IMPLANTABLE MEDICAL SYSTEM INCLUDING MULTIPLE SENSING MODULES

• US 20100030043A1
• Filed: 07/30/2008
• Published: 02/04/2010
• Est. Priority Date: 07/30/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Kuhn, Jonathan L.
• Granted Patent: US 10,080,499 B2
• Time in Patent Office: Days
• US Class Current: 600/339
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/0086 using infrared radiation
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61N 1/36542 controlled by body motion, e.g. acceleration
• CPC Class Codes: A61N 1/3655 controlled by body or blood temperature
• CPC Class Codes: A61N 1/36557 controlled by chemical substances in blood
• CPC Class Codes: A61N 1/36564 controlled by blood pressure
• CPC Class Codes: A61N 1/36578 controlled by mechanical motion of the heart wall, e.g. measured by an accelerometer or microphone

Abstract

A medical system includes at least two sensing modules that each generate an optical signal that changes as a function of a physiological parameter of a patient. The sensing modules may be coupled to a common light source and a common receiver via an optically transmissive member. At least a first sensing module that is closest to the light source along a length of the optically transmissive member may include a waveguide to split the light emitted by the light source. A first portion of the light may be directed toward the first sensing module and a second portion of the light may be directed toward a second sensing module that is placed downstream of the first sensing module in a direction substantially along the direction of light flow through the optically transmissive member and away from the light source.

Claims

1. An implantable medical system comprising:

a light source that emits light;

an implantable optically transmissive member optically coupled to the light source;

a light dividing member that divides the light from the light source into at least a first portion and a second portion;

a first sensing module optically coupled to the optically transmissive member, wherein the first sensing module receives the first portion of light and generates a first optical signal; and

a second sensing module optically coupled to the optically transmissive member, wherein the second sensing module generates a second optical signal, and wherein the optically transmissive member guides the second portion of the light toward the second sensing module.

2. The implantable medical system of claim 1, wherein the light dividing member comprises a first light dividing member that divides the light from the light source into at least the first portion and the second portion, the system further comprising a second light dividing member that divides the second portion of the light into at least a third portion and at least a fourth portion, wherein the second sensing module receives the third portion of the light.

3. The implantable medical system of claim 2, further comprising a third sensing module optically coupled to the optically transmissive member, wherein the optically transmissive member guides the fourth portion of the light toward the third sensing module.

4. The implantable medical system of claim 1, further comprising a receiver that receives the first optical signal and the second optical signal and generates electrical signals based on the first and second optical signals, and a processor that determines a physiological parameter value of a patient based on at least one of the first or second optical signals

5. The implantable medical system of claim 1, further comprising a light deflection member that directs the first portion of the light from the optically transmissive member to the first sensing module.

6. The implantable medical system of claim 1, wherein the first sensing module comprises a first light filter that filters a first wavelength of light from the first portion of the light, wherein the first optical signal comprises the first wavelength of light, and wherein the second sensing module comprises a second light filter that filters a second wavelength of light from the second portion of the light, wherein the second optical signal comprises the second wavelength of light.

7. The implantable medical system of claim 6, wherein the first and second wavelengths of light are substantially similar.

8. The implantable medical system of claim 6, wherein the first and second wavelengths of light are different.

9. The implantable medical system of claim 6, wherein at least one of the first or second light filters comprises a diffuse reflective surface.

10. The implantable medical system of claim 6, wherein at least one of the first or second light filters comprises an optical material disposed within the first or second sensing modules.

11. The implantable medical system of claim 1, further comprising a receiver that receives a third optical signal and extracts the first and second optical signals from the third optical signal.

12. The implantable medical system of claim 11, wherein the first and second optical signals comprise different wavelengths of light, wherein the receiver extracts the first and second optical signals from the third optical signal based on known wavelengths of light of the first and second optical signals.

13. The implantable medical system of claim 1, wherein the first portion of the light is greater than or equal to the second portion of the light.

14. The implantable medical system of claim 1, wherein the first portion of the light is less than or equal to the second portion of the light.

15. The implantable medical system of claim 1, wherein the light dividing member comprises a waveguide.

16. The implantable medical system of claim 15, wherein the waveguide defines an optical path through which the light emitted by the light source propagates and a reflective surface partially occluding the optical path, wherein the reflective surface directs the first portion of the light to the first sensing module.

