System and Method for Detection of Pulmonary Embolism

• US 20090281396A1
• Filed: 03/30/2009
• Published: 11/12/2009
• Est. Priority Date: 05/07/2008
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Liao, Wangcai, Zhang, Yunlong, Mi, Bin, Stahmann, Jeffrey
• Granted Patent: US 8,147,415 B2
• Time in Patent Office: Days
• US Class Current: 600/301
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/02108 from analysis of pulse wave characteristics
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/08 Detecting, measuring or recording devices for evaluating the respiratory organs A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/6846 specially adapted to be brought in contact with an internal body part, i.e. invasive
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor

Abstract

Systems and methods provide for ambulatorily sensing pulmonary artery pressure from within a patient, and producing a pulmonary artery pressure measurement from the sensed pulmonary artery pressure. Power is ambulatorily provided within the patient to facilitate sensing of the pulmonary artery pressure and producing of the pulmonary artery pressure measurement. Acute pulmonary embolism is detected based on a change or rate of change in the pulmonary artery pressure measurement. An alert is preferably generated in response to detecting pulmonary embolism.

Claims

1. A method, comprising:

ambulatorily sensing pulmonary artery pressure from within a patient;

producing a pulmonary artery pressure measurement from the sensed pulmonary artery pressure;

ambulatorily providing power within the patient to facilitate the sensing of the pulmonary artery pressure and the producing of the pulmonary artery pressure measurement; and

detecting acute pulmonary embolism based on a change in the pulmonary artery pressure measurement.

2. The method of claim 1, comprising sensing a cardiac electrical signal, wherein timing of the pulmonary artery pressure measurement is based at least in part on the sensed cardiac electrical signal.

3. The method of claim 1, comprising producing a pulmonary artery pressure waveform indicative of the sensed pulmonary artery pressure, wherein the pulmonary artery pressure measurement is derived from the pulmonary artery pressure waveform.

4. The method of claim 3, wherein detecting acute pulmonary embolism comprises detecting acute pulmonary embolism based on a change in a feature of the pulmonary artery pressure waveform relative to a threshold, the feature comprising a morphological feature of the pressure waveform and the threshold comprising a baseline of the morphological feature established for the patient.

5. The method of claim 1, wherein detecting acute pulmonary embolism comprises detecting acute pulmonary embolism based on the change in the pulmonary artery pressure measurement relative to a threshold, the threshold comprising a baseline pulmonary artery pressure value determined for the patient using at least one of patient specific data and patient population data indicative of acute pulmonary embolism.

6. The method of claim 1, wherein detecting acute pulmonary embolism comprises detecting acute pulmonary embolism from within the patient.

7. The method of claim 1, wherein detecting acute pulmonary embolism comprises detecting acute pulmonary embolism externally from the patient.

8. The method of claim 1, comprising wirelessly communicating the pulmonary artery pressure measurement from a location at which the pulmonary artery pressure is measured to a second location within the patient, wherein detecting acute pulmonary embolism comprises detecting acute pulmonary embolism at the second location.

9. The method of claim 1, comprising wirelessly communicating the pulmonary artery pressure measurement from a location at which the pulmonary artery pressure is measured to a second location externally of the patient, wherein detecting acute pulmonary embolism comprises detecting acute pulmonary embolism at the second location.

10. The method of claim 1, comprising facilitating wired communication of the pulmonary artery pressure measurement from a location at which the pulmonary artery pressure is measured to a second location within the patient, wherein detecting acute pulmonary embolism comprises detecting acute pulmonary embolism at the second location.

11. The method of claim 1, comprising:

sensing a cardiac electrical signal; and

discriminating between acute pulmonary embolism and myocardial infarction based on a change of the pulmonary artery pressure measurement relative to a change in a feature of the sensed cardiac electrical signal.

12. The method of claim 11, wherein the feature of the sensed cardiac electrical signal comprises an ST segment of the sensed cardiac electrical signal, and discriminating between acute pulmonary embolism and myocardial infarction comprises:

detecting myocardial infarction as a change in a feature of the ST segment; and

detecting acute pulmonary embolism as a change in the pulmonary artery pressure measurement in the absence of an appreciable change in the ST segment feature or other myocardial infarction-associated feature of the sensed cardiac electrical signal.

13. The method of claim 1, comprising discriminating between acute pulmonary embolism and primary pulmonary hypertension based on a rate of change of the pulmonary artery pressure measurement.

14. The method of claim 1, comprising:

sensing a parameter indicative of heart failure from within the patient; and

discriminating between acute pulmonary embolism and heart failure induced pulmonary hypertension based on a rate of change of the pulmonary artery pressure measurement and a change in the sensed parameter.

