Implantable optical sensor and method for use

• US 8,290,557 B2
• Filed: 12/12/2007
• Issued: 10/16/2012
• Est. Priority Date: 12/12/2007
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Davis, Timothy J., Roberts, Jonathan P., Reinke, James D., Kuhn, Jonathan L., Knowles, Shawn D.
• Primary Examiner(s): Winakur, Eric
• Assistant Examiner(s): Liu, Chu Chuan (JJ)
• Application Number:
  US11/955,025
• Publication Number:
  US 20090156918A1
• Time in Patent Office: 1,770 Days
• Field of Search: 600/310, 600322-327, 600331-333, 600341-342, 600/500, 600/502, 607/6, 607/17
• US Class Current: 600/310
• CPC Class Codes: A61B 2562/0233 Special features of optical sensors or probes classified in A61B5/00
• CPC Class Codes: A61B 2562/043 in a linear array
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/0086 using infrared radiation
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/6846 specially adapted to be brought in contact with an internal body part, i.e. invasive

Abstract

An implantable medical device includes a hermetically sealed housing and a first light emitting diode (LED) enclosed within the housing configured to detect light corresponding to a selected light wavelength. A conductive element extends from the LED for carrying a current signal corresponding to the light detected by the LED, the intensity of the detected light being correlated to a change in a physiological condition in a body fluid volume or a tissue volume proximate the LED.

Claims

1. An implantable medical device, comprising:

a hermetically sealed housing;

a first light emitting diode (LED) enclosed within the housing and configured to detect ambient light penetrating through body tissue of a patient corresponding to a first selected light wavelength;

a sensor module; and

a conductive element for carrying a current signal from the first LED to the sensor module, the current signal corresponding to an intensity of the detected ambient light, wherein the sensor module estimates, based on the intensity of the ambient light detected by the first LED, a change in a physiological condition in one of a body fluid volume and a tissue volume proximate the first LED, and wherein the intensity of the ambient light detected by the first LED is correlated to the change in the physiological condition.

2. The device of claim 1 further comprising an elongated body having a proximal end, the housing being positioned along the elongated body and the sensor module being coupled to the proximal end, wherein the conductive element comprises an insulated conductor extending between the proximal end and the housing for carrying a current signal responsive to the light detection from the first light emitting diode to the proximal end.

3. The device of claim 1 further comprising a second LED for detecting light having a second selected light wavelength.

4. The device of claim 3 wherein the light detected by the second LED is correlated to the change in the physiological condition.

5. The device of claim 1 further comprising a second LED for emitting light having a wavelength corresponding to the first selected light wavelength.

6. The device of claim 1 further comprising a wideband light emitting device for emitting light detected by the first LED.

7. The device of claim 1 wherein the first selected wavelength corresponds to red light and further comprising a second light emitting diode for detecting a second selected light wavelength corresponding to infrared light.

8. The device of claim 3 wherein the light detected by the first LED is normalized by the light detected by the second LED.

9. A method for sensing color for use in an implantable medical device, comprising:

detecting ambient light penetrating through body tissue of a patient scattered by one of a body fluid volume and tissue volume using a first light emitting diode (LED) responsive to a first selected light wavelength; and

estimating a change in a physiological condition in the one of the body fluid volume and the tissue volume in response to the ambient light,

wherein an intensity of the ambient light having the first selected light wavelength is correlated to the change in the physiological condition.

10. The method of claim 9 further comprising detecting light using a second LED responsive to a second selected light wavelength.

11. The method of claim 10 wherein an intensity of the light detected by the second LED is correlated to the change in the physiological condition.

12. The method of claim 9 further comprising emitting light having a wavelength corresponding to the first selected light wavelength using a second LED.

13. The method of claim 9 further comprising emitting light having a wideband of wavelengths.

14. The method of claim 9 wherein the first selected wavelength corresponds to red light, and further comprising detecting a second selected light wavelength corresponding to infrared light using a second light emitting diode.

15. The method of claim 10 wherein the light detected by the first LED is normalized by the light detected by the second LED.

16. An implantable medical device, comprising:

a hermetically sealed housing;

an opto-electronic device configured for sensing a narrow band of light wavelengths of ambient light passing through a body of a patient;

a sensor module; and

a conductive element for carrying a current signal from the opto-electronic device to the sensor module, the current signal corresponding to an intensity of the ambient light, wherein the sensor module estimates, based on the intensity of the ambient light detected by the opto-electronic device, a change in a physiological condition in one of a body fluid volume and a tissue volume proximate the opto-electronic device,

the intensity of the sensed light being correlated to the change in the physiological condition.