WO1983004171A1 - Detecteur de cadence cardiaque - Google Patents

Detecteur de cadence cardiaque Download PDF

Info

Publication number
WO1983004171A1
WO1983004171A1 PCT/US1982/000751 US8200751W WO8304171A1 WO 1983004171 A1 WO1983004171 A1 WO 1983004171A1 US 8200751 W US8200751 W US 8200751W WO 8304171 A1 WO8304171 A1 WO 8304171A1
Authority
WO
WIPO (PCT)
Prior art keywords
detector
output
rate
wave
predetermined
Prior art date
Application number
PCT/US1982/000751
Other languages
English (en)
Inventor
Mir Imran
Steve Andrew Kolenik
Original Assignee
Mirowski, Mieczyslaw
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mirowski, Mieczyslaw filed Critical Mirowski, Mieczyslaw
Priority to GB08400719A priority Critical patent/GB2130101B/en
Priority to DE3249966A priority patent/DE3249966C2/de
Priority to JP57502212A priority patent/JPS59500895A/ja
Priority to NL8220240A priority patent/NL194661C/nl
Priority to PCT/US1982/000751 priority patent/WO1983004171A1/fr
Priority to DE19823249490 priority patent/DE3249490C2/de
Priority to CA000404527A priority patent/CA1193325A/fr
Publication of WO1983004171A1 publication Critical patent/WO1983004171A1/fr

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/024—Detecting, measuring or recording pulse rate or heart rate
    • A61B5/0245—Detecting, measuring or recording pulse rate or heart rate by using sensing means generating electric signals, i.e. ECG signals
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
    • A61B5/7235—Details of waveform analysis
    • A61B5/7239—Details of waveform analysis using differentiation including higher order derivatives

