Source: https://patents.google.com/patent/JP2004173790A/en
Timestamp: 2020-01-20 05:09:05
Document Index: 334538031

Matched Legal Cases: ['art 56', 'art 56', 'art 56', 'art 8', 'art 8', 'art 8', 'art 8', 'art 8', 'art 8', 'art\n9']

JP2004173790A - Heart treatment equipment - Google Patents
JP2004173790A
JP2004173790A JP2002341367A JP2002341367A JP2004173790A JP 2004173790 A JP2004173790 A JP 2004173790A JP 2002341367 A JP2002341367 A JP 2002341367A JP 2002341367 A JP2002341367 A JP 2002341367A JP 2004173790 A JP2004173790 A JP 2004173790A
JP2002341367A
2002-11-25 Application filed by Terumo Corp, テルモ株式会社 filed Critical Terumo Corp
2002-11-25 Priority to JP2002341367A priority Critical patent/JP2004173790A/en
2004-06-24 Publication of JP2004173790A publication Critical patent/JP2004173790A/en
210000002216 Heart Anatomy 0 abstract title 10
230000000638 stimulation Effects 0 abstract 4
210000001186 Vagus Nerve Anatomy 0 abstract 2
230000010247 heart contraction Effects 0 abstract 1
In a heart treatment apparatus, spontaneous cardiac contraction is suppressed, and a cardiac rhythm is controlled to a low value.
A heart pulse generator for stimulating the heart, a nerve pulse generator for stimulating the vagus nerve, a heart event detector for detecting a spontaneous event of the heart, a heart pulse generator and a nerve pulse A control means 2 for controlling the generating means 5 is provided. When the heart rate is lower than a predetermined rate, the control means 2 activates the heart pulse generating means 3 to perform heart stimulation, and when the heart rate is higher than a predetermined rate. Activates the nerve pulse generating means to stimulate the vagus nerve.
The present invention relates to a cardiac treatment apparatus for preventing tachyarrhythmia and controlling the heart rate to a low value in order to prevent sudden cardiac death in patients with organic heart disease.
Of the sudden deaths, particularly those caused by heart disease, are called sudden cardiac deaths, and the number is about 50,000 annually in the country. The immediate cause of sudden cardiac death is the occurrence of ventricular tachycardia or ventricular fibrillation, which causes hemodynamic breakdown, called lethal arrhythmia.
A ventricular tachycardia in which the ventricle pulsates abnormally prematurely, or ventricular fibrillation in which the individual muscle fibers that make up the ventricle begin to be excited separately and the entire ventricle trembles little by little, triggers the heart pump. Function is reduced or lost, and the necessary blood cannot be pumped to the whole body. As a result, consciousness is lost due to a decrease in cerebral blood flow, and death may occur unless appropriate measures are taken immediately. Ventricular tachycardia and ventricular fibrillation frequently occur in patients with organic heart disease such as myocardial infarction and cardiomyopathy.
Antiarrhythmic drugs are commonly used to prevent sudden cardiac death. Cardiovascular trials in the United States confirm that beta-blockers and group III antiarrhythmic drugs with beta-blocking activity are effective from the perspective of improving life prognosis, especially in cases of organic heart disease with reduced left ventricular function Is being done. The β-blocker has an action of mainly lowering the heart rate by its pharmacological action, and is effective for suppressing a rapid heart beat.
By reducing the heart rate in this way, it is possible to reduce the occurrence of ventricular premature contractions that induce ventricular tachycardia and ventricular fibrillation, and further reduce the myocardial oxygen consumption due to the decrease in heart rate. It is believed that this will improve the state of oxygen deficiency at the site of myocardial injury and prevent the occurrence of ventricular tachycardia and ventricular fibrillation and the recurrence of new myocardial infarction.
In order to stabilize the heart rate, a heart treatment device called a so-called pacemaker is used. FIG. 7 shows an example of a conventional pacemaker. The normal operation of a pacemaker is to generate a stimulation pulse of a predetermined width at a set cycle for the heart.
For this reason, a conventional heart treatment apparatus (pacemaker) 50 includes a control means 51, a heart pulse generation means 52 for generating a heart stimulation pulse for stimulating the heart, and a heart event for detecting a spontaneous beat (event) of the heart. It comprises a detecting means 53, a cardiac electrode lead 54 and a cardiac stimulating electrode 55 which supply a stimulation pulse to the heart and transmit a cardiac event to the cardiac event detecting means 53.
In the control means 51, a clock generator and a counter (not shown) are arranged in order to control the heart pulse generation means 52 to generate a stimulation pulse at a predetermined cycle. Each time the counter is reset, it starts counting clocks.
