US3865119A - Heartbeat actuator with controlled pulse amplitude - Google Patents

Heartbeat actuator with controlled pulse amplitude Download PDF

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Publication number
US3865119A
US3865119A US349809A US34980973A US3865119A US 3865119 A US3865119 A US 3865119A US 349809 A US349809 A US 349809A US 34980973 A US34980973 A US 34980973A US 3865119 A US3865119 A US 3865119A
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Prior art keywords
actuator
heartbeat
resistances
impulses
amplitude
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Expired - Lifetime
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US349809A
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English (en)
Inventor
Bengt Svensson
Gunnar Wallin
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Siemens AG
Siemens Corp
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Siemens Corp
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Publication date
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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/18—Applying electric currents by contact electrodes
    • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
    • A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
    • A61N1/362—Heart stimulators

Definitions

  • a heartbeat actuator particularly an implantable heartbeat actuator has means for automatically lower- I P t 11) t [30] Forelgn Application y a a 2 74 0 ing the amplitude of stimulating impulses produced by 1 1972 Germany O the beat actuator.
  • the invention is particularly characterized by a stepwise switching device operated in [52] US. Cl. 112/4193]; rhythm with the Stimulating impulses and used for I ..i-..4.i....P....419 Rn Connecting Switching elements influence the [58 ⁇ meld of Search 1 amplitude of the stimulating impulses.
  • PULSE AMPLITUDE This invention relates to a heartbeat actuator, particularly an implantable heartbeat actuator having means for automatically lowering the amplitude of stimulating impulses produced by the beat actuator.
  • Beat actuators of this type have the purpose of deter mining the threshold value of the stimulus of the heart by means of the actuator.
  • the actuator is influenced by action of a magnetic field upon a switch sensitive to the magnetic field and provided in the actuator, so that it operates with a fixed frequency and so that the amplitude of the produced stimulating impulses is continuously lowered.
  • a measure for calcuand when using an n-step binary counter as the stepwise switching device it is possible to provide with n lating the threshold valve of the stimulus of the heart is provided from the number of produced effective impulses of the heartbeat maker calculated from the switching of the switch which depends upon the magnetic field up to an absence of an answer from the irritated heart.
  • the lowering of the amplitude of the stimulating impulses can be produced by using the charging condition of a condenser which can be charged through a resistance, to operate the charging current of that condenser which is discharged through the heart for producing a stimulating impulse.
  • this manner of producing the lowering of the amplitudes results in a poorly definable gradation of the amplitudes and the reproduction of the gradation cannot be carried out with sufficient precision and replaceability.
  • An object of the present invention is to produce a heartbeat maker ofthe described type wherein the lowering of the amplitudes of the stimulating impulses takes place in precisely definable steps.
  • the reproduction of the gradation should be possible with simple and cheap means. All these objects should be carried out by the least possible number of structural elements requiring a small amount of space.
  • An object of the present invention can be accomplished by providing a stepwise switching device operated in rhythm with the stimulating impulses for connecting switching elements influencing the amplitude of the stimulating impulses.
  • the elements are so dimensioned that the lowering of the impulses takes place in predetermined preferably equal steps.
  • a digital counter is used as the stepwise switching device and is preferably made as an integrated structure. In this manner a space saving and cheap switching device is produced.
  • switching elements influencing the amplitude of the threshold value of the stimulus preferably fixed resistances are used which are small and cheap and the value of which can be fixed very precisely.
  • the amount of the amplitude of a stimulating impulse is determined by the charge condition of a condenser discharging for impulse production.
  • the fixed resistances are switched on by the stepwise switching device into the charging circuit of the condenser.
