff are connected to a first port. A pressure transducer for sensing the pressure in the cuff is connected to a second port. A pair of pressure differential switches, which activate an alarm when a pressure difference developes across them, are connected anti-parallelly between the pump/valve and the transducer. The differential switches also deactivate the pump/valve upon detection of an occlusion.

Abstract: An automatic tourniquet including a mechanism for inflating and deflating a cuff, a pressure sensing mechanism, and a mechanism for displaying the pressure. The pressure sensing mechanism includes a pressure transducer producing a pair of digital signals, and a mechanism for adjusting the signals so that the pressures at which the transitions between the digital quanta occur for one signal are different from the pressures at which the transitions occur for the other signal. The mechanism for adjusting includes a mechanism for setting the signals to be equal at a selected pressure, and a mechanism for offsetting the signals from each other by a voltage corresponding to one-half a digital quantum. The offset signals are summed by a microprocessor to produce a display with twice the resolution of the individual signals.

Abstract: An adjustment assembly for a disc brake includes a nut (26) and a threaded stem (28). The threaded stem (28) defines a first diameter portion (72) and a second diameter portion (76) which cooperate to form a differential area sealingly engaging an inwardly extending partition (68). The partition (68) also forms a passage (88) to communicate fluid pressure to both portions (72, 76) so that the differential area and pressure communicating passage are compactly arranged at the partition (68).

Abstract: A master cylinder includes a housing (24) forming a bore (26) for receiving a first piston (38) and a second piston (40). Each piston is movable during braking to generate fluid pressure within a first pressure chamber (54) and a second pressure chamber (58), respectively. The first piston (38) is made from a stamping to define a uniform thin wall therefor. The stamped piston (38) forms a longitudinal body (84) movable relative to a fixed lip seal (32) and a base (86) defining a pocket (88) for receiving an input member (22).

Abstract: A vacuum brake booster is coupled to a master cylinder at the same time that an output member for the vacuum brake booster is adjusted relative to a piston for the master cylinder. The adjustment is carried out by a plunger adapted to activate a bonding material for bonding the plunger to the output member.

Abstract: A universal joint includes a first member and a second member joined via a coupling assembly. The coupling assembly includes a pair of washer-like seats engageable with ball studs carried by the pair of members and a nut and bolt assembly. The nut and bolt assembly cooperates with one of the washer-like elements to define a stop and the one washer-like elements defines a stop with at least one of the ball studs and/or one of the members to permit easy assembly of the universal joint and smaller members.

Abstract: A hydraulic brake booster includes a housing with a bore for receiving a first piston, a second piston and a valve assembly. The valve assembly includes a sleeve with a bore receiving a first valve member and a second valve member. The valve member cooperates with an input member to define a cavity within the sleeve and a resilient travel block is disposed within the cavity in engagement with the valve member and the input member.

Abstract: A fluid level indicator is provided for a master cylinder to generate a signal in response to the fluid level reaching a predetermined level. The fluid level indicator includes a carrier assembly for holding a magnet and moving the same within a master cylinder reservoir. A reed switch is activated by the magnet in a given position.

Abstract: A drum brake assembly and adjuster therefor includes a wire element supporting a pawl and yieldably opposing movement of the pawl away from a rest position. The wire element is releasably connected to the pawl and a brake shoe for the drum brake assembly.