Multimodal Brain Sensing Lead

• US 20130123600A1
• Filed: 11/09/2012
• Published: 05/16/2013
• Est. Priority Date: 11/10/2011
• Status: Active Grant

• Current Assignee: Neuropace Inc.
• Original Assignee: Neuropace Inc.
• Inventors: Tcheng, Thomas K.
• Granted Patent: US 10,123,717 B2
• Time in Patent Office: Days
• US Class Current: 600/378
• CPC Class Codes: A61B 2562/0209 Special features of electrodes classified in A61B5/24, A61B5/25, A61B5/283, A61B5/291, A61B5/296, A61B5/053
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 2562/0285 Nanoscale sensors
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 2562/063 in a linear array
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/14553 specially adapted for cerebral tissue
• CPC Class Codes: A61B 5/165 Evaluating the state of mind, e.g. depression, anxiety
• CPC Class Codes: A61B 5/291 for electroencephalography [EEG]
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/4082 Diagnosing or monitoring movement diseases, e.g. Parkinson, Huntington or Tourette
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61B 5/6868 Brain
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61N 1/025 Digital circuitry features of electrotherapy devices, e.g. memory, clocks, processors
• CPC Class Codes: A61N 1/0531 Brain cortex electrodes
• CPC Class Codes: A61N 1/0534 : Electrodes for deep brain stimulation
• CPC Class Codes: A61N 1/36064 : Epilepsy
• CPC Class Codes: A61N 1/36067 : Movement disorders, e.g. tremor or Parkinson disease stimulating motor muscle A61N1/36003
• CPC Class Codes: A61N 1/36082 : Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease
• CPC Class Codes: A61N 1/36132 : using patient feedback
• CPC Class Codes: A61N 1/36139 : with automatic adjustment

Abstract

A medical lead with at least a distal portion thereof implantable in the brain of a patient is described, together with methods and systems for using the lead. The lead is provided with at least two sensing modalities (e.g., two or more sensing modalities for measurements of field potential measurements, neuronal single unit activity, neuronal multi unit activity, optical blood volume, optical blood oxygenation, voltammetry and rheoencephalography). Acquisition of measurements and the lead components and other components for accomplishing a measurement in each modality are also described as are various applications for the multimodal brain sensing lead.

Claims

1. An implantable medical lead with multimodal sensing capability, comprising:

a lead body having a proximal portion and a distal portion, the lead body further characterized by at least one lumen extending substantially between the proximal portion and the distal portion, wherein

the proximal portion is configured to be connected to a power source, a ground and other electronics for acquiring measurements from a patient'"'"'s body, the distal portion having a plurality of components configurable with the power source, the ground and the other electronics to acquire a first sensor measurement corresponding to a first sensing modality and a second sensor measurement corresponding to a second sensing modality, the first and second sensing modalities being different from each other; and

a plurality of conductors extending through at least one lumen and, at the proximal portion, in operable communication with the power source, the ground and the other electronics and, at the distal portion, in operable and selectable communication with the plurality of components, a number of conductors of the plurality of conductors sufficient to enable acquisition of the first and second sensor measurements.

2. The implantable medical lead of claim 1 wherein the first sensing modality and the second sensing modality are selected from the group consisting of a field potential measurement modality, a single unit activity measurement modality or a multi unit measurement modality, an optical measurement modality, a rheoencephalography measurement modality, and a voltammetry measurement modality.

3. The implantable medical lead of claim 1 wherein at least one of the plurality of components is further configurable with the power source, the ground and the other electronics to deliver a form of therapy at the distal portion.

4. The implantable medical lead of claim 3 wherein the form of therapy is electrical stimulation therapy.

5. The implantable medical lead of claim 4 wherein the electrical stimulation therapy is of a type selected from a charge-balanced pulsatile electrical stimulation therapy, a non-charge balanced pulsatile electrical stimulation therapy.

6. The implantable medical lead of claim 1 wherein the first sensing modality is a neuronal field potential measurement modality, the second sensing, modality is a rheoencephalography modality, and the plurality of components include at least four electrically conductive elements, and each electrically conductive element of the at least four electrically conductive elements is spaced apart from an adjacent electrically conductive element by a nonconductive element.

7. The implantable medical lead of claim 6 wherein the at least four electrically conductive elements are ring electrodes.

