SENSORS IMPLANTABLE INTO A PATIENT'S BODY, SYSTEMS, AND METHODS OF USING THE SAME

• US 20190038214A1
• Filed: 08/07/2018
• Published: 02/07/2019
• Est. Priority Date: 08/07/2017
• Status: Active Application

• Current Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Inventors: Mikhail, George, Leszko, Filip, Pierson, Glen, Wakley, Brett Ivan, Venkatasubramanian, Arun, Lemdiasov, Rosti
• Application Number:
  US16/056,623
• Publication Number:
  US 20190038214A1
• Time in Patent Office: Days
• CPC Class Codes: A61B 2562/0261 Strain gauges
• CPC Class Codes: A61B 2562/043 in a linear array
• CPC Class Codes: A61B 2562/182 Electrical shielding, e.g. using a Faraday cage
• CPC Class Codes: A61B 5/0004 characterised by the type of physiological signal transmitted
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/45 For evaluating or diagnosing the musculoskeletal system or teeth A61B5/1036, A61B5/1074, A61B7/006 take precedence
• CPC Class Codes: A61B 5/4504 Bones A61B5/4547 takes precedence
• CPC Class Codes: A61B 5/4538 Evaluating a particular part of the muscoloskeletal system or a particular medical condition
• CPC Class Codes: A61B 5/6878 Bone
• CPC Class Codes: G01R 19/255 using analogue/digital converters of the type with counting of pulses during a period of time proportional to voltage or current, delivered by a pulse generator with fixed frequency
• CPC Class Codes: G01R 27/02 Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant by measuring phase angle only G01R25/00
• CPC Class Codes: H01Q 1/526 Electromagnetic shields
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

In one example, a sensor is configured to be implanted into a patient'"'"'s body. The sensor has at least one sensing element, a measurement device in communication with the at least one sensing element, and an internal wireless communicator in communication with the measurement device. The at least one sensing element includes a resistor, and the measurement device includes a capacitor. The measurement device measures a discharge time of the capacitor through the resistor so as to generate a measurement value that is proportional to a value of an anatomical property of the anatomical body, such as strain, that is observed by the sensor. The internal wireless communicator wirelessly communicates the measurement value through skin of the patient to an external wireless communicator situated outside of the patient'"'"'s body.

Claims

1. A sensor configured to be implanted into a patient, the sensor comprising:

at least one sensing element;

a measurement device in communication with the at least one sensing element, the measurement device including at least one capacitor and configured to measure a discharge time of the at least one capacitor through the at least one sensing element so as to generate a measurement value that is proportional to a value of an anatomical property of the patient observed by the sensor; and

an internal wireless communicator in communication with the measurement device, the wireless communicator configured to wirelessly communicate the measurement value through skin of the patient to an external wireless communicator situated outside of the patient'"'"'s body.

2. The sensor of claim 1, wherein the at least one sensing element comprises a resistor, and the measurement device is configured to measure the discharge time of the at least one capacitor through the resistor so as to generate the measurement value.

3. The sensor of claim 1, wherein the measurement device comprises a time-to-digital converter configured to measure discharge time of the capacitor through the at least one sensing element.

4. The sensor of claim 3, wherein the measurement device comprises a clock, and the time-to-digital converter is configured to increment in response to a clock signal of the clock.

5. The sensor of claim 1, wherein the sensor comprises a strain gauge that includes the at least one sensing element.

6. The sensor of claim 5, wherein the strain gauge includes a substrate that carries the at least one sensing element, and the at least one sensing element includes at least first and second sensing elements, wherein the first and second sensing elements are non-parallel to one another.

7. The sensor of claim 1, wherein the internal wireless communicator comprises a radio-frequency identification (RFID) transponder.

8. The sensor of claim 1, comprising a power device configured to supply power to the measurement device, wherein the power device includes an energy harvesting device configured to capture energy from radio waves communicated to the sensor.

9. A sensor configured to be implanted into a patient, the sensor comprising:

a semiconductor strain gauge having a substrate and first, second, and third sensing elements arranged on the substrate such that the first, second, and third sensing elements are non-parallel to one another;

a measurement device in communication with the first to third sensing elements, the measurement device configured to generate a measurement value that is proportional to a value of an anatomical property of the patient observed by the sensor; and

an internal wireless communicator in communication with the measurement device, the wireless communicator configured to wirelessly communicate the measurement value through skin of the patient to an external wireless communicator situated outside of the patient.

10. The sensor of claim 9, wherein each of the first to third sensing elements comprises a resistor, and the measurement device is configured to measure the discharge time of the at least one capacitor through each resistor so as to generate the measurement value.

11. The sensor of any one of claim 9, wherein the measurement device includes at least one capacitor and is configured measure a discharge time of the at least one capacitor through the resistor of each of the first to third sensing elements so as to generate the measurement value.

12. The sensor of claim 11, wherein the measurement device comprises a time-to-digital converter configured to measure the discharge time through each resistor.

13. The system of claim 9, wherein each sensing element comprises a semiconductor bar-type strain gauge.

14. The system of claim 9, wherein each sensing element has a first end, and a second end that is offset from the first end along a central axis, and each sensing element comprises a resistor that is linear bar that extends between the first and second ends along the central axis.

15. A sensor configured to be implanted into a patient, the sensor comprising:

at least one sensing element;

a measurement device in communication with the at least one sensing element, the measurement device configured to generate a measurement value that is proportional to a value of an anatomical property of the patient observed by the sensor;

an antenna having at least one inductive antenna coil that is wound in a first direction, the antenna coil configured to wirelessly transmit the measurement value to a reader outside of the patient; and

a shield disposed below the antenna, the shield having at least one inductive shield coil that is connected in series with the antenna coil and is wound in a second direction, opposite the first direction.

16. The sensor of claim 15, wherein the shield coil has a number of turns that is less than a number of turns of the antenna coil.

17. The sensor of claim 15, wherein the at least one shield coil is configured to generate a magnetic field in a direction that opposes a magnetic field of the at least one antenna coil.

18. The sensor of claim 15, wherein the shield is disposed between the antenna and the at least one sensing element.

19. The sensor of claim 18, wherein the shield is disposed between the at least one sensing element and the measurement device.

20. The sensor of claim 18, wherein the shield is disposed between the antenna and the measurement device.