Systems and methods for deriving relative physiologic measurements

• US 20060064134A1
• Filed: 09/17/2004
• Published: 03/23/2006
• Est. Priority Date: 09/17/2004
• Status: Abandoned Application

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Von Arx, Jeffrey A., Mazar, Scott T., Chavan, Abhi
• Application Number:
  US10/943,626
• Publication Number:
  US 20060064134A1
• Time in Patent Office: Days
• US Class Current: 607/17
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 2560/045 with a separable interface unit, e.g. for communication
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61N 1/36564 controlled by blood pressure

Abstract

One embodiment of the present invention relates to a system for deriving physiologic measurement values that are relative to ambient conditions. In one embodiment, the system comprises an implantable medical device (“IMD”) and an external monitor. The IMD is adapted to determine an absolute physiologic parameter value within a patient'"'"'s body, and communicate the absolute physiologic parameter value outside the patient'"'"'s body, for example, to the external monitor. Further, the external monitor is adapted to receive the absolute physiologic parameter from the IMD and obtain an ambient condition value outside the body that can affect the absolute physiologic parameter value. The external monitor then calculates a relative physiologic parameter value from the ambient condition value and the absolute physiologic parameter value.

Claims

1. A system for deriving relative physiologic measurement values, comprising:

an implantable medical device (“

IMD”

) operable to determine an absolute physiologic parameter value within a patient'"'"'s body, and communicate the absolute physiologic parameter value outside the patient'"'"'s body; and

an external monitor operable to;

receive the absolute physiologic parameter from the IMD;

obtain an ambient condition value outside the body that can affect the absolute physiologic parameter value; and

calculate a relative physiologic parameter value from the ambient condition value and the absolute physiologic parameter value;

wherein the external monitor is further operable to communicate the relative physiologic parameter value to the IMD, and wherein the IMD is further operable to receive the relative physiologic parameter value and store it in a memory.

2. The system as recited in claim 1, wherein the absolute physiologic parameter value is marked with a time stamp, and wherein the external monitor selects an ambient condition value that is obtained at a time reasonably close to the time stamp time to calculate the relative physiologic parameter value.

3. The system as recited in claim 1, wherein the IMD is further operable to communicate the relative physiologic parameter value to an external computing device.

4. The system as recited in claim 1, wherein the external monitor is further operable to store the relative physiologic parameter value in a memory.

5. The system as recited in claim 1, wherein the absolute physiologic parameter value comprises a blood pressure value, wherein the ambient condition value comprises an ambient pressure value, and wherein the relative physiologic parameter value comprises the blood pressure value relative to the ambient pressure value.

6. The system as recited in claim 5, wherein the relative physiologic parameter value is calculated by subtracting the ambient pressure value from the blood pressure value.

7. The system as recited in claim 5, wherein the blood pressure value is determined by:

measuring the blood pressure value with a pressure sensor; and

adjusting the measured blood pressure value with a sensor specific adjustment factor to obtain an absolute blood pressure value.

8. The system as recited in claim 5, wherein the blood pressure can be intravascular or intracardiac blood pressure.

9. The system as recited in claim 1, wherein the external monitor is operable to measure the ambient condition value.

10. The system as recited in claim 1, wherein the external monitor is operable to receive the ambient condition value from an ambient condition source.

11. The system as recited in claim 1, wherein the external monitor comprises a wireless communication device carried on or near the patient'"'"'s body.

12. The system as recited in claim 11, wherein the external monitor is a monitor device selected from the group consisting of:

a monitor device adapted to be worn around a patient'"'"'s body part;

a monitor device that can be connected to a belt;

a monitor device that can be worn as a patch;

a personal digital assistant (PDA);

a monitor device that can be carried in a pocket or a personal carry bag; and

a customized cell phone or pager.

13. The system as recited in claim 1, wherein the external monitor comprises an external computing device selected from the group consisting of a personal computer, an IMD programmer, an IMD repeater device located in a patients residence, and a backend computing system.

14. The system as recited in claim 1, wherein the IMD and the external monitor are operable to communicate via a wireless communication connection selected from the group consisting of:

a radio frequency communication connection;

an acoustic communication connection;

an electric field communication connection; and

an optical communication connection.

15. The system as recited in claim 1, wherein the IMD is selected from the group consisting of a physiologic parameter sensor, a pacemaker, a defibrillator, a bi-ventricular pacer, a ventricular assist blood pump, a drug delivery pump, a drug infusion device, a neurostimulating device, an intra-ocular shunt, and an intra-cranial shunt.

16. The system as recited in claim 1, wherein the IMD is operable to provide therapy to a patient, and wherein the IMD uses the relative physiologic parameter value to determine the proper therapy to provide to the patient.

17. The system as recited in claim 16, wherein the therapy is selected from the group consisting of cardiac pacing therapy, anti-tachycardia therapy, drug delivery therapy, neurostimulation therapy, and blood pump therapy.

18. The system as recited in claim 1, wherein:

the IMD comprises a processor operable to generate patient therapy information based at least in part on the relative physiologic parameter value;

the IMD is further operable to communicate the patient therapy information to the external monitor; and

the external monitor comprises a patient communication interface operable to provide the patient therapy information to the patient.

