U.S. patent application number 15/589471 was filed with the patent office on 2017-11-16 for waveguide neural interface device.
This patent application is currently assigned to NeuroNexus Technologies, Inc.. The applicant listed for this patent is NeuroNexus Technologies, Inc.. Invention is credited to Mayurachat Ning Gulari, Daryl R. Kipke, KC Kong, John P. Seymour.
Application Number | 20170326382 15/589471 |
Document ID | / |
Family ID | 43970375 |
Filed Date | 2017-11-16 |
United States Patent
Application |
20170326382 |
Kind Code |
A1 |
Seymour; John P. ; et
al. |
November 16, 2017 |
WAVEGUIDE NEURAL INTERFACE DEVICE
Abstract
Waveguide neural interface devices and methods for fabricating
such devices are provided herein. An exemplary interface device
includes a neural device comprising an exterior neural device
sidewall extending to a distal end portion of the neural device, an
array of electrode sites supported by a first face of the neural
device sidewall. The array includes a recording electrode site. The
exemplary interface device further includes a waveguide extending
along the neural device, the waveguide having a distal end to emit
light to illuminate targeted tissue adjacent to the recording
electrode site, and a light redirecting element disposed at the
distal end of the waveguide. The light redirecting element
redirects light traveling through the waveguide in a manner that
avoids direct illumination of the recording electrode site on the
first face of the neural device sidewall.
Inventors: |
Seymour; John P.; (Ann
Arbor, MI) ; Gulari; Mayurachat Ning; (Ann Arbor,
MI) ; Kipke; Daryl R.; (Dexter, MI) ; Kong;
KC; (Ann Arbor, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NeuroNexus Technologies, Inc. |
Ann Arbor |
MI |
US |
|
|
Assignee: |
NeuroNexus Technologies,
Inc.
Ann Arbor
MI
|
Family ID: |
43970375 |
Appl. No.: |
15/589471 |
Filed: |
May 8, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14521552 |
Oct 23, 2014 |
9643027 |
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15589471 |
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12940748 |
Nov 5, 2010 |
8870857 |
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14521552 |
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61321089 |
Apr 5, 2010 |
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61258494 |
Nov 5, 2009 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61N 5/0622 20130101;
Y10T 29/49016 20150115; A61B 5/0084 20130101; A61B 5/4076 20130101;
A61B 2562/0233 20130101; A61N 2005/0643 20130101; A61N 2005/0626
20130101; A61B 5/04001 20130101; A61B 2562/046 20130101 |
International
Class: |
A61N 5/06 20060101
A61N005/06; A61B 5/00 20060101 A61B005/00; A61B 5/00 20060101
A61B005/00; A61B 5/04 20060101 A61B005/04 |
Claims
1. A waveguide neural interface device comprising: a neural device
configured for implanting in tissue, the neural device comprising
an exterior neural device sidewall extending to a distal end
portion of the neural device; an array of electrode sites supported
by a first face of the neural device sidewall, wherein the array of
electrode sites are configured to electrically communicate with
their surroundings and comprises at least one recording electrode
site; a waveguide extending along at least a portion of the neural
device, the waveguide having a proximal end to receive light from a
light source and a distal end to emit the light to illuminate
targeted tissue adjacent to the at least one recording electrode
site; and a light redirecting element disposed at the distal end of
the waveguide, the light redirecting element configured to redirect
light traveling through the waveguide in a manner that avoids
direct illumination of the at least one recording electrode site on
the first face of the neural device sidewall.
2. The waveguide neural interface device of claim 1, wherein the at
least one recording electrode site is configured to sample
illuminated tissue.
3. The waveguide neural interface device of claim 1, wherein the
waveguide is an optical fiber supported by the first face of the
neural device sidewall.
4. The waveguide neural interface device of claim 3, wherein the
optical fiber include a beveled tip as the light redirecting
element, the beveled tip having an angle that refracts emitted
light away from the array of electrode sites.
5. The waveguide neural interface device of claim 1, wherein the
waveguide comprises: an inner waveguide core formed over the lower
cladding material; and an upper cladding material portion that
partially covers the inner waveguide core.
6. The waveguide neural interface device of claim 5, wherein the
light redirecting element comprises an opening in the upper
cladding material portion that exposes the inner waveguide core,
wherein the opening is angled within respect to a longitudinal axis
of the waveguide.
7. The waveguide neural interface device of claim 6, wherein the
opening in the upper cladding material portion that exposes the
inner waveguide core exposes an edge of the inner waveguide core
such that light is emitted from a side surface of the inner
waveguide core and from a top surface of the inner waveguide
core.
8. The waveguide neural interface device of claim 1, wherein the
light redirecting element includes a reflector disposed at the
distal end of the waveguide.
9. The waveguide neural interface device of claim 8, wherein the
distal end of the waveguide is tapered towards the reflector.
10. The waveguide neural interface device of claim 9, wherein a
reflective surface of the reflector is parallel to the first face
of the neural device sidewall and the waveguide directs light
toward the reflector at an angle relative to the reflective
surface.
11. A waveguide neural interface device comprising: a neural device
substrate having an elongate shape, the neural device substrate
having a first face that is positioned opposite a second face; an
array of electrode sites disposed on the first face of the neural
device substrate, wherein the array of electrode sites are
configured to electrically communicate with their surroundings and
comprises at least one recording electrode site; and a waveguide
extending along the second face of the neural device substrate, the
waveguide having a proximal end to receive light from a light
source and a distal end to emit the received light to illuminate
targeted tissue adjacent to the at least one recording electrode
site, wherein the distal end of the waveguide have a light
directing feature that extends laterally beyond a lateral edge of
the neural device substrate, the light redirecting feature
configured to redirect the received light toward the first face of
the neural device substrate and around the neural device
substrate.
12. The waveguide neural interface device of claim 11, wherein the
light redirecting feature extends laterally beyond three sides of
the neural device substrate.
13. The waveguide neural interface device of claim 11, wherein the
distal end of the waveguide extends beyond a distal end of the
neural device substrate and the distal end of the waveguide
includes an angled tip to facilitate insertion of the waveguide
neural interface device into tissue.
14. The waveguide neural interface device of claim 11, wherein a
distal end of the neural device substrate includes an angled tip to
facilitate insertion of the waveguide neural interface device into
tissue.
15. The waveguide neural interface device of claim 14, wherein a
distal end of the waveguide includes an angled tip to facilitate
insertion of the waveguide neural interface device into tissue.
16. The waveguide neural interface device of claim 11, wherein the
waveguide has a first thickness and the neural device substrate has
a second thickness, the first thickness being greater than the
second thickness such that the waveguide structurally supports the
neural device substrate.