Definitions

  • the present invention relates to a heart rate detector system, and more particularly, to an improved heart rate detector capable of use with an implantable defibrillator for defibrillating the heart of a patient when the patient experiences a life-threatening arrhythmia.
  • an apex electrode is applied to the external intrapericardial or extrapericardial surface of the heart, and acts against a base electrode which can be either similarly conformal or in the form of an intravascular catheter.
  • Such electrode arrangements of the prior art as disclosed in the aforementioned patent of Heilman et al, can employ independent pacing tips associated with either a base electrode or an apex electrode, or both.
  • the prior art probability density function detector when the probability density function is satisfied, fibrillation of the heart is indicated.
  • the prior art probability density function detector if not optimally adjusted, can be "triggered” not only by actual ventricular fibrillation, but also by some forms of high rate ventricular tachycardia, and low rate ventricular tachycardia as well, particularly in the presence of ventricular conduction abnormalities.
  • the possibility of such triggering in the presence of some high rate tachycardia is acceptable because high rate tachycardia often can be fatal if present at such a rate that sufficient blood pumping no longer is accomplished.
  • a probability density function circuit responsive to differentiated ECG signals from the heart electrodes, is used in conjunction with a heart rate circuit whereby the probability density function (PDF) circuit activates a defibrillator pulse generator only when the PDF circuit is enabled by the heart rate circuit.
  • PDF probability density function
  • Such enabling occurs when the heart rate exceeds a predetermined value reflecting what is considered to be a dangerous high rate tachycardia.
  • Heart rate detectors per se, are known in the art. Such heart rate detectors are typically designed to be responsive to incoming ECG waveforms of a predetermined type.
  • the zero-crossing points of the ECG waveform reflect a periodic event in the cardiac cycle.
  • the ECG waveform is characterized by rather steep slopes, for example when the rate of change of the R-wave voltage is steep, or spiky, then the use of such a system to detect the zero-crossings loses accuracy.
  • the steep slope R-wave complex with its accompanying Q and S segments, results in multiple counts per cardiac cycle, giving an artificially high rate reading, which could, in certain cases, be significant.
  • a heart rate detector responsive to those ECG signals having steep or "spiky" slopes. Some such detectors respond to the ECG signal and provide an output responsive to such steep slope signals. Such output may be provided by a slew rate detector which compares the slope, or slew rate, with a slew rate threshold and provides an output signal reflecting the number of high slew rate signals detected.
  • a problem inherent in such a system is the detection of a heart rate when the ECG signal is more sinusoidal than spiky. In such cases, the slew rate, or rate of change of the ECG voltage versus time, characteristic is small. Thus, the detector may not pick up such signals, thus, resulting in detection of an inaccurate low heart rate.
  • prior art heart rate detectors fail to provide the required flexibility in monitoring ECG signals characterized by both spiky ECG waveforms and the more sinusoidal ECG waveforms.
  • Prior art detectors can be designed to work very efficiently with one or the other of such waveforms, but not both. Therefore, it has been determined that a need exists to provide a flexible, accurate and reliable heart beat rate detector that is operable over a broad range of detected ECG waveforms.
  • a heart rate detector system that results in a highly accurate measurement of the heart rate for a variety of monitored ECG signal shapes.
  • Such heart rate detector has particular utility in an automatic implantable defibrillator system wherein the heart rate detector is used in conjunction with a probability density function circuit, such combination as described in the co-pending Langer et al patent application.
  • the heart rate detector of the present invention also has significant utility in a heart pacing system or in any other environment where the heart rate is required to be reliably, efficiently and accurately measured.
  • the heart rate detector of the present invention is responsive to an incoming ECG signal having a series of wave packets, each wave packet including P, Q, R, S and T waves, as is well-defined in the art.
  • the heart rate detector includes two mutually exclusive detection circuits that are responsive to incoming ECG waves having different characteristics. These detection circuits are coupled with an output circuit. Depending upon the incoming ECG wave characteristic, the coupling circuit automatically and selectively couples one of the two detection circuits with the output circuit to provide an accurate count of the heart rate.
  • the two mutually exclusive detection circuits of the present invention include a high slew rate detector, and an amplitude threshold detector.
  • the high slew rate detector is coupled with the output circuit.
  • the threshold amplitude detector is coupled with the output circuit.
  • the slew rate detector circuit provides an accurate determination of the heart rate. If, however, the incoming ECG waves have a slew rate below the predetermined level, and such "low" slew rate signals occur at a predetermined rate, then the amplitude threshold detector circuit provides an accurate determination of the heart rate.
  • the preferred embodiment of the present invention provides an input for receiving an ECG signal.
  • a slew rate detector circuit is coupled with the input for detecting an ECG wave shape having a slew rate above a predetermined threshold and providing an output signal for each detected wave shape.
  • an amplitude threshold detector circuit that detects an ECG wave shape having a predetermined amplitude and provides an output signal for each detected wave shape.
  • An output circuit is provided to receive the two detector output signals.
  • a coupling circuit selectively couples only one or the other of the detector circuits with the output circuit.
  • the high slew rate detector circuit is coupled with the output circuit when a predetermined number of high slew rate signals from the slew rate detector occur at a substantially constant frequency over a first predetermined time period. When such conditions occur, the high slew rate detector remains coupled with the output circuit for as long as high slew rate signals occur within at least a second predetermined time period. At all other times, the output circuit is coupled with the amplitude threshold detector
  • Figure 1 is a block diagram of the heart rate detector of the present invention in a defibrillator circuit.
  • Figure 2 is a block diagram of the double-duty delay circuit shown in Figure 1.
  • the heart rate detector 2 of the present invention responds to amplified, incoming ECG waveforms and includes a slew rate detector 4 and an amplitude threshold detector 6, each coupled with an input circuit 8 that provides the amplified ECG waveforms.
  • a slew rate detector 4 and an amplitude threshold detector 6 are coupled, via a coupling circuit 10, with a digital rate comparator output circuit 12 depending on the characteristics of the ECG waveforms.
  • the comparator output circuit 12 processes the aggregate signals received from the slew rate detector 4 and amplitude threshold detector 6 (the total signals reflecting the number of heart beats), and provides a detector output signal (on line 14) when the heart rate exceeds a predetermined, or preprogrammed, rate over a predetermined period of time.
  • the heart rate detector 2 may have utility in a broad range of applications, such as implantable defibrillators or pacers, or external monitoring equipment.
  • a heart rate detector in a defibrillator circuit is shown.
  • a probability density function circuit 16 is provided having its input responsive to an amplified and differentiated ECG signal.
  • Logic circuitry 18 interconnects the PDF circuit output with the heart rate detector output such that the PDF circuit 16 is coupled with the defibrillating pulse generator (not shown) only upon occurrence of a detector output signal, which reflects high rate tachycardia. Details of the circuitry will now be described.
  • ECG input terminal 20 is coupled to suitable heart electrodes (not shown), via an interface (not shown), to receive an ECG input signal.
  • the heart electrodes may include a superior vena cava (or base) electrode and an apical cup (or patch) electrode in association with a patient's heart.
  • Such electrodes are schematically shown in the co-pending Langer et al patent application, incorporated by reference herein.
  • the incoming ECG signal includes a series of wave packets reflecting heart beats, each wave packet including P, Q, R, S and T waves as is understood in the art. Each wave packet defines a cardiac cycle, as the term is used herein.
  • the input terminal 20 is connected with a conventional ECG amplifier 22 having an automatic gain control (AGC) circuit 24.
  • AGC automatic gain control
  • the slew rate detector 4 includes a differentiator and absolute value circuit 26 which takes the absolute value of the first derivative of the incoming amplified ECG signal. This absolute value of the first derivative is defined as the slew rate, which is the instantaneous rate of voltage change per unit of time. In the context of the present invention, the slew rate can be suitably measured in terms of microvolts per millisecond.