19. A method for deriving relative physiologic measurement values, comprising:

an implantable medical device (“

IMD”

) determining an absolute physiologic parameter value within a patient'"'"'s body;

communicating the absolute physiologic parameter value to an external monitor outside the patient'"'"'s body;

the external monitor obtaining an ambient condition value outside the body that can affect the absolute physiologic parameter value;

calculating a relative physiologic parameter value from the ambient condition value and the absolute physiologic parameter value;

communicating the relative physiologic parameter value from the external monitor to the IMD, and

storing the relative physiologic parameter value in a memory in the IMD.

20. The method as recited in claim 19, further comprising the steps of:

the IMD marking the absolute physiologic parameter value with a time stamp; and

the external monitor selecting an ambient condition value that is obtained at a time reasonably close to the time stamp time to calculate the relative physiologic parameter value.

21. The method as recited in claim 19, further comprising the step of-communicating the relative physiologic parameter value from the IMD to an external computing device.

22. The method as recited in claim 19, further comprising the step of the external monitor storing the relative physiologic parameter value in a memory.

23. The method as recited in claim 19, wherein the absolute physiologic parameter value comprises a blood pressure value, wherein the ambient condition value comprises an ambient pressure value, and wherein the relative physiologic parameter value comprises the blood pressure value relative to the ambient pressure.

24. The method as recited in claim 23, wherein the step of calculating a relative physiologic parameter value comprises subtracting the ambient pressure value from the blood pressure value.

25. The method as recited in claim 23, wherein the step of determining the blood pressure value, comprises:

measuring the blood pressure value with a pressure sensor; and

adjusting the blood pressure value with a sensor specific adjustment factor to obtain an absolute blood pressure value.

26. The method as recited in claim 23, wherein the blood pressure can be intravascular or intracardiac blood pressure.

27. The method as recited in claim 19, wherein the step of the external monitor obtaining an ambient condition value comprises the external monitor measuring the ambient condition value.

28. The method as recited in claim 19, wherein the step of the external monitor obtaining an ambient condition value comprises the external monitor receiving the ambient condition value from an ambient condition source.

29. The method as recited in claim 19, wherein the external monitor comprises a wireless communication device carried on or near the patient'"'"'s body.

30. The method as recited in claim 29, wherein the external monitor is a monitor device selected from the group consisting of:

a monitor device adapted to be worn around a patient'"'"'s body part;

a monitor device that can be connected to a belt;

a monitor device that can be worn as a patch;

a personal digital assistant (PDA);

a monitor device that can be carried in a pocket or a personal carry bag; and

a customized cell phone or pager.

31. The method as recited in claim 19, wherein the external monitor comprises an external computing device selected from the group consisting of a personal computer, an IMD programmer, an IMD repeater device located in a patients residence, and a backend computing system.

32. The method as recited in claim 19, wherein the steps of communicating the measured absolute physiologic parameter value to an external monitor and communicating the relative physiologic parameter value from the external monitor to the IMD comprise communicating via a wireless communication connection selected from the group consisting of:

a radio frequency communication connection;

an acoustic communication connection;

an electric field communication connection; and

an optical communication connection.

33. The method as recited in claim 19, wherein the IMD is selected from the group consisting of a physiologic parameter sensor, a pacemaker, a defibrillator, a bi-ventricular pacer, a ventricular assist blood pump, a drug delivery pump, a drug infusion device, a neurostimulating device, an intra-ocular shunt, and an intra-cranial shunt.

34. The method as recited in claim 19, further comprising:

the IMD determining a proper therapy to provide to the patient using the relative physiologic parameter value; and

the IMD providing the proper therapy to the patient.

35. The method as recited in claim 34, wherein the therapy is selected from the group consisting of cardiac pacing therapy, anti-tachycardia therapy, drug delivery therapy, neurostimulation therapy, and blood pump therapy.

36. The method as recited in claim 19, further comprising:

the IMD generating patient therapy information based at least in part on the relative physiologic parameter value;

communicating the patient therapy information from the IMD to the external monitor; and

the external monitor providing the patient therapy information to the patient via a communication interface.

37. A system for deriving relative blood pressure values, comprising:

an implantable medical device (“

IMD”

) operable to determine blood pressure within a patient'"'"'s body, and communicate the blood pressure outside the patient'"'"'s body; and

an external monitor operable to;

receive the blood pressure from the IMD;

obtain an ambient pressure value outside the body; and

calculate a relative blood pressure value from the ambient pressure value and the blood pressure;

wherein the external monitor is further operable to communicate the relative blood pressure value to the IMD, and wherein the IMD is further operable to receive the relative blood pressure and store it in a memory.

38. The system as recited in claim 37, wherein the blood pressure can be intravascular or intracardiac blood pressure.

39. The system as recited in claim 37, wherein the absolute physiologic parameter value is marked with a time stamp, and wherein the external monitor selects an ambient condition value that is obtained at a time reasonably close to the time stamp time to calculate the relative physiologic parameter value.

40. The system as recited in claim 37, wherein the IMD is operable to provide therapy to a patient, and wherein the IMD uses the relative blood pressure value to determine the proper therapy to provide to the patient.

41. The system as recited in claim 37, wherein:

the IMD comprises a processor operable to generate patient therapy information based at least in part on the relative blood pressure value; and

the IMD is further operable to communicate the patient therapy information to an external communication device operable to provide the therapy information to the patient or a health care provider.