The cardiac event detecting means 53 detects that the cardiac potential has exceeded a certain level by the cardiac stimulation electrode 25 arranged in the ventricle, and detects an event of the heart 56 via the cardiac electrode lead 24. . The detection of this cardiac event also resets the counter in the control means 21 and starts counting.
Thus, the counter is reset every time a heart stimulation pulse for stimulating the heart 56 is generated or each time the heart 56 spontaneously beats, so that the generation of the heart stimulation pulse is always set from the time of detection. After a period corresponding to the rate.
In such a heart treatment apparatus, when the heart beat is slower than the set rate, the heart rate can be stabilized and maintained at the set rate by the heart stimulation pulse from the heart pulse generating means 52. If the movement was faster than the set rate, it could not respond, and it was not possible to prevent the occurrence of ventricular tachycardia or ventricular fibrillation.
In general, it is known that when the signal activity of the sympathetic nerve increases, the heart activity (heart rate and cardiac output) increases, and when the signal activity of the vagus nerve (parasympathetic nerve) increases, the heart activity (heart rate) decreases. Based on this principle, a technique has been proposed in which the heart rate is kept low by electrically stimulating the vagus nerve (for example, see Patent Document 1). This patent document 1 discloses a method of detecting a heart rate and controlling a vagal nerve stimulation frequency so that the heart rate is within a desired range at rest.
Further, there has been proposed a heart treatment apparatus in which energy required for prevention of tachyarrhythmia and acute treatment is reduced, and particularly effective for defibrillation (for example, see Patent Document 2). In Patent Document 2, a block for nerve cardioversion is provided in addition to a pacemaker block for sending a stimulation pulse to the heart in a dearrhythmia and tachycardia. Then, electrodes are connected to both the sympathetic nerve that activates cardiac activity and the vagus nerve that suppresses cardiac activity, sends an activation current that activates the heart to the vagus nerve, and sends a suppression current that inhibits the heart to the sympathetic nerve, A cardiac therapy device for neurocardioverter defibrillation is disclosed.
International Patent Application No. PCT / USOO / 28046 (WO 01/26729)
However, in pharmacotherapy, in order to maintain the heart rate at a low value, the relationship between the amount of β-blocker to be administered and the patient's heart rate is determined in advance, and based on this relationship, medication is performed to achieve a desired heart rate. The amount and dosing interval need to be determined. Since the relationship between the dose and the heart rate changes constantly depending on the patient's autonomic tone, it is necessary to constantly measure the blood concentration of the drug and the heart rate to adjust the time and volume of drug administration. However, there is a problem that it is very complicated and it is practically difficult to precisely control the heart rate to a low value. In addition, overdose and forgetting to take the drug were considered, and it was difficult to suppress the heart rate to a low value by medication.
Further, in the heart treatment device described in Patent Document 1, since nerves are continuously stimulated, effects on other organs, such as excessive secretion of stomach acid, insulin, glucagon, and patients with a history of asthma, Side-effect problems such as inducing asthma attacks can be significant. Furthermore, in the device described in Patent Literature 1, when the heart rate falls below a desired range, only measures to stop the vagus nerve stimulation or reduce the stimulation frequency can be performed. The heart rate does not recover immediately and it is difficult to stabilize the heart rate.
Further, the heart treatment device described in Patent Literature 2 operates in response to the occurrence of ventricular fibrillation of the heart, and thus cannot prevent ventricular fibrillation before it occurs. Leaving this ventricular fibrillation leads to death in a few minutes, and it is essential to perform defibrillation in order to treat it, but defibrillation may cause cardiac dysfunction due to myocardial cell membrane destruction, In addition, even if the defibrillation energy is reduced by using nerve stimulation in combination, there is no alternative to performing defibrillation, and there is a problem that the defibrillation is exposed to the possibility of tissue damage.
The present invention has been made in view of such a problem, and provides a heart treatment apparatus in which the heart rate of a patient is automatically controlled to a desired value or a low value within a desired range. The purpose is to do.
In order to achieve the above object, the heart treatment apparatus according to claim 1 includes a heart pulse generation unit that generates a heart stimulation pulse for stimulating a heart, and a nerve stimulation generation unit that generates a nerve stimulation signal for stimulating a vagus nerve. A heart event detection means for detecting a spontaneous event of the heart, and a control means for controlling the heart pulse generation means and the nerve stimulation generation means, wherein the control means is provided by the heart pulse generation means at a predetermined rate. Generating a cardiac stimulation pulse and canceling the next scheduled generation of a cardiac stimulation pulse from the cardiac pulse generating means when the response of the cardiac event detection means is earlier than the predetermined rate; A neural stimulation signal is generated from the generating means.
