Abstract: The present invention relates to methods and apparatus for detection and treatment of syncope in an implantable medical device, and particularly to detection of syncope as a function of a predetermined increase in one or more respiration parameter and drop in heart rate and optionally delivering a pacing therapy in response thereto. The onset of a syncopal episode is declared when the patient's respiration rate and/or tidal volume and/or minute ventilation increases by a predetermined increment or threshold and a heart rate drops below a threshold heart rate drop. The threshold heart rate drop is preferably established as a function of the change in the respiration parameter.

Abstract: An automatic rate response sensor mode switch is implemented in an implantable medical device to monitor and isolate any sensor in an integrated sensor scheme. The isolated sensor is based on identification of problems associated with the sensor. The implantable medical device will switch to operate with the remainder sensor(s). Specifically, an algorithm tests and determines sensor status to initiate and operate the sensor mode switch. The software continuously monitors, isolates or qualifies a sensor to come back on-line automatically.

Abstract: A cardiac rhythm management device includes a dual chamber pacemaker, especially designed for treating congestive heart failure. The device incorporates a program microcontroller which is operative to adjust the pacing site, AV delay and interventricular delay of the pacemaker so as to achieve optimum hemodynamic performance. Atrial cycle lengths measured during transient (immediate) time intervals following a change in the site, AV delay and interventricular delay are signal processed and a determination can then be made as to which particular configuration yields the optimum performance. Paced transient beats following periods of baseline beats are synchronized to the patient's respiratory cycle to minimize effects of respiratory noise on atrial cycle length measurements.

Abstract: A system and method for automatically adjusting the operating parameters of a rate-adaptive cardiac pacemaker. In accordance with the method, maximum exertion levels attained by the patient are measured at periodic intervals and stored. The stored maximum exertion levels may then be used to update a long-term maximal exertion level, and the slope of the rate-response curve is adjusted to map the updated long-term maximal exertion level to a maximum allowable pacing rate. The stored maximum exertion levels may also be used to update a sensor target rate which is used to adjust the slope of the rate response curve.

Abstract: Implantable medical devices (IMDs) for detection and measurement of cardiac mechanical and electrical function employ a system and method for determining mechanical heart function and measuring mechanical heart performance of upper and lower and left and right heart chambers without intruding into a left heart chamber through use of a dimension sensor. The dimension sensor or sensors comprise at least a first sonomicrometer piezoelectric crystal mounted to a first lead body implanted into or in relation to one heart chamber that operates as an ultrasound transmitter when a drive signal is applied to it and at least one second sonomicrometer crystal mounted to a second lead body implanted into or in relation to a second heart chamber that operates as an ultrasound receiver.

Abstract: Myocardial performance is assessed using a combination of electrical and mechanical criteria. More specifically, this assessment may be based on a QT interval based on electrogram (EGM) readings and on first and second heart sounds. The timing relationships between the QT interval and the first and second heart sounds can be used to evaluate certain systolic, diastolic, and systolic/diastolic parameters relating to myocardial performance. In addition, these parameters may be used to automatically drive therapies. For example, myocardial performance parameters obtained from the QT interval and from the timing of the first and second heart sounds may be used to optimize the AV delay and to optimize multisite pacing.

Abstract: An implantable device having enhanced capabilities for monitoring a patient's heart rate and respiration trends over extended periods of time is disclosed. The information collected by the implantable device may be stored and telemetered to an associated external device such as a device programmer for display and analysis. Heart rates are measured by measuring the time intervals between sensed depolarizations of a chamber of the patient's heart and preceding sensed depolarizations or delivered pacing pulses. Intervals may be measured in the ventricle and/or atrium of the patient's heart. According to another aspect of the invention, an implanted impedance sensor is employed to monitor minute ventilation. The heart rate and minute ventilation data is used to develop long-term trend data used for diagnostic purposes. In one embodiment of the invention, heart interval and minute ventilation measurements are taken only during defined time periods of the night and/or day when the patient is at rest.

Abstract: An implanted device-implemented method of detecting and monitoring congestive heart failure in a patient includes performing ongoing measurements of changes in local impedance of a portion of the patient's body between at least two electrodes on the exterior of the implanted device, the changes representing ventilation of the patient, and including measuring the patient's respiratory rate and respiratory amplitude. A body-implantable device is adapted to detect and monitor congestive heart failure in a patient, and includes a circuit module coupled to plural surface electrodes of the device arranged and adapted, when the device is implanted, for contacting tissue in a portion of the patient's body generally occupied by the lungs, to monitor changes in local impedance of said body portion, and to detect the patient's EKG.