17. The waveguide neural interface device of claim 11, wherein the
waveguide comprises: an inner core; a cladding layer surrounding
the inner core, wherein a material of the inner core and a material
of the cladding layer cooperate to provide internal reflection to
the waveguide; and an optically dissipating portion formed in the
cladding layer to selectively emit the light toward the targeted
tissue.
18. The waveguide neural interface device of claim 17, wherein the
optically dissipating portion comprises an opening formed in the
cladding layer and a coating layer of a light dissipating material
contacting the inner core.
19. A waveguide fabrication process, the process comprising:
depositing a sacrificial material layer onto a substrate;
depositing a lower cladding material layer onto the sacrificial
material layer; forming an inner waveguide core on the lower
cladding material layer; depositing an upper cladding material
layer over the inner waveguide core, a portion of the upper
cladding material layer contacting the lower cladding material
layer; and forming an aperture in the upper cladding material layer
to provide an optically dissipating portion of a waveguide
including the inner waveguide core so that light introduced into
the waveguide is emitted from the aperture.
20. The waveguide fabrication process of claim 19, further
comprising: forming a coating layer over the upper cladding
material layer and aperture; and patterning the coating layer to
remove at least a portion of the coating layer from over the upper
cladding material layer.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S.
patent application Ser. No. 14/521,552, entitled "WAVEGUIDE NEURAL
INTERFACE DEVICE," filed on Oct. 23, 2014, now U.S. Pat. No.
9,643,027, which is a divisional application of U.S. patent
application Ser. No. 12/940,748, also entitled "WAVEGUIDE NEURAL
INTERFACE DEVICE," filed on Nov. 5, 2010, now U.S. Pat. No.
8,870,857, which claims the benefit of U.S. Provisional Application
Nos. 61/258,494, filed Nov. 5, 2009, and 61/321,089, filed Apr. 5,
2010, all of which are incorporated herein in their entirety by
this reference.
TECHNICAL FIELD
[0002] This invention relates generally to the neural device field,
and more specifically to an improved waveguide neural interface
device in the neural device field.
BACKGROUND
[0003] Advances in neuroscience have largely depended on the
advance of technology, which continually provides new methods to
perturb neural circuits and measure the circuit's response. One
recent advance is the use of optogenetic tools to perturb neural
circuits, particularly neural circuits with cell-type specificity.
Optogenetics creates light-sensitive ion channels for optical
stimulation of neural assemblies, and therefore allow experimenters
or medical practitioners to selectively excite neural channels
and/or inhibit other neural channels with high precision.
Optogenetic technology is driving demand for new techniques and
products to couple light stimulation with high-density neural
recordings. Intracortical opto-electrical devices or "optrodes"
provide the ultimate combination of perturbation and monitoring
capabilities. However, the technology and application of
conventional optrode devices are raw and inefficient. Commercial
systems are not available and current techniques have limitations
in most experiments. For instance, many neuroscientists modify
commercially available optical fibers for use in their optogenetic
studies, but these have drawbacks that limit practical
applications, including having only one-dimensional light output,
and being brittle and dangerous due to being made of fused silica.
Furthermore, an electrical artifact, known as the Becquerel or
photoelectrochemical effect, arises when an electrode is placed in
a conductive medium and illuminated even at low intensity. In the
Becquerel effect, incident light produces a current that affects
low frequency potentials, thereby confounding some neural recording
applications.
[0004] Thus, there is a need in the neural interface field, which
includes the clinical treatment of neurological disorders, to
create an improved waveguide neural interface device. This
invention provides such an improved waveguide neural interface
device.
BRIEF DESCRIPTION OF THE FIGURES
[0005] FIG. 1A is a front schematic view of one variation of a
waveguide neural interface device 100 according to the present
invention;
[0006] FIGS. 1B, 1C, and 1D are side schematic views of various
embodiments of waveguide neural interface devices according to the
present invention;
[0007] FIG. 2 is a side schematic view of the neural interface
device 100 shown in FIG. 1;
[0008] FIGS. 3A and 3B are front and side schematic views,
respectively, of another variation of a waveguide interface device
according to the present invention;
[0009] FIGS. 4A and 4B are front and side schematic views,
respectively, of another variation of a waveguide interface device
according to the present invention;
[0010] FIGS. 5A and 5B are front and side schematic views,
respectively, of another variation of a waveguide interface device
according to the present invention;
[0011] FIGS. 6A and 6B are front and side schematic views,
respectively, of another variation of a waveguide interface device
according to the present invention;
[0012] FIGS. 7 and 8 are schematics of branched variations of the
waveguide neural interface device of the first preferred
embodiment;
[0013] FIGS. 9A, 9B, and 9C are front, side, and back view
schematics, respectively, of the circuit board of the waveguide
neural interface device of a preferred embodiment;
[0014] FIGS. 9D and 9E are schematics of variations of the circuit
board of the waveguide neural interface device of a preferred
embodiment;
[0015] FIG. 10 is a schematic of one variation of the waveguide
neural interface device of a second preferred embodiment;
[0016] FIGS. 11A and 11B are schematics of a perspective view and
cross-sectional view of FIG. 11A taken along line A-A,
respectively, of another variation of the waveguide neural
interface device of a second preferred embodiment;
[0017] FIGS. 11C and 11D are schematics of a top view and
cross-sectional view of FIG. 11C taken along the line B-B,
respectively, of another variation of the waveguide neural
interface device of a second preferred embodiment;
[0018] FIG. 12A is a side view schematic of a conventional
optrode;
[0019] FIGS. 12B and 12C are side view schematics of variations of
the waveguide neural interface device of a second preferred
embodiment;
[0020] FIG. 12D is a plot of light intensity as a function of depth
or longitudinal distance along the waveguide, for a conventional
optrode and the waveguide neural interface device of a second
preferred embodiment;
[0021] FIGS. 13A, 13B, 13C, and 13D are schematics of the
fabrication process of a thin-film waveguide of the waveguide
neural interface device of a second preferred embodiment;
[0022] FIGS. 14A, 14B, 14C, and 14D are schematics of the waveguide
component, the neural device component, and two possible assembled
perspective views, respectively, of the waveguide neural interface
device of a second preferred embodiment;
[0023] FIGS. 15A, 15B, 15C, 15D, and 15E are schematics of the
method of making a waveguide neural interface device of a preferred
embodiment; and
[0024] FIG. 16 is a schematic of the method of making a waveguide
neural interface device of another preferred embodiment.