According to the first aspect of the present invention, when the cardiac event detecting means does not detect a cardiac event within a predetermined period, a cardiac stimulation pulse is generated by the cardiac pulse generating means at a predetermined rate, and the cardiac event detection is performed. When the means becomes faster than the predetermined rate, the neural stimulation generating means is operated to generate the neural stimulation signal without generating the cardiac stimulation pulse from the cardiac pulse generating means, so that the heart rate of the patient is always set to a desired value. It can be kept low.
According to a second aspect of the present invention, there is provided a heart treatment apparatus for generating a heart stimulation pulse for stimulating the heart, a nerve stimulation generation unit for generating a nerve stimulation signal for stimulating the vagus nerve, and a spontaneous heart. Controlling a cardiac event detecting means for detecting an event, a cardiac event analyzing means for analyzing a situation of occurrence of a spontaneous event of the heart in response to the cardiac event detecting means, the cardiac pulse generating means and the nerve pulse generating means Control means for generating a cardiac stimulation pulse by the heart pulse generating means at a predetermined rate, and in response to the cardiac event analyzing means, for generating the next scheduled cardiac pulse generation. Means for canceling the generation of a cardiac stimulation pulse from the means, and generating a nerve stimulation signal from the nerve stimulation generating means. .
A heart treatment apparatus according to a second aspect is characterized in that a cardiac event analysis unit is added to the configuration of the heart treatment apparatus according to the first aspect. As a result of the cardiac event analysis, the vagus nerve is not stimulated if the spontaneous cardiac event is within the allowable limit.
According to a third aspect of the present invention, there is provided the cardiac treatment apparatus according to the second aspect, wherein the cardiac event analyzing means includes an event interval analyzing means. 4. The heart treatment apparatus according to claim 3, wherein the event interval analyzing means compares a time from a response of the cardiac pulse generating means or the cardiac event detecting means to the detection of the next spontaneous event with a predetermined time. It is characterized by having.
According to a fifth aspect of the present invention, in the heart treatment apparatus, when the cardiac event analyzing means detects the number of cardiac events a plurality of times, the nerve stimulation generating means generates a nerve stimulation signal to stimulate the vagus nerve. I have.
According to the heart treatment apparatus of the fifth aspect, the vagus nerve is stimulated only when a predetermined number of cardiac events are detected, so that the vagus nerve is stimulated in response to instantaneous heart rate fluctuations. Nothing.
The heart treatment device according to claim 6, wherein the atrial pulse generating means for generating an atrial stimulation pulse for stimulating the atrium, the nerve stimulation generating means for generating a nerve stimulation signal for stimulating the vagus nerve, and the spontaneous event of the atrium. Atrial event detecting means for detecting, atrial event analyzing means for analyzing the occurrence of spontaneous atrial events in response to the atrial event detecting means, control for controlling the atrial pulse generating means and the neural stimulation generating means Means for generating atrial stimulation pulses at a predetermined rate by atrial pulse generating means, and generating atrial stimulation pulses from the next scheduled atrial pulse generating means in response to the atrial event analyzing means. Control means for canceling the signal and generating a neural stimulation signal from the neural stimulation generating means; and a ventricular event detecting a spontaneous ventricular event. A detection means, an atrioventricular delay timer that starts counting when the atrial event is detected or an atrial event is stimulated, and a counting time of the atrioventricular delay timer exceeds a predetermined desired atrioventricular delay time. A ventricular pulse generating means for stimulating the ventricle when the ventricle is stimulated.
According to the heart treatment apparatus of the sixth aspect, the atrioventricular delay timer is provided, and if no ventricular event is detected even when the preset atrioventricular delay time has elapsed, the ventricle is stimulated. Coordinated contraction can be maintained. With this configuration, when the atrial heart rate is controlled at a low level by vagal nerve stimulation, the atrial heart rate is stabilized, but the cooperative contraction of the atria and the ventricles may not be maintained. Can be achieved.
Hereinafter, a first embodiment of a heart treatment apparatus according to the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a configuration of a heart treatment apparatus according to a first embodiment of the present invention. The heart treatment apparatus 1 includes a control unit 2, a heart pulse generation unit 3 for generating a heart stimulation pulse for stimulating the heart, a heart event detection unit 4 for detecting a spontaneous event of the heart, and a neural stimulation pulse signal for stimulating the vagus nerve. It is constituted by a nerve pulse generating means 5 for generating. The cardiac stimulation electrode 7 connected to the cardiac electrode lead 6 is inserted and connected to the right ventricle of the heart 8, and the nerve stimulation electrode 10 connected to the nerve electrode lead 9 is connected to the vagus nerve 11.
The cardiac stimulation electrodes 7 include a myocardial electrode implanted in the heart muscle, so-called myocardium, and a catheter electrode for inserting an electrode from the vena cava to the ventricle. The catheter electrode is usually inserted into the lower right ventricle from the vena cava through the right atrium and the atrioventricular valve. The nerve stimulation electrode 10 is usually arranged so as to be wound around the vagus nerve 11. The region around which the nerve stimulation electrode 10 is wound is preferably the neck region or the right center position of the lateral carotid artery.
