Systems, devices and methods for caloric vestibular stimulation having an impedance monitor and/or temperature sensor

• US 9,655,772 B2
• Filed: 06/18/2012
• Issued: 05/23/2017
• Est. Priority Date: 12/17/2010
• Status: Active Grant

• Current Assignee: Scion Neurostim Incorporated
• Original Assignee: Scion Neurostim, LLC
• Inventors: Rogers, Lesco L., Black, Robert D., Smith, Lanty L.
• Primary Examiner(s): Hindenburg, Max
• Assistant Examiner(s): Danega, Renee
• Application Number:
  US13/525,817
• Publication Number:
  US 20120316625A1
• Time in Patent Office: 1,800 Days
• Field of Search: 607113
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61F 2007/0005 Ears
• CPC Class Codes: A61F 2007/0075 using a Peltier element, e.g. near the spot to be heated or cooled
• CPC Class Codes: A61F 2007/0093 programmed
• CPC Class Codes: A61F 2007/0095 with a temperature indicator
• CPC Class Codes: A61F 2007/0096 with a thermometer
• CPC Class Codes: A61F 2007/0296 Intervals of heating alternated with intervals of cooling
• CPC Class Codes: A61F 7/007 characterised by electric heating
• CPC Class Codes: A61F 7/12 Devices for heating or cooling internal body cavities
• CPC Class Codes: A61N 1/36036 of the outer, middle or inner ear
• CPC Class Codes: A61N 2/002 in combination with another treatment
• CPC Class Codes: A61N 2/006 for magnetic stimulation of nerve tissue

Abstract

An in-ear stimulation device for administering caloric stimulation to the ear canal of a subject includes (a) first and second earpieces configured to be insertable into the ear canals of the subject; (b) at least first and second thermoelectric devices thermally coupled to respective ones of the first and second earpieces; (c) a first heat sink thermally coupled to the first thermoelectric device opposite the first earpiece and a second heat sink thermally coupled to the second thermoelectric device opposite the second earpiece; and (d) a controller comprising a waveform generator in communication with the first and second thermoelectric devices, the waveform generator configured to generate a first control signal to control a first caloric output to the first thermoelectric device and a second control signal to control a second caloric output to the second caloric device.

Claims

1. An in-ear stimulation device for administering caloric stimulation to the ear canal of a subject, comprising:

(a) first and second earpieces configured to be insertable into the ear canals of the subject;

(b) at least first and second thermoelectric devices thermally coupled to respective ones of the first and second earpieces;

(c) a first heat sink thermally coupled to the first thermoelectric device opposite the first earpiece and a second heat sink thermally coupled to the second thermoelectric device opposite the second earpiece;

(d) an electrical connection that electrically connects the first and second earpieces, and

(e) a controller comprising an impedance monitor configured to measure an impedance value between the first and second earpieces and to determine whether the first and second earpieces are inserted into the ear canals of the subject responsive to the impedance value, wherein the impedance monitor is configured to correlate the impedance value with a thermal impedance and/or thermal conductance of an interface between the first and second earpieces and the ear canal of the subject.

2. The in-ear stimulation device of claim 1, wherein the impedance value comprises resistive and capacitive components.

3. The in-ear stimulation device of claim 1, wherein the electrical connection comprises a metal wire that electrically connects the first and second earpieces.

4. The in-ear stimulation device of claim 1, wherein the controller further comprises a waveform generator in communication with the first and second thermoelectric devices, the waveform generator configured to generate a first control signal to control a first caloric output to the first thermoelectric device and a second control signal to control a second caloric output to the second thermoelectric device.

5. The in-ear stimulation device of claim 4, wherein the controller comprises a memory configured to store waveform data and/or impedance values, and a patient module that is configured to determine whether a subject has complied with a treatment plan based on whether the stored impedance values are consistent with the first and second earpieces being correctly positioned during administration of the treatment.

6. The in-ear stimulation device of claim 1, wherein the impedance module is configured to deliver an electrical current via the electrical connector to one of the first and second earpieces.