Abstract: Various embodiments provide techniques and systems that can ensure that patients with congestive heart failure receive pacing therapy that optimizes their hemodynamic performance in view of various variables that pertain to the patient. Exemplary variables can include, without limitation, the time of day, patient posture and activity level.

Abstract: An intro-aortic balloon catheter system and method for determining cardiac output with the system including a distal end for insertion into an aorta and a proximal end opposed to the distal end, a balloon portion in proximity to the distal end which repeatedly expands and contracts so as to assist the pumping action of the heart, a catheter tube connected to the balloon portion with the catheter tube having a lumen introducing a pressurized gas into the balloon portion and leading the pressurized gas out from the balloon portion and a temperature sensor attached to the catheter tube and being electrically coupled to a connector at the proximal end of the catheter tube.

Abstract: An implantable cardiac stimulation device is programmed to administer pacing therapy in response to a postural change in a patient's position and a confirmation of that postural change using a cross-check parameter. The stimulation device is equipped with a position sensor to sense a position parameter indicative of when a patient changes from a horizontal position to an upright position. The stimulation device further monitors a cross-check parameter that is affected or modulated by position changes. When the position sensor indicates a postural change and the cross-check parameter confirms this change as being sufficient to induce orthostatic hypotension, the device administers cardiac pacing therapy to the patient.

Abstract: An implantable cardiac pacemaker (1) comprising a control device (2) including a position detector connected to a movement sensor, wherein the position detector has a classification device (23) for recognizing short movements. Preferably the position detector has a memory device (25).

Abstract: A method and system of adapting heart rate in cardiac tissue based on two types of sensed information is provided. A pulse is transmitted to the cardiac tissue. An activity signal is received. A first interval signal is also received and the pacing rate is adapted based on the first interval signal. A second interval signal is then received and the adapted pacing rate is verified using the second interval signal.

Abstract: Cardiac electrical events are detected by comparing signal vectors with pre-determined classification zones representative of different cardiac events. The signal vector is generated by sensing the voltages between various combinations of electrodes, such as A-tip to V-tip, A-tip to A-ring, and A-ring to V-ring. The signal vector is compared with a set of classification zones corresponding to different events, such as P-waves, R-waves, T-waves, A-pulses, and V-pulses, to determine whether the vector lies within any of the classification zones. In this manner, cardiac events are detected using only the voltages received from the electrodes and no refractory periods or blanking periods are required to distinguish one event from another. The classification zones vary from patient to patient and a technique is provided herein for generating a set of vector classification zones for a particular patient.

Abstract: An implantable cardiac stimulation device is programmed to administer pacing therapy in response to a change in a patient's position and a drop in blood pressure. The stimulation device is equipped with a position sensor to sense a position parameter indicative of when a patient changes from a supine position to an upright position and a pressure sensor to sense a pressure parameter indicative of a patient's blood pressure. The device administers cardiac pacing therapy to the patient based on both the position parameter and the pressure parameter.

Abstract: A system and method for use in an implantable cardiac device permits the monitoring of progression and regression in heart disease, such as congestive heart failure. During a monitoring period, a sensing circuit produces an electrogram signal of the patient's heart and a sound sensor produces a phonocardiogram of the patient's heart. A processor determines a predetermined characteristic of the heart sounds, such as amplitude, time intervals between selected heart sounds, and time intervals between selected heart sound and selected electrogram features for each cardiac cycle occurring during a monitoring period. The predetermined characteristics are thereafter averaged and stored in a memory for later retrieval. Relative changes in the average time intervals over time provides an indication of the progression or regression of the heart disease.

Abstract: This document discusses cardiac rhythm management systems and methods using the MVC-to-AE time between mitral valve closure (“MVC”) and aortic ejection (“AE”) of the same heart contraction, sometimes referred to as the isovolumic contraction time (“ICVT”). In one example, the MVC-to-AE time is used for predicting which patients will respond to cardiac resynchronization therapy (CRT), or other therapy. In another example, the MVC-to-AE time is used as a wellness indicator. In a further example, the MVC-to-AE time is used to select or control a therapy or therapy parameter. In one example, the MVC and AE are obtained using an accelerometer signal, however, plethysmography, tonometry, or other techniques may alternatively be used.