8. The implantable medical lead of claim 1 wherein the plurality of components include at least four ring electrodes axially spaced substantially the same distance apart from each other and disposed in the distal portion near a distalmost end thereof, the first sensor measurement is a neuronal field potential measurement acquired as a first voltage difference between a first ring electrode of the at least four ring electrodes and a second ring electrode of the at least four ring electrodes or as a second voltage difference between the first ring electrode of the at least four ring electrodes and a reference electrode, and the second sensor measurement is a rheoencephalography measurement acquired as a third voltage difference between a first ring electrode of the at least four ring electrodes and a second ring electrode of the at least four ring electrodes in response to a waveform impressed between a third ring electrode of the at least four ring electrodes and a fourth ring electrode of the at least four ring electrodes.

9. The implantable medical lead of claim 1 wherein the plurality of components include at least one lens, at least one light emitting diode and at least one photodetector to acquire an optically-generated sensor measurement as the first sensor measurement and the plurality of components further include at least one electrical conductive member isolated by adjacent nonconductive members to acquire a neuronal field potential measurement as the second sensor measurement.

10. The implantable medical lead of claim 1 wherein the plurality of components include at least one lens, at least one light emitting diode and at least one photodetector to acquire an optically-generated sensor measurement as the first sensor measurement and the plurality of components further include at least four electrical conductive members isolated by adjacent nonconductive members to acquire a neuronal field potential measurement or a rheoencephalography measurement as the second sensor measurement.

11. An implantable brain lead comprising:

a proximal portion;

a distal portion;

a lead body characterized by at least one lumen extending substantially between the proximal portion and the distal portion, the proximal portion adapted to be connected to a device with a control module, a signal generator and a signal processor, the distal portion having a plurality of components adapted to rest adjacent to or within brain tissue; and

a number of conductors extending in the at least one lumen to operably connect the plurality of components, either directly or indirectly, with the device, and wherein a lead comprising the lead body is configurable to acquire measurements from the brain tissue in at least two different sensing modalities.

12. The implantable medical lead of claim 11 wherein the at least two different sensing modalities are selected from the group consisting of a field potential measurement modality, a single unit activity measurement modality or a multi unit measurement modality, an optical measurement modality, a rheoencephalography measurement modality, and a voltammetry measurement modality.

13. The implantable brain lead of claim 12 wherein the at least two different sensing modalities corresponds to a first measurement from which an field potential assessment can be made, a second measurement from which a rheoencephalography assessment can be made, a third measurement from which an optical blood volume assessment or an optical blood oxygen measurement can be made;

and a fourth measurement from which a voltammetric assessment can be made; and

the plurality of components include at least four macroelectrodes separated from each other by nonconductive elements and configured to acquire the first measurement and the second measurement, a lens, a light source and a photodetector configured to acquire the third measurement; and

at least two microelectrodes and at least one counter electrode configured to acquire the fourth measurement.

14. The implantable brain lead of claim 13 wherein the macroelectrodes are formed from a material including platinum and the microelectrodes are formed from a material including ultrananocrystalline diamond-coated metal.

15. The implantable brain lead of claim 13 wherein the macroelectrodes are formed from a platinum-iridium alloy and the microelectrodes are formed from glassy carbon, pyrolytic graphite, or a carbon paste.

16. The implantable brain lead of claim 11 wherein the at least two different sensing modalities correspond to:

a first measurement from which a field potential assessment may be made;

a second measurement from which a rheoencephalography assessment may be made, a third measurement from which an optical assessment may be made, a fourth measurement from which a voltammetry assessment may be made, a fifth measurement from which a single unit activity or multi unit activity assessment may be made; and

the plurality of components include at least four macroelectrodes separated from each other by nonconductive elements and configured to acquire the first measurement and the second measurement, a lens, a light source and a photodetector configured to acquire the third measurement, and at least two microelectrodes and a counter macroelectrode configured to acquire the fourth measurement and the fifth measurement.

17. A method of configuring a system including a sensor-bearing implantable medical lead and a device adapted to interface with the sensor-bearing implantable medical lead to acquire measurements corresponding to activity in or near a brain in at least two distinct sensing modalities, comprising;

forming the sensor-bearing implantable medical lead with a substantially cylindrical lead body having a proximal portion and a distal portion, the lead body further formed with at least one lumen extending substantially between the proximal portion and the distal portion;

providing a plurality of connectors in the proximal portion, each connector of the plurality of connectors adapted to be connected to one or more of a power source, a ground, or other electronics for acquiring a first set of measurements corresponding to a first sensing modality and for acquiring a second set of measurements corresponding to a second sensing modality, the first and second sensing modalities being different from each other;

providing a plurality of components in the distal portion, at least one of the plurality of components adapted to be used in acquiring the first set of measurements and at least one of the plurality of components adapted to be used in acquiring the second set of measurements;

providing a plurality of conductors extending through the at least one lumen and adapted to, at the proximal portion, be operably and selectively connected to the power source, the ground and the other electronics and, at the distal portion, to be operably and selectively connected with the plurality of components, a number of conductors of the plurality of conductors sufficient to enable acquisition of the first set and the second set of measurements; and

providing a releasable connection between the pluralities of connectors in the proximal portion of the sensor-bearing implantable medical lead to the device, the device adapted to provide the power, the ground and the other electronics for acquiring the first set of measurements and the second set of measurements.

