MASS ATTRIBUTE DETECTION THROUGH PHRENIC STIMULATION

• US 20100125306A1
• Filed: 11/11/2009
• Published: 05/20/2010
• Est. Priority Date: 11/14/2008
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: McCabe, Aaron R., Rockweiler, Holly, Laughner, Jacob I.
• Granted Patent: US 8,781,578 B2
• Time in Patent Office: Days
• US Class Current: 607/9
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/1104 induced by stimuli or drugs; A61B5/1102 takes precedence; investigating medicinal preparations G01N33/15
• CPC Class Codes: A61B 5/1107 Measuring contraction of parts of the body, e.g. organ, muscle apparatus for measuring work or force in general G01L
• CPC Class Codes: A61B 5/4878 Evaluating oedema
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61N 1/3601 of respiratory organs
• CPC Class Codes: A61N 1/3611 Respiration control stimulating respiratory organs A61N1/3601
• CPC Class Codes: A61N 1/36542 controlled by body motion, e.g. acceleration
• CPC Class Codes: A61N 1/36578 controlled by mechanical motion of the heart wall, e.g. measured by an accelerometer or microphone
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371

Abstract

According to certain examples, an implanted medical device is used to determine a mass attribute of a patient. The patient'"'"'s phrenic nerve is stimulated, and the diaphragmatic response is measured by an accelerometer. The measured response is analyzed in certain embodiments to determine a mass attribute. This information can help in the diagnosis of, and efficient response to, edema.

Claims

1. A system comprising:

an accelerometer configured to sense an acceleration signal indicative of a response to a stimulation of a phrenic nerve of a patient;

a processing circuit in communication with the accelerometer, the processing circuit configured to;

receive information from the acceleration signal;

determine a mass attribute of the patient based on the received information from the acceleration signal; and

provide an indication of the mass attribute to a user or process.

2. The system of claim 1, wherein the accelerometer comprises a multi-axis accelerometer, and wherein the processing circuit is configured to use information about a directional component of the acceleration signal sensed by the multi-axis accelerometer to determine the mass attribute of the patient.

3. The system of claim 1, wherein the processing circuit is configured to determine a thoracic mass of the patient.

4. The system of claim 1, wherein the processing circuit is configured to determine a systemic mass of the patient.

5. The system of claim 1, wherein the processing circuit is configured to determine the mass attribute that comprises an estimated composition, wherein the estimated composition comprises at least one of:

a body mass index, a fluid component level, a fatty tissue component level, or a lean tissue component level.

6. The system of claim 1, comprising a telemetry circuit operatively connected to the processing circuit, the telemetry circuit configured to wirelessly communicate information based on the mass attribute.

7. The system of claim 6, further comprising an external computing interface comprising a display, wherein the external interface is configured to receive the information based on the mass attribute from the telemetry circuit and to display an indication based on the mass attribute on the display.

8. The system of claim 1, further comprising an implantable phrenic nerve stimulation circuit configured to provide the stimulation to the phrenic nerve of the patient.

9. The system of claim 8, wherein the implantable phrenic nerve stimulation circuit is configured to be implanted in or on a heart of the patient.

10. A method performed by a medical device comprising:

receiving a signal indicative of a response in a patient to a stimulation of a phrenic nerve; and

determining a mass attribute of the patient based at least in part on the received signal.

11. The method of claim 10, wherein determining the mass attribute comprises determining an approximate composition, wherein the approximate composition comprises at least one of:

a body mass index, a fluid component level, a fatty tissue component level, or a lean tissue component level.

12. The method of claim 10, wherein determining the mass attribute comprises measuring a peak-to-peak amplitude of the acceleration signal.

13. The method of claim 10, wherein determining the mass attribute comprises determining a frequency response of the acceleration signal.

14. The method of claim 10, wherein sensing the acceleration signal comprises using a multi-axis accelerometer, and wherein determining the mass attribute comprises using a directional component of the sensed acceleration signal indicative of the response to the stimulation of the phrenic nerve.

15. The method of claim 10, comprising:

determining whether the mass attribute meets a specified criterion; and

generating an alert signal when the mass attribute meets the specified criterion.

16. The method of claim 10, comprising providing the stimulation of the phrenic nerve.

17. The method of claim 16, wherein providing the stimulation of the phrenic nerve comprises using an electrode implanted in or on a heart of the patient.

18. The method of claim 17, further comprising selecting a pacing vector, a pulse width, and a pulse amplitude sufficient to stimulate the phrenic nerve.

19. The method of claim 16, wherein providing the stimulation of the phrenic nerve comprises timing the stimulation of the phrenic nerve to be provided at a specified portion of at least one of a cardiac cycle or a respiratory cycle.

20. The method of claim 10, comprising comparing the mass attribute to a systemic mass value.

21. The method of claim 10, wherein determining the mass attribute comprises determining a systemic mass of the patient.

22. A system comprising:

means for receiving a signal indicative of a response in a patient to a stimulation of a phrenic nerve; and

means for determining a mass attribute of the patient based at least in part on the received signal.