Abstract: An implantable cardiac stimulation device and method provides reliable sensing of cardiac events to support cardiac pacing or fibrillation detection. The device comprises a sensing circuit that senses the cardiac events in accordance with a plurality of threshold characterizing parameters. A parameter control adjusts the threshold parameters responsive to the rate of the sensed cardiac events in a manner which precludes positive feedback to prevent continued oversensing, undersensing, or noise sensing.

Abstract: ECG recording apparatus 1 includes a port 2 for connection to ECG electrodes and a microphone 3 for detecting vocal signals, Processing electronics store a recording of the vocal signals and the physiological data on the storage medium 4.

Abstract: An implantable cardiac stimulation device and method optimizes pacing effectiveness of a patient's heart. A pulse generator delivers right and left pacing pulses to corresponding right and left chambers of the heart with a selected pacing delay between the right pacing pulse and the left pacing pulse wherein the selected pacing delay is within a continuum from left chamber pacing only, to simultaneous right and left chamber pacing, and to right chamber pacing only. A sensor senses a parameter, such as ventricular pressure, associated with pacing effectiveness. A control circuit selects the pacing delay, which maximizes the sensed parameter.

Abstract: A method and system for automatically adjusting the operating parameters of a rate-adaptive cardiac pacemaker in which maximum exertion levels attained by the patient are measured at periodic intervals and stored in order to compute or update a maximum exercise capacity. The slope of the rate-response curve is then adjusted to map an exertion level corresponding to the updated maximum exercise capacity to a maximum allowable pacing rate. In accordance with the invention, a maximum exercise capacity is determined by cross-checking periodic maximum exertion level sensor values with a motion-level sensor value.

Abstract: Methods of adjusting output mapping in response to historical signal input data relative to a reference value, and apparatus to perform the methods. The methods are suited for use in adjusting rate-adaptive pacemakers in response to a patient's demonstrated activity relative to a predetermined activity level. The methods include using historical physiologic sensor input to derive a patient's activity. The methods further include tuning a rate-adaptive curve in response to a demonstrated exertion level and a demonstrated exertion time indicative of a breadth and frequency of a patient's activity above some reference value. Pacemakers adapted to perform the methods include a processor, at least one physiologic sensor, a variable-rate pulse generator and a memory for storing historical physiologic sensor data.

Abstract: A method and system of adapting heart rate in cardiac tissue based on two types of sensed information is provided. A pulse is transmitted to the cardiac tissue. An activity signal is received. A first interval signal is also received and the pacing rate is adapted based on the first interval signal. A second interval signal is then received and the adapted pacing rate is verified using the second interval signal.

Abstract: An implantable cardiac stimulation device which determines stimulation based upon the patient's body position and activity level while eliminating special implantation or calibration procedures. To eliminate such special implantation and calibration procedures, the stimulation device correlates the patient's body position using a multi-axis DC accelerometer or other sensor during times of high activity and determines a patient's standing position value. During other times, the stimulation device compares the signals from the accelerometer to the standing position value to determine the patient's current body position. Based upon the current body position and the activity level, the stimulation device determines the necessary stimulation to deliver to the patient.

Abstract: A self-calibrating rate-adaptive cardiac pacemaker is provided. The pacemaker comprising a first measuring and processing device for detecting a first, predominantly sympathetically influenced physiological parameter and for obtaining a rate control parameter, which has a control input for controlling the functional dependency of the rate control parameter on the first physiological parameter, in particular a response factor and/or an upper limit rate; and a stimulator unit for producing and outputting stimulation pulses at a stimulation rate which is determined by the rate control parameter, having a second measuring and processing device for detecting and evaluating a second, predominantly vagally influenced physiological parameter and for outputting a calibration signal which is dependent on the evaluation result, to the control input of the first measuring and processing device.

Abstract: A method and apparatus for providing congestive heart failure therapy status. An electronic device, preferably a cardiac rhythm management device, capable of measuring transthoracic impedance and for sensing a level of physical activity is implanted in a patient. The transthoracic impedance signal is processed to obtain an estimate of the subject's minute ventilation, respiratory rate, tidal volume, inspiratory rate and expiratory rate. From accelerometer measured activity, an estimate is obtained of oxygen uptake, carbon dioxide production and work rate.

