Abstract: The apparatus for pacing a heart in accordance with the heart rate needed to produce a required cardiac output while the person is exercising, comprises a pacer adapted to be implanted in a human body and having a pulse generator and control circuitry (e.g. including a microprocessor) therein, a pacing lead adapted to be implanted in a heart and having a distal electrode adapted to engage and supply pacing pulses to a right ventricle of a heart and, a pacer sensor for sensing right ventricular systolic pressure mounted on the lead. An algorithm and routine utilizing same are stored in the control circuitry (microprocessor) and are adapted to relate right ventricular systolic pressure and/or the time derivative of the pressure sensed with the required heart rate needed to supply a desired cardiac output and to cause the pacer to pace the heart at the required heart rate when the heart is not naturally paced.

Abstract: A process and apparatus for providing an electrophysiologic indicator of reversible myocardial ischemic injury as well as a procedure and apparatus for providing a method of assessing the status of myocardial preservation during elective cardioplegic arrest in order to assure complete electromechanical arrest from the onset of the application of the standard cardioplegic techniques. The procedure for establishing an indication of reversible myocardial ischemic injury involves implanting multiple electrodes in the myocardial tissue and sensing the instantaneous unipolar electrical potentials of the electrodes and comparing those sensed potentials with a series of registered potentials for healthy tissue.

Abstract: Cerebral palsy treatment apparatus and methodology employs a transcutaneous electronic wave to suppress pain and increase motor function. A first positive contact electrode is placed at the frontalis, and a second negative contact electrode is placed at the occiput of the head. Alternatively, the first positive contact electrode is placed at the cervical spinous process and the second negative contact electrode is placed at each affected muscle. An electronic current wave comprising relatively high frequency pulses with a low frequency amplitude modulation is then applied between the first to the second electrodes.

Abstract: A system for stimulating a grasping action by a paralyzed hand. The system includes a sensor arrangement for detecting movement of a shoulder by the paralyzed person. The sensor transmits shoulder movement signals to a computerized controller which generates stimulation signals for stimulation electrodes mounted within a cuff worn about the forearm which supports the hand to be stimulated. Closed loop control is accomplished by use of a glove to which are attached a length sensor and a pressure sensor connected for alternative selection. Stimulation of deeply buried muscles is accomplished by arranging the stimulation electrodes into side-by-side electrode sets which are so positioned as to produce focusing of stimulation energy at the location of the subject muscle.

Abstract: A battery powered implantable cardiac pacer includes a battery consumption monitor circuit which develops within an internal counter a cumulative count of battery consumption in milliampere hours. The consumption count may be read out to an external indicator by a multiplex circuit to provide to the user an indication of battery life remaining. An over-current feature within the monitor circuit provides an alarm signal in the event that battery consumption exceeds a predetermined maximum level.

Abstract: An interrogator for remotely interrogating an internal counter of a scoliosis treatment device. An internal counter of the treatment device is incremented for those periods of time in which the treatment level of the device is in excess of a compliance level. The interrogator communicates with the internal counter by means of two serial data lines. On one data line the interrogator generates a clock signal to the internal counter for incrementing the device and on the other data line the interrogator receives a pulse indicating the internal counter has overflowed. By incrementing the internal counter through a full cycle of its maximum count the counter will retain the count present when it is interrogated. Additionally, by counting the number of, clock counts comprising the period from the overflow signal to the end of a full cycle a duplication of the count in the remote internal counter can be stored in the interrogator and subsequently displayed.

Abstract: The programming of pulse intervals and the inhibition of the output of an implanted cardiac pacemaker are disclosed. The occurrence of either an output pulse from the implanted unit or of cardiac activity allows for synchronization of the programming unit with the implanted device so the external programmer can control the pulse timing sequence of the implanted unit. The implanted unit can be programmed after each pulse, or as required, to obtain a pulse sequence which may be used to provoke, or terminate, tachyarrhythmias, thus enabling non-invasive electrophysiologic studies, or therapeutic stimulation.

Abstract: A process for aiding the operation of the heart muscle comprising periodically sending to the heart during at least certain heart cycles sub-threshold test impulses and detecting whether there occurs a systole in response during a time window following the test impulse. In the case of a response, the heart is stimulated at a frequency higher than the heart frequency in course of operation.

Abstract: Dental electronic analgesia apparatus and methodology employs a transcutaneous electronic wave to suppress perceived pain during trauma associated with dental procedures. A first electrode is placed on the buccal side of the gum adjacent the work area, and second electrodes are disposed on the web of the ipsalateral hand and on the ipsalateral trapezius origin. An electronic current wave comprising relatively high frequency pulses with a low frequency amplitude modulation is then applied between the first to the second electrodes.The apparatus of the instant invention has been found to block pain in most subjects with a low level current without any chemical intervention--or with a reduced dosage of local anesthesia.

Abstract: Disclosed is an implantable bone growth stimulator which needs no internal battery or large buffer capacitor. A receiving coil in a preferred embodiment, a ferrite core coil, receives RF energy from a transmitter external to the patient. The received RF energy is voltage doubled and rectified and provided to a constant current generator which in turn supplies a constant amount of current between implanted cathodes and an implanted anode. In preferred embodiments, the receiving coil, power supply, and cathodes are one unit which is located in place on an internal fixation device attached to the bones near the fracture site. In another embodiment, only the cathodes are located in the vicinity of the fracture site and the receiver coil voltage multiplier circuit and constant current source are located remote from the fracture site.