DETAILED DESCRIPTION
[0025] The following description of embodiments of the invention is
not intended to limit the invention to these preferred embodiments,
but rather to enable any person skilled in the art to make and use
this invention. As used herein and unless stated otherwise, the
term "dissipation" (and its derivatives) is used to refer to the
dissipation of light as a result of diffusion, scattering (e.g.,
single event scattering or multiple event scattering), or any
suitable emission or redirection of light.
1. Waveguide Neural Interface Device of a First Preferred
Embodiment
[0026] As shown in FIGS. 1 and 2, the waveguide neural interface
device 100 of a first preferred embodiment includes: a neural
device 110 implantable in tissue and including an array of
electrode sites 112 that electrically communicate with their
surroundings, in which the array of electrode sites 112 includes at
least one recording electrode site; and a waveguide 120 coupled to
the neural device that includes a light directing element 122 that
carries light along a longitudinal axis and redirects carried light
to illuminate selectively targeted tissue. The waveguide 120, which
is preferably formed separately from the neural device 110,
redirects at least a portion of the carried light laterally away
from the longitudinal axis, and the recording electrode site is
preferably configured to sample illuminated tissue. The waveguide
neural interface device of this embodiment provides greater
flexibility and functionality to the design space of neural
electrical-optical devices, or "optrodes". The waveguide neural
interface device may provide a one-dimensional optical stimulation
pattern (e.g., FIGS. 1 and 3-6), or at least a two-dimensional
optical stimulation pattern (e.g., FIGS. 10 and 11). The waveguide
neural interface device preferably provides such optical
stimulation patterns with neural recording capabilities for
applications of optogenetic techniques. For example, the device may
enable the control and monitoring of neural activity with spatial
selectivity, and temporal resolution and duration that are useful
for clinical treatment and mechanistic investigation of neural
assemblies. The waveguide neural interface device 100 is preferably
used to provide optical stimulation and neural monitoring in
clinical applications (e.g., treatment of Parkinson's disease,
epilepsy, depression, obesity, hypertension, but may be used in any
condition where stimulation is useful as a treatment, or any
suitable condition) and/or in any suitable research applications
(e.g., for linking and mapping behavior to the collective activity
of neural assemblies). Combining highly specific 2D and 3D neural
probes (having electrical sensing and/or stimulation) with optical
sensing and/or stimulation may significantly increase possible
experimental and clinical applications. The waveguide neural
interface device is preferably insertable or implantable in neural
tissue, and more preferably brain tissue, but may be used with any
suitable tissue.
[0027] The neural device 110 functions to provide structure for the
array of electrode sites 112, and in some cases, for insertion
and/or implantation of the waveguide neural interface device into
tissue. The neural device 110 may be a neural probe such as that
described in U.S. Patent Application No. 2008/0208283, which is
included in its entirety by this reference. Alternatively, the
neural device 110 may be any suitable neural probe or suitable
structure. As shown in FIGS. 1-9, the neural device 110 includes an
electrode substrate and an array of electrode sites 112 coupled to
the electrode substrate. The array of electrode sites 112
preferably includes one or more recording electrode sites that
sample illuminated tissue, and may further include one or more
stimulation electrode sites that provide electrical stimulation. At
least a portion of the array of electrode sites 112, particularly
the recording electrode sites, are preferably located adjacent to
the light directing element 122 of the waveguide 120, in a manner
to avoid direct illumination on the electrode site, thereby
reducing or eliminating impact of the Becquerel effect on signals
obtained through the neural interface device and improving the
accuracy of data collection in the neural interface device. The
neural device 110 is preferably substantially planar and includes a
front face and a back face behind or opposite the front face.
Although the front and back faces are preferably flat, the neural
device 110 may alternatively have a curved shape, such as one in
which the front and/or back faces are concave, convex, or wavy. In
an alternative version, the neural device 110 is approximately
cylindrical and the electrode sites 112 are arranged axially along
and/or circumferentially around the neural device. The neural
device 110 may alternatively have any suitable shape or
cross-section, such as elliptical or rectangular. The neural device
may be flexible (e.g., may include a flexible interconnect coupled
to an electrode substrate) or rigid (e.g., electrode substrate
coupled to a rigid backing, rigid carrier, or other rigid
structure).
[0028] The waveguide 120 functions to redirect light away from the
waveguide neural interface device to optically stimulate targeted
tissue. In some embodiments, as shown in FIG. 6, the waveguide 120
may further function as a carrier or other structure for providing
structural support of the waveguide neural interface device for
insertion into tissue. In these embodiments, the waveguide 120 is
preferably rigid or rigid enough to provide support for insertion
into tissue. For example, the neural device 110 may be a flexible
neural probe substrate, with the waveguide 120 relatively thick and
rigid and the neural probe substrate relatively thin and/or
flexible. The waveguide 120 may be tapered, narrowing towards a
distal end of the waveguide, to reduce tissue damage during
insertion into the tissue. The waveguide 120 preferably receives
light along its longitudinal axis from a light source, but may
alternatively receive light in any suitable manner. For receiving
light, the waveguide may have a relatively large cross-section for
mating to an optical connector that provides the light. The
waveguide 120 may carry the light through internal reflection, or
any suitable method. The waveguide 120 may be rigid, semi-rigid, or
flexible. The waveguide 120 is preferably a thin-film structure
such as one formed by one or more of several suitable fabrication
processes including: micro-opto-electro-mechanical systems (MOEMS),
photolithography, microembossing, thermal nanoimprint lithography
(NIL), combined nanoimprinting and photolithography (CNP), and/or
any suitable fabrication process. Example waveguide materials for
these fabrication techniques include but are not limited to organic
materials such as SU-8, Poly(methyl methacrylate) (PMMA),
perfluoropolymers, polydimethylsiloxane (PDMS), parylene, and/or
inorganic materials such as silicon dioxide (SiO.sub.2), silicon
nitride, silicon oxynitride, and silica. However, the waveguide may
alternatively be an optical fiber or any suitable light-carrying
waveguide made of any suitable material.
[0029] As shown in FIGS. 1-6, the waveguide 120 preferably includes
a light directing element 122 that directs light laterally away
from the longitudinal axis of the waveguide (i.e., the directed
light is aimed or travels in a direction having a nonzero component
perpendicular to the longitudinal axis of the waveguide). The light
directing element 122 may be one or more of several variations,
including one or more features that refract, reflect, focus, and/or
scatters light, and/or perform any suitable manipulation of light.
In a preferred embodiment, the waveguide 120 further includes an
inner core and a cladding layer over the core, and the core and
cladding material preferably facilitate internal reflection along
the waveguide. The waveguide may undergo photolithographic
processes to pattern the cladding and selectively expose the core,
such that the light directing portion of the waveguide includes the
exposed core.
