Heart treatment equipment and heart treatment method

• US 20060052831A1
• Filed: 09/23/2005
• Published: 03/09/2006
• Est. Priority Date: 03/24/2003
• Status: Active Grant

• Current Assignee: Terumo Kabushiki Kaisha (Terumo Corporation)
• Original Assignee: Terumo Corporation
• Inventors: Fukui, Yoshihito
• Granted Patent: US 7,336,997 B2
• Time in Patent Office: Days
• US Class Current: 607/9
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362

Abstract

Heart treatment equipment and a heart treatment method directed to prevention of a fatal arrhythmia by detecting a physical exercise or a mental stress by using a sensor and thereafter controlling the vagus nerve stimulation, wherein sensor means for detecting various living body information for generating a signal which designates degree of a sympathetic tone is provided and heart rate threshold for carrying out the vagus nerve stimulation is adjusted according to the living body information detected by the sensor means. Further, a nerve stimulation parameter for adjusting the strength of the vagus nerve stimulation is adjusted in response to the degree of the patient sympathetic tone.

Claims

1. Heart treatment equipment comprising:

nerve stimulation means for generating a nerve stimulation signal which stimulates a vagus nerve;

heart activity measuring means for measuring a heart activity;

heart activity threshold control means for setting a heart activity threshold when stimulating said vagus nerve by said nerve stimulation means;

heart activity comparing means for comparing an output of said heart activity measuring means and said threshold; and

sensor means for sensing a living body information,

wherein said heart activity threshold control means controls said threshold in response to an output of said sensor means.

2. Heart treatment equipment according to claim 1, wherein said heart activity measuring means measures a heart rate, and said nerve stimulation means generates said nerve stimulation signal in a case when said heart rate measured by said heart activity measuring means exceeds said threshold.

3. Heart treatment equipment according to claim 1, wherein said heart activity measuring means measures a heartbeat interval, and said nerve stimulation means generates said nerve stimulation signal in a case when said measured heartbeat interval goes under said threshold.

4. Heart treatment equipment according to claim 1 further comprising nerve stimulation signal control means for controlling a parameter of said nerve stimulation signal in response to the output of said sensor means.

5. Heart treatment equipment according to claim 4, wherein the parameter of said nerve stimulation signal is at least one of a period between pulses, a pulse width, a number of pulses, a pulse voltage, a pulse current, a delay time, a rest time and a repetitive number or a multiple combination chosen from these.

6. Heart treatment equipment according to claim 1, wherein said sensor means senses a vetricle contractility.

7. Heart treatment equipment according to claim 1, wherein said ventricle contractility is related to any one of a QT time, an intraventricular electrogram area, a pre-ejection time, a stroke volume and a ventricle pressure.

8. Heart treatment equipment according to claim 1, wherein said sensor means senses a body motion.

9. Heart treatment equipment according to claim 1, wherein said sensor means senses breathing.

10. Heart treatment equipment according to claim 1, wherein said sensor means senses blood.

11. Heart treatment equipment comprising:

nerve stimulation means for generating a nerve stimulation signal which stimulates a vagus nerve;

heart activity measuring means for measuing an atrium activity;

heart activity threshold control means for setting a heart activity threshold when stimulating said vagus nerve by said nerve stimulation means;

means for comparing an output of said heart activity measuring means and said threshold;

sensor means for sensing a ventricle contractility;

atrioventricular delay time measuring means for starting a clocking in response to said atrium activity; and

atrioventricular delay time comparator means for emanating an output which carries out a ventricle stimulation when an output of said atrioventricular delay time measuring means exceeds a predetermined set value,

wherein said sensor means senses said ventricle contractility concurrently with said ventricle stimulation and said heart activity threshold control means controls said threshold in response to an output of said sensor means.

12. Heart treatment equipment according to claim 11, wherein a heart rate is measured as said atrium activity and said nerve stimulation means generates said nerve stimulation signal in a case when said measured heart rate overruns said threshold.

13. Heart treatment equipment according to claim 11, wherein a heartbeat interval is measured as said atrium activity and said nerve stimulation means generates said nerve stimulation signal in a case when said measured heartbeat interval goes under said threshold.