  • the differentiator and absolute value circuit 26 is conventional and known to those of ordinary skill in the art.
  • the slew rate value from the differentiator 26 is provided as an input to a conventional threshold comparator 28.
  • the slew rate is compared with a predetermined slew rate threshold value.
  • a slew rate output signal is provided on the comparator output line 30.
  • the slew rate threshold is predetermined before the unit is implanted and is set by adjusting the variable resistor 32 connected to the negative input terminal 34 of the comparator 28.
  • slew rate also can be set, or programmed, from outside the body by telemetry or other appropriate techniques.
  • the slew rate threshold may be set depending upon the ECG characteristics of the particular patient, but typically should be set so as to provide a slew rate output signal only for relatively high slew rates, i.e., slew rates resulting from ECG signals of relatively spiky, or high slope, angles.
  • the slew rate output signals are provided over line 30 to the input of a monostable (one-shot) multivibrator 36 having a variable refractory period.
  • the monostable multivibrator 36 provides a uniform output pulse on line 38, as is well known in the art. This output pulse is defined herein as the wave detector, or slew rate detector, output signal, or pulse.
  • each cardiac cycle includes a wave packet of P, Q, R, S and T waves.
  • the R wave slew rate will be sufficiently high to provide a slew rate output signal from the comparator 28 to the monostable multivibrator 36.
  • one of the other waveforms within the wave packet, particularly the P or T waves might also have a high slew rate such that the slew rate threshold value set by the variable resistor 32 is exceeded.
  • the refractory period of the monostable multivibrator 36 is adjusted, via input terminals 40, so that when a slew rate output signal from comparator 28 triggers the monostable multivibrator 36, subsequent slew rate output signals occurring within a predetermined refractory time period do not further trigger the multivibrator.
  • the refractory period is set so that only one slew rate output signal within a wave packet, or cardiac cycle, will trigger the multivibrator 36.
  • the multivibrator trigger point is inhibited for a certain refractory period, typically, between 100 and 200 milliseconds. This rate can be set depending upon the patient's normal heart rate. If the patient has a relatively low heart rate, then the refractory period should be set higher than would be the case for a patient with a high heart rate. Similarly, if the patient has a high heart rate, then the refractory period is set lower, to ensure that each slew rate output signal from the slew rate threshold comparator 28 is counted.
  • the refractory period is preset for a particular patient prior to implantation.
  • an automatic variable refractory period adjustment mechanism may be provided, and implanted, to vary the refractory period depending upon heart rate changes.
  • the monostable multivibrator 36 of the present invention is a conventional circuit and its design is known to one of ordinary skill in the art.
  • the multivibrator 36 provides a uniform pulse output on line 38 (the wave detector output signal or pulse).
  • the width of the output pulse should not be so wide that the monostable multivibrator 36 does not reset in time to receive subsequent slew rate output signals from the comparator 28 indicative of subsequent heart beats.
  • the pulse width should not be so narrow that the multivibrator is retriggered upon receipt of a subsequent slew rate output signal within the same wave packet.
  • the wave detector output signal from the monostable multivibrator 36 is provided on the output line 38 of the monostable multivibrator, which line 38 is coupled with an AND gate 42 of the coupling circuit 10, to be described further below.
  • the second detector circuit of the present invention is the amplitude threshold detector 6.
  • This threshold detector 6 includes a conventional high gain amplifier 44 having one input 46 grounded and the other input 48 connected with the ECG amplifier via a low-pass filter 47.
  • the low-pass filter 47 filters out ECG waveforms having "spiky" characteristics and passes only the more sinusoidal ECG waveforms.
  • the amplifier 44 responds to amplified ECG signals having an R-wave greater than a predetermined value.
  • the amplifier 44 When the amplified ECG signal exceeds the threshold, which is arbitrarily chosen as ground, then the amplifier 44 provides a zero-crossing output signal which is coupled to AND gate 50 of the coupling circuit 10.
  • Coupling circuit 10 is defined herein as the logic circuit comprised of AND gates 42 and 50, OR gates 52 and 54, double-duty delay circuit 56, and inverters 58 and 60. These circuit elements are interconnected in such a manner that the outputs of the slew rate detector circuit 4 and amplitude threshold, or zerocrossing, detector 6 are coupled with the digital rate comparator output circuit 12.
  • AND gate 42 receives the wave detector output signal over line 38.
  • the AND gate 42 output line 62 is connected to the input of OR gate 54.
  • the amplitude threshold, or zero-crossing, detector 6 output is connected, via line 64, to the input of AND gate 50.
  • the AND gate 50 output line 66 is coupled to the OR gate 54.
  • OR gate 54 receives either the zero-crossing output signals (over line 66) or wave detector output signals (over line 62) depending upon which of AND gates 42 and 50 is enabled.
  • the OR gate 54 output is provided, over line 68, to the digital rate comparator output circuit 12. The signals from the output of OR gate 54 reflect the number of heart beats detected.
  • AND gate 42 has three inputs 70, 72, 74. One of the inputs 72 is connected to the output line 38 from the monostable multivibrator 36 and receives the wave, or slew rate, detector output signals. Input 70 of the AND gate 42 is connected to a slew rate detector inhibit line 76. If, under certain circumstances, it is desired to monitor ECG signals solely using the zero-crossing detector 6, a zero input over line 76 to the AND gate 42 may be provided which will disenable the AND gate 42. Such inhibition of the slew rate detector may be justified depending upon the ECG waveforms of a particular patient.
  • the input terminal 70 of the AND gate 42 is at a high or "1" state.
  • the third input terminal 74 of the AND gate 42 is coupled with a double-duty delay circuit 56 via an invertor 60.
  • the double-duty delay circuit 56 is designed such that its output 80 is normally at high, or "1", state.
  • the "1" state is inverted by inverter 60 so that the AND gate terminal 74 has a low, or "zero” state, and AND gate 42 is disabled.
  • the output of the delay circuit 56 is also coupled to an OR gate 52 which has an output line 78 coupled with AND gate 50.
  • the double-duty delay output 80 When the double-duty delay output 80 is in a high, or "1", state, the "1" signal is transferred through the OR gate 52 over line 78 to the input terminal 82 of the AND gate 50, thus enabling the AND gate 50 to pass zero-crossing output signals from the zero-crossing detector 6 to the OR gate 54 and, in turn, to the digital rate comparator 12.
  • the double-duty delay circuit output 80 is low, or in a "0" state, the third terminal 74 of the AND gate 42 is enabled, and the terminal 82 of the AND gate 50 is disenabled. Wave, or slew rate, detector output signals from the monostable multivibrator 36 are thus coupled through AND gate 42 to OR gate 54 and, in turn, to the digital rate comparator output circuit 12.
  • the double-duty delay circuit 56 alternately enables one of the AND gates 42 and 50 so that either the zero-crossing detector 6 or the slew rate detector 4 is coupled to the digital rate comparator output circuit 12.
  • the double-duty delay circuit 56 is shown in detail in Figure 2.
  • the circuit includes an input 84 which is coupled with the output line 38 of the monostable multivibrator 36 and thus receives wave detector output pulses from the wave, or slew rate, detector circuit 4. These wave detector output pulses are provided to input 202 of a conventional digital counter 200.
  • the counter 200 has a second input 204 that receives clocking pulses, such as a 32Hz clock signal.
  • the counter 200 counts the clocking pulses and, if a predetermined number of clocking pulses are consecutively counted, the counter 200 provides a high, or "1", signal on the counter output line 206. For example, if clocking pulses provided at input 204 are counted for a predetermined time period, e.g., 2 seconds, then the counter 200 output becomes high, or in its "1" state. However, the counter 200 is reset upon receipt of each wave detector output pulse provided to input 202. When reset, the counter output is low, or in its "0" state.
  • the counter output line 206 is connected to input 208 of a conventional set-reset flip-flop 210.
  • the flip-flop 210 has a second input 212 and an output 80.
  • the output 80 is coupled to inverter 50 and OR gate 52, as described with respect to Figure 1.
  • the flip-flop 210 has the following characteristics. When a high, or “1”, signal is provided at input 208, the output 80 is high, or in its “1” state. When a high, or “1”, signal is provided at input 212, in a manner to be described, the output 80 is low, or in its “0” state.
  • the flip-flop 210 is controlled, and switches state, solely by "1" signals applied to one of the inputs 208 and 212.
  • Output line 80 is further coupled to input 214 of AND gate 216.