In addition, the nerve stimulation electrode 10 can be arranged so as to stimulate the vagus nerve 11 adjacent to the blood vessel wall by placing a catheter electrode in the blood vessel. The placement region is preferably in the subclavian vein.
The control unit 2 includes a heart stimulation interval timer 12, a heart stimulation interval set value storage unit 13, and a count value of the heart stimulation interval timer 12 and a heart stimulation interval set value (predetermined rate: (1 second) and a nerve pulse control unit 15.
The cardiac event detecting means 4 acquires electrocardiogram information from the cardiac stimulation electrode 7 connected to the heart 8 via the cardiac electrode lead 6. Then, a cardiac event is detected based on the acquired electrocardiogram information, and the detected cardiac event is supplied to the cardiac stimulation interval timer 12 of the control means 2 and the nerve pulse control means 15. When the cardiac event detection means 4 notifies the heart event detection means 4 of the detection of a cardiac event earlier than a predetermined rate, the control means 2 instructs the heart pulse generation means 3 to generate a heart stimulation pulse for stimulating the next scheduled heart 8. A command is issued to cancel, and the nerve pulse generation means 5 is instructed to generate a nerve stimulation pulse for stimulating the vagus nerve 11 via the nerve electrode lead 9.
More specifically, when the pulsation of the heart 8 is transmitted to the heart stimulating electrode 7, the electric pulse signal is detected by the cardiac event detecting means 4, and this is used as a heart stimulating interval timer 12 and a neural pulse controlling means 15 in the control means 2. Supplied to The heart stimulation interval timer 12 is reset by this detection pulse, and starts counting clocks from a clock generator (not shown) provided inside the heart stimulation interval timer 12.
The heart stimulus interval set value storage means 13 stores a numerical value (predetermined rate) that determines a predetermined heart rate corresponding to each heart disease patient, and is stored in the heart stimulus interval set value storage means 13. The setting value (predetermined rate) and the count value of the heart stimulation interval timer 12 are constantly compared by the comparing means 14.
When the count value of the heart stimulation interval timer 12 becomes larger than the set value stored in the heart stimulation interval set value storage means 13, it is necessary to accelerate the heart beat. To generate a cardiac stimulation pulse, and send the cardiac stimulation pulse to the cardiac stimulation electrode via the cardiac stimulation lead 6.
When the count value of the heart stimulation interval timer 12 is smaller than the set value stored in the heart stimulation interval set value storage means 13, that is, when the heart rate of the heart is faster than a predetermined rate, the heart pulse is generated. The nerve pulse control means 15 is operated to control the nerve pulse generation means 5 to generate the nerve stimulation pulse without generating the cardiac stimulation pulse from the means 3, and the nerve stimulation control means 15 generates the nerve stimulation pulse. A stimulation pulse is given to stimulate the vagus nerve 11. As a result, the heart rate of the heart 8 is shifted to a lower direction.
The above operation will be described in more detail with reference to the flowchart of FIG. 2 showing the operation of the heart treatment apparatus of the present embodiment. First, the heart stimulation interval timer 12 reset by the generation of a heart stimulation pulse or the detection of a heart event is started (step S1). Next, it is determined whether a heart event has been detected (step S2). If a heart event has been detected, that is, in this case, the heart rate is earlier than a predetermined rate, the timer is reset. Along with (Step S3), a nerve stimulation pulse is generated to stimulate the vagus nerve (Step S4).
Next, if no cardiac event is detected in the determining step S2, the comparing means 14 determines whether or not the cardiac stimulation interval timer 12 has timed out (step S5). In this determination step S5, it is determined whether or not the heart stimulation interval timer 12 is larger than a heart stimulation interval set value (predetermined rate) set in advance for each heart disease patient. If a cardiac event is not detected after the lapse of the set time, it is determined that a time-out has occurred, and a cardiac stimulation pulse is generated by the cardiac pulse generation means 3 (step S6).
Then, with the generation of the cardiac stimulation pulse, the cardiac stimulation interval timer 12 is reset (step S7), and if it is determined in step 5 that the timeout has not occurred, the detection of the next cardiac event is awaited.
As described above, in the first embodiment of the present invention, if no spontaneous cardiac contraction is detected within an interval period (predetermined rate) corresponding to a desired low heart rate, the cardiac stimulation interval is timed out. If so, a cardiac stimulation is performed to maintain a desired heart rate, and if spontaneous systole is detected within the interval, the occurrence of spontaneous systole after the next heart cycle is reduced to a desired low. Vagal nerve stimulation is performed in order to delay the value to an interval corresponding to the heart rate of the value, and control is performed for each heartbeat so that the heart rate is maintained at a desired low value.