7. The in-ear stimulation device of claim 6, wherein the impedance module is configured to detect whether the first and second earpieces and the subject form a closed circuit or an open circuit, and a closed circuit indicates a higher degree of thermal contact between the first and second earpieces than an open circuit.

8. The in-ear stimulation device of claim 7, wherein the impedance module is configured to determine if a degree of thermal contact between the earpieces and the subject is sufficient by determining whether the impedance value is within a predefined range.

9. The in-ear stimulation device of claim 4, wherein the impedance module is configured to provide feedback to the waveform module such that the waveform module increases or decreases an amplitude of the first and second waveform control signals in response to a degree of thermal contact determined by the impedance module based on the impedance value of the electrical connector.

31. The in-ear stimulation device of claim 4, further comprising a heart rate monitor, wherein a caloric vestibular stimulation (CVS) delivered by the device is titrated in response to a heart rate variability measurement.

32. The in-ear stimulation device of claim 31, wherein the waveform generator of the controller is configured to adjust the first and second control signals in response to heart rate variability measurements after an application of a treatment waveform.

33. The in-ear stimulation device of claim 4, wherein the first caloric output and the second caloric output are selected based on a region of a brain in which stimulation is desired.

34. The in-ear stimulation device of claim 4, wherein the first caloric output and the second caloric output vary over time so that the firing rates of the vestibular hair cells are modulated over time.

10. An in-ear stimulation device for administering caloric stimulation to the ear canal of a subject, comprising:

(a) at least one earpiece configured to be insertable into the ear canal of the subject;

(b) at least one thermoelectric devices thermally coupled to the at least one earpiece;

(c) a first heat sink thermally coupled to the at least one thermoelectric device opposite the at least one earpiece earpiece;

(d) a temperature sensor thermally coupled to the at least one earpiece, and

(e) a controller comprising a temperature monitor configured to measure a temperature value of the at least one earpiece and to determine whether the at least one earpiece is inserted into the ear canal of the subject responsive to the temperature value, wherein the temperature monitor is configured to determine that the at least one earpiece is inserted into the ear canal of the subject when a temperature value increases prior to delivery of a control signal by the waveform generator, and the temperature monitor is configured to determine that the at least one earpiece is not inserted into the ear canal of the subject when a temperature value does not increase prior to delivery of a control signal by the waveform generator.

11. An in-ear stimulation device for administering caloric stimulation to the ear canal of a subject, comprising:

(a) at least one earpiece configured to be insertable into the ear canal of the subject;

(b) at least one thermoelectric devices thermally coupled to the at least one earpiece;

(c) a first heat sink thermally coupled to the at least one thermoelectric device opposite the at least one earpiece earpiece;

(d) a temperature sensor thermally coupled to the at least one earpiece, and

(e) a controller comprising a temperature monitor configured to measure a temperature value of the at least one earpiece and to determine whether the at least one earpiece is inserted into the ear canal of the subject responsive to the temperature value.

12. The in-ear stimulation device of claim 11, wherein the controller further comprises a waveform generator in communication with the at least one thermoelectric device, the waveform generator configured to generate a control signal to control a caloric output to the at least one thermoelectric device.

13. The in-ear stimulation device of claim 11, wherein the temperature monitor is configured to determine that the at least one earpiece is inserted into the ear canal of the subject when a number of cycles during a delivery of a control signal by the waveform generator is less than a number of cycles during delivery of the control signal when the earpiece is not inserted into the ear.

14. The in-ear stimulation device of claim 11, wherein the temperature monitor is configured to compare the control signal from the waveform generator with the temperature output and to determine a degree of thermal contact between the earpiece and the ear canal based on a lag time between a temperature driven by the control signal and the temperature output.

15. The in-ear stimulation device of claim 14, wherein a longer delay between a temperature driven by the control signal and the temperature output indicates increased thermal contact compared to a shorter delay between the control signal and the temperature output.

