Non-invasive segmentable three-dimensional microelectrode array patch for neurophysiological diagnostics and therapeutic stimulation
Inventors
Rajaraman, Swaminathan • Bragg, Julian A. • Ross, James D. • Preyer, Amanda
Assignees
Publication Number
US-9700221-B2
Publication Date
2017-07-11
Expiration Date
2034-03-06
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
Implementations disclosed herein provide for a microneedle electrode system comprising a microneedle electrode patch connected to external electronics. The microneedle electrode patch comprises a first flexible substrate having a plurality of conductive pads disposed thereon, a plurality of three-dimensional, individually addressable microneedle electrode arrays where each array has a plurality of microneedles extending from an upper surface thereof and a lower surface adapted to contact a corresponding one of the plurality of conductive pads disposed on the first substrate, and a second flexible substrate having a plurality of openings defined therein dimensioned to accommodate at least a portion of the upper surface of the microneedle electrode array from which the microneedles extend. Each of the conductive pads is disposed in electrical communication with a corresponding one of the plurality of microneedle electrode arrays and the first and second substrate are bonded together such that each one of the plurality of microneedle electrode arrays extends through a corresponding one of the plurality of openings defined in the second substrate.
Core Innovation
The invention provides a microneedle electrode system comprising a microneedle electrode patch with a first flexible substrate featuring multiple conductive pads, a plurality of three-dimensional, individually addressable microneedle electrode arrays, and a second flexible substrate with openings to accommodate the microneedle arrays. Each microneedle electrode array has microneedles extending from its upper surface and a lower surface adapted to contact the conductive pads, allowing for direct electrical communication.
The background describes the problem of electrode positioning errors in traditional nerve conduction studies, which can cause increased current requirements, patient discomfort, and unintentional stimulation of adjacent nerves, as well as recording artifacts and reduced signal quality. Larger electrodes do not solve these problems and may increase noise and artifact. Additionally, traditional approaches are limited by stimulus artifacts and difficulty in precisely assessing nerve function over short lengths due to electrode placement limitations.
This invention addresses these issues by enabling precise, minimally invasive, and segmentable electrical stimulation and recording from target nerves and muscles via individually addressable and spatially arranged microneedle electrode arrays. This structure allows improved localization, reduced stimulation artifacts, and enhanced signal fidelity, while facilitating repeatable and user-independent operation in neurophysiological diagnostics and therapeutic stimulation.
Claims Coverage
There are four independent claims that define the inventive features of the microneedle electrode patch, system, and associated method.
Microneedle electrode patch with flexible substrates and electrical communication
A microneedle electrode patch comprising: - A first flexible substrate with at least one conductive pad and an associated conductive trace near the edge. - At least one microneedle electrode array made from a conductive substrate with a plurality of microneedles on its upper surface and a lower surface that contacts the conductive pad, where the array has a coating. - A second flexible substrate with at least one opening to accommodate the microneedle array, bonded such that electrical communication is established, and the microneedles are sized and shaped to pierce the stratum granulosum of mammalian skin.
Microneedle electrode patch with microneedle arrays of specified height
A microneedle electrode patch comprising: - A first flexible substrate with at least one conductive pad and corresponding conductive trace. - At least one microneedle electrode array as above with a coating, wherein the microneedles have a height of about 100 to about 1000 micrometers above the array upper surface. - A second flexible substrate with openings for the arrays, wherein the patch is assembled with electrical communication as in the previous feature.
Microneedle electrode system with individually addressable microneedle arrays and external electronics
A microneedle electrode system comprising: - A microneedle electrode patch with a first flexible substrate carrying multiple conductive pads, each with a conductive trace and distal electrical contact. - Multiple microneedle electrode arrays with a coating, each contacting a conductive pad and extending through corresponding openings in a second flexible substrate. - External electronics connected to each array, adapted to stimulate or record electrical activity from each array. - Each microneedle electrode array is individually addressable and can be functionally integrated to form an effective electrode, with microneedles sized and shaped to pierce the stratum granulosum of mammalian skin.
Microneedle electrode system with microneedle arrays of specified height
A microneedle electrode system comprising: - A microneedle electrode patch as above, where microneedle arrays have a height of about 100 to about 1000 micrometers above the array upper surface. - External electronics connect to each microneedle array, adapted to stimulate or record electrical activity and allow selective integration of the arrays as effective electrodes.
Method for using microneedle electrode system for stimulation and recording
A method comprising: 1. Providing a microneedle electrode system as described, including a patch with flexible substrates, conductive pads, microneedle arrays with coating, and external electronics to individually address each array. 2. Applying the patch to a target region with at least one nerve and a muscle. 3. Selectively stimulating a first portion of the microneedle arrays. 4. Selectively recording evoked electrical activity from at least a second portion of the microneedle arrays.
The independent claims cover the construction of a microneedle electrode patch with flexible substrates and defined microneedle geometry, the integration of systems enabling addressed stimulation/recording via external electronics, specified microneedle heights, and methods for using such systems for targeted stimulation and signal acquisition.
Stated Advantages
Reduces the degree of operator training required to perform neurodiagnostic studies.
Allows comparative studies and measurement of parameters such as local nerve conduction velocity in a straightforward and repeatable manner.
Minimizes or eliminates confounding factors from anatomic variability and operator-dependent electrode placement.
Enables significant improvement in signal fidelity for a dramatic reduction in electrode footprint.
Improves signal-to-noise ratio by recording only over the area of interest and reduces current required for stimulation.
Allows electrical signals to bypass outer layers of skin, reducing resistance and increasing signal fidelity.
Microneedle electrode arrays demonstrate nearly an order of magnitude reduction in impedance for a much smaller area compared to standard electrodes.
Can algorithmically determine optimal electrode placement to improve validity and repeatability of nerve conduction studies.
Allows a single microneedle electrode array to perform both stimulation and recording, reducing the need for separate electrodes.
Enables multiple simultaneous recording sites to expedite exams and reduce operator demands.
Differential stimulation patterns allow selective assessment of sensory and motor nerve fibers without moving the recording sites.
Permits home monitoring of neurophysiological parameters with minimal user intervention.
Documented Applications
Performing nerve conduction studies and related neurophysiological measurements.
Functional nerve assessment using nerve-mapping via array recordings.
Algorithmic determination of subcutaneous nerve course for improved electrode placement.
Conducting inching studies in conditions such as carpal tunnel syndrome by measuring at multiple locations along the same nerve.
Selective assessment of sensory and motor components of mixed nerves through differential stimulation patterns.
Therapeutic stimulation, including monitoring and modulating response to stimulus in disorders such as migraine or occipital neuralgia.
Home monitoring of neurophysiological parameters for patients with nerve disease, enabling detection of disease progression.
Interested in licensing this patent?