FIG. 3 shows a configuration of a heart treatment apparatus according to a second embodiment of the present invention. The difference from the embodiment of the present invention shown in FIG. 1 is that the cardiac treatment apparatus further includes a cardiac event analysis means 16. 3, components corresponding to those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals.
The operations of the control means 2, the cardiac pulse generating means 3, the cardiac event detecting means 4, and the nerve pulse generating means 5 are the same as those in the embodiment shown in FIG. The cardiac event detecting means 4 detects a cardiac event such as a pulsation on the basis of electrocardiographic information obtained via a cardiac electrode lead 6 from a cardiac stimulation electrode 7 connected to the heart 8 and converts the detected cardiac event into a cardiac event analyzing means. 16 and the heart stimulation interval timer 12.
The cardiac event analysis means 16 comprises an event interval holding means 17, an event interval set value storage means 18, and a comparison means 19. The detection signal (event information) from the cardiac event detection means 4 is supplied to the event interval holding means 17. The event interval holding means 17 receives the time signal from the heart stimulation interval timer 12 of the control means 2 and holds the time at which a cardiac event is detected. That is, the time interval of the cardiac event is measured by the cardiac stimulation interval timer 12.
On the other hand, the event interval set value storage unit 18 sets a predetermined time shorter than a predetermined period of the predetermined rate as a set value. That is, in the case of a person whose heart beats once per second in a steady state, the set value is a time interval shorter than 1 second, for example, 0.7 seconds. Then, the comparing unit 19 compares the time interval of the cardiac event held by the event interval holding unit 17 with the set value stored in the event interval set value storage unit 18, for example, 0.7 seconds. When the measurement time interval is smaller than the set value (for example, when the time interval between cardiac events is 0.6 seconds), an output signal is obtained from the comparison means 19, and this output signal is used as the nerve pulse control means 15. To supply.
The nerve pulse control unit 15 receives an output signal from the comparison unit 19 when a cardiac event is detected at a time interval earlier than the set value stored in the event interval set value storage unit 18 and receives the output signal from the nerve pulse generation unit 5. To send a control pulse. The nerve pulse generator 5 receives a signal from the nerve pulse controller 15 and generates a nerve stimulation pulse. The nerve stimulation pulse is supplied to the nerve stimulation electrode 10 via the nerve stimulation power lead 9, and the vagus nerve 11 Give to.
FIG. 4 is a flowchart showing the operation of the heart treatment apparatus according to the second embodiment of the present invention. First, the heart stimulation interval timer 12 starts (step S11) and waits for detection of a heart event.
Next, it is determined whether or not a cardiac event has been detected (step S12). If a cardiac event has not been detected, it is determined whether or not the cardiac interval has timed out, that is, stored in the cardiac stimulation interval set value storage means 13. It is determined whether the set value exceeds, for example, one second (step S17). If there is no timeout, the detection of a cardiac event is awaited. If a heart event is detected in step S12 before this timeout, it means that the heart rate is faster than the predetermined rate, so that the event interval measurement is stopped by the event interval holding means 17 and the measured value at that time is held. At the same time as (Step S13), the heart stimulation interval timer is reset (Step S14).
Subsequently, it is determined whether the held event interval measurement value is smaller than a set value (for example, 0.7 seconds, which varies depending on the patient) stored in the event interval set value storage unit 18 (step S15). When the time interval (measured value) of the held heart event is smaller than the set value stored in the event interval set value storage means 18, a command is sent to the nerve pulse control means 15 and the nerve pulse generation means 5 is instructed. A nerve stimulation pulse is generated, and a nerve stimulation pulse is given to the vagus nerve 11 via the nerve stimulation electrode 10 (step S16). If it is determined in the determination step S15 that the measured time interval of the cardiac event is larger than the set value stored in the event interval set value storage means 18, the neural stimulation and the heart stimulation are not performed and the step S12 is performed. Return to and wait for the detection of the next cardiac event.
If no heart event is detected in the determination step S12, and if it is determined in step S17 that the cardiac stimulation interval timer 12 has timed out, that is, if the cardiac stimulation interval timer 12 If the heart stimulus interval set value (for example, 1 second) preset for each heart disease patient stored in the stimulus interval set value storage means 13 is larger than the heart stimulus pulse, the heart pulse generator 3 generates a heart stimulus pulse. (Step S18).
When the heart stimulus pulse is generated, the heart stimulus interval timer 12 is reset (step S19). If it is determined in step S17 that the timeout has not occurred, the process returns to step S12 as described above to return to the next heart event. Will be waiting for the detection.