17. The implantable medical system of claim 16, wherein the reflective surface comprises a gold or aluminum surface.

18. The implantable medical system of claim 1, wherein the light dividing member comprises a beam splitter.

19. The implantable medical system of claim 1, wherein the light dividing member comprises at least one of a reflective surface or a prism.

20. The implantable medical system of claim 1, wherein at least one of the first or second sensing modules comprises a sensing element that modulates at least one of an amplitude, wavelength, phase, frequency or velocity of the light to generate at least one of the first or second optical signals.

21. The implantable medical system of claim 20, wherein the sensing element comprises at least one of a deflectable member or a resonating beam.

22. The implantable medical system of claim 1, wherein at least one of the first or second sensing modules comprises an optical resonance sensor that modulates a frequency of the first portion or the second portion of the light, respectively.

23. The implantable medical system of claim 1, wherein the light dividing member comprises a waveguide that directs the first portion of the light toward tissue of a patient and receives light that is emitted by the light source and reflected by blood of the patient, the received light comprising the first optical signal, wherein the first optical signal is indicative of a blood oxygen saturation level of the patient.

24. The implantable medical system of claim 1, wherein the first and second sensing modules are distributed along a length of the optically transmissive member.

25. The implantable medical system of claim 1, wherein the optically transmissive member comprises a first segment and a second segment, wherein the first sensing module is optically coupled to the first and second segments and the second sensing module is optically coupled to the second segment.

26. An implantable medical system comprising:

a light source that emits light;

a receiver;

an optically transmissive member optically coupled to the light source and comprising a first segment and a second segment;

a first sensing module optically coupled to the first and second segments of the optically transmissive member, wherein the light emitted by the light source propagates through the first segment to the first sensing module, and wherein the first sensing module generates a first optical signal based on the light emitted by the light source; and

a second sensing module optically coupled to the second segment of the optically transmissive member, wherein light emitted by the light source propagates through the first and second segments to the second sensing module, and wherein the second sensing module generates a second optical signal based on the light emitted by the light source,

wherein the receiver receives the first and second optical signals via the optically transmissive member.

27. The implantable medical device of claim 26, further comprising a processor that determines a physiological parameter characteristic of a patient based on at least one of the first or second optical signals.

28. The implantable medical device of claim 27, wherein the physiological parameter characteristic comprises at least one of a pressure, a blood oxygen saturation level, temperature, patient movement, acoustic vibrations, or cardiac activity.

29. The implantable medical system of claim 27, wherein the first sensing module comprises a first optical member and the second sensing module comprises a second optical member, wherein the first and second optical signals have respective wavelengths corresponding to the index of refraction of the first and second optical members, respectively.

30. The implantable medical system of claim 26, wherein the receiver receives a third optical signal via the optically transmissive member and extracts the first and second optical signals from the third optical signal.

31. The implantable medical system of claim 30, wherein the first and second optical signals comprise different wavelengths of light, wherein the receiver extracts the first and second optical signals from the third optical signal based on known wavelengths of light of the first and second optical signals.

32. The implantable medical system of claim 26, further comprising:

a first light deflection member that directs at least a first percentage of the light from the light source to the first sensing module; and

a second light deflection member that directs at least a second percentage of the light to the second sensing module.

33. The implantable medical system of claim 26, further comprising a light dividing member that divides the light from the light source into at least a first portion and a second portion, wherein the first sensing module receives the first portion of the light and the optically transmissive member guides the second portion of the light toward the second sensing module.

34. A method comprising:

controlling a light source within a medical device housing to emit light;

transmitting the light through an optically transmissive member to first and second sensing modules optically coupled to the optically transmissive member, the first sensing module comprising a light dividing member that divides the light into at least a first portion and a second portion, wherein the first sensing module receives the first portion of the light and the optically transmissive member guides the second portion of the light toward the second sensing module;

receiving a first optical signal generated by the first sensing module based on the first portion of the light;

receiving a second optical signal generated by the second sensing module based on the second portion of the light; and

determining a physiological parameter value of a patient based on at least one of the first or second optical signals.

35. The method of claim 34, further comprising receiving a third optical signal via the optically transmissive member and extracting the first and optical signals from the third optical signal.

36. The method of claim 35, wherein the first and second optical signals comprise different wavelengths of light, wherein extracting the first and optical signals from the third optical signal comprises extracting the first and second optical signals from the third optical signal based on known wavelengths of light of the first and second optical signals.