[0030] In a first variation, as shown in FIG. 1B, the light
directing element 122 includes a refractor 122a that refracts
carried light away from the waveguide 120 at a particular angle of
refraction. The refractor may be located at a distal end of the
waveguide. For example, the distal end may include an angled tip
whose shape is configured to refract light carried by the
waveguide. As another example, the distal end may additionally
and/or alternatively include material having a different index of
refraction than the rest of the waveguide. The refractor 122a may
additionally and/or alternatively be located at any suitable
location along the length of the waveguide 120. For example, as
shown in FIG. 2, the waveguide may include one or more angled
refractors 122a that each distributes a portion of the carried
light away from the waveguide 120 through refraction. The light
directing element may include any suitable number of refractors of
any suitable size or shape.
[0031] In a second variation, as shown in FIGS. 1C and 4A, the
light directing element includes a reflector 122b that reflects
carried light away from the waveguide 120 or back along the
longitudinal axis. The reflector 122b may be a thin film of
reflective metal, a mirror, or any suitable kind of reflector. The
surface roughness of this reflector may be increased or decreased
to modulate the directionality or focus of the light path. The
reflector may be located at a distal end of the waveguide 120. For
example, the distal end of the waveguide may include a reflector
that is angled to reflect carried light away from the waveguide at
a certain angle. As another example, the distal end of the
waveguide may include a reflector 224 that reflects carried light
back in a proximal direction along the longitudinal axis, which may
be useful to recapture light that "misses" or bypasses other light
directing elements. In this example, the reflected light, which
otherwise would be lost, is preferably given another opportunity to
be directed away from the waveguide 120 by another light directing
element, thereby increasing efficiency of the waveguide neural
interface device. The reflector 122b may additionally and/or
alternatively be located at any suitable location along the length
of the waveguide. The light directing element may further include
any suitable number of reflectors.
[0032] In a third variation, as shown in FIG. 1D, the light
directing element includes a lens 122c that focuses light to a
point away from the waveguide 120. The lens 122c, which may be a
tubular lens or any suitable lens, is preferably configured to
converge carried light to a focal point outside of the waveguide
120, diverge the carried light, or direct the carried light in any
suitable manner. The lens may have a focal length preselected to
focus light to targeted tissue. Alternatively, the lens may have an
adjustable and/or variable focal length that enables the lens to
focus light at an adjustable distance away from the waveguide,
thereby providing another dimension of control of tissue targeting.
Examples of adjustable lens include temperature-controlled lens
(e.g., liquid crystal lens) and voltage-controlled lens (e.g.,
ferroelectric lens). The light directing element may further
include any suitable number of lenses which may be manufactured
separately and modularly assembled inside the opening in the device
aperture 114.
[0033] In a fourth variation, the light directing element 122
includes a scattering element that scatters carried light away from
the waveguide 120 or back along the longitudinal axis, in
applications similar to the reflector. The scattering element may
include a distributed Bragg reflector, surface corrugations, an
optically dissipating coating, optically dissipating molecules
embedded in the waveguide 120, and/or any suitable kind of
scattering element. The light directing element may further include
any suitable number of scattering elements.
[0034] The waveguide 120 may include one or more light directing
elements 122, and where there are multiple light directing
elements, the light directing elements may be one or more of the
variations in any suitable combination. Furthermore, the waveguide
120 may include an arrangement of a plurality of light directing
elements longitudinally and/or laterally along the waveguide in any
suitable pattern, thereby distributing carried light away from the
waveguide in any suitable manner. Each light directing element may
redirect a portion of the carried light from a different point on
the waveguide. In particular, each light directing element may
redirect a portion of the carried light at a different distance
along the length of the waveguide.
[0035] In some variations, the waveguide 120 may further include a
filter, such as one that allows only a certain bandwidth of light
to pass. For example, in applications in which only a portion of
illuminated tissue is configured to be stimulated by a certain
color or wavelength, the filter allowing that color or wavelength
to pass may consequently allow only the receptive portion of
illuminated tissue to be stimulated, thereby providing another
dimension of tissue targeting.
[0036] The waveguide neural interface device may include any
suitable combination of the neural device 110, waveguide 120, and
one or more light directing elements 122. In a first variation of
the waveguide neural interface device, as shown in FIGS. 1A-1D, the
array of electrode sites 112 is located on a front face 110a of the
neural device 110, and the waveguide 120 is coupled to or mounted
on a back face 110b of the neural device 110, where the front face
110a of the neural device may be any suitable face of the neural
device (and may be defined as any face including at least a portion
of the array of electrode sites) and the back face 110b is on an
opposite side of (or "behind") the front face. The "front face" In
this variation, the neural device 110 preferably includes an
aperture 114 that extends between the back face and front face. The
aperture 114 is preferably a through hole, but may include any
suitable aperture such as a grating, a mesh-like structure, filter,
or any suitable structure that permits passage of light. The
aperture may additionally and/or alternatively include a
translucent material that permits passage of light from the
waveguide. The array of electrode sites 112 and the light directing
element 122 are preferably located relative to the aperture 114
such that the light directing element of the waveguide 120
redirects light through the aperture 114 to illuminate tissue
adjacent to the electrode sites. For example, as shown in FIG. 1A,
the array of electrode sites 112 may be arranged around the
perimeter of the aperture 114. The light directing element 122 may
include a refractor that refracts light through the aperture of the
neural device, a reflector that reflects light through the aperture
of the neural device, and/or a lens that focuses light through the
aperture. The neural device 110 may include additional apertures
that are distributed along the length of the neural device and
corresponding to a light directing element.
[0037] In a second variation of the waveguide neural interface
device, as shown in FIGS. 3 and 4, the array of electrode sites 112
is located on the front face 110a of the neural device 110 and the
waveguide 120 is coupled to or mounted on the front face of the
neural device adjacent to the array of electrode sites 112. The
waveguide 120 may include one or more of any combination of light
directing element variations. For example, the front-mounted
waveguide includes a refractor 122a and/or reflector 122b light
directing element on the distal end of the waveguide that refracts
and/or reflects light at an angle that illuminates tissue adjacent
to the array of electrode sites 112. As another example, as shown
in FIG. 2, the waveguide 120 may include one or more light
directing elements positioned along the length of the waveguide,
such that each light directing element distributes at least a
portion of the carried light away from the waveguide 120 through
refraction, reflection, a lens, or any suitable light directing
element.
[0038] In a third variation of the waveguide neural interface
device, as shown in FIG. 5, the waveguide 120 extends laterally
beyond the electrode substrate or other portion of the neural
device 110. In this variation, the light directing element may
extend laterally beyond the neural device, and include any of the
refractor, reflector, lens, and/or scattering element variations as
described above, or any suitable variation of a light direction
element.