  • the present invention further provides that the least possible number of resistances can be used if their size is arranged in steps according to a geometrical series and if they can be combined individually with each other.
  • the least possible number of resistances can be used if their size is arranged in steps according to a geometrical series and if they can be combined individually with each other.
  • FIG. 1 is a switch circuit illustrating the basis of the present invention.
  • FIG. 2 is a diagram showing the desired stepwise arrangement of the amplitudes as a function of time.
  • FIG. 3 is a switch circuit showing the various parts causing the lowering of the impulses.
  • FIG. 1 shows an amplifier 1, a switch 2 dependent upon a magnetic field, a trigger circuit 3, an astable multivibrator 4, a monostable multivibrator 5, a socalled dosing circuit 6 and an outlet switch 7 of a heartbeat actuator.
  • the outgoing impulses of the heartbeat actuator reach through the outlet clamp 8 the heart of the patient.
  • the same conduit receives the EKG signals of the heart and transmits them to the amplifier.
  • a sequence of impulses is produced in the multivibrator 4 corresponding to the switching time of this' multivibrator; this sequence of impulses closes through the monostable tipping stage the switch 7 for a short time when there is an impulse and provides that a stimulating impulse is transmitted to the heart.
  • FIG. 2 shows the desired run of the amplitudes, whereby the amplitude A of impulses produced by the beat actuator is shown as a function of the time t.
  • the horizontal broken line indicates the threshold value of the stimulus of the heart and the two vertical broken lines show the limits of the time period during which the switch dependent upon the magnetic field was actuated by the application of a magnet.
  • An arrow shows the first impulse of the series of impulses the amplitude of which is smaller than the threshold value of the stimulus of the heart and thus is not sufficient any more for stimulating the heart.
  • geometric row is used to indicate the dimensioning and interconnection of resistances whereby the amplitude of exciting impulses is lowered in equal steps.
  • a similar arrangement is described by A. Watson as A Staircase Function Generator in Electronic Engineering, May 1965, pg, 329.
  • FIG. 3 shows the switch connections of the dosing circuit as well as the construction of the switch 7.
  • the switch 7 consists of a transistor T through which a condenser C can be discharged. Normally the transistor is locked so that the condenser C can be charged through the resistance R,. However, as soon as an impulse from the monostable multivibrator 5 reaches the base of the transistor through the voltage dividers R R the transistor becomes conducting and permits the discharge of the condenser to the heart of the patient.
  • the reserve resistance of the heart is indicated as R, in FIG. 3.
  • resistance combinations of R1, R2, R3 and R4 will be switched on in the rhythm of the beat actuator impulses; they determine by voltage division the voltage with which the condenser can be charged between two following impulses ofthe monostable multivibrator 5.
  • the values of the resistances are geometrically stepped and thus when they are switched jointly they permit the formation of a linear resistance row.
  • the switch elements I to IV are made in digital structure. They switch the resistances on and off one after the other depending upon impulses supplied from the monostable multivibrator 5, so that all possibilities of the joint connection of the resistances R1 to R4 are exhausted.
  • the switching elements I to IV are provided with the usual connection indications, so that further description is unnecessary.
  • the present invention makes it possible to determine the threshold value of the stimulus heart with simple and cheap parts requiring little space in a continuously reproduceable way and with precision and safety. Thus it is possible to determine expected life duration of the heartbeat actuator relatively to the required amplitude height provided by the heart threshold value of the stimulus.
  • a heartbeat actuator particularly an implantable heartbeat actuator, comprising a condenser, a charging circuit connected with said condenser for controlling pulse amplitude, means producing stimulating impulses, said charging circuit including a digital counter actuated by the pulses and a plurality of resistances connected thereto, whereby the counter combines the resistances to control pulse amplitude, said resistances having values arranged according to a geometrical row, means combining said resistances with each other, and means connected with said condenser and said impulse-producing means for applying the generated impulses to the heart, the combined resistances being switched into said charging circuit by said counter so that the lowering of the amplitudes takes place in predetermined equal steps.