  • the other input 218 of AND gate 216 is connected to input 84 to receive pulses from the slew rate detector circuit 4.
  • the AND gate 216 is enabled to pass wave detector output pulses from the slew rate detector circuit 4. These wave detector output pulses are passed by AND gate 216 to an RC circuit 220.
  • the RC circuit 220 includes a capacitor 222 and resistor 224 connected in parallel.
  • the output of RC circuit 220 is connected to an inverter 226.
  • the inverter 226 output is connected to a reset terminal 228 of a counter 230, substantially identical in operation to the previously described counter 200, and including a second input 232 coupled to a predetermined clocking source, such as a 32Hz clocking signal.
  • a wave detector output pulse from the slew rate detector circuit 4 is passed by AND gate 216 to the RC circuit 220, the capacitor 222 is immediately charged and begins a gradual exponential decay, as is well known in the art. The decay time depends on the RC characteristics.
  • the RC characteristics are such that upon receipt of a wave detector output pulse, the capacitor 222 is substantially immediately charged to a voltage level exceeding the threshold needed for the inverter 226 to change its state. The capacitor then gradually decays until the voltage drops below the threshold. If a second wave detector output pulse is received by the RC circuit before the voltage drops below the threshold, then the inverter 226 remains in its changed state, until the voltage drops below the threshold. It is thus seen that if a predetermined number of wave detector output pulses are received by the RC circuit 220, and if these output signals are spaced apart by a predetermined time, the threshold voltage level, at which the inverter 226 is operative, will continuously be exceeded.
  • the RC characteristic is correlated with the predetermined time period of the counter 230, as will be described below. Let us suppose that the output 80 in its
  • the "1" input to inverter 226 is inverted to a "0" output which is provided to the reset terminal 228 of the counter 230.
  • the counter 230 thus is enabled, and begins to count the 32Hz signals provided at its other input 232.
  • the input voltage to the inverter 226 will fall below threshold, i.e., to a "0" state, the inverter 226 output will switch back to a "1" state, and thus will reset the counter (at terminal 228).
  • This reset will occur before the counter 230 has counted its predetermined number of clock pulses; i.e., the reset will occur before a predetermined (2 sec.) time interval.
  • the output of counter 230 will not have changed its state to a "1” output; rather the counter 230 remains at its "0” state and the flip-flop 210 is not reset.
  • the flip-flop 80 remains in its "1" state.
  • the slew rate detector circuit 4 is coupled to the digital rate comparator 12 ( Figure 1). So long as further high slew rate signals are provided at least every two seconds to terminal 84, the output 80 remains in its "0" state. From the above description, it should be apparent that to maintain the input voltage to inverter 226 above the threshold level, and hence to maintain counter 230 in its high state (so that the zero-crossing detector 6 is uncoupled from, and the slew rate detector circuit 4 is coupled to, the digital rate comparator 12), the wave detector output pulses from the slew rate detector circuit 4 must occur above a particular rate and must also occur at substantially equal spacing.
  • the predetermined time period of the counter 230 is two seconds, and further assume that it is desirable to "switch over" to the slew rate detector circuit 4 when two consecutive wave detector output pulses are received.
  • the capacitor charges up, substantially instantaneously, to exceed the threshold voltage of inverter 226, and then begins to decay. If the second consecutive wave detector output pulse occurs 1/2 second later, and no further pulse is received within the 2 second window, then the voltage to inverter 226 will fall below the threshold level before the 2 second period of counter 230 is completed.
  • the counter 230 will be reset the "instant” the capacitor voltage falls below the threshold of inverter 226, and hence will not change from its “0” state, maintaining the output 80 in its “1” state; no "changeover” to the slew rate detector circuit 4 occurs.
  • the double-delay circuit 56 functions in the following manner. Assume, as a starting point, that the zero-crossing detector 6 is coupled to the digital rate comparator output circuit 12. The double-duty delay circuit output 80 is in its "1" state. Wave detector output signals from the slew rate detector circuit 4 are now received. The double-duty delay circuit 56, over a first predetermined time period, counts the number of wave detector output signal pulses that have a relatively constant frequency. If the number of constant frequency, i.e., substantially uniformly spaced, pulses exceeds a predetermined number within the first predetermined time period, then the double-duty delay output line 80 is shifted from a normally high to a low, or "0" state.
  • the second predetermined time period may be the same length as the first predetermined time period. If subsequent wave detector output pulses occur within the second predetermined time period, the delay circuit output 80 remains in its "0" state. If, however, the time period between successive wave detector output signal pulses increases, i.e., if no wave detector output signal pulses occur within the second predetermined time period, then the delay circuit 56 output 80 switches from its "0" state to its high, or "1" state.
  • the zero-crossing detector 6 is uncoupled from, and the slew rate detector 4 is coupled to, the digital rate comparator output circuit 12. If, however, the number of high slew rate output signals falls below a predetermined level, in a predetermined time period, then the coupling circuit 10 couples the zero-crossing detector 6 with the digital rate comparator output circuit 12. Such zero-crossing detector 6 remains coupled to the output circuit 12 until the double-duty delay circuit 56 again switches state, as described above.
  • the coupling circuit 10 of the present invention thus ensures that when the ECG signal is characterized by "spiky", or high slew rate waveforms, the slew rate detector 4 is used to monitor the ECG signals. On the other hand, if the slew rate of the incoming ECG signal is more sinusoidal, then the coupling circuit 10 couples the zero-crossing detector 6 to the output circuit 12. This alternate switching between the detectors 4 and 6 ensures a reliable and accurate count of the heart beats.
  • the initial wave detector output signals from the multivibrator 36 which are provided to the double-duty delay circuit 56, will not be enabled by the AND gate 42 to pass to the OR gate 54, since the AND gate 42 is not enabled until after a first predetermined time period.
  • the first predetermined time period is set between 1 and 5 seconds, with the 2-5 seconds preferred.
  • the number of heart beats that are missed by the heart rate detector circuit 2 will be relatively small since the double-duty delay circuit 56 is designed so that the first and second predetermined time periods are not so great that the missed heart beats would have a critical effect.
  • the output circuit 12 includes a digital rate comparator 86.
  • the digital rate comparator is of conventional design (such as including a digital magnitude comparator, a latch and a counter) and has an input 88 coupled with the output line 69 of the OR gate 54 from the coupling circuit 10.
  • the signals at the input 88 reflect the number of heart beats from either the zero-crossing detector 6 or the slew rate detector 4.
  • the digital rate comparator 86 includes program rate input terminals 90 for reading into the digital rate comparator a predetermined, or preprogrammed, rate.
  • the digital rate comparator 86 receives the heart beat signals and determines, on a beat-by-beat basis, the actual heart rate.
  • Delay circuit 93 which could be an integrator as is well known in the art, integrates the comparator output signals over a predetermined time and provides a detector output signal on line 14 if the number of comparator output rate signals exceeds a predetermined number in a predetermined time.
  • the delay circuit 93 provides a safety feature to prevent spurious signals from starting the defibrillating pulse generator.
  • The. delay circuit 93 may provide an output signal if two comparator output pulses are received within a four second interval.
  • the digital rate comparator 86 also includes readout terminals 94 for reading out the actual heart rate. This actual heart rate readout may not be needed for defibrillator or pacer operations, but circumstances may exist where the actual rate is desired. If the device is implanted in a human body, the readout can be by telemetry or the like.
  • the detector output signal on line 14 is provided to the inputs of two AND gates 96 and 98.
  • AND gate 96 has, as its other input, the output from the PDF circuit 16.
  • the output of AND gate 96 is coupled to an OR gate 100 which, in turn, is coupled to a defibrillator pulse generator (not shown) to initiate a defibrillating shock.
  • the AND gate 96 is enabled, and the PDF circuit is coupled with the defibrillating pulse generator.
  • AND gate 98 has, at terminal 102, a high or "1" input to enable the defibrillating pulse generator to be activated solely by the output 14 of the heart rate detector circuit. If such feature is not desired, then the terminal 102 of the AND gate 98 has an inhibit or "0" input.