[0039] Other variations of the waveguide neural interface device
include any suitable combination of the above variations, such as
one in which the array of electrode sites 112 is located on the
front face of the neural device 110 and the waveguide 120 is both
coupled to the back face of the neural device having an aperture
and extends laterally beyond a portion of the neural device, such
that some carried light is directed away from the waveguide 120
through the aperture and some carried light is directed away from
the waveguide from the lateral extension.
[0040] The waveguide 120 is preferably formed separately from the
neural device 110, and coupled to the neural device 110 during
assembly as described below. However, the waveguide may
alternatively be integrally formed with the neural device (such as
at the wafer level during fabrication of the waveguide neural
interface device).
[0041] In some embodiments, the waveguide neural interface device
may include multiple branches and/or multiple waveguides configured
to interface with different targeted regions of tissue. The modular
integration of multiple branches, multiple waveguides, and/or
multiple arrays of electrode sites enables targeting of different
regions of tissue while reducing overall size and footprint of the
equipment and potentially reducing external connections to a single
external connection. For example, as shown in FIG. 7, the neural
device 110 may include a first branch 116a and a second branch
116b, in which a first waveguide 120a is coupled to the first
branch and a second waveguide is coupled to the second branch.
Additional waveguides may be distributed on the first, second, or
more branches of the neural device in any suitable manner (e.g.,
two waveguides on one branch and a third on another branch, as
shown in FIG. 9D). The branches may be positioned front to back
relative to each other and/or side to side relative to each other
(FIG. 7), or in any suitable orientation. As another example, as
shown in FIG. 8, the neural device 110 may include a first branch
and a second branch passing through different access points in the
skull, in which the array of electrode sites 112 (or a subset of
the array of electrode sites, such as a portion that includes
stimulation electrode sites and/or some recording electrode sites)
is coupled to the first branch and the waveguide is coupled to the
second branch. The branches of the neural device 110 may be
flexible or rigid, such as on a flexible or rigid substrate.
Alternatively, a portion of the branches on a single neural device
may be flexible, while another portion of the branches may be
rigid.
[0042] The waveguide neural interface device preferably further
includes a circuit board 130 that interfaces with at least one of
the array of electrode sites 112 and the waveguide 120. As shown in
FIGS. 9A-9C, the circuit board is preferably double faced (or
"double sided") and includes an electrical face 130a having
electrical components 132 that interface with the array of
electrode sites 112 and an optical face 130b having optical
components 134 that interface with the waveguide 120. The circuit
board may be a single board with two faces or two boards coupled
back-to-back with fasteners, adhesive, or in any suitable manner.
By separating the electrical and optical components, the circuit
board may permit maximization of space on the circuit board and
reduce noise coupling. The waveguide 120 preferably couples
directly to the optical face 130b of the circuit board and the
neural device 110 preferably couples directly to the electrical
face of the circuit board. This "modular" coupling assembly may be
aided by features to improve component alignment, such as fiducial
marks, tabs, and/or corresponding alignment holes 142.
Alternatively, as shown in FIG. 9D, the circuit board may include
an electrical region having electrical components 132 and an
optical region having optical components 134, in which both the
electrical and optical regions are located on the same face or side
of the circuit board 130. In another variation, each face of the
circuit board may include a mixture of electrical and optical
components (i.e., each face includes a portion of the total
electrical components and a portion of the total optical
components). In one variation, the circuit board may include
folding portions that fold over a main face of the circuit board.
For example, a folding portion may include a light source 136 that,
when the folding portion is folded over the main face of the
circuit board, meets and couples to a waveguide 120. In another
variation, as shown in FIG. 9E, the circuit board may include two
faces that sandwich the waveguide and/or neural device (the circuit
board may fold or include two separate sandwiching pieces), which
may advantageously allow modular construction of the circuit board
and reduce noise coupling or other incidental interactions on the
circuit board. The electrical components 132 preferably include
various passive or active electrical components, bond pads for the
array of electrode sites, a connector for interfacing the neural
device 110 to external components (e.g., a flexible interconnect
that carries electrical lines for the array of electrode sites),
current driver 133 for a diode or LED, control electronics for
providing a control signal, a battery power source, and/or any
suitable electronics. The optical components 134 preferably include
one or more light collecting elements 137, light focusing elements
139, optical filters, and/or any suitable optical components. The
optical face may further include one or more light sources coupled
to the waveguide or waveguides. The light source 136 may be a
circuit board-mounted light-emitting diode (LED), a laser diode, a
vertical cavity surface-emitting laser (VCSEL), or any suitable
laser or light source. However, the light source may be an external
light source such as a laser, laser diode, or one or more LEDs.
Coupling light from an external light source or from a circuit
board-mounted light source may be accomplished using one or more
techniques, and the number of coupling options is increased by
using modular components 110 and 120. For example, coupling the
light source and the waveguide may involve mounting any number of
collecting elements 137 (e.g., spherical lens, biconvex lens,
plano-convex lens) and focusing elements 139 (e.g, gradient index
(GRIN) lens, spherical lens, biconvex lens, plano-convex lens)
between the light source and the waveguide. Coupling may also use
butt coupling that directly couples the light source and the
waveguide. Surface emitting LEDs may be mounted vertically (e.g.,
DIP socket on a "surf" board) or horizontally on the same circuit
board and rely on reflective elements to direct the path into one
or more longitudinally mounted waveguides. However, any suitable
coupling means may be used to couple the light source to the one or
more waveguides.
[0043] Fabrication of the waveguide 120 preferably further includes
releasing the waveguide from the substrate through any suitable
process, and cut to a suitable, predetermined length. The process
of building, releasing, then cutting the waveguide 220 may be
useful to improve modularity of the process and/or customizations
of specific waveguide neural interface devices, such as for the
specific customization of shape and distribution of the optically
portions and dimensions of the overall waveguide. The light
directing elements 122 may also be controlled and formed in the
process of cutting or etching the waveguide to create various tip
profiles and angles.
2. Waveguide Neural Interface Device of a Second Preferred
Embodiment
[0044] As shown in FIGS. 10 and 11, the waveguide neural interface
device 200 of a second preferred embodiment includes: a neural
device 210 implantable in tissue and including an array of
electrode sites 212 that electrically communicate with their
surroundings, in which the array of electrode sites includes at
least one recording electrode site, and a waveguide 220 coupled to
the neural device 210 that carries light along a longitudinal axis
and includes an optically dissipating portion 222 that dissipates
the carried light to illuminate selectively targeted tissue. At
least a portion of the dissipated light preferably travels
laterally away from the longitudinal axis from the optically
dissipating portion 222, and the recording electrode site is
preferably configured to sample illuminated tissue which may be
electrically excited by the illumination. The waveguide neural
interface device of the second preferred embodiment is preferably
used in a similar manner as the first preferred embodiment.