As described above, in the second embodiment of the present invention, if the heart contraction is not detected spontaneously during the interval corresponding to the desired low heart rate, the desired heart rate is maintained. The heart stimulation is performed at the same time as the timeout of the interval. If a spontaneous cardiac contraction is detected during the interval period, the time interval from the cardiac stimulation performed immediately before the detection or the spontaneous cardiac contraction to the present detection is measured, and the measured value is calculated for each heart disease patient. Vagus nerve stimulation is performed only when the value is smaller than a predetermined set value. As this set value, an interval (short cycle) corresponding to a heart rate slightly larger than a predetermined rate is selected. Therefore, no vagus nerve stimulation is performed for spontaneous cardiac contractions from a predetermined rate to a range of heart rates slightly larger (shorter heart rate).
Further, as a modification of the second embodiment of the present invention, the configuration of the cardiac event analysis means 16 is changed to a configuration in which the measured value of the cardiac event time interval measured and held by the event interval holding means 17 is stored in the event interval set value storage. The neural stimulation pulse may be generated only when a plurality of cardiac events earlier than the set value stored in the means 18 are detected. That is, only when the output signal of the comparison means 19 is obtained a plurality of times, the nerve pulse control means 15 may be operated, and the nerve pulse generation means 5 may generate a nerve stimulation pulse to perform vagus nerve stimulation.
According to this modification, a neural stimulation pulse is not generated for an instantaneous increase in heart rate such as a heart rate variability due to respiratory movement, and a neural stimulation pulse is generated only when a cardiac event is repeatedly detected multiple times. Therefore, a nerve stimulation pulse can be generated only when a continuous increase in the heart rate is detected, and there is no need to perform unnecessary nerve stimulation.
FIG. 5 is a configuration diagram of a heart treatment apparatus according to a third embodiment of the present invention. Components corresponding to those of the first embodiment of the present invention shown in FIG. 1 and the second embodiment of the present invention shown in FIG. 3 are denoted by the same reference numerals.
In the second embodiment of the present invention shown in FIG. 3, the cardiac event analysis means 16 detects a cardiac event based on electrocardiogram information obtained via a cardiac stimulation electrode lead 6 from a cardiac stimulation electrode 7 provided in a ventricle. However, in the third embodiment, electrocardiogram information is acquired by an atrial stimulation electrode 24 installed in the atrium via an atrial stimulation electrode lead 23 and transmitted to an atrial event analyzing means 20.
The atrial event analyzing means 20 is different from the cardiac event analyzing means 16 shown in FIG. 3 in that the location where the event information is obtained is the atrium, but the configuration and operation are the same as those of the cardiac event analyzing means 16. The description is omitted here.
In the third embodiment of the present invention, a ventricular event detecting means 25 for detecting ventricular event information from a ventricular stimulating electrode 28 via a ventricular stimulating electrode lead 27, and an atrial event detecting or atrial pulse generating means An OR circuit 29 which outputs an output when any of the atrial stimulation pulses is generated from 21; a counting is started by the output of the OR circuit 29; The atrioventricular delay timer 30 to be stopped, the atrioventricular delay set value storage means 31 for storing a desired atrioventricular delay time in advance, and the output of the atrioventricular delay timer 30 and the atrioventricular delay set value storage means 31 are stored. An atrio-ventricular delay comparing means 32 for comparing a desired atrio-ventricular delay time and a ventricular pulse generating means 26 for performing ventricular stimulation based on an output from the atrio-ventricular delay comparing means 32.
The atrial event information detected by the atrial event detecting means 22 is sent to the atrial event analyzing means 20, and through the same processing as in the second embodiment of the present invention shown in FIG. In some cases, the nerve pulse generating means 5 is controlled by the nerve pulse control means 15 to generate a vagus nerve stimulation pulse, and when no atrial event is detected for a predetermined period, an output is obtained from the comparing means 14 and the atrial pulse generating means 21 is output. Thus, a stimulation pulse is applied to the atrial stimulation electrode 24 via the atrial stimulation electrode lead 23 to stimulate the atria.
Here, when either the atrial stimulation pulse is generated or the atrial event detecting means 22 detects an atrial event, an output is generated from the OR circuit 29, and the atrioventricular delay timer 30 starts counting. I do. This counting is continued until ventricular event detection information is obtained from the ventricular event detecting means 25. When the ventricular event information is detected, the atrioventricular delay timer 30 outputs a delay time from the detection of the atrial event or the generation of the atrial stimulation pulse to the detection of the ventricular event. The desired atrioventricular delay time stored in the atrioventricular delay set value storage means 31 is compared.
If no ventricular event is detected even after the desired atrioventricular delay time stored in the atrioventricular delay set value storage means 31 has passed, an output is supplied from the atrioventricular delay comparison means 32 to the ventricular pulse generation means 26. Then, a ventricular stimulation pulse is given to the ventricular stimulation electrode 28 via the ventricular stimulation electrode lead 27.
