Abstract: An ultrasound scanning system including an array of ultrasound transducers and a transporter for moving the transducers over a human back. The movement of the ultrasound transducers define a plane and a position transducer produces a position signal representative of the position of the ultrasound transducers in the plane. There is a means for producing a range signal representative of the distance between the transducers and the objects imaged in the back. The range signals are digitized and stored in an array in a digital memory with the position of each stored range signal in the array corresponding to the position of the transducer from which the range signal was obtained in the plane at the time the range signal was received. The range information is printed on a page or displayed on a cathode ray tube with the position of the printed data on the page or the data displayed on the cathode ray tube corresponding to the position on the plane of the back from which the data was obtained.

Abstract: Apparatus and technique for monitoring physiological parameters. An acoustic sensor or microphone is placed in close proximity to the chest of a patient having one or two prosthetic heart valves. These heart valves produce clicks characteristic of opening and closing action. The acoustic sensor picks up the sound of these clicks and transfers them as electrical energy to a transmitter unit. The transmitter unit processes the analog signal, converts it to a digital signal and establishes the key timing factors involved. This digital data is stored in a memory buffer within the transmitter. Subsequently, this information is modulated and placed on telephone lines for transmission to a central monitoring site. At the monitoring site a demodulator returns the data to baseband digital signals. A computer at the central monitoring site displays the information in the time domain and also converts the information for display in the frequency domain.

Abstract: A heart monitor for transtelephonic monitoring of heart activity and of the functioning of implantable heart valves. The monitor is provided with foam electrodes for monitoring heart activity and with a microphone for simultaneous acoustic monitoring of heart valve function. The monitor is adapted for easy use by the inclusion of an electrode gel reservoir and a pump for transferring gel to the electrodes. A cover for protection of the electrodes is provided. Movement of the cover to expose the electrodes activates the pump and moistens the electrodes with gel. Closing the cover seals the electrodes and prevents evaporation of the gel.

Abstract: An ultrasound scanning system having a linear array of ultrasound transducers and a transporter system for moving the transducers along the human back. There is a means for producing a position signal indicative of the position of the array along the plane of the back, and a means for producing a range signal representative of the distance of objects interacting with the ultrasound signal from the transducer. An output means, such as a printer or cathode ray tube display, is responsive to the range signal and the position signal to produce an output representative of the structure of the body imaged during the back scan.

Abstract: An ultrasonic imaging module including a housing having an internal fluid-filled chamber, and an ultrasonic transducer producing a beam of ultrasonic energy. The transducer includes a piezoelectric transducer element and a ball-shaped ultrasonic window rotatably mounted in a bearing in one wall of the chamber for transmitting the beam of ultrasonic energy to the object to be ultrasonically scanned while rolling on the object. A source of pressured fluid is connected to the chamber and the relative size of the bearing and roller-ball window are such that a film of ultrasonic coupling fluid is applied from the chamber to the surface of the object to be scanned as the roller-ball window turns in the bearing during the scanning process. An ultrasonic lens mounted in the chamber between the transducer element and the ball-window compensates for the effect of the sphericity of the window on the ultrasonic beam.

Abstract: A body implantable lead having an anchoring sleeve slideably affixed thereto. The anchoring sleeve is generally cylindrical in shape, having a cylindrical lumen through which the main body of the body implantable lead passes. Since the lumen within the anchoring sleeve is smaller than the diameter of the electrode fixation device at the distal end and the electrical connector at the proximal end of the body implantable lead, the anchoring sleeve is fixedly, though slideably attached to the body implantable lead. The anchoring sleeve is molded of a body compatible material such as silicone or polyurethane. Small serrations of body compatible material within the lumen of the anchoring sleeve generate sufficient friction such that the anchoring sleeve does not slide along the body implantable lead from the sheer force of gravity. The distal end of the anchoring sleeve is tapered or otherwise suitably shaped to permit it to occlude a permanent lead introducer and/or blood vessel during implantation.

Abstract: An ultrasound scanning system particularly adapted for scanning large body areas such as the back. There is a plurality of ultrasound transducers, each mounted in a transducer shoe, and each shoe in turn mounted on a plunger which seats in the bore of a housing so that it is free to move independently from the other transducers in a direction parallel to the bore, but is constrained to move with the other transducers in the two perpendicular directions. A spring seated in the bore between the housing and the plunger provides a bias force to maintain a positive and uniform contact between the transducer and the back.

Abstract: Technique of and apparatus for multiplexing the power and signal leads of an implantable piezoresistive pressure transducer. A semiconductor switching circuit multiplexes the two leads between the transducer element and the electronic processing element. During the charge cycle, the switching circuit connects the power source to the two leads. The power source charges a capacitor located within the resistive bridge of the piezoresistive transducer. A sensing cycle causes the switching circuitry to remove the power source from the two leads, and to switch the two leads to the input circuit of the sensing electronics. Optional steering diodes may be employed in the resistive bridge to minimize heating of two of the resistors caused by charging current. The sensing circuit employs a sample and hold technique so that the sensed output is supplied constantly over time without the interruptions caused by the switching circuit action of charging the capacitor within the resistive bridge.

Abstract: A body implantable lead having a barrel-shaped ring electrode with the ends of the barrel embedded into the lead casing material. A cylindrical flange within the bore of the ring electrode contacts the lead conductor. The lead and electrode are formed by placing the lead in a press with the electrode between a pair of collets with elliptical working surfaces and the lead casing and conductor passing through the axial bore of the collets, and forcing the collets together to shape the electrode and to force the ends of the ring into the casing and the flange into contact with the lead conductor.

