ULTRA LOW POWER CHARGING IMPLANT SENSORS WITH WIRELESS INTERFACE FOR PATIENT MONITORING

• US 20160058324A1
• Filed: 07/01/2015
• Published: 03/03/2016
• Est. Priority Date: 07/01/2014
• Status: Abandoned Application

• Current Assignee: Injectsense, Inc.
• Original Assignee: Injectsense, Inc.
• Inventors: CAO, ARIEL
• Application Number:
  US14/789,942
• Publication Number:
  US 20160058324A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 2562/085 combined with means for recording calibration data
• CPC Class Codes: A61B 3/0025 characterised by electronic signal processing, e.g. eye models
• CPC Class Codes: A61B 3/16 for measuring intraocular pressure, e.g. tonometers
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/0004 characterised by the type of physiological signal transmitted
• CPC Class Codes: A61B 5/076 Permanent implantations telemetry using implanted circuitry A61B5/0031; implanted stimulators for therapy A61N1/3605, A61N1/362, A61N1/372
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/6867 specially adapted to be attached or implanted in a specific body part A61B5/6847 takes precedence
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B

Abstract

Methods and devices for monitoring intra-ocular pressure of a patient using a miniature implantable sensor device are provided herein. Methods include obtaining multiple pressure measurements each day during an increment of an extended monitoring period according to a sampling program and wirelessly transmitting stored measurement data and wirelessly charging the device. Measurements and data process is performed with low power requirements such that sampling can be performed hourly for at least one week using energy stored on the miniature device and measurement data can be transmitted and the device charged rapidly when an external portable data acquisition/charging device is held in proximity to the device. In one aspect, methods include switching between differing use modes and powering the sampling device with a high impedance battery by switching between a supercapacitor and the battery with a microcontroller to perform impedance conversion.

Claims

1. A telemetry method for monitoring IOP, the method comprising:

obtaining a plurality of IOP measurements IOP within a vitreous body of an eye of a patient with a sensor device implanted within the vitreous body, wherein the plurality of pressure measurements are obtained over a monitoring period and powered by an energy storage component of the implantable sensor device;

storing IOP data corresponding to the plurality of pressure measurements on a recordable memory of the implantable sensor device for at least the monitoring period; and

wirelessly transmitting the IOP data from the implantable sensor device to an external device when the external device is in proximity to the implantable sensor device.

3. The method of claim 1, further comprising:

processing the plurality of pressure measurements with a processor of the implanted sensor device such that the IOP information corresponds to a trend or variation in IOP over the time increment.

4. The method of claim 1, further comprising:

obtaining measurements of second order effects associated with the plurality of pressure measurements with a reference sensor of the sensor device.

5. The method of claim 4, further comprising:

processing the plurality of pressure measurements to account for the second order effects associated with the plurality of pressure measurements with the reference sensor.

6. The method of claim 1, wherein obtaining the plurality of pressure measurements comprises measuring pressure within the vitreous body with a sensing membrane of the pressure sensor disposed entirely within the vitreous body.

7. The method of claim 1, wherein obtaining the plurality of pressure measurements comprises measuring pressure with the pressure sensor of the sensor multiple times each day during the time increment of at least a week.

8. The method of claim 7, wherein obtaining the plurality of pressure measurements according to the sampling program comprises measuring pressure with the pressure sensor up to every hour during the time increment.

9. The method of claim 7, wherein obtaining the plurality of pressure measurements according to the sampling program comprises measuring pressure with the pressure sensor at regular sampling intervals, the regular sampling interval within a range of 5 minutes and 2 hours.

10. The method of claim 1, further comprising:

switching between differing use modes of the sensor device by use of a microcontroller, wherein the differing use modes include any of;

a factory initialization mode, a real-time sampling mode, a baseline sampling mode, a variable data acquisition profile mode, an IOP data processing mode, a data verification mode, an alert mode, a recharge mode, an exception mode, and a patient therapy mode.

11. The method of claim 1, wherein obtaining the plurality of pressure measurements comprises measuring pressure with the pressure sensor at a first sampling rate, wherein the first sampling rate is a fixed sampling rate.

12. The method of claim 11, wherein obtaining the plurality of pressure measurements comprises measuring pressure with the pressure sensor at a second sampling rate based on one or more detected conditions.

13. The method of claim 12, wherein the second sampling rate is higher than the first sampling rate and the physiological condition is a measured IOP exceeding a pre-determined threshold.

14. The method of claim 12, wherein the second sampling rate is a variable rate based on the one or more conditions.

15. The method of claim 12, wherein the one or more conditions includes waking hours of the patient.

16. The method of claim 15, wherein the second sampling rate comprises sampling every hour during waking hours.

17. The method of claim 1, wherein obtaining the plurality of pressure measurements during the time increment is powered by energy stored in the energy storage component of the sensor device received in a single charging of the energy storage component, the time increment being at least one week.

