Medtronic, Inc.

Vitatron Medical B. V.

Vitafin N.v.

Alexis C Renirie

Koen J Weijand

Richard P Houben

Vincent J Schouten

Godefridus J Weijs

Malcolm J Begemann

Frederik H Wittkampf

Kornelis A Mensink

Jan P Schuimer

David Flammang

Frank Van Leeuwen

There is provided an implanted system and method for delivering subsonic mechanical waves to one or more selected patient areas, said areas including the patient's heart and/or lungs. The mechanical waves are delivered for the purpose of treating fibrillation or like arrhythmias, for enhancing lung gas exchange, enhancing cardiac muscle fiber relaxation, and enhancing coronary perfusion. Mechanical waves are generated in a frequency range of about 1,100,000 Hz, and preferably 1-50,000 Hz. The waves may be delivered continuously for short or long time periods, or may be controlled in timing either with respect to detected portions of a patient's heartbeat signal or in response to a detected event such as fibrillation. In one preferred embodiment, the implantable system includes a defibrillation shock generator and control for responding to a defibrillation event by first delivering a sequence of mechanical waves and then delivering an electrical defibrillation shock. In another embodiment, the system and method treat incipient fibrillation or arrhythmia by delivering mechanical waves of predetermined timing to the patient's heart and/or lungs. In a specific embodiment, mechanical waves are delivered through an array of transducers to the patient's atrial wall, to treat atrial fibrillation.

System for delivering mechanical waves

System and a corresponding method for treating defibrillation in a heart

A system and method of providing for cardiac pacing which incorporates modulation of the pacing rate in order to minimize variations in ventricular power output, e.g., variation related to patient respiratory phases. In a preferred embodiment, pacing rate is increased during inspiration relative to expiration, to restore a measure of the normal rate modulation which occurs in a normal person. Patient respiration is monitored and a respiration signal is processed to determine the timing of rate modulation. Parameters representative of respiratory changes, such as right ventricular volume and right ventricular blood pressure are also monitored and, together with respiration amplitudes changes, are used to determine an incremental rate signal for controlling the extent of rate variation. Heart rate and patient activity are also sensed, to provide further control of rate modulation, with maximum modulation being provided when the patient is sleeping, and minimal or no modulation being provided when the patient is active. The system of this invention is applicable in combination with conventional pacing systems, or can be adapted to special clinical applications.

System and method for respiration-modulated pacing

There is provided an implantable system and method for monitoring pancreatic beta cell electrical activity in a patient in order to obtain a measure of a patient's insulin demand and blood glucose level. A stimulus generator is controlled to deliver stimulus pulses so as to synchronize pancreatic beta cell depolarization, thereby producing an enhanced electrical signal which is sensed and processed. In a specific embodiment, the signal is processed to determine the start and end of beta cell depolarization, from which the depolarization duration is obtained. In order to reduce cardiac interference, each stimulus pulse is timed to be offset from the QRS signal which can interfere with the pancreas sensing. Additionally, the beta cell signals are processed by a correction circuit, e.g., an adaptive filter, to remove QRS artifacts, as well as artifacts from other sources, such as respiration. The thus obtained insulin demand signal is used either to control delivery of insulin from an implanted insulin pump, or to control ongoing pancreatic stimulation of a form to enhance insulin production.

System for pancreatic stimulation and glucose measurement

There is provided an implanted system and method for delivering subsonic mechanical waves to one or more selected patient areas, the areas including the patient's heart and/or lungs. The mechanical waves are delivered for the purpose of treating fibrillation or like arrhythmias, for enhancing lung gas exchange, enhancing cardiac muscle fiber relaxation, and enhancing coronary perfusion. Mechanical waves are generated in a frequency range of about 1-100,000 Hz, and preferably 1-50,000 Hz. The waves may be delivered continuously for short or long time periods, or may be controlled in timing either with respect to detected portions of a patient's heartbeat signal or in response to a detected event such as fibrillation. In one preferred embodiment, the implantable system includes a defibrillation shock generator and control for responding to a defibrillation event by first delivering a sequence of mechanical waves and then delivering an electrical defibrillation shock. In another embodiment, the system and method treat incipient fibrillation or arrhythmia by delivering mechanical waves of predetermined timing to the patient's heart and/or lungs. In a specific embodiment, mechanical waves are delivered through an array of transducers to the patient's atrial wall, to treat atrial fibrillation.

System and method of mechanical treatment of cardiac fibrillation

There is provided a system for automatically responding to insulin demand without any need for external monitoring or injecting of insulin into the diabetic patient. The system provides for sensing glucose levels internally, and responding by stimulating either the pancreas or a transplant of pancreatic islets in order to enhance insulin production. The enhancing stimulation is delivered at a rate greater than the burst rate, or is otherwise controlled so that the depolarization burst constitutes a greater portion of each islet electrical cycle, thereby resulting in increased insulin production. The system also provides for continuous glucose monitoring, and reacts to sensed hypoglycemia by delivering stimulus pulses timed to reduce the burst durations, and thus to inhibit insulin production. In another embodiment, the system responds to a good intake signal, either externally or internally generated, by going through a time response algorithm to provide a stimulation-enhanced insulin response which simulates the natural response. In yet another embodiment, the functionality of an islet transplant is continually monitored, and performance data is logged and down loaded on command to an external programmer. The stimulation of patient pancreatic cells may be combined with administration of a hypoglycemic agent.