[0045] The neural device 210 of the second preferred embodiment is
preferably similar to the neural device 110 of the first preferred
embodiment. The neural device 210 preferably includes an electrode
substrate that is layered over the waveguide 220, and the electrode
substrate preferably includes at least a portion of the array of
electrode sites 212.
[0046] The waveguide 220 of the second preferred embodiment of the
waveguide neural device functions to redirect light away from the
waveguide neural interface device to optically stimulate targeted
tissue. The waveguide 220 of the second preferred embodiment of the
waveguide neural interface device may be similar to that of the
first preferred embodiment. The waveguide 220 may be cylindrical
(e.g., an optical fiber or other cylindrical waveguide, as in FIG.
10), substantially planar (e.g., a thin-film waveguide, as in FIG.
11A), or any suitable shape. In this embodiment, the waveguide 220
preferably includes one or more optically dissipating portions 222
that dissipate light away from the waveguide neural interface
device. The optically dissipating portions 222 may be elongated
"light ports" that are substantially rectangular, elliptical,
circular, or any suitable shape. The particular shape and
distribution of optically dissipating portions may depend on the
specific application and desired customization. As shown in FIG.
11B, the dissipated light preferably travels laterally away from
the longitudinal axis of the waveguide 220 (i.e., the dissipated
light travels in a direction having a nonzero component
perpendicular to the longitudinal axis of the waveguide). The
dissipated light preferably has substantially uniform intensity as
a function of distance along the waveguide 220, and preferably as a
function of distance along the optically dissipating portion. As
shown in FIGS. 12A and 12D, conventional optical fiber optrodes
provide light axially in only one dimension from one end of the
optical fiber, which results in uncontrolled scattering, conical
spreading and a rapidly declining intensity as a function of
distance along the waveguide (i.e. depth of the device when
inserted into tissue). In contrast, as shown in FIGS. 12B-12D, the
waveguide neural interface device described herein preferably
enables at least two-dimensional light with controlled scattering
and a uniform intensity as a function of distance along the
waveguide, although in some alternative embodiments the device may
provide light in any suitable pattern of distribution and/or
intensity.
[0047] The waveguide 220 includes an inner core 230 and a cladding
layer 232 over the core, and the core and cladding material are
preferably selected such that the core and cladding cooperate to
facilitate internal reflection. The waveguide 220 preferably
undergoes photolithographic processes to pattern the cladding and
selectively expose the core, such that the optically dissipating
portion 222 of the waveguide includes the exposed core. However,
the optically dissipating portion 222 may alternatively be formed
in any suitable manner. The optically dissipating portion may
include a dissipating material to further define the amount of
light diffusion. The amount of light diffusion that the optically
dissipating portion 222 provides is at least partially dependent on
the amount of surface roughness of the core, the specific
properties of the dissipating material, width of the optically
dissipating portion relative to the total waveguide width, and
waveguide thickness. During fabrication, many if not all of these
parameters can be closely controlled, providing for precise
specificity in waveguide features and detailed customization of the
waveguide neural interface device for a variety of
applications.
[0048] In one variation of a waveguide fabrication process, as
shown in FIG. 13A, a sacrificial layer of material 238 is deposited
onto a substrate 236, and a lower cladding layer 232a of cladding
material is deposited (e.g. through CVD, PECVD, spinning processes
or any suitable deposition process) onto the sacrificial layer. As
shown in FIG. 13B, the core material is deposited onto the
structure and patterned to form the inner core 230. An upper
cladding layer 232b of cladding material is deposited over the core
230, followed by deposition and patterning of a hard mask. The
upper cladding layer 232b is preferably patterned with a suitable
patterning process that selectively removes the upper cladding
layer 232b and/or roughens the core surface to form the optically
dissipating portion 222. The exposed core surface may additionally
and/or alternatively be texturized in any suitable manner to form
the optically dissipating portion 222. The optional, controlled
addition of a dissipating medium (e.g, diffusive and/or scattering
material) to the exposed core may further affect the amount of
light dissipation that the optically dissipating portion provides.
In one variation, as shown in FIG. 13C, a coating layer 234 of a
light dissipating material (e.g., aluminum oxide, titanium dioxide,
diamond powder, or any suitable material) may be deposited and
patterned over the exposed core. For example, the addition of an
optically dissipating material may be similar to that described in
U.S. Pat. Nos. 5,946,441 and 5,580,932, which are incorporated in
their entirety by this reference. The dissipating material is
preferably biocompatible, has a refractive index greater than that
of the waveguide core, and has low optical absorption. In another
variation, molecules of the light dissipating material may be
embedded in the exposed core using ion implantation or diffusion or
any appropriate means of embedding. Furthermore,
wavelength-sensitive light dissipating molecules could be applied
to different "ports" in the waveguide at various locations to
selectively control light emission as a function of wavelength
(e.g., provide spatial control of light output for another
dimension of customization), such as that described in U.S. Pat.
No. 7,194,158, which is incorporated in its entirety by this
reference.
[0049] Depositing and patterning the optically dissipating layer
may alternatively be performed before depositing the upper cladding
layer of cladding material. Fabrication of the waveguide 220
preferably further includes releasing the waveguide from the
substrate through any suitable process, and cut to a suitable,
predetermined length. The process of building, releasing, then
cutting the waveguide 220 may be useful to improve modularity of
the process and/or customizations of specific waveguide neural
interface devices, such as for the specific customization of shape
and distribution of the optically dissipating portions and
dimensions of the overall waveguide. Alternatively, the final
length of the waveguide 220 may be etched with another hard mask
prior to release from the substrate. In some preferred embodiments,
the overall length of the waveguide 220 may be between 3-400 mm
long and/or up to 200 .mu.m in thickness, depending on the
application.
[0050] In one specific example, a waveguide includes a core of SU-8
(supplied by MicroChem) and cladding layers of Cytop CTL-809M
(supplied by Asahi Glass). Cytop includes a lower index of
refraction (n=1.34) than SU-8 (n-1.59), such that the combination
of the two materials forms a waveguide with internal reflection.
The sacrificial layer, lower cladding layer, core, and upper
cladding layer are preferably formed as described above. The upper
cladding layer is then patterned with an oxygen plasma to expose
and roughen the core surface. A dissipating layer of aluminum oxide
approximately 300 nm thick is sputter deposited in place of the
removed upper cladding layer. The layer of aluminum oxide is then
patterned using buffer hydrofluoric (HF) acid. The waveguide is
then released from the wafer and diamond-scribed to a desired
length. In this example, the waveguide thickness is on the order of
approximately 30 .mu.m.