FIG. 6 is a flowchart showing the operation of the cardiac treatment apparatus according to the third embodiment of the present invention.
First, the heart stimulation interval timer 12 starts (step S21) and waits for detection of a heart event.
Next, it is determined whether or not an atrial event has been detected (step S22). If no atrial event has been detected, it is determined whether or not the cardiac interval has timed out, that is, stored in the cardiac stimulation interval set value storage means 13. It is determined whether the set value exceeds, for example, 1 second (step S27). If there is no timeout, the process waits for detection of an atrial event. If an atrial event is detected in step S22 before this timeout, it means that the heart rate is earlier than the predetermined rate, so that the event interval measurement unit 17 stops the event interval measurement and holds the measured value at that time. At the same time as (Step S23), the heart stimulation interval timer is reset (Step S24).
Subsequently, it is determined whether the held event interval measurement value is smaller than a set value (for example, 0.7 seconds, which varies depending on the patient) stored in the event interval set value storage unit 18 (step S25). When the time interval (measured value) of the held heart event is smaller than the set value stored in the event interval set value storage means 18, a command is sent to the nerve pulse control means 15 and the nerve pulse generation means 5 is instructed. A nerve stimulation pulse is generated, and a nerve stimulation pulse is given to the vagus nerve 11 via the nerve stimulation electrode 10 (step S26). When it is determined in the determination step S25 that the measured time interval of the cardiac event is larger than the set value stored in the event interval set value storage unit 18, the process proceeds to step S22 without performing the nerve stimulation or the atrial stimulation. Return to and wait for the detection of the next cardiac event.
In addition, when the atrial event is not detected in the determination step S22 and when it is determined in the determination step S27 that the heart stimulation interval timer 12 has timed out, that is, when the heart stimulation interval timer 12 If the heart stimulus interval set value (for example, 1 second) preset for each heart disease patient stored in the interval set value storage means 13 is greater than the predetermined value, the atrial pulse generation means 21 generates an atrial stimulus pulse. (Step S28).
Then, with the generation of the atrial stimulation pulse, the heart stimulation interval timer 12 is reset (step S29). If it is determined in the determination step S27 that the timeout has not occurred, the process returns to the step S22 as described above to return to the next atria. It will wait for an event to be detected.
Regardless of whether or not nerve stimulation is performed in step S26, if an atrial event is detected or an atrial stimulation pulse is generated, the atrioventricular delay timer 30 starts (step S30). Then, it is determined whether or not a ventricular event is detected by the ventricular event detecting means 25 (step S31). When a ventricular event is detected, the atrioventricular delay timer 30 is stopped (step S32), and the detection of the next atrial event is awaited. If no ventricular event is detected in the determination step S31, it is determined whether or not the atrioventricular delay timer 30 has timed out (step S33). When the atrioventricular delay timer 30 has timed out, that is, when a ventricular event is not detected even after the elapse of a predetermined desired atrioventricular delay time, the ventricular pulse generating means 26 generates a ventricular stimulation pulse to generate a ventricular stimulation pulse. Is performed (step S34).
In general, vagus nerve stimulation has the effect of delaying atrioventricular conduction time.Thus, when atrial heart rate is controlled to a low value by vagus nerve stimulation, atrial heart rate is stabilized, but cooperative contraction of atria and ventricles is maintained. May not be possible. The third embodiment of the present invention provides a solution to this problem. An atrio-ventricular delay timer 30 is provided, and if no ventricular event is detected even after a preset atrio-ventricular delay time, the ventricle is not detected. By providing stimulation, it is possible to maintain cooperative contraction of the atria and ventricles.
According to the present invention, when there is a spontaneous heart contraction having a heart rate slightly higher than a predetermined rate, it is possible to avoid frequent vagal nerve stimulation and preserve spontaneous heart activity as much as possible. In addition, when applied as an implantable device, the number of times of vagus nerve stimulation can be reduced, so that power consumption associated with vagus nerve stimulation is reduced, leading to a longer life.
As described above, the heart treatment apparatus of the present invention has been described based on the illustrated embodiment. However, the present invention is not limited to this, and includes an implantable cardiac pacemaker, an extracorporeal cardiac pacemaker, and an implantable defibrillator. The present invention can be applied to an apparatus having a heart rate control mechanism based on heart stimulation.
As described above, according to the present invention, based on the detection of a spontaneous heart event or the analysis of the occurrence of a spontaneous heart event, a heart excitement state higher than a desired heart rate as a control target value is detected. And can perform vagal nerve stimulation. In addition, the vagal nerve stimulation according to the present invention makes it possible to delay the interval of occurrence of spontaneous cardiac events from an interval corresponding to a desired heart rate which is a control target value. Since the range in which the operation is not performed can be set as an allowable range, the heart pacing is performed only at the necessary range with the heart rate, and the heart rhythm can be efficiently controlled to a low value.