System and method for enhancement of glucose production by stimulation

A rate responsive pacemaker is provided having the capability of automatically adjusting the lower rate limit (LRL) for sleep, or nighttime. The pacemaker has a temperature sensor for determining patient blood temperature, and processes patient blood temperature data to obtain an average daily low value of nighttime blood temperature. The pacemaker monitors blood temperature to determine a drop below a threshold which is coupled to the average daily low value, as well as when the rate of temperature change exceeds a predetermined limit, these two coincident conditions suggesting onset of nighttime and/or sleep. Lower rate limit is decremented, preferably by a predetermined amount at onset of nighttime, and is automatically incremented when patient blood temperature and/or time of day indicate the end of nighttime.

Rate responsive pacemaker adapted to adjust lower rate limit according

A system and method for sensing and providing an indication of one or more diabetes-related blood constituents of a patient, the system being based upon an ECG sensor which processes patient ECG signals, either surface, or intracardiac or epicardial, for determining a measure of a blood constituent such as insulin or glucose, or both insulin and glucose. The system has processing capability for correlating selected parameters of the ECG signal with patient blood insulin or blood glucose, to provide the insulin or glucose level. Additionally, the system is provided with input capability for enabling the patient to input data such as the time of meal intake, which is representative of glucose intake, which data is incorporated in making a determination of patient insulin need. The system can be in a first external wearable embodiment, or in a second implantable embodiment which utilizes a pacing-type lead for picking up intracardiac or epicardial signals. In either the wearable or implantable embodiment, the output response may be simply an indication of patient insulin and/or glucose need provided by an external display, and may also include automatic control of insulin injection to the patient.

System and method for continuous monitoring of diabetes-related blood

A cardiac pacemaker and method of operation of such pacemaker is disclosed comprising a single lead having conventional ventricular pacing and sensing electrode means as well as atrial sensors adapted to be positioned in the patient's atrim without any contact with the atrial wall, for sensing atrial wall movement and for generating information signals representative of the atrial wall movement. The free-floating atrial sensor is utilized in providing information for making a determination of a number of cardiac conditions, including analysis of direction of P waves to determine whether sensed signals are anterograde or retrograde.

Pacing system and method for physiological stimulation of the heart

A pacing system and method of programming the rate of said system is disclosed, wherein the pacemaker comprises circuitry for receiving a first group of simple on-off magnetic pulses which are accumulated and translated into the decades portion of the desired heartbeat rate (in bpm), and also for receiving a second group of pulses which are translated into the units count of the desired pacing rate in bpm. The circuitry provides that an initial portion of the programming signal is inspected relative to predetermined criteria, so that such initial portion acts also as an enabling key for accepting the overall programming signal. The doctor simply applies a simple hand held magnet t times according to the desired tens component of the programmed rate in bpm, maintains the magnet applied for at least a predetermined number of pacer intervals, and then applies the magnet u times corresponding to the units component of the desired heart rate, thereby programming the pacer to operate at tu bpm.

Programmable pacer and method of external programming

A switching power delivery means for use with a relatively low voltage power source, adapted to be used in conjunction with a converter for providing a raised voltage supply to a load, wherein the load is characterized by having a first circuit portion which is voltage sensitive and draws a low current, and a second circuit portion which draws a high current and is relatively insensitive to supply deviations, comprising a switching circuit alternately connecting said respective circuit portions through respective converters to the supply so that the voltage sensitive circuit is not affected by the loading of the high current circuit.

Long life cardiac pacer with switching power

A circuit is disclosed for providing automatic detection of end of life of a battery source, particularly a lithium iodine type battery source characterized by a sharply increased internal resistance characteristic near end of life. The circuit periodically samples the short circuit output current of the source, the sampling being done at a high switching speed and for an extremely short time duration so that power consumption is minimized and only the resistive component which causes the knee in the resistance characteristic is measured. In the embodiment as incorporated in a cardiac pacer device, detection of the internal resistance knee is utilized to cause a step change in an operating characteristic of the pacer, such as stimulus rate, whereby end of life can be accurately monitored.

Circuit and method for detecting battery source end of life

A cardiac pacer for providing stimulus signals for pacing a human heart, adapted to utilize a lithium-type battery source having an internal resistance which increases with the energy depletion of such source, and having an interface circuit adapted to transfer power from the lithium-type battery source to the circuitry for providing stimulus signals, which interface circuit provides transfer characteristics which are a programmed function of said lithium source internal resistance.

Cardiac pacer with pre-programmed power source interface means

A low current drain amplifier system, adaptable for use in cardiac pacers and other applications requiring low current drain operation, having an amplifier path comprising transconductance amplifier means characterized by having the circuit characteristic of a current source at its output, the transconductance amplifier means direct driving an active circuit having a high impedance input, and a current source supply for maintaining fixed current operation of the amplifier system elements. In the preferred embodiment, the amplifier path contains a first OTA operating as an amplifier of received signals, the first OTA having its output direct coupled to an input of a second OTA which operates as a comparator, the output of the comparator OTA being direct connected to an IC transistor element.

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Berg en Dal, Netherlands

Alexis C Renirie