Abstract: A method and apparatus are used to provide therapy to a patient experiencing ventricular dysfunction or heart failure. At least one electrode is located in a region associated with nervous tissue, such as nerve bundles T1-T4, in a patient's body. Electrical stimulation is applied to the at least one electrode to improve the cardiac efficiency of the patient's heart. One or more predetermined physiologic parameters of the patient are monitored, and the electrical stimulation is adjusted based on the one or more predetermined physiologic parameters.

Abstract: An active implantable device having a sensor capable of detecting signals indicative of the conditions of the wearer of the device; a processor capable of selectively identifying, from signals detected by the sensor, particular conditions of the wearer of the device such as to require urgent assistance, an actuator capable of inducing the performance of therapeutic actions on the body of the wearer upon the occurrence of the particular conditions of the wearer of the device and a telemetry system capable of signaling from the body of the wearer of the device the occurrence of the particular conditions of the wearer of the device.

Abstract: An active implantable medical device, notably a cardiac pacemaker, enslaved to at least a physiological parameter which comprises at least one effort sensor (MV) having a plurality of determinable states, for measuring a primarily physiological parameter and delivering a signal which is a function of effort exerted by a patient bearing the device and at least one activity sensor (G) having a plurality of determinable states, for measuring a primarily physical parameter and delivering a signal which is indicative of the activity of the patient bearing the device. The determinable states of the respective sensors are determined and the relative sequence of successive changes in the state of the respective sensors are identified and analyzed periodically according to predetermined criteria. A command escape interval (IECONSIG) controlling the enslaved functioning of the device is determined from the analyzed states of the sensors.

Abstract: An intrabody implantable system for long-term, real time monitoring of at least one parameter associated with heart performance.

Abstract: A pacing system which determines a dual indicated rate (DIR) corresponding to a desired pacing rate of the heart of the patient by selecting the maximum between an activity indicated rate (AIR) and a metabolic indicated rate (MIR). The activity indicated rate is a pacing rate that is determined based upon a well-known acceleration-based sensor. The metabolic indicated rate is a desired pacing rate of the heart as determined based upon a well-known metabolic sensor, such as a minute ventilation sensor. Determining the dual indicated rate by selecting between the two rates provided by these two sensors results in the advantageous use of the activity indicated rate during periods of low-level and brisk activity and the use of the metabolic indicated rate during periods of high exertion.

Abstract: A method and apparatus for providing congestive heart failure therapy status. An electronic device, preferably a cardiac rhythm management device, capable of measuring transthoracic impedance and for sensing a level of physical activity is implanted in a patient. The transthoracic impedance signal is processed to obtain an estimate of the subject's minute ventilation, respiratory rate and tidal volume. From accelerometer measured activity, an estimate is obtained of oxygen uptake and carbon dioxide production. Ratios of tidal volume to respiratory rate, tidal volume to inspiratory time, minute ventilation to carbon dioxide production and oxygen uptake to heart rate are meaningftil status indicators for assessing the efficacy of particular therapy regimens to CHF patients.

Abstract: A rate-adaptive pacemaker includes an impedance measuring device for measuring a waveform over time of the intracardial impedance over at least a predetermined portion of one cardiac cycle. An impedance processing device obtains an impedance value from the waveform. A rate determining device is connected downstream of the impedance processing device, and controlled by a sequence controller, determines the adaptive stimulation rate (HR) using the impedance value. The impedance processing device has an integrator stage for determining the time integral of the impedance waveform over the predetermined portion of the cardiac cycle as the primary impedance value.

Abstract: A rate responsive active implantable medical device having at least one effort sensor, measuring a parameter which is predominantly physiological (VE) and delivering an output signal which is a function of the effort developed by a patient carrying the device, and at least one activity sensor, measuring a parameter which predominantly physical. The devices operates to (a) measure periodically at the two sensors “couples of values” (12, 14, 16; 22, 24, 26) corresponding to a given level of effort developed by the patient; (b) establish a characteristic function of the measured couples of values (10, 20), and (c) evaluate over the course of time this established characteristic, by seeking a possible increase in the signals delivered by the effort sensor as compared to the signals delivered by the activity sensor, indicative of the patient's metabolic demand (cardiac output requirements).

Abstract: An ischemia detector has a sensor unit which determines the systolic pressure of a subject, a unit wherein a relation is established between the systolic pressure and the subject's heart rate, as the heart rate is varied over a range, and an analyzer which determines the occurrence of ischemia from this relation.

