Neurostimulation system for preventing magnetically induced currents in electronic circuitry

Patent metadata

Field	Value
Publication number	US-9220901-B2
Application number	US-201313801596-A
Country	US
Kind code	B2
Filing date	Mar 13, 2013
Priority date	Mar 16, 2012
Publication date	Dec 29, 2015
Grant date	Dec 29, 2015

Abstract

A neurostimulation device capable of being placed between an active stimulation state and an inactive stimulation state and method of using same. The neurostimulation device comprises a plurality of electrical terminals configured for being respectively coupled to a plurality of stimulation electrodes, a first solid-state switching device coupled to a first one of the electrical terminals, a variable power source coupled to the first switching device, and a controller configured for, when the neurostimulation device is in the inactive stimulation state, prompting the variable power source to selectively output a relatively low voltage to place the first switching device into a first open state and a relatively high voltage to place the first switching device into a second open state.

First claim

What is claimed is:

1. A neurostimulation device capable of being placed between a stimulation mode for delivery of a series of stimulation pulses and a standby mode, comprising:
a plurality of electrical terminals configured for being respectively coupled to a plurality of stimulation electrodes;
a first solid-state switching device coupled to a first one of the electrical terminals, wherein the first solid-state switching device has a closed state in which current can flow through the first solid-state switching device and first and second open states in which flow of current through the first solid-state switching device is prevented if the current is below a threshold;
a variable power source coupled to the first switching device; and
a controller configured for placing the neurostimulation device in the stimulation mode for delivering the series of stimulation pulses and placing the neurostimulation device in the standby mode when not delivering the series of stimulation pulses, wherein the controller is further configured for, when the neurostimulation device is in the standby mode, prompting the variable power source to selectively output a relatively low voltage to place the first switching device into a first open state and a relatively high voltage to place the first switching device into a second open state and, when the neurostimulation device is in the stimulation mode for delivering the series of stimulation pulses, prompting the variable power source to output the relatively high voltage to place the first switching device into the second open state during conveyance of each of the pulses in the series of stimulation pulses and into the closed state between the pulses of the series.

2. The neurostimulation device of claim 1 , further comprising a second solid-state switching device coupled to a second one of the electrical terminals, wherein the second solid-state switching device has a closed state in which current can flow through the second solid-state switching device and first and second open states in which flow of current through the second solid-state switching device is prevented if the current is below a threshold,
wherein the first and second switching devices are shorted to each other, wherein the variable power source is coupled to the second switching device, and the controller is configured for, when the neurostimulation device is in the standby mode, prompting the variable power source to selectively output the relatively low voltage to place the second switching device into the first open state and the relatively high voltage to place the second switching device into the second open state and, when the neurostimulation device is in the stimulation mode for delivering the series of stimulation pulses, prompting the variable power source to output the relatively high voltage to place the second switching device into the second open state during conveyance of each of the pulses in the series of stimulation pulses and into the closed state between the pulses of the series of stimulation pulses.

3. The neurostimulation device of claim 2 , wherein each of the first and second switching devices comprises two complementary transmission gate switches.

4. The neurostimulation device of claim 3 , wherein the two complementary transmission gate switches comprises an N-channel metal-oxide semiconductor (NMOS) transistor and a P-channel metal-oxide semiconductor (PMOS).

5. The neurostimulation device of claim 2 , further comprising at least one stimulation source, wherein the controller is configured for prompting the at least one stimulation source to convey the series of stimulation pulses between the first and second electrical terminals when the neurostimulation device is in the stimulation mode, and for prompting the variable power source to ground the first switch after the conveyance of each of the pulses to place the first switching device into a closed state.

6. The neurostimulation device of claim 2 , further comprising a passive charge recovery circuit comprising the first and second switching devices and configured and arranged, when coupled to the plurality of stimulation electrodes through the plurality of electrical terminals, to permit charge balancing between the plurality of stimulation electrodes when the first and second switching devices are both in the closed state.

7. The neurostimulation device of claim 1 , wherein the relatively low voltage is less than five volts, and the relatively high voltage is greater than ten volts.

8. The neurostimulation device of claim 1 , further comprising telemetry circuitry configured for receiving a signal external to the neurostimulation device, wherein the controller is configured for prompting the variable power source to output the relatively high voltage in response to the external signal.

9. The neurostimulation device of claim 8 , further comprising a sensing mechanism configured for deactivating the neurostimulation device in the presence of an external magnetic field, wherein the controller, in response to the external signal, is configured for preventing the neurostimulation device from being deactivated.

10. The neurostimulation device of claim 9 , wherein the controller is configured for preventing the neurostimulation device from being deactivated by disabling the sensing mechanism.

11. The neurostimulation device of claim 1 , wherein the variable power supply comprises a battery configured for outputting the relatively low voltage, and a high voltage circuit coupled to the battery and configured for increasing an output voltage of the battery for outputting the relatively high voltage.

12. The neurostimulation device of claim 11 , wherein the controller is configured for turning off the high voltage circuit to pass the relative low voltage from the battery to the first switching device, and for turning on the high voltage circuit to output the relatively high voltage from the high voltage circuit to the first switching device.

13. The neurostimulation device of claim 1 , wherein the first switching device has a control terminal, and the controller is configured for, when the neurostimulation device is in the standby mode, prompting the variable power source to selectively output the relatively low voltage to the control terminal of the first switching device and the relatively high voltage to the control terminal of the first switching device.

14. A method of preventing induced electrical current in the neurostimulation device of claim 1 , the neurostimulation device being associated with a patient exposed to external energy, the method comprising:
placing the neurostimulation device in the standby mode;
applying the relatively low voltage to the first switching device when the neurostimulation device is in the standby mode, thereby placing the first switching device in the first open state;
applying the relatively high voltage to the second switching device when the neurostimulation device is in the standby mode, thereby placing the first switching device in the second open state; and
applying the external energy to the patient, thereby inducing a voltage on the first electrical terminal, wherein the induced voltage is at a level that is prevented from conducting current through the first switching device when in the second open state that would otherwise be conducted through the first switching device when in the first open state.

15. The method of claim 14 , wherein the external energy is magnetic energy.

16. The method of claim 14 , wherein the magnetic energy is a gradient magnetic field generated by a magnetic r

Assignees

• Boston Scient Neuromodulation

Inventors

• Gururaj Kiran
• Weerakoon Pujitha
• Marnfeldt Goran N
• Parramon Jordi
• Murtonen Salomo
• Feldman Emanuel

Classifications

• A61N1/36

  for stimulation · CPC title

• A61N1/08

  Arrangements or circuits for monitoring, protecting, controlling or indicating {(for external stimulators A61N1/3603; for implantable neurostimulators A61N1/36128; for heart stimulators A61N1/37; for defibrillators A61N1/3925)} · CPC title

• A61N1/3605

  Implantable neurostimulators for stimulating central or peripheral nerve system · CPC title

• A61N1/36142 Primary

  for improving safety · CPC title

• A61N2001/086

  Human Necessities · mapped topic