System for and method of treating a malfunctioning heart

• US 5,330,505 A
• Filed: 05/08/1992
• Issued: 07/19/1994
• Est. Priority Date: 05/08/1992
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Leonard Bloom
• Inventors: Cohen, Todd J.
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): GETZOW, SCOTT M
• Application Number:
  US07/879,909
• Time in Patent Office: 802 Days
• Field of Search: 128/419 PG, 128/419 D
• US Class Current: 607/6
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters

Abstract

A system for treating the malfunctioning heart of a patient includes means which derive at least one electrical signal from the patient'"'"'s heart and means which derive at least two physiologic signals from or related to the patient'"'"'s circulatory system. The physiologic signals, or functions thereof, are weighted and algebraically summed in a central processing unit, which may be a programmable microprocessor, having a RAM and a ROM, receives and responds to the at least one electrical signal and to the at least two physiologic signals. Output means, which may include a heart assist pump, pacers, drug delivery devices and cardioverting/-defibrillating apparatuses, controlled by the central processing unit provides corrective measure(s) to the patient. Heart-rate zone signals and the algebraic sum, at any given time effect selection of a particular treatment modality, if needed. Adjustable or variable baselines, against which a representation of the current, short-term magnitude of the selected physiologic parameter or parameters are provided. The variable baseline(s) is (are) a representation of the selected physiologic parameter(s) determined over a long term of greater duration than the short term over which the current magnitude(s) of the parameter(s) is (are) measured. The system may be used to carry out a method according to a corresponding series of steps.

Claims

1. A system for treating a malfunctioning heart comprising means for supplying a plurality of treatment modalities to a patient, a plurality of sensors for sensing respective parameters reflecting condition of a patient, means responsive to outputs from at least two of said sensors of at least two of said parameters reflecting condition of a patient for producing respective signal representations of the parameters, means for weighing the respective signal representations, means for processing output from the means for weighing to develop control output for selectively enabling the means for supplying a plurality of treatment modalities to a patient to effect selection of respective ones of treatment modalities as called for by the control output.

2. The system of claim 1, wherein the respective sensors comprise a first sensor for sensing mixed venous O₂ saturation and a second sensor for sensing activity level of a patient.

3. The system of claim 2, wherein the first sensor is positionable in the right ventricle of a heart.

4. The system of claim 2, wherein the first sensor is positionable in the right atrium of a heart.

5. The system of claim 2, wherein said second sensor comprises an accelerometer positionable to respond to motion of a patient.

6. The system of claim 1, wherein one of said at least two sensors comprises a temperature sensor positionable within an interior portion of the body of a patient.

7. The system of claim 1, wherein one of said at least two sensors comprises a temperature sensor positionable to sense temperature of blood within an interior portion of the body of a patient.

8. The system of claim 1, wherein one of said at least two sensors comprises a pH sensor operatively positionable to sense pH of blood at a site within the circulatory system of a patient.

9. The system of claim 1, wherein one of said at least two sensors is a pressure sensor.

10. The system of claim 9, wherein said means for producing signal representations includes means responsive to output from the pressure sensor for producing a signal representation of right ventricle pulse pressure.

11. The system of claim 9, wherein said means for producing signal representations includes means responsive to output from the pressure sensor for producing a signal representation of right ventricular systolic pressure.

12. The system of claim 9, wherein said means for producing signal representations includes means responsive to output from the pressure sensor for producing a signal representation of right atrial pressure.

13. The system of claim 9, wherein said means for producing signal representations includes means responsive to output from the pressure sensor for producing a signal representation of rapid change in arterial pressure.

14. The system of claim 1, wherein said at least two sensors comprise a first sensor for sensing mixed venous O₂ saturation and a second sensor for sensing a temperature of a patient.

15. The system of claim 14, wherein said second sensor is a temperature sensor positionable within an interior body portion of a patient.

16. The system of claim 14, wherein said second sensor is a temperature sensor positionable to sense temperature of blood of a patient.

17. A system for treating a malfunctioning heart comprising means for supplying a plurality of treatment modalities to a patient;

means for producing respective signal representations of at least two parameters reflecting condition of a patient, said means for producing respective signal representations including means for providing a baseline signal for at least one of the at least two parameters;

means for developing a short term signal of the at least one parameter and means for comparing the short term signal of the at least one parameter with the baseline signal to develop a difference signal as a function of the at least one parameter;

means for weighing the difference signal function of the at least one parameter and remaining respective signal representations of at least the other parameter, means for processing output from the means for weighing to develop control output for selectively enabling the means for supplying a plurality of treatment modalities to the patient to effect selection of respective ones of treatment modalities as called for by the control output.

18. The system of claim 17, wherein said means for providing a baseline signal comprise means for providing a varying long term baseline signal for at least one of the parameters against which the short term signal is compared to develop the difference signal function of the at least one parameter.