Abstract: A medical device system such as a pacemaker system is provided wherein pressure signals representative of a patient's cardiac movements are transmitted through a pacing lead to the pacemaker, where they are sensed and utilized for control of pacemaker operation. In a preferred embodiment, the invention utilizes a standard pacing lead, which may already be in place within the patient, the lead having a lumen through which relative pressure signals are transmitted from the patient's heart to the proximal end of the lead. The proximal end of the lead is connected to a pressure sensor, mounted either in the pacemaker header portion or within the hermetically sealed pacemaker can. The sensor signals are coupled to appropriate processing circuitry and are used for control of one or more pacing parameters, such as pacing rate.

Abstract: An accelerometer device which can be mounted on a substrate, e.g., a circuit board enclosed in a medical device, includes an accelerometer sensing element having an axis of sensitivity and further includes first and second multilayer end caps. The substrate generally defines a mounting plane. The accelerometer sensing element includes a device body having a longitudinal axis extending between generally parallel first and second ends thereof and further includes a principal surface extending between the first and second ends of the device body parallel to the longitudinal axis. The axis of sensitivity of the sensing element is generally perpendicular to a plane defined by the principal surface. Further, the accelerometer sensing element includes conductive pad regions on each of the first and second ends of the device body.

Abstract: In an apparatus for determining the AV transmission time or AV delay in the heart, the apparatus having a signal-sensor arrangement that is disposed in the heart and detects a natural cardiac action, further having at least one signal output and a processing unit that has at least one signal input that is connected to the signal output of the signal-sensor arrangement for calculating the natural AV transmission time based on the detected cardiac action, the signal-receiver arrangement includes a pressure-sensor arrangement that is disposed in the vicinity of the tricuspid valve in the right atrium and/or in the right ventricle for detecting intracardial pressure changes associated with the opening of the tricuspid valve.

Abstract: An implantable dual transducer apparatus for use with an implantable medical device and control method are disclosed. The dual transducer assembly includes two physiologic sensors coupled to the medical device via a pair of lead conductors. Switching circuitry is controlled by the medical device to selectively activate and deactivate the two physiologic sensors by application of a supply voltage of an appropriate polarity. Each sensor of the dual transducer assembly is connected to the pair of lead conductors through a respective power switch. In response to the polarity of the supply voltage applied to the lead conductors, the power switches activate or deactivate their respective sensor in an alternating manner. Selective activation of one of the sensor while concurrently deactivating the other sensor of the dual transducer assembly provides for reduced power consumption and reliable communication of sensor data and other information transmitted over the pair of lead conductors.

Abstract: A self-calibrating adaptive-rate cardiac pacemaker having a measuring and processing device for measuring the course over time of a physiological variable over a predetermined portion of a heart cycle and for obtaining a course parameter from the course over time, a stimulation parameter determining device downstream of the measuring and processing device and controlled by a sequence controller for determining a stimulation parameter value, in particular the adaptive stimulation rate, a body sensor connected to one input of the stimulation parameter determining device, for detecting an exertion variable, whose signal is used jointly with the course parameter to determine the stimulation parameter value, and a stimulator unit for generating and outputting stimulation pulses at the determined stimulation parameter value.

Abstract: 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.

Abstract: There is provided a pacemaker system having the feature of delivering a ventricular safety pulse (VSP) following an early ventricular sense (VS), wherein the pacemaker automatically determines whether VSPs are to be delivered following early VSs, and if yes, with what timing. The pacemaker gathers data following delivered VSPs, which data contains information indicative of whether each early VS was indeed the result of a spontaneous R wave, or was due to crosstalk from a prior delivered atrial pace pulse. This data is processed and, when it presents a high statistical confidence, is used to make a determination of whether to respond with the assumption of a true R wave, or of crosstalk. If the data is not statistically significant, the pacemaker delivers VSPs in a normal fashion, e.g., at the end of a programmable VSP interval timed out following delivery of an atrial pace pulse.

Abstract: Method and apparatus for automatically setting a variable upper rate limit for the pacing pulse signal provided by a rate adaptive implantable pacemaker which relies on a non-physiological sensor to determine the pacing needs of the patient. A physiological parameter of the patient's condition is sensed and used to determine an upper limit for the pacing rate otherwise called for based on the reading of the non-physiological sensor. In a disclosed embodiment, the ventricular preejection period is monitored as the physiological parameter, and the rate of change of this parameter is utilized to set the upper limit of the pacing pulse rate.