Abstract: A piezoelectric device and method are provided for setting or adjusting parameters or functions of an implanted device, such as the pacing rate of a pacer, at the will of its user/wearer or others, simply by making slight impacts on the user/wearer's body near the implanted piezoelectric device. The device has a piezoelectric sensor which picks up the physical impact and converts it to an electrical signal. Additional amplification and detection/decoding circuits can be provided to strengthen the signal and to separate intentional impacts from any unintentional impacts and noise.

Abstract: An analog data transmission circuit for a biomedical implant employs a linear amplifier to modulate the impedance of a resonant circuit tuned to an externally generated constant carrier frequency. The resonant circuit comprises a tuned coil in circuit with a linear modulating switch and a digital modulating switch. The digital switch is gated by the digital data output from digital control circuitry within the implant. The linear amplifier output drives the linear modulation switch. The switches are preferably matched pairs of MOSFET's of opposite polarity having complementary parasitic diodes which form a phantom diode bridge. The bridge acts as a full wave rectifier and boosts the bias voltage on the sources of the FET pair forming the linear modulation switch such that the radiated amplitude is independent of the distance of the programming head. A timed power-up circuit supplies power to the amplifier and starts a square wave calibration period in response to the approach of the programming head.

Abstract: An exercise-responsive cardiac pacemaker is provided which physiologically controls the stimulation rate of a heart by sensing the venous blood temperature in the right ventricle of the heart. A temperature sensing means which includes a thermistor produces an output signal which is sent to an algorithm implementing means for implementing the output signal by an algorithm which represents the mathematical function between venous blood temperature in the right ventricle and heart rate in a normally functioning heart. The algorithm implementing means produces an output signal which is variable between a maximum and minimum level corresponding to the desired maximum and minimum levels of heart rate in a normally functioning heart. The algorithm implementing means is also programmable by telemetry after implantation. A cardiac pacemaker is connected to the algorithm implementing means and is responsive thereto in order to variably control the stimulation rate of the heart.

Abstract: The system includes a sensor assembly comprising a body implantable physiological sensor for controlling a body implantable action device operable to act upon the body in response to changes in a physiological parameter sensed by the sensor. The body implantable action device can be a heart pacing device, a drug infusion pump, or other device which acts upon a human body. The sensor assembly includes a transmitter for transmitting coded signals to the action device which has programming circuitry for deciphering the signals received from the sensor assembly generated by the sensor which is in a location away from the location of the action device. Once these signals have been deciphered, the programming circuitry can adjust the output from the action device, such as the rate and A-V delay of pacing pulses from the pacing circuitry.

Abstract: The present invention relates to a process and device for detecting the response of the heart to an electrical stimulation pulse, comprising: collecting, after the end of the stimulation pulse, a first signal v which represents the electrode potential in open circuit and of which the variation in time t, from an original instant t.sub.o is of substantially logarithmic form: ##EQU1## v.sub.o being the value of v at instant t.sub.o and k being a parameter connected in particular with the duration and amplitude of the stimulation pulse, converting the first signal v into a second signal of which the variation in time is substantially linear and, detecting in said second signal a non-linear component representing the signal produced by the provoked contraction of the heart.

Abstract: Electrical stimulation through externally applied electrodes is used to control discharge from a stoma. The electrical signals applied to the electrodes have a frequency in the range of 10 Hz to 80 Hz, and a voltage level in the range of 20 volts to 60 volts. Apparatus for effecting the electrical stimulation is described. The electrodes may be ECG electrodes or formed as a pair of discs molded into an insulating pad.

Abstract: Bone fractures previously considered incurable are healed non-invasively by applying to electrodes coupled to the skin of a living body in the vicinity of a bone fracture an alternating voltage having a wave form that is symmetrical with respect to the axis, a frequency in the range 20-100 KHz and a value in the range from about 2 to 10 volts peak to peak.

Abstract: A rate responsive pacer which paces the heart at a rate dependent on detected variations in the stroke volume of the heart.

Abstract: A personal electrocardiology recorder having body electrodes for detecting heart action signals, an amplifier, a signal converter for converting the detected signals into signals recordable on magnetic tape, and a tape recorder, wherein the body electrodes are disposed directly on the tape recorder casing, the measuring and reference electrodes being disposed on a first wall and the earthing electrode being disposed on a wall other than the first wall, and wherein a microphone for recording a spoken description of the symptoms is provided. The recorder can be carried permanently by patients and can be switched on during the occurrence of corresponding symptoms for recording a diagnostically relevant ECG phase.

Abstract: An implant communication system is disclosed for use with an enclosure having a tuned coil mounted therein that is implanted in a patient. A low impedance shunt circuit is connected across the tuned coil, with the impedance of the shunt circuit being modulated in accordance with a data signal. The tuned coil reradiates the phase and amplitude of an externally generated magnetic carrier signal at a selected frequency. A second shunt circuit is connected across the tuned coil for changing its tuning, to enable the tuned frequency to correspond to the selected frequency.