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  • Health & Medical Sciences (AREA)
  • Radiology & Medical Imaging (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Cardiology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Electrotherapy Devices (AREA)
  • Percussion Or Vibration Massage (AREA)
US349809A 1972-04-11 1973-04-10 Heartbeat actuator with controlled pulse amplitude Expired - Lifetime US3865119A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2217400A DE2217400A1 (de) 1972-04-11 1972-04-11 Herzschrittmacher

Publications (1)

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US3865119A true US3865119A (en) 1975-02-11

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US349809A Expired - Lifetime US3865119A (en) 1972-04-11 1973-04-10 Heartbeat actuator with controlled pulse amplitude

Country Status (5)

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US (1) US3865119A (enExample)
JP (1) JPS499885A (enExample)
DE (1) DE2217400A1 (enExample)
FR (1) FR2179861A1 (enExample)
NL (1) NL7217209A (enExample)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4114628A (en) * 1977-05-31 1978-09-19 Rizk Nabil I Demand pacemaker with self-adjusting threshold and defibrillating feature
DE2944637A1 (de) * 1978-11-06 1980-05-14 Medtronic Inc Programmierbares medizinisches geraet
DE2944636A1 (de) * 1978-11-06 1980-05-14 Medtronic Inc Impulsgenerator fuer medizinische geraete
US4273132A (en) * 1978-11-06 1981-06-16 Medtronic, Inc. Digital cardiac pacemaker with threshold margin check
US4295468A (en) * 1979-10-24 1981-10-20 Cardiac Pacemakers, Inc. Cardiac pacer testing system
US4520825A (en) * 1982-04-30 1985-06-04 Medtronic, Inc. Digital circuit for control of gradual turn-on of electrical tissue stimulators
US4735204A (en) * 1984-09-17 1988-04-05 Cordis Corporation System for controlling an implanted neural stimulator
USRE33420E (en) * 1984-09-17 1990-11-06 Cordis Corporation System for controlling an implanted neural stimulator
US5209228A (en) * 1990-10-26 1993-05-11 Allegheny-Singer Research Institute Electronic pacemaker testing device
US5309096A (en) * 1991-08-26 1994-05-03 Siemens Aktiengesellschaft Magnetic field detector for a medical device implantable in the body of a patient
US5370668A (en) * 1993-06-22 1994-12-06 Medtronic, Inc. Fault-tolerant elective replacement indication for implantable medical device
US5387228A (en) * 1993-06-22 1995-02-07 Medtronic, Inc. Cardiac pacemaker with programmable output pulse amplitude and method

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5124913U (enExample) * 1974-08-01 1976-02-24
DE2939173A1 (de) * 1979-09-27 1981-04-16 Siemens AG, 1000 Berlin und 8000 München Herzschrittmacher

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3517663A (en) * 1968-04-15 1970-06-30 Gen Electric Threshold analyzer for an implanted heart stimulator
US3631860A (en) * 1969-10-27 1972-01-04 American Optical Corp Variable rate pacemaker, counter-controlled, variable rate pacer
US3638656A (en) * 1968-08-26 1972-02-01 Liechti Ag Fred Method and apparatus for monitoring and stimulating the activity of the heart
US3669120A (en) * 1969-07-11 1972-06-13 Rovsing As Christian Device for starting or stimulating heart contractions

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3517663A (en) * 1968-04-15 1970-06-30 Gen Electric Threshold analyzer for an implanted heart stimulator
US3638656A (en) * 1968-08-26 1972-02-01 Liechti Ag Fred Method and apparatus for monitoring and stimulating the activity of the heart
US3669120A (en) * 1969-07-11 1972-06-13 Rovsing As Christian Device for starting or stimulating heart contractions
US3631860A (en) * 1969-10-27 1972-01-04 American Optical Corp Variable rate pacemaker, counter-controlled, variable rate pacer

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4114628A (en) * 1977-05-31 1978-09-19 Rizk Nabil I Demand pacemaker with self-adjusting threshold and defibrillating feature
DE2944637A1 (de) * 1978-11-06 1980-05-14 Medtronic Inc Programmierbares medizinisches geraet
DE2944636A1 (de) * 1978-11-06 1980-05-14 Medtronic Inc Impulsgenerator fuer medizinische geraete
US4273132A (en) * 1978-11-06 1981-06-16 Medtronic, Inc. Digital cardiac pacemaker with threshold margin check
US4295468A (en) * 1979-10-24 1981-10-20 Cardiac Pacemakers, Inc. Cardiac pacer testing system
US4520825A (en) * 1982-04-30 1985-06-04 Medtronic, Inc. Digital circuit for control of gradual turn-on of electrical tissue stimulators
US4735204A (en) * 1984-09-17 1988-04-05 Cordis Corporation System for controlling an implanted neural stimulator
USRE33420E (en) * 1984-09-17 1990-11-06 Cordis Corporation System for controlling an implanted neural stimulator
US5209228A (en) * 1990-10-26 1993-05-11 Allegheny-Singer Research Institute Electronic pacemaker testing device
US5309096A (en) * 1991-08-26 1994-05-03 Siemens Aktiengesellschaft Magnetic field detector for a medical device implantable in the body of a patient
US5370668A (en) * 1993-06-22 1994-12-06 Medtronic, Inc. Fault-tolerant elective replacement indication for implantable medical device
US5387228A (en) * 1993-06-22 1995-02-07 Medtronic, Inc. Cardiac pacemaker with programmable output pulse amplitude and method
US5402070A (en) * 1993-06-22 1995-03-28 Medtronic, Inc. Fault-tolerant elective replacement indication for implantable medical device

Also Published As

Publication number Publication date
DE2217400A1 (de) 1973-10-25
JPS499885A (enExample) 1974-01-28
FR2179861A1 (enExample) 1973-11-23
NL7217209A (enExample) 1973-10-15

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