Abstract

Dispositif détecteur de cadence cardiaque, destiné notamment à être utilisé dans un défibrillateur implantable. Le dispositif détecteur de cadence cardiaque comprend deux circuits détecteurs distincts (4, 6), chacun sensible à des ondes d'électrocardiogramme (ECG) (2) de caractéristiques différentes. L'un des circuits détecteurs (4) est sensible aux ondes ECG dont les cadences de balayage dépassent un seuil prédéterminé. L'autre circuit détecteur (6) est sensible à des ondes ECG ayant une forme plus sinusoïdale. Un circuit de couplage (10) couple automatiquement un des deux circuits détecteurs (4, 6) à un circuit de sortie (12), tel qu'un comparateur de cadence cardiaque (86). Dans un mode spécifique de réalisation, le comparateur de cadence cardiaque détermine la cadence cardiaque, compare celle-ci à une cadence prédéterminée (90) et, si la cadence caridaque dépasse la cadence prédéterminée pendant un laps de temps prédéterminé (93), il produit un signal de sortie (100). Le signal de sortie peut être utilisé pour commander un circuit de défribillation qui soumet le patient à un choc de défribillation.
PCT/US1982/000751 1982-05-28 1982-05-28 Detecteur de cadence cardiaque WO1983004171A1 (fr)