[0051] In another variation of a waveguide fabrication process, as
shown in FIG. 14, the waveguide 220 is an optical fiber with an
internal core 230 and an outer cladding layer 232 around the core.
Similar to the first variation of a waveguide fabrication process,
the cladding layer is preferably patterned to selectively remove
the cladding layer to expose and/or roughen the core surface. The
exposed core surface may additionally and/or alternatively be
texturized in any suitable manner to form the optically dissipating
portion. The optional, controlled addition of a dissipating coating
and/or embedded dissipating molecules to the core surface may
further define the optically dissipating portion. Additional
alternative processes for creating the waveguide 220 are described
in U.S. Pat. No. 5,946,441, entitled "Light-diffusing device for an
optical fiber, methods of producing and using same, and apparatus
for diffusing light from an optical fiber", which is incorporated
in its entirety by this reference.
[0052] The electrode substrate of the neural device 210 is
preferably layered over the waveguide 220, and more preferably in
such a manner that the optically dissipating portion of the
waveguide is adjacent to at least a portion of the array of
electrode sites. The waveguide neural interface device may include
any suitable combination of the neural device 210 and waveguide
220. As shown in FIGS. 10 and 14, in a first variation, the
electrode substrate is wrapped around the waveguide 220. In this
variation, the electrode substrate preferably includes at least one
aperture 214 that corresponds to the optically dissipating portion
222 of the waveguide 220 such that the dissipated light is
scattered through the aperture 214 to illuminate tissue. The
aperture 214 may be formed in the neural device 210 prior to
wrapping around the waveguide 220, or may be formed after wrapping
around the waveguide. Furthermore, the optically dissipating
portion 222 may be formed in the waveguide 220 before or after
wrapping the electrode substrate around the waveguide. At least a
portion of the array of electrode sites 212 is preferably near or
adjacent to the aperture 214 such that at least one recording
electrode site is configured to sample illuminated tissue. The
aperture 214 may be substantially rectangular, circular,
elliptical, or any suitable shape. As another example, the aperture
214 may be elongated in the direction of the longitudinal axis of
the waveguide, as shown in FIG. 10. The aperture 214 of the
electrode substrate is preferably similar in shape and size to an
underlying optically dissipating portion 222 of the waveguide 220,
but the aperture may alternatively be smaller or larger than the
optically dissipating portion 222. The electrode substrate may be
permanently attached to the waveguide 220 such that its position
relative to the waveguide is fixed. Alternatively, the electrode
substrate may be non-permanently attached to the waveguide, such
that the neural device is adjustable along the length and/or in
rotation around the waveguide 220, such that the aperture 214 acts
as a movable window that selectively allows light from the
optically dissipating portion, thereby adding another dimension of
customization. The dissipated light preferably has substantially
uniform intensity as a function of distance along the aperture 214.
Further, the electrode substrate may include multiple apertures,
each corresponding to an optically dissipating portion. The number
of apertures in the electrode substrate may be less than, equal to,
or greater than the number of optically dissipating portions. In
one method of fabrication, the cladding removal and aperture 214
may be created simultaneously using laser ablation, followed by the
deposition of the diffusive medium. Alternatively, the cladding
removal and aperture formation may occur separately using any
suitable technique such as ablation or selective etching.
[0053] In another variation, a dissipative portion 222 may
alternatively and/or additionally be deposited or otherwise
integrated in the electrode substrate. In this variation, the
cladding 232 is selectively removed from the waveguide but the
light dissipating material may be realized in the electrode
substrate and not directly on the waveguide. Alignment of the
diffusive layer to the corresponding cladding occurs during
assembly. A transparent adhesive may be applied to improve light
coupling to the diffusive region.
[0054] In a second variation, as shown in FIG. 11A, the waveguide
220 preferably extends laterally beyond the electrode substrate or
other portion of the neural device 210, and more preferably the
optically dissipating portion 222 of the waveguide 220 extends
laterally beyond the electrode substrate. As shown in FIGS.
12B-12D, the dissipated light preferably travels laterally away
from the longitudinal axis of the waveguide 220 and preferably has
substantially uniform intensity as a function of distance along the
waveguide. In this variation, the waveguide 220 may include a
single continuous optically dissipating portion (FIG. 12B) or two
or more optically dissipating portions (FIG. 12C) to create
discontinuous illumination along the length of the waveguide.
[0055] In a third variation, as shown in FIGS. 11C and 11D, the
waveguide 220 is preferably mounted on a first side of the device
210 (e.g., the top of the device 210). In this variation, the
optically dissipating portion is located on the waveguide that such
that optically dissipating portion emits light through the side of
the waveguide and/or through the top of the waveguide by diffusing
and/or scattering light along the length of at least a portion of
the waveguide. The optically dissipating portion may be formed on
any suitable edge, side, and/or face to emit light in any suitable
direction. Similar to the second variation, the waveguide may
include a single continuous optically dissipating portion or two or
more separate optically dissipating portions to create
discontinuous illumination along the length of the waveguide. One
advantage of such a device is to create uniform intensity of light
in a local tissue volume near the diffusive element and do so over
a relatively long spatial dimension, such as the angled edge shown
in FIG. 11C.
[0056] As shown in FIG. 14A, the waveguide 220 may further include
a reflector tip that reflects carried light along the longitudinal
axis. The reflector tip may be similar to that described in the
first preferred embodiment of the waveguide neural interface
device. By reflecting carried light back along the longitudinal
axis, light that otherwise would be lost is returned along the
waveguide 220 for potential redirection through the optically
dissipating portion, thereby increases efficiency.
[0057] Additional variations of the waveguide neural interface
device may include any suitable combination of the neural device
210, array of electrode sites, and waveguide 220. For example, the
waveguide neural interface device may include both a light
direction element of the first preferred embodiment and an
optically dissipating portion of the second preferred
embodiment.
[0058] In some embodiments, similar to that of the first preferred
embodiment, the waveguide neural interface device of the second
preferred embodiment may include multiple branches and/or multiple
waveguides configured to interface with different regions of
tissue, and preferably includes a circuit board that interfaces
with at least one of the array of electrode sites and the
waveguide. The circuit board in the second preferred embodiment is
preferably similar to that of the first preferred embodiment.