19. The system of claim 17, wherein said means for providing a baseline signal comprises means for providing a varying long term baseline signal for at least one of the parameters against which the short term signal is compared to develop a ratio thereof as the function of the at least parameter.

20. A system for treating a malfunctioning heart comprising means for supplying a plurality of treatment modalities to a patient;

means for producing respective signal representations of at least two parameters reflecting condition of a patient, said means for producing respective signal representations including means for providing a baseline signal for at least one of the parameters, means for developing a short term signal of the at least one parameter and means for comparing the short term signal of the at least one parameter to develop a ratio signal thereof as a function of the at least one parameter; and

means for weighing the ratio signal function of the at least one parameter and remaining respective signal representations of the at least other parameters, means for processing output from the means for weighing to develop control output for selectively enabling the means for supplying a plurality of treatment modalities to the patient to effect selection of respective ones of treatment modalities as called for by the control output.

21. A method of treating a malfunctioning heart comprising, determining at least two parameters reflective of condition of a patient, weighing the respective determined parameters, algebraically summing the weighted parameters, and treating a patient with respective treatment modalities in accordance with the magnitude of the algebraic sum.

22. The method of claim 21, wherein the step of determining at least two parameters comprise determining mixed venous O₂ saturation and determining activity level of the patient.

23. The method of claim 22, wherein the step of determining mixed venous O₂ saturation comprises determining mixed venous O₂ saturation in the right ventricle of the heart of a patient.

24. The method of claim 22, wherein the step of determining mixed venous O₂ saturation comprises determining mixed venous O₂ saturation in the right atrium of a patient.

25. The method of claim 21, wherein the step of determining at least two parameters comprises determining the intensity of movement of the patient.

26. The method of claim 21, wherein the step of determining at least two parameters comprises determining temperature of an interior portion of the body of a patient.

27. The method of claim 21, wherein the step of determining at least two parameters comprises determining temperature of blood within an interior portion of the body of a patient.

28. The method of claim 21, wherein the step of determining at least two parameters comprises determining pH of blood within a patient.

29. The method of claim 21, wherein the step of determining at least two parameters comprises determining pressure at a site of the circulatory system of a patient.

30. The method of claim 29, wherein the step of determining pressure comprises determining right ventricular pulse pressure.

31. The method of claim 29, wherein the step of determining pressure comprises determining right ventricular systolic pressure.

32. The method of claim 29, wherein the step of determining pressure comprises determining right atrial pressure.

33. The method of claim 29, wherein the step of determining pressure comprises determining rapid change in arterial pressure.

34. The method of claim 21, wherein the step of determining at least two parameters comprise determining mixed venous blood O₂ saturation and determining temperature of the patient.

35. The method of claim 34, wherein the step of determining temperature comprises determining temperature of an interior body portion of the patient.

36. The method of claim 34, wherein the step of determining temperature comprises determining blood temperature of the patient.

37. The method of claim 21, including providing a baseline for at least one of the parameters, determining magnitude of the at least one parameter on a short term basis and determining the difference between the baseline and short term magnitude of the parameter as the function of the at least one parameter prior to weighing.

38. A method for treating a malfunctioning heart comprising, determining at least two parameters reflective of condition of a patient, providing a varying long term baseline of the at least one parameter based on variation of the parameter over a long term, determining magnitude of the at least one parameter on a short term basis and determining the difference between the varying baseline and the magnitude of the parameter as the function of the at least one parameter prior to weighing, weighing the respective determined parameters, algebraically summing the weighted parameters and treating a patient with respective treatment modalities in accordance with the magnitude of the algebraic sum.

39. A method of treating a malfunctioning heart comprising, determining at least two parameters reflective of condition of a patient, providing a baseline for at least one of the parameters, determining magnitude of the at least one parameter on a short term basis and determining the ratio of the baseline to the short term magnitude of the parameter as the function of the at least one parameter, weighing the determined ratio and respective ones of the determined other parameter or parameters, algebraically summing the weighted ratio and the other weighted parameter or parameters and treating a patient with respective treatment modalities in accordance of the magnitude of the algebraic sum.

40. A method for treating a malfunctioning heart comprising, determining at least two parameters reflective of condition of a patient, providing a varying long term baseline of the at least one parameter based on variation of the parameter over a long term, determining magnitude of the at least one parameter on a short term basis and determining the ratio of the varying baseline to the magnitude of the parameter as the function of the at least one parameter prior to weighing, weighing the respective determined parameters, algebraically summing the weighted parameters and treating a patient with respective treatment modalities in accordance with the magnitude of the algebraic sum.

41. A system for treating a malfunctioning heart comprising means for supplying a plurality of treatment modalities to a patient including cardioversion/defibrillation;

means for sensing activity level of a patient;

means for sensing heart rate of the patient;

means, responsive to outputs from said means for sensing activity level and said means for sensing heart rate, for developing respective controlling outputs reflective of condition of the patient for selectively enabling said means for supplying a plurality of treatment modalities to said patient to effect selection of respective ones of treatment modalities as called for by the controlling outputs.