Priority Applications (7)

Application Number Priority Date Filing Date Title
GB08400719A GB2130101B (en) 1982-05-28 1982-05-28 Heart rate detector
DE3249966A DE3249966C2 (fr) 1982-05-28 1982-05-28
JP57502212A JPS59500895A (ja) 1982-05-28 1982-05-28 心拍数検出装置
NL8220240A NL194661C (nl) 1982-05-28 1982-05-28 Hartslagfrequentiedetector-inrichting.
PCT/US1982/000751 WO1983004171A1 (fr) 1982-05-28 1982-05-28 Detecteur de cadence cardiaque
DE19823249490 DE3249490C2 (de) 1982-05-28 1982-05-28 Vorrichtung zum Erfassen der Herzaktion
CA000404527A CA1193325A (fr) 1982-05-28 1982-06-04 Detecteur de rythme cardiaque

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US1982/000751 WO1983004171A1 (fr) 1982-05-28 1982-05-28 Detecteur de cadence cardiaque

Publications (1)

Publication Number Publication Date
WO1983004171A1 true WO1983004171A1 (fr) 1983-12-08

Family

ID=22168024

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1982/000751 WO1983004171A1 (fr) 1982-05-28 1982-05-28 Detecteur de cadence cardiaque

Country Status (6)

Country Link
JP (1) JPS59500895A (fr)
CA (1) CA1193325A (fr)
DE (2) DE3249490C2 (fr)
GB (1) GB2130101B (fr)
NL (1) NL194661C (fr)
WO (1) WO1983004171A1 (fr)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5558098A (en) * 1995-11-02 1996-09-24 Ventritex, Inc. Method and apparatus for detecting lead sensing artifacts in cardiac electrograms
US8050751B2 (en) 2008-07-31 2011-11-01 Medtronic, Inc. Periodic beat detection to detect artifacts in a cardiac electrogram
US9408548B2 (en) 2011-03-25 2016-08-09 Zoll Medical Corporation Selection of optimal channel for rate determination
CN105877738A (zh) * 2015-01-09 2016-08-24 宁波高新区利威科技有限公司 一种生理参数监护系统信号放大器
US9659475B2 (en) 2011-03-25 2017-05-23 Zoll Medical Corporation System and method for adapting alarms in a wearable medical device
US9684767B2 (en) 2011-03-25 2017-06-20 Zoll Medical Corporation System and method for adapting alarms in a wearable medical device
US10252070B2 (en) 2015-09-08 2019-04-09 Zoll Medical Corporation Secure limited components for use with medical devices
US10272010B2 (en) 2015-03-20 2019-04-30 Zoll Medical Corporation Systems and methods for testing a medical device
US10426342B2 (en) 2016-03-31 2019-10-01 Zoll Medical Corporation Remote access for ambulatory medical device
US10493289B2 (en) 2010-07-09 2019-12-03 Zoll Medical Corporation System and method for conserving power in a medical device
US10602945B2 (en) 2018-03-13 2020-03-31 Zoll Medical Corporation Telemetry of wearable medical device information to secondary medical device or system
US10646707B2 (en) 2017-11-30 2020-05-12 Zoll Medical Corporation Medical devices with rapid sensor recovery
US10674911B2 (en) 2016-03-30 2020-06-09 Zoll Medical Corporation Systems and methods of integrating ambulatory medical devices
US10835449B2 (en) 2015-03-30 2020-11-17 Zoll Medical Corporation Modular components for medical devices
US10918877B2 (en) 2018-09-28 2021-02-16 Zoll Medical Corporation Battery lock for ambulatory medical device
US10932726B2 (en) 2018-03-16 2021-03-02 Zoll Medical Corporation Monitoring physiological status based on bio-vibrational and radio frequency data analysis
US10960213B2 (en) 2018-03-12 2021-03-30 Zoll Medical Corporation Verification of cardiac arrhythmia prior to therapeutic stimulation
US11213691B2 (en) 2017-02-27 2022-01-04 Zoll Medical Corporation Ambulatory medical device interaction
US11709747B2 (en) 2016-01-08 2023-07-25 Zoll Medical Corporation Patient assurance system and method
US11942222B2 (en) 2018-06-18 2024-03-26 Zoll Medical Corporation Medical device for estimating risk of patient deterioration

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5871507A (en) * 1997-06-06 1999-02-16 Pacesetter Ab Implantable cardiac assist device having differential signal detection between unipolar atrial and ventricular leads using signal morphology analysis
KR20220148178A (ko) 2020-03-09 2022-11-04 가부시키가이샤 가네카 제세동용 전기 장치, 및 제세동 신호의 발생 방법