18. The method of claim 1, further comprising:

wirelessly receiving data associated with the sampling program from the external device and updating the sampling program.

19. The method of claim 1, wherein wirelessly transmitting the IOP data is carried out by one or more coils of the sensor device and a corresponding coil of the external device.

20. The method of claim 1, further comprising:

charging the energy storage component by inductive coupling between one or more coils of the implantable sensor device with a corresponding coil of the external device.

21. The method of claim 20, wherein wirelessly transmitting the IOP information to the external device is performed concurrently or sequentially with receiving charging energy.

22. The method of claim 1, further comprising:

wirelessly receiving energy from the external device to charge the sensor device by storing the wirelessly received energy in the energy storage component of the sensor device while implanted.

23. The method of claim 22, wherein wirelessly receiving charging energy comprises inducing a voltage on a receiving coil of the sensor device with a corresponding coil of an external device magnetically coupled with the receiving coil.

24. The method of claim 23, wherein the voltage induced in the receiving coil is regulated by a voltage regular and a rectifier so as to provide a stable power supply to the implanted sensor device.

25. The method of claim 23, wherein the sensor device includes a decoupling capacitor configured to store sufficient energy from the voltage induced in the receiving coil to operate the sensor device for a duration of at least one week.

26. The method of claim 23, wherein operating the sensor device consumes about 1 μ

Watt of power or less during measuring and storing of pressure measurement data such that the sensor device can operate for a duration of at least one week before recharging.

27. The method of claim 19, further comprising:

transitioning into a sleep mode consuming about 1 nW of power or less during periods of time outside of obtaining the plurality of pressure measurements, transmitting data and wirelessly receiving charging energy.

28. The method of claim 19, wherein the device sends and receives data associated with the pressure measurements and receiving energy to power the device according to a passive RFID configuration upon receiving RF energy transmitted by the external device.

2. The method, wherein the plurality of pressure measurements are obtained according to a sampling program stored on the memory of the implantable sensor device.

29. A method of calibrating an implantable pressure sensor device, the method comprising:

obtaining a plurality of pressure measurements with the implantable sensor device under controlled conditions at differing values of one or more controlled parameters;

determining variations between the plurality of pressure measurements at the differing values of the one or more controlled parameters, wherein the variations correspond to mechanical characteristics affecting the plurality of pressure measurements that are particular to the implantable sensor device; and

storing calibration data associated with the determined variations in a memory of the implantable sensor device for use in adjusting in-situ measurements obtained from the sensor device while implanted to improve accuracy of plurality of pressure measurements.

30. The method of claim 29, further comprising:

storing the calibration data with a unique identifier associated with the implantable sensor device such that an external device communicatively coupled with the sensor device while implanted receives the stored calibration data for use in processing the plurality of measurements received from the device having the unique identifier.

31. The method of claim 29, wherein the implantable sensor device comprises an IOP sensor, the plurality of measurements comprise a plurality of pressure measurements and the one or more controlled parameters comprise a pressure and/or a temperature.

32. An implantable sensor device for measuring IOP of an eye of a patient, the device comprising:

a pressure sensor adapted for measuring a plurality of pressure measurements, wherein the pressure sensor is configured such that a pressure sensing membrane of the pressure sensor is disposed entirely within a vitreous body of the eye;

a control unit coupled to the pressure sensor and comprising a processor configured to control sampling of pressure measurements with the pressure sensor according to a sampling program;

an energy storage component coupled to the control unit and configured to wirelessly receive energy while implanted sufficient to power sampling and storage of the plurality of pressure measurements for a time increment of an extended monitoring period; and

one or more coils adapted to wirelessly receive energy for charging of the energy storage component and to wirelessly transmit and receive data associated with the plurality of pressure measurements.

33. The sensor device of claim 32, wherein the control unit is configured to:

initiate wireless communication with an external device for wireless communication and/or receiving of charging energy upon detection of the external device in proximity to the implanted sensor device;

perform charging and wireless communication concurrently or sequentially when the external device is in proximity to the implanted device; and

/or

optimize wireless charging and/or wireless communication based on a detected distance between the external device and the implanted sensor device.

34. The sensor device of claim 32 wherein the sensor device comprises a chip-scale package formed, at least in part, on a wafer or rigid substrate, wherein the one or more coils are coiled in-plane with the sensor device.

35. The sensor device of claim 32, wherein the implantable sensor device is configured so as to obtain multiple pressure measurements each day for a time increment of at least one week powered by the energy stored in a thin-film battery from a single charging and store IOP information associated with the plurality of pressure measurements for the time increment,

wherein the sensor device is configured to perform impedance conversion by switching back and forth between a supercapacitor and the thin-film battery such that energy for obtaining multiple pressure measurements is received from the supercapacitor.