16. An in-ear stimulation method for administering caloric stimulation to the ear canal of a subject, the method comprising:

positioning at least a portion of an in-ear stimulation device in the ear canals of the subject, the in-ear stimulation device comprising;

(a) first and second earpieces configured to be insertable into the ear canals of the subject;

(b) at least first and second thermoelectric devices thermally coupled to respective ones of the first and second earpieces;

(c) a first heat sink thermally coupled to the first thermoelectric device opposite the first earpiece and a second heat sink thermally coupled to the second thermoelectric device opposite the second earpiece; and

(d) an electrical connection that electrically connects the first and second earpieces, and

measuring with an impedance monitor an impedance value between the first and second earpieces;

determining whether the first and second earpieces are inserted into the ear canals of the subject responsive to the impedance value; and

correlating the impedance value with a thermal impedance and/or thermal conductance of an interface between the first and second earpieces and the ear canal of the subject.

17. The in-ear stimulation method of claim 16, wherein the impedance value comprises resistive and capacitive components.

18. The in-ear stimulation method of claim 16, wherein the electrical connection comprises a metal wire that electrically connects the first and second earpieces.

19. The in-ear stimulation method of claim 16, generating with a waveform generator a first control signal to control a first caloric output to the first thermoelectric device and a second control signal to control a second caloric output to the second thermoelectric device.

20. The in-ear stimulation method of claim 19, further comprising storing waveform data and/or impedance values, and determining whether a subject has complied with a treatment plan based on whether the stored impedance values are consistent with the first and second earpieces being correctly positioned during administration of the treatment.

21. The in-ear stimulation method of claim 16, further comprising delivering an electrical current via the electrical connector to one of the first and second earpieces.

22. The in-ear stimulation method of claim 19, further comprising detecting whether the first and second earpieces and the subject form a closed circuit or an open circuit, wherein a closed circuit indicates a higher degree of thermal contact between the first and second earpieces than an open circuit.

23. The in-ear stimulation method of claim 22, further comprising determining if a degree of thermal contact between the earpieces and the subject is sufficient by determining whether the impedance value is within a predefined range.

24. The in-ear stimulation method of claim 19, further comprising providing feedback to the waveform module such that the waveform module increases or decreases an amplitude of the first and second waveform control signals in response to a degree of thermal contact determined by the impedance module based on the impedance value of the electrical connector.

35. The method of claim 19, further comprising adjusting the first and second control signals in response to a heart rate variability measurement.

25. An in-ear stimulation method for administering caloric stimulation to the ear canal of a subject, the method comprising:

positioning at least a portion of an in-ear stimulation device in the ear canals of the subject, the in-ear stimulation device comprising;

(a) at least one earpiece configured to be insertable into the ear canal of the subject;

(b) at least one thermoelectric devices thermally coupled to the at least one earpiece;

(c) a first heat sink thermally coupled to the at least one thermoelectric device opposite the at least one earpiece earpiece; and

(d) a temperature sensor thermally coupled to the at least one earpiece, measuring a temperature value of the at least one earpiece; and

determining whether the at least one earpiece is inserted into the ear canal of the subject responsive to the temperature value.

26. The in-ear stimulation method of claim 25, further comprising generating a control signal with a waveform generator to control a caloric output to the at least one thermoelectric device.

27. The in-ear stimulation method of claim 25, further comprising determining that the at least one earpiece is inserted into the ear canal of the subject when a temperature value increases prior to delivery of a control signal by the waveform generator, determining that the at least one earpiece is not inserted into the ear canal of the subject when a temperature value does not increase prior to delivery of a control signal by the waveform generator.

28. The in-ear stimulation device of claim 25, further comprising determining that the at least one earpiece is inserted into the ear canal of the subject when a number of cycles during a delivery of a control signal by the waveform generator is less than a number of cycles during delivery of the control signal when the earpiece is not inserted into the ear.

29. The in-ear stimulation device of claim 25, further comprising comparing the control signal from the waveform generator with the temperature output and to determine a degree of thermal contact between the earpiece and the ear canal based on a lag time between a temperature driven by the control signal and the temperature output.

30. The in-ear stimulation device of claim 29, wherein a longer delay between a temperature driven by the control signal and the temperature output indicates increased thermal contact compared to a shorter delay between the control signal and the temperature output.