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3144019A (en) * 1960-08-08 1964-08-11 Haber Edgar Cardiac monitoring device
US3343528A (en) * 1964-10-09 1967-09-26 Lindsay J Kirkham Electrocardiographic switching system
US3554187A (en) * 1965-10-21 1971-01-12 Humetrics Corp Method and apparatus for automatically screening of electrocardiac signals
US3554188A (en) * 1969-02-27 1971-01-12 Zenith Radio Corp Heartbeat frequency monitor
US3569852A (en) * 1969-01-23 1971-03-09 American Optical Corp Frequency selective variable gain amplifier
US3858574A (en) * 1972-11-03 1975-01-07 Robert E Page Pulse rate and amplitude monitor
US3878833A (en) * 1973-10-09 1975-04-22 Gen Electric Physiological waveform detector
US3903874A (en) * 1973-08-27 1975-09-09 Mediscience Technology Corp Cardiographic signal processing means and method
US4083366A (en) * 1976-06-16 1978-04-11 Peter P. Gombrich Heart beat rate monitor
US4202340A (en) * 1975-09-30 1980-05-13 Mieczyslaw Mirowski Method and apparatus for monitoring heart activity, detecting abnormalities, and cardioverting a malfunctioning heart

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2524829A1 (de) * 1974-03-26 1976-10-07 Herwig Dipl Ing Dr Thoma Vorrichtung zur erkennung der herzaktion unter extremen bedingungen
US4184493A (en) * 1975-09-30 1980-01-22 Mieczyslaw Mirowski Circuit for monitoring a heart and for effecting cardioversion of a needy heart

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3144019A (en) * 1960-08-08 1964-08-11 Haber Edgar Cardiac monitoring device
US3343528A (en) * 1964-10-09 1967-09-26 Lindsay J Kirkham Electrocardiographic switching system
US3554187A (en) * 1965-10-21 1971-01-12 Humetrics Corp Method and apparatus for automatically screening of electrocardiac signals
US3569852A (en) * 1969-01-23 1971-03-09 American Optical Corp Frequency selective variable gain amplifier
US3554188A (en) * 1969-02-27 1971-01-12 Zenith Radio Corp Heartbeat frequency monitor
US3858574A (en) * 1972-11-03 1975-01-07 Robert E Page Pulse rate and amplitude monitor
US3903874A (en) * 1973-08-27 1975-09-09 Mediscience Technology Corp Cardiographic signal processing means and method
US3878833A (en) * 1973-10-09 1975-04-22 Gen Electric Physiological waveform detector
US4202340A (en) * 1975-09-30 1980-05-13 Mieczyslaw Mirowski Method and apparatus for monitoring heart activity, detecting abnormalities, and cardioverting a malfunctioning heart
US4083366A (en) * 1976-06-16 1978-04-11 Peter P. Gombrich Heart beat rate monitor

Cited By (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5558098A (en) * 1995-11-02 1996-09-24 Ventritex, Inc. Method and apparatus for detecting lead sensing artifacts in cardiac electrograms
US8050751B2 (en) 2008-07-31 2011-11-01 Medtronic, Inc. Periodic beat detection to detect artifacts in a cardiac electrogram
US10493289B2 (en) 2010-07-09 2019-12-03 Zoll Medical Corporation System and method for conserving power in a medical device
US9990829B2 (en) 2011-03-25 2018-06-05 Zoll Medical Corporation System and method for adapting alarms in a wearable medical device
US10755547B2 (en) 2011-03-25 2020-08-25 Zoll Medical Corporation System and method for adapting alarms in a wearable medical device
US9684767B2 (en) 2011-03-25 2017-06-20 Zoll Medical Corporation System and method for adapting alarms in a wearable medical device
US11291396B2 (en) 2011-03-25 2022-04-05 Zoll Medical Corporation Selection of optimal channel for rate determination
US10219717B2 (en) 2011-03-25 2019-03-05 Zoll Medical Corporation Selection of optimal channel for rate determination
US11393584B2 (en) 2011-03-25 2022-07-19 Zoll Medical Corporation System and method for adapting alarms in a wearable medical device
US10269227B2 (en) 2011-03-25 2019-04-23 Zoll Medical Corporation System and method for adapting alarms in a wearable medical device
US11417427B2 (en) 2011-03-25 2022-08-16 Zoll Medical Corporation System and method for adapting alarms in a wearable medical device
US9408548B2 (en) 2011-03-25 2016-08-09 Zoll Medical Corporation Selection of optimal channel for rate determination
US10813566B2 (en) 2011-03-25 2020-10-27 Zoll Medical Corporation Selection of optimal channel for rate determination
US9659475B2 (en) 2011-03-25 2017-05-23 Zoll Medical Corporation System and method for adapting alarms in a wearable medical device
US11699521B2 (en) 2011-03-25 2023-07-11 Zoll Medical Corporation System and method for adapting alarms in a wearable medical device
CN105877738A (zh) * 2015-01-09 2016-08-24 宁波高新区利威科技有限公司 一种生理参数监护系统信号放大器
US11701006B2 (en) 2015-03-20 2023-07-18 Zoll Medical Corporation Systems and methods for testing a medical device
US10744057B2 (en) 2015-03-20 2020-08-18 Zoll Medical Corporation Systems and methods for testing a medical device
US10272010B2 (en) 2015-03-20 2019-04-30 Zoll Medical Corporation Systems and methods for testing a medical device
US11213211B2 (en) 2015-03-20 2022-01-04 Zoll Medical Corporation Systems and methods for testing a medical device
US10835449B2 (en) 2015-03-30 2020-11-17 Zoll Medical Corporation Modular components for medical devices
US11877979B2 (en) 2015-03-30 2024-01-23 Zoll Medical Corporation Modular components for medical devices
US11666772B2 (en) 2015-09-08 2023-06-06 Zoll Medical Corporation Secure limited components for use with medical devices
US10960221B2 (en) 2015-09-08 2021-03-30 Zoll Medical Corporation Secure limited components for use with medical devices
US10252070B2 (en) 2015-09-08 2019-04-09 Zoll Medical Corporation Secure limited components for use with medical devices
US11709747B2 (en) 2016-01-08 2023-07-25 Zoll Medical Corporation Patient assurance system and method
US11432722B2 (en) 2016-03-30 2022-09-06 Zoll Medical Corporation Systems and methods of integrating ambulatory medical devices
US10674911B2 (en) 2016-03-30 2020-06-09 Zoll Medical Corporation Systems and methods of integrating ambulatory medical devices
US11202569B2 (en) 2016-03-31 2021-12-21 Zoll Medical Corporation Remote access for ambulatory medical device
US10426342B2 (en) 2016-03-31 2019-10-01 Zoll Medical Corporation Remote access for ambulatory medical device
US11213691B2 (en) 2017-02-27 2022-01-04 Zoll Medical Corporation Ambulatory medical device interaction
US11771886B2 (en) 2017-11-30 2023-10-03 Zoll Medical Corporation Medical devices with rapid sensor recovery
US10646707B2 (en) 2017-11-30 2020-05-12 Zoll Medical Corporation Medical devices with rapid sensor recovery
US10960213B2 (en) 2018-03-12 2021-03-30 Zoll Medical Corporation Verification of cardiac arrhythmia prior to therapeutic stimulation
US11964159B2 (en) 2018-03-12 2024-04-23 Zoll Medical Corporation Verification of cardiac arrhythmia prior to therapeutic stimulation
US11534098B2 (en) 2018-03-13 2022-12-27 Zoll Medical Corporation Telemetry of wearable medical device information to secondary medical device or system
US10602945B2 (en) 2018-03-13 2020-03-31 Zoll Medical Corporation Telemetry of wearable medical device information to secondary medical device or system
US10932726B2 (en) 2018-03-16 2021-03-02 Zoll Medical Corporation Monitoring physiological status based on bio-vibrational and radio frequency data analysis
US11826174B2 (en) 2018-03-16 2023-11-28 Zoll Medical Corporation Monitoring physiological status based on bio-vibrational and radio frequency data analysis
US11942222B2 (en) 2018-06-18 2024-03-26 Zoll Medical Corporation Medical device for estimating risk of patient deterioration
US10918877B2 (en) 2018-09-28 2021-02-16 Zoll Medical Corporation Battery lock for ambulatory medical device