18. The method of claim 17 wherein the first and second measurements correspond to sensing modalities selected from the group consisting of a field potential measurement modality, a single unit activity measurement modality or a multi unit measurement modality, an optical measurement modality, a rheoencephalography measurement modality, and a voltammetry measurement modality.

19. The method of claim 17 wherein providing a plurality of components in the distal portion includes:

providing four electrodes being a first, second, third and fourth electrode, each electrode of the four electrodes separated horn any adjacent electrode by a nonconductive element, the first, second, third and fourth electrodes provided so that the first electrode is the furthest of the four electrodes from a distalmost end of the distal portion, the second electrode is the next furthest, the fourth electrode is the closest to the distalmost end, and the third electrode is the next closest, wherein the first sensing modality is an field potential sensing modality and the first set of measurements is acquired using at least one of the four electrodes, and wherein the second sensing modality is a rheoencephalographic measurement modality and the second set of measurements is acquired using all four of the first second, third and fourth electrodes.

20. The method of claim 19 wherein providing a plurality of components in the distal portion includes:

providing four electrodes being a first, second, third and fourth electrode, each electrode of the four electrodes separated from any adjacent electrode by a nonconductive element, the first, second, third and fourth electrodes provided so that the first electrode is the furthest of the four electrodes from a distalmost end of the distal portion, the second electrode is the next furthest, the fourth electrode is the closest to the distalmost end, and the third electrode is the next closest, wherein the first sensing modality is a field potential measurement modality and the first set of measurements is acquired using at least one of the four electrodes, and wherein the second sensing modality is a rheoencephalographic measurement modality and the second set of measurements is acquired using all four of the first, second, third and fourth electrodes.

21. The method of claim 20 wherein the plurality of connectors and plurality of conductors are configured to allow acquisition of a monopolar field electric potential measurement by measuring a fourth voltage difference between the fourth electrode and a reference electrode comprising an outer case of the device, and wherein the plurality of connectors and plurality of conductors are further configured to allow acquisition of a rheoencephalographic measurement by impressing a waveform across the first and fourth electrodes and measuring a fifth voltage difference in response to the waveform between the second and third electrodes.

22. The method of claim 20 wherein the plurality of connectors and plurality of conductors are configured to allow acquisition of a bipolar field electric potential measurement by measuring a sixth voltage difference between any of the first, second, third and fourth electrodes and any different one of the first, second, third, and fourth electrodes, and wherein the plurality of connectors and plurality of conductors are further configured to allow acquisition of a rheoencephalographic measurement by impressing a waveform across the first and fourth electrodes and measuring a fifth voltage difference in response to the waveform between the second and third electrodes.

23. A system for acquiring measurements corresponding to brain activity in multiple sensing modalities comprising:

an implantable medical lead comprising;

a lead body with a substantially circular cross-section and having a proximal portion and a distal portion, the lead body further characterized by at least one lumen extending substantially between the proximal portion and the distal portion;

a plurality of components in the distal portion, at least one of the plurality of components adapted to be used in acquiring one or more sets of measurements corresponding to different sensing modalities;

a plurality of conductors extending through the at least one lumen and configured to, at the distal portion, to be operably and selectively connected with the plurality of components and, at the proximal portion, to be operably and selectively connected to an

implantable medical device, a number of conductors of the plurality of conductors sufficient to enable acquisition of each set of measurements of the one or more sets of measurements, wherein the implantable medical device comprises;

a plurality of receptacles adapted to selectively communicate with the plurality of conductors in the implantable medical lead;

a signal processor configured to process signals received from the plurality of conductors in the implantable medical lead to acquire one or more of the one or more sets of measurements;

a signal generator to provide one or more signals through the plurality of conductors in the implantable medical lead to acquire one or more of the one or more sets of measurements;

a memory to store information corresponding to any or all of the signals received from the plurality of conductors, the signals processed by the signal processor and the signals generated by the signal generator;

a power source;

a system ground; and

a control module configured to control functioning of at least the signal processor, the signal generator, the memory, and the power source; and

a releasable connector adapted to connect the plurality of conductors in the implantable medical lead with the plurality of receptacles in the implantable medical device.