FIG. 1 is a diagram showing a configuration example of a heart treatment apparatus according to a first embodiment of the present invention.
FIG. 2 is an operation flowchart of the heart treatment apparatus according to the first embodiment shown in FIG. 1;
FIG. 3 is a diagram illustrating a configuration example of a heart treatment apparatus according to a second embodiment of the present invention.
FIG. 4 is an operation flowchart of the heart treatment apparatus according to the second embodiment shown in FIG. 3;
FIG. 5 is a diagram illustrating a configuration example of a heart treatment apparatus according to a third embodiment of the present invention.
FIG. 6 is an operation flowchart of the heart treatment apparatus according to the third embodiment shown in FIG. 5;
FIG. 7 is a configuration example of a conventional heart treatment apparatus.
1, 50 ... heart treatment device
2, 51 ... control means
3, 52... Heart pulse generating means
4, 53 ... heart event detecting means
5 ... Neural pulse generating means
6, 54 ... cardiac electrode lead
7, 55 ... cardiac stimulation electrode
8, 56 ... heart
9 ... Neural electrode lead
10 ... Neural stimulation electrode
11 ... vagus nerve
16 ... heart event analysis means
20 ・ ・ ・ Atrial event analysis means
21 ... Atrial pulse generating means
22 ... ventricular event detecting means
26 ... ventricular pulse generating means
30 ・ ・ ・ Atrioventricular delay timer
31 ・ ・ ・ Atrioventricular delay set value storage means
32 ・ ・ ・ Atrioventricular delay comparison means
Heart pulse generating means for generating a heart stimulation pulse for stimulating the heart,
Nerve stimulation generating means for generating a nerve stimulation signal for stimulating the vagus nerve;
Heart event detection means for detecting a spontaneous event of the heart;
Control means for controlling the heart pulse generating means and the nerve stimulation generating means,
The control means generates a cardiac stimulation pulse by the heart pulse generating means at a predetermined rate, and when a response of the cardiac event detecting means is earlier than the predetermined rate, the next scheduled cardiac pulse generation is performed. A heart stimulation pulse from the means is canceled, and a nerve stimulation signal is generated from the nerve stimulation generating means.
Cardiac event analysis means for analyzing the occurrence of spontaneous events of the heart in response to the heart event detection means;
The control means generates a cardiac stimulation pulse by the cardiac pulse generating means at a predetermined rate, and responds to the cardiac event analyzing means to generate a cardiac stimulation pulse from the next scheduled cardiac pulse generating means. A heart treatment apparatus, wherein the generation is canceled and a nerve stimulation signal is generated by the nerve stimulation generating means.
3. The heart treatment apparatus according to claim 2, wherein the cardiac event analysis means analyzes an event interval.
The event interval analysis means compares the time from the response of the heart pulse generation means or the heart event detection means to the detection of the next spontaneous event, and a predetermined set value, The heart treatment device according to claim 3.
3. The heart treatment apparatus according to claim 2, wherein the cardiac event analyzing means generates a neural stimulation signal by the neural stimulation generating means when detecting a plurality of cardiac events.
Atrial pulse generating means for generating an atrial stimulation pulse for stimulating the atria,
Atrial event detection means for detecting spontaneous events in the atria;
In response to the atrial event detection means, atrial event analysis means for analyzing the occurrence of atrial spontaneous events,
Control means for controlling the atrial pulse generating means and the neural stimulation generating means, wherein the atrial pulse generating means generates atrial stimulation pulses at a predetermined rate and responds to the atrial event analyzing means, and Control means for canceling the generation of atrial stimulation pulses from the atrial pulse generating means being performed, and generating a nerve stimulation signal from the nerve stimulation generating means,
Ventricular event detection means for detecting spontaneous ventricular events;
An atrioventricular delay timer that starts counting when the atrial event is detected or the atrial event is stimulated;
A heart treatment device comprising: a ventricular pulse generating means for stimulating a ventricle when the counting time of the atrioventricular delay timer exceeds a predetermined atrioventricular delay time set in advance.
JP2002341367A 2002-11-25 2002-11-25 Heart treatment equipment Pending JP2004173790A (en)
JP2002341367A JP2004173790A (en) 2002-11-25 2002-11-25 Heart treatment equipment
JP2004173790A true JP2004173790A (en) 2004-06-24
ID=32703753
JP2002341367A Pending JP2004173790A (en) 2002-11-25 2002-11-25 Heart treatment equipment
JP (1) JP2004173790A (en)
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