Also Published As

Publication number Publication date
GB8400719D0 (en) 1984-02-15
NL194661C (nl) 2002-11-04
DE3249490T1 (de) 1984-08-09
NL8220240A (nl) 1984-04-02
NL194661B (nl) 2002-07-01
GB2130101A (en) 1984-05-31
JPH0428370B2 (fr) 1992-05-14
GB2130101B (en) 1985-10-30
CA1193325A (fr) 1985-09-10
DE3249490C2 (de) 1989-05-11
JPS59500895A (ja) 1984-05-24
DE3249966C2 (fr) 1991-09-19

Similar Documents

Publication Publication Date Title
US4393877A (en) Heart rate detector
WO1983004171A1 (fr) Detecteur de cadence cardiaque
US4475551A (en) Arrhythmia detection and defibrillation system and method
US5010887A (en) Noise discrimination in implantable pacemakers
US4776338A (en) Cardiac pacer for pacing a human heart and pacing method
US3528428A (en) Demand pacer
EP0341297B1 (fr) Detecteurs de marge de detection pour des dispositifs electromedicaux implantables
US4000461A (en) R-wave detector
US4473078A (en) Cardiac arrhythmia analysis system
EP0601775B1 (fr) Détection d'évènement cardiaques dans les dispositifs implantables
US4432375A (en) Cardiac arrhythmia analysis system
US5269300A (en) Automatic sensitivity control in an implantable cardiac rhythm management system
JP3548177B2 (ja) 心臓刺激装置用の波形弁別装置
CA1210819A (fr) Methode et appareil pour corriger les anomalies de la fonction cardiaque au moyen de chocs de faible intensite
US4940054A (en) Apparatus and method for controlling multiple sensitivities in arrhythmia control system including post therapy packing delay
US4796620A (en) System for sensing abnormal heart activity by means of heart rate acceleration and deceleration detection
US5103819A (en) Implantable cardiac stimulator with state machine for automatically controlling gain
EP0009255B1 (fr) Défibrillateur ventriculaire automatique
US5431687A (en) Impedance timed defibrillation system
JP2601762B2 (ja) 電気的除細動器
CA1323070C (fr) Methode et appareil permettant de distinguer l'arythmie d'un bruit emis par un appareil de regulation de l'arythmie
EP1150742B1 (fr) Dispositif implantable a reglage de detection automatique
WO1982000415A1 (fr) Systeme et procede de detection d'arythmie
US4393874A (en) Bradycardia event counting and reporting pacer
JPS6125387B2 (fr)

Legal Events

Date Code Title Description
AK Designated states

Designated state(s): DE GB JP NL

RET De translation (de og part 6b)

Ref document number: 3249490

Country of ref document: DE

Date of ref document: 19840809

WWE Wipo information: entry into national phase

Ref document number: 3249490

Country of ref document: DE