14. Heart treatment equipment according to claim 11, wherein the sensor means sensing said ventricle contractility is an intracardiac electrogram sensor.

15. Heart treatment equipment according to claim 14, wherein said intracardiac electrogram sensor is either one of a QT time sensor and an intraventricular electrogram area sensor.

16. Heart treatment equipment according to claim 11 further comprising nerve stimulation signal control means for controlling a parameter of said nerve stimulation signal in response to the output of said sensor means.

17. Heart treatment equipment according to claim 16, wherein the parameter of said nerve stimulation signal is at least one of a period between pulses, a pulse width, a number of pulses, a pulse voltage, a pulse current, a delay time, a rest time and a repetitive number or a multiple combination chosen from these.

18. A heart treatment method comprising:

a step for sensing a living body information;

a heart activity measuring step for measuring a heart activity;

a heart activity comparing step for comparing said heart activity measuring result with a threshold; and

a step for stimulating a vagus nerve in a case when it is judged by said heart activity comparing step that said heart activity increases,

wherein there is included a step for changing said threshold in response to said sensed living body information.

19. A heart treatment method according to claim 18, wherein a heart rate is measured as said heart activity and a nerve stimulation signal is generated in a case when said measured heart rate exceeds said threshold.

20. A heart treatment method according to claim 18, wherein a heartbeat interval is measured as said heart activity and a nerve stimulation signal is generated in a case when said measured heartbeat interval goes under said threshold.

21. A heart treatment method according to claim 18, wherein said living body information is information relating to a ventricle contractility.

22. A heart treatment method according to claim 21, wherein said ventricle contractility is related to any one of a QT time, an intraventricular electrogram area, a pre-ejection time, a stroke volume and a ventricle pressure.

23. A heart treatment method according to claim 18, wherein said living body information is information relating to a body motion of a patient.

24. A heart treatment method according to claim 18, wherein said living body information is information relating to breathing of a patient.

25. A heart treatment method according to claim 18, wherein said living body information is information relating to blood of a patient.

26. A heart treatment method according to claim 18, wherein a parameter of said nerve stimulation signal is further controlled in response to said sensed living body information.

27. A heart treatment method according to claim 26, wherein the parameter of said nerve stimulation signal is at least one of a period between pulses, a pulse width, a number of pulses, a pulse voltage, a pulse current, a delay time, a rest time and a repetitive number or a multiple combination chosen from these.

28. A heart treatment method comprising:

a heart activity measuring step for measuring an atrium activity;

a heart activity comparing step for comparing said heart activity measuring result with a threshold;

a step for stimulating a vagus nerve in a case when it is judged by said heart activity comparing step that said atrium activity increases;

a step for sensing a ventricle contractility;

a step for starting a clocking of an atrioventricular delay time in response to said atrium activity;

a step for comparing whether or not said clocked atrioventricular delay time exceeds a predetermined set value and carrying out a ventricle stimulation when it exceeds said predetermined set value;

a step for measuring said ventricle contractility concurrently with said ventricle stimulation; and

a step for changing said threshold in response to said measured ventricle contractility.

29. A heart treatment method according to claim 28, wherein a heart rate is measured as said atrium activity and a nerve stimulation signal is generated in a case when said measured heart rate exceeds said threshold.

30. A heart treatment method according to claim 28, wherein a heartbeat interval is measured as said atrium activity and a nerve stimulation signal is generated in a case when said measured heartbeat interval goes under said threshold.

31. A heart treatment method according to claim 28, wherein the step for sensing said ventricle contractility is carried out by an intracardiac electrogram sensor.

32. A heart treatment method according to claim 31, wherein said intracardiac electrogram sensor is either one of a QT time sensor and an intraventricular electrogram area sensor.

33. A heart treatment method according to claim 32, wherein a parameter of said nerve stimulation signal is further controlled in response to an output of said sensor.

34. A heart treatment method according to claim 33, wherein the parameter of said nerve stimulation signal is at least one of a period between pulses, a pulse width, a number of pulses, a pulse voltage, a pulse current, a delay time, a rest time and a repetitive number or a multiple combination chosen from these.