15. The method of claim 1, comprising discriminating between chronic pulmonary embolism and primary pulmonary hypertension based on one or more of a fractional pulse pulmonary artery pressure derived from a waveform indicative of the sensed pulmonary artery pressure, a coefficient of variation of the pulmonary artery pressure derived from the pulmonary artery pressure waveform, and a fractional time to half the area under the pulmonary artery pressure waveform.

16. The method of claim 1, comprising sensing cardiac electrical signals and verifying detection of acute pulmonary embolism using the sensed cardiac electrical signals.

17. The method of claim 1, comprising generating an alert in response to detection of acute pulmonary embolism, and communicating the alert outside of the patient'"'"'s body.

18. A system, comprising:

an implantable pressure sensor configured to ambulatorily sense pulmonary artery pressure from within a patient, the pressure sensor comprising;

a support structure comprising a stabilizing arrangement configured to stabilize the pressure sensor within a pulmonary artery of the patient;

a pressure transducer;

a communications device coupled to the pressure transducer, the communications device configured to effect wireless transmission of a pulmonary artery pressure waveform out of the patient'"'"'s heart, the pressure transducer and the communications device supported by the support structure; and

a battery configured to supply power for the pressure transducer and the communications device; and

a processor communicatively coupled to the communications device of the pressure sensor, the processor executing programmed instructions for detecting acute pulmonary embolism based on a change in a pulmonary artery pressure measurement derived from the pulmonary artery pressure waveform.

19. The system of claim 18, wherein the processor is disposed in a body implantable housing, the body implantable housing comprising a communications device configured to effect wireless communications between the processor and the communications device of the pressure sensor.

20. The system of claim 18, wherein the processor is disposed in a body implantable housing and coupled to the communications device of the pressure sensor via a lead.

21. The system of claim 18, wherein the processor is disposed in a body implantable housing, the system comprising a patient-external system comprising a communications device configured to effect wireless communications with the processor.

22. The system of claim 18, wherein the processor is disposed in a patient-external system, the patient-external system comprising a communications device configured to effect wireless communications with the communications device of the pressure sensor.

23. The system of claim 18, comprising a portable patient-external system disposed in a housing configured for hand-held manipulation and a patient-external server system, the housing of the portable patient-external system comprising communications circuitry configured to effect wireless communications with the communications device of the pressure sensor and communications with the patient-external server system, the processor disposed in at least one of the housing of the portable patient-external system and the patient-external server system.

24. The system of claim 18, wherein the implantable pressure sensor comprises a charging circuit responsive to an acoustic or inductive signal, the charging circuit generating energy for powering the pressure sensor in response to the acoustic or inductive signal.

25. The system of claim 18, wherein the support structure of the pressure sensor comprises a stent graft configured to radially contract during implantation in the pulmonary artery and expand to stabilize the pressure sensor at an implant site within the pulmonary artery.

26. The system of claim 18, wherein the communications device coupled to the pressure sensor comprises an acoustic communications device.

27. The system of claim 18, wherein the communications device coupled to the pressure sensor comprises at least one of an inductive, optical, or RF communications device.

28. The system of claim 18, comprising a sensor configured to sense a cardiac electrical signal, wherein the processor executes programmed instructions for discriminating between acute pulmonary embolism and myocardial infarction based on a change of the pulmonary artery pressure waveform relative to a change in a feature of the sensed cardiac electrical signal.

29. The system of claim 28, wherein the feature of the sensed cardiac electrical signal comprises a feature of an ST segment of the sensed cardiac electrical signal, wherein the processor executes programmed instructions for detecting myocardial infarction as a change in the ST segment feature and for detecting acute pulmonary embolism as a change in the pulmonary artery pressure measurement in the absence of an appreciable change in the ST segment feature or other myocardial infarction-associated feature of the sensed cardiac electrical signal.

30. The system of claim 18, wherein the processor executes programmed instructions for discriminating between acute pulmonary embolism and primary pulmonary hypertension based on a rate of change of the pulmonary artery pressure measurement.

31. The system of claim 18, comprising a sensor configured to sense a parameter indicative of heart failure from within the patient, wherein the processor executes programmed instructions for discriminating between acute pulmonary embolism and heart failure induced pulmonary hypertension based on a rate of change of the pulmonary artery pressure measurement and a change in the sensed parameter.

32. The system of claim 18, wherein the processor executes programmed instructions for discriminating between chronic pulmonary embolism and primary pulmonary hypertension based on one or more of a fractional pulse pulmonary artery pressure derived from the pulmonary artery pressure waveform, a coefficient of variation of the pulmonary artery pressure derived from the pulmonary artery pressure waveform, and a fractional time to half the area under the pulmonary artery pressure waveform.

33. The system of claim 18, comprising a sensor configured to sense a cardiac electrical signal, wherein the processor executes programmed instructions for verifying detection of acute pulmonary embolism using the sensed cardiac electrical signals.