Abstract: A rate adaptive cardiac pacemaker having a first sensor for measuring a physiologic parameter reflecting metabolic demand and a second sensor for measuring a parameter reflecting the physical motion or activity of the patient, wherein the second sensor is used to generate a dynamic target pacing rate which the first sensor is optimized to over time, thereby reducing the time constant for the adaptation of the first sensor and minimizing the amount of clinical time required to initialize the cardiac pacemaker.

Abstract: An improved sensor and related method for multi-axial measurement of motion for an implantable medical device is disclosed. The sensor has a wide variety of applications, including use as a cardiac wall motion sensor or a physical activity sensor. The sensor includes first and second conductors over which the motion measurements are made. A first transducer provides a first motion measurement indicative of sensor acceleration during a first phase, while a second transducer provides a second motion measurement indicative of sensor acceleration during a second phase. The first and second transducers are connected in parallel so as to provide the first and second motion measurements to an implantable medical device over the first and second conductors. The first and second phases are non-overlapping periods of time so that the motion measurements from each transducer are time division multiplexed. The sensor provides motion measurements that may either be compensated or uncompensated for temperature effects.

Abstract: A cardiac pacemaker includes circuitry which receives a raw impedance signal from the sensor leads of the pacemaker, derives data from the impedance signal that is descriptive of the impedance signal over an entire (or a large part of the) cardiac cycle, develops first order parameters which define that cycle, and provides these parameters to a microprocessor for control of the pacing signal. These parameters may also be used to determine other information about the functioning of the pacemaker. The present invention may also be applied to the determination of tachycardia of an intrinsically paced heart, as well as other applications.

Abstract: The respiratory function of a patient is measured for diagnostic purposes using a cardiac rhythm management device. Monitoring of the respiratory activity is initiated after a microprocessor in the cardiac rhythm management device determines that the patient has been at rest for a predetermined length of time. A respiration related signal is derived from either an accelerometer signal or from an impedance sensor, depending upon which produces a signal has the higher signal-to-noise ratio. The signal from either the accelerometer or impedance measuring mechanism is low-pass filtered to obtain a respiratory signal component. The respiratory signal component is digitized and sent to the microprocessor for analysis. The microprocessor can be programmed in either of two modes of analysis. In the first mode, the peak-to-peak values of the respiratory signal component over a number of fixed time interval is summed, obtaining the minute volume.

Abstract: In an implantable pacemaker the pacing rate is adjusted in synchrony with the respiration of the patient to thereby mimic respiratory sinus arrhythmia noted in healthy patients. Preferably, first a metabolic demand parameter pacing parameter is derived from a metabolic demand of the patient, such as minute volume, and then this parameter is adjusted using a respiration detector. The adjustment may be made dependent on the exercise level of the patient, his age and his physical fitness.

Abstract: A system and method for predicting the effect of patient self-care actions on a disease control parameter. A future disease control parameter value X(t.sub.j) at time t.sub.j is determined from a prior disease control parameter value X(t.sub.i) at time t.sub.i based on an optimal control parameter value R(t.sub.j) at time t.sub.j, the difference between the prior disease control parameter value X(t.sub.i) and an optimal control parameter value R(t.sub.i) at time t.sub.i, and a set of differentials between patient self-care parameters having patient self-care values S.sub.M (t.sub.i) at time t.sub.i and optimal self-care parameters having optimal self-care values O.sub.M (t.sub.i) at time t.sub.i. The differentials are multiplied by corresponding scaling factors K.sub.M. The system includes an input device for entering the patient self-care values S.sub.M (t.sub.i). A memory stores the optimal control parameter values R(t.sub.i) and R(t.sub.j), the prior disease control parameter value X(t.sub.

Abstract: An active implantable medical device, particularly a cardiac pacemaker, which is enslaved to a signal representative of acceleration, having a measuring circuit (10) comprising at least one sensor (12) delivering a signal of acceleration, and circuits (22-24) to deliver, in response to the signal of acceleration, a parameter of enslavement of at least one function of the device, particularly that of a cardiac stimulation frequency. According to the invention, a circuit (24) operates to limit, in the detection of increase in acceleration, a value linked to the module of the signal of acceleration. Preferably, the limitation is operated on a value proportional to the square of the signal of acceleration, more particularly on a quadratic sum of individual acceleration components (X.sub.i, Y.sub.i, Z.sub.i) according to at least two distinct axes delivered by a respective number of sensors.