3. Method of Assembling a Waveguide Neural Interface Device
[0059] As shown in FIGS. 15A-15E, the method of making a waveguide
neural interface device S300 of a preferred embodiment includes the
steps of: providing a neural device that includes a plurality of
electrode sites S310; providing a waveguide, separate from the
neural device, that is configured to carry light along a
longitudinal axis and includes a light directing element that
redirects the carried light away from the waveguide S320; providing
a circuit board, separate from the neural device and the waveguide,
that is configured to interface with the plurality of electrode
sites and the waveguide S330; orienting the light emitting element
of the waveguide to a predetermined angular orientation relative to
the neural device S340, in which the predetermined angular
orientation is based on a selected direction of redirected light;
and coupling each structure of the group S350 comprising the neural
device, the waveguide, and the circuit board to at least one of the
other structures in the group, in which coupling includes fixing
the waveguide at the predetermined angular orientation relative to
the neural device S352.
[0060] The method of making the waveguide neural interface device
S300 is a modular, cost-effective approach that has several
potential advantages. First, the method may provide high spatial
resolution, since the waveguide can be rotated along any axis to
transform a planar x-y dimension into an effective z-axis dimension
that would otherwise be difficult to achieve. Second, the method
may enable manufacture of custom waveguides neural interface
devices that are capable of region-specific illumination, while
avoiding cost and yield problems that would otherwise occur. In
other words, if the waveguide and neural device are integrated at
the wafer-level, then the number of desirable/useful permutations
of waveguide neural interface device design is so large that it
impedes the profitability of the sale of such a device. The method
can overcome this problem, transcending the practical limits of a
wafer-level approach. Third, the method may separate yield issues
in one aspect of either the neural device or waveguide fabrication,
thereby improving average yield and lowering overall cost of the
final combination waveguide neural interface product. However, in
alternative embodiments, the method of making the waveguide neural
interface device may include any suitable steps. For example, a
portion or all of the neural device, waveguide, and circuit board
components may be fabricated in an integrated fashion (e.g.,
fabricated in sequence with any photolithographic processes and/or
any suitable technique, without the post-fabrication assembly
described in method 300). For example, the neural device and the
waveguide may be fabricated together in sequence as an integrated
structure, and then coupled to the circuit board after
fabrication.
[0061] The steps of providing a neural device S310, providing a
waveguide S320, and providing a circuit board S330 preferably
include providing a neural device or neural probe, waveguide, and
circuit board similar to those described above in the first
preferred embodiment 100 and/or second preferred embodiment 200 of
the waveguide neural interface device, but may alternatively
include providing any suitable neural device, waveguide, and/or
circuit board. Furthermore, although the method is primarily
illustrated with a waveguide neural interface device of the first
preferred embodiment, the method may be performed to assemble that
of the second preferred embodiment (FIGS. 14 and 16) or any
suitable waveguide neural interface device preferably having at
least separate neural device and waveguide components, and perhaps
additionally having a separate circuit board component.
[0062] Step S340, which includes the step of orienting the light
directing element of the waveguide to a predetermined angular
orientation, functions to set the direction of redirected light to
a particular direction. As shown in FIG. 15B, the step of
orientating the light directing element preferably includes
rotating the waveguide about the longitudinal axis of the waveguide
to the predetermined angular orientation S342. However, the
waveguide may be rotated about any suitable axis. Furthermore, the
step of orienting the light directing element of the waveguide may
include translating the waveguide along a longitudinal, lateral, or
any suitable axis S344. Orienting the waveguide in this manner
preferably enables another dimension of spatial variance along
another axis, particularly features typically in an x-y plane to
become features in the z-axis when rotated relative to the neural
device. Step S340 enables further customization of the waveguide
neural interface device.
[0063] Step S350, which includes the step of coupling each
structure of the group comprising the neural device, the waveguide,
and the circuit board to at least one of the other structures in
the group, functions to fix and assemble the structures of the
group to form the waveguide neural interface device. Step S350
preferably includes fixing the waveguide at the predetermined
angular orientation relative to the neural device and/or circuit
board. In step S350, the three components (neural device,
waveguide, and circuit board) may be mounted or attached in any
order. In a first variation, as shown in FIG. 15C, step S350
includes coupling the waveguide and the circuit board to form a
waveguide-circuit board structure S362 and coupling the neural
probe and the waveguide-circuit board structure S364. In this
variation, coupling the waveguide and the circuit board S350 may
include coupling the waveguide to an optical face of the circuit
board having optical components and coupling the neural device to
an electrical face of the circuit board having electrical
components. In a second variation, as shown in FIG. 15D, step S350
includes coupling the neural device and the circuit board to form a
neural device-circuit board structure S372 and coupling the
waveguide and the neural device-circuit board structure S374. In a
third variation, as shown in FIG. 15E, step S350 includes coupling
the waveguide and the neural device to form a waveguide-neural
device structure S382 and coupling the circuit board and the
waveguide-neural device structure S384. In summary of the
variations of step S350, any order of assembly of the neural
device, waveguide and circuit board may be used: (1) couple the
waveguide and the circuit board, then couple the neural device and
the waveguide-circuit board structure, (2) couple the neural device
and the circuit board, then couple the waveguide and the neural
device-circuit board structure; or (3) couple the waveguide and the
neural device, then couple the circuit board and the
waveguide-neural device structure. In any of these variations of
step S350, coupling the circuit board to the waveguide may include
coupling an optical coupler that transfers light from a light
source to the waveguide. In any of these variations of step S350,
coupling the circuit board to the neural device may include
coupling an interconnect (e.g., a flexible interconnect) between
the neural device and the circuit board to transfer electrical
signals. The coupling step S350 may include layering or stacking
two of the components (e.g. layering the neural device over the
waveguide), wrapping one component (e.g., wrapping the neural
device over the waveguide), connecting end to end (e.g., coupling
the circuit board to an axial end of the neural device or
waveguide), and/or any suitable coupling step. Furthermore, in
other embodiments additional intermediary components may be
introduced to indirectly couple any two of the structures. For
example, both the neural device and the waveguide may be coupled to
a common base such as a carrier, without the neural device and the
waveguide being directly coupled to each other.
[0064] Step S350 of coupling may be performed manually and/or with
machine assistance. One or more of the components may include
features to aid component alignment, such as fiducial marks, tabs,
and/or corresponding alignment holes. The steps of coupling any two
of the structures may include applying an epoxy such a medical
grade epoxy (e.g., Epoxy Tek H70E-2 or 320, which is designed to
shield light) or a UV-curable epoxy, or using fasteners, or any
suitable adhesive or other means for coupling. The steps of
coupling any two of the structures may additionally and/or
alternatively include applying a polymer overcoat around at least
two of the structures in the group.
[0065] As a person skilled in the art will recognize from the
previous detailed description and from the figures and claims,
modifications and changes can be made to the preferred embodiments
of the invention without departing from the scope of this invention
defined in the following claims.
* * * * *