Abstract: An ultrasonic transducer system for scanning a body including an ultrasonic transducer mounted in a transducer shoe and means for applying acoustic coupling fluid to the transducer/body interface as the shoe moves along the interface. The means for applying the coupling fluid includes a fluid reservoir and a fluid dispensing channel in the transducer shoe, a position transducer for producing a signal proportional to the movement of the dispensing means along the transducer/body interface, a microprocessor responsive to the signal, and a stepping motor driven pump controlled by the microprocessor to pump fluid from the fluid reservoir to the dispensing channel in an amount determined by the movement of the dispensing means along the ultrasonic transducer/body interface.

Abstract: Apparatus for technique for monitoring physiological parameters. An acoustic sensor or microphone is placed in close proximity to the chest of a patient having one or two prosthetic heart valves. These heart valves produce clicks characteristic of opening and closing action. The acoustic sensor picks up the sound of these clicks and transfers them as electrical energy to a transmitter unit. The transmitter unit processes the analog signal, converts it to a digital signal and establishes the key timing factors involved. This digital data is stored in a memory buffer within the transmitter. Subsequently, this information is modulated and placed on telephone lines for transmission to a central monitoring site. At the monitoring site a demodulator returns the data to baseband digital signals. A computer at the central monitoring site displays the information in the time domain and also converts the information for display in the frequency domain.

Abstract: An activity sensor mounted within the pacer detects the general activity level of the patient and alters the escape interval of the pacer between a preset minimum and maximum in response to the detected activity level of the patient.

Abstract: An insertion tool for use with an improved cardiac pacing lead of the type having a barbed electrode and a flexible base pad disposed over the electrode. The insertion tool is provided with a slot for engaging the flexible base pad and a groove for engaging the lead body at an angle to the base pad, exposing the barbed electrode. The lead body is provided with an enlarged diameter segment for frictionally engaging the insertion tool.

Abstract: A semiconductor circuit for protecting battery powered electronic devices from damage due to polarity reversal. A metal oxide semiconductor is employed in series with the power source to switch the power input as appropriate. A first embodiment simply disables the power source input upon improper polarity. A second embodiment actually reverses the effective polarity to the load. Because the source-to-drain impedance of the metal oxide semiconductor device is resistive, a number of protection devices may be used in parallel to achieve an arbitrarily low voltage drop between power source and load for a given current drain.

Abstract: A length of tubing having an inside diameter equal to the diameter of a biomedical lead is slit along a direction parallel to its axis, with the length of the slits being equal to the desired circumference for lead anchor lobes. The tubing is slipped over the lead body and compressed so that the slit portions of the body expand into lobes, and while the tubing is compressed its ends are heated and compressed until they fuse to the lead body.

Abstract: A biomedical stimulation lead wherein the lead body is preformed into a helical configuration to assist in anchoring the lead. The lead includes a non-conducting member extending forward of the lead electrode along the axis of the lead body, and tines extending perpendicularly from the member. The tines are flat in a plane perpendicular to the axis of the lead.

Abstract: A wristwatch size cardiac monitoring apparatus which is worn on the wrist of one arm which in a first mode use a conductive material housing as one electrode which is held firmly in contact with the wrist of the arm on which it is worn. A finger of the other arm is placed on a receiving electrode of the casing which acts as a second electrode. Together, these two electrodes provide a lead I electrocardiac signal to the electronics within the housing. The monitoring apparatus can operate in a second mode when an external belt and set of sensors is plugged into a jack in the side of the housing. The set of sensors are positioned using the belt on opposite sides of the patient's chest just below the pectoral muscles and in contact with the skin. Additionally, there is described circuitry which is used to operate the rate monitor with either the internal or the external sensors.

Abstract: A body implantable connector for connecting to an implantable device, such as an electrical lead. The connector has a sheath for frictionally fitting over the end of the lead, the sheath being of a pliant material of sufficient strength to resist breaking under the forces normally exerted on the connector, but sufficiently pliable to deform under the frictional forces created between the sheath and lead when they are urged in opposite directions, so that when a force is exerted to pull the sheath from the lead it will stretch causing its diameter to decrease and grip the lead more tightly. In one embodiment a wire extends longitudinally within the sheath and mates with a lumen in the conductor of the lead to make electrical connection to the lead. A means for compressing the sheath about the lead, such as a suture or O-ring, may be used to further secure the sheath to the lead.

Abstract: A body implantable connector for connecting a plurality of implantable devices, such as connecting an extension to a lead. There is a sheath having two open ends, one of which frictionally fits over the end of the lead and the other of which fits over the end of the extension. The sheath is of pliant material of sufficient strength to resist breaking under the forces normally exerted on the connector, but sufficiently pliable to deform and to contract about the lead and the extension under the frictional forces created between the sheath and the lead, and the sheath and the extension when the lead and the extension are urged in a direction tending to separate them. A wire extends longitudinally within the sheath and mates with lumens in the conductors of the lead and the extension to make electrical connection between the lead and the extension. There is a member within the sheath, intermediate the open ends of the sheath, and integrally formed with the sheath which supports the wire within the sheath.

Abstract: A programmable pacemaker pulse generator capable of operating in several atrial and ventricular pacing modes having atrial and ventricular sense amplifiers and output circuits and programmable memory and clock controlled digital timing circuits for selectively delivering stimulating pulses to the heart in an atrial synchronous mode of operation. The ventricular sense amplifier has a blanking and refractory period following the sensing of a ventricular heartbeat or the occurrence of a stimulation pulse. Delay means operatively connected to the atrial sense amplifier operate to trigger the generation of a ventricular stimulating pulse after an A-V delay interval following a sensed atrial depolarization. The A-V delay interval is lengthened by means responsive to the detection of two or more ventricular depolarizations without an intervening atrial depolarization, so as to avoid the application of a ventricular stimulating pulse into the vulnerable period (or T-wave) of the heart.