U.S. patent application number 15/883493 was filed with the patent office on 2018-06-07 for implantable optical feedthrough connector.
This patent application is currently assigned to Circuit Therapeutics, Inc.. The applicant listed for this patent is Circuit Therapeutics, Inc.. Invention is credited to David Angeley, Brian Andrew Ellingwood, Greg Stahler.
Application Number | 20180156994 15/883493 |
Document ID | / |
Family ID | 55218284 |
Filed Date | 2018-06-07 |
United States Patent
Application |
20180156994 |
Kind Code |
A1 |
Stahler; Greg ; et
al. |
June 7, 2018 |
IMPLANTABLE OPTICAL FEEDTHROUGH CONNECTOR
Abstract
Configurations are described for creating and using separable
optical feedthroughs. These are especially useful in their at least
semi-hermetic form when integrated with implantable photomedical
devices. One embodiment is directed to a system for operatively
coupling an optical output from a light source positioned inside of
a sealed housing to an external optical fiber, comprising: a first
optical fiber disposed adjacent to the light source and configured
to receive at least a portion of the optical output; a second
optical fiber operatively coupled to the first optical fiber and
configured to capture at least a portion of an output from the
first optical fiber; a primary seal operatively coupled to the
housing between the light source and the second optical fiber that
is at least partially transparent; and a secondary seal positioned
between the second optical fiber and the environment.
Inventors: |
Stahler; Greg; (Belmont,
CA) ; Angeley; David; (Charlottesville, VA) ;
Ellingwood; Brian Andrew; (Sunnyvale, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Circuit Therapeutics, Inc. |
Menlo Park |
CA |
US |
|
|
Assignee: |
Circuit Therapeutics, Inc.
Menlo Park
CA
|
Family ID: |
55218284 |
Appl. No.: |
15/883493 |
Filed: |
January 30, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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15478111 |
Apr 3, 2017 |
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15883493 |
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14812881 |
Jul 29, 2015 |
9645332 |
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15478111 |
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62030446 |
Jul 29, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 6/4248 20130101;
G02B 6/3816 20130101; G02B 6/3821 20130101; G02B 6/4292 20130101;
G02B 6/3817 20130101; G02B 6/32 20130101 |
International
Class: |
G02B 6/42 20060101
G02B006/42; G02B 6/38 20060101 G02B006/38; G02B 6/32 20060101
G02B006/32 |
Claims
1. A system for operatively coupling an optical output from a light
source positioned inside of a sealed housing to an external optical
fiber, comprising: a. a first optical fiber disposed adjacent to
the light source and configured to receive at least a portion of
the optical output; b. a second optical fiber operatively coupled
to the first optical fiber and configured to capture at least a
portion of an output from the first optical fiber; c. a primary
seal operatively coupled to the housing between the light source
and the second optical fiber that is at least partially
transparent; and d. a secondary seal positioned between the second
optical fiber and the environment.
Description
RELATED APPLICATION DATA
[0001] The present application is a continuation application of
U.S. patent application Ser. No. 15/478,111, filed on Apr. 3, 2017,
which is a continuation application of U.S. patent application Ser.
No. 14/812,881, filed on Jul. 29, 2015, which claims priority to
U.S. Provisional Application Ser. No. 62/030,446, filed Jul. 29,
2014. The foregoing applications are hereby incorporated by
reference into the present application in their entirety. Priority
to the aforementioned applications is hereby expressly claimed in
accordance with 35 U.S.C. .sctn..sctn. 119, 120, and 365 and any
other applicable statutes.
FIELD OF THE INVENTION
[0002] The present invention relates generally to systems, devices,
and processes for optical feedthrough, and especially to hermetic
optical feedthroughs for medical devices.
BACKGROUND
[0003] The ability to carry light from within a sealed enclosure to
an illumination target is typically accomplished using a simple
window or fiber optic coupler. However, these measures do not
suffice to make the light source enclosure and the optical delivery
means separable, and nominally hermetically sealed once joined,
such as may be desired in an implantable medical device. Such
implantable medical devices may be of use in photomedical and
optogenetic therapies. Such systems are also described in
International Appl. No. PCT/US2013/000262, which shares at least
one inventor in common with the present application, and is hereby
incorporated by reference in its entirety.
SUMMARY
[0004] One embodiment is directed to a system for operatively
coupling an optical output from a light source positioned inside of
a sealed housing to an external optical fiber, comprising: a first
optical fiber disposed adjacent to the light source and configured
to receive at least a portion of the optical output; a second
optical fiber operatively coupled to the first optical fiber and
configured to capture at least a portion of an output from the
first optical fiber; a primary seal operatively coupled to the
housing between the light source and the second optical fiber that
is at least partially transparent; and a secondary seal positioned
between the second optical fiber and the environment. The first
optical fiber may be housed within a ferrule. The ferrule may form
the primary seal. The ferrule may be housed within a connector
body. The connector body may form the primary seal. The ferrule may
comprise a material selected from the group consisting of: fused
silica, glass, zirconia, stainless steel, titanium, brass, and
copper. The connector body may comprise a material selected from
the group consisting of: fused silica, glass, zirconia, stainless
steel, titanium, brass, and copper. The seal may be formed by a
technique selected from the group consisting of: brazing,
soldering, and adhering. The primary seal may be formed by a
technique selected from the group consisting of: brazing,
soldering, and adhering. The primary seal may comprise an element
selected from the group consisting of: a ferrule, a connector body,
an optical window, and a lens. The distal surface of the first
optical fiber and the proximal surface of the second optical fiber
may be in physical contact. Light may be emitted from the first
optical fiber and subsequently focused by a lens through the
primary seal and onto the proximal face of the second optical
fiber. The primary seal further may comprise a physical
registration feature that mates with a complementary registration
feature in a housing that contains the second optical fiber. The
physical registration feature may be selected from the group
consisting of: a recessed feature, and a raised feature. The second
optical fiber may be housed within a ferrule. The ferrule may
comprise a material selected from the group consisting of: fused
silica, glass, zirconia, stainless steel, titanium, brass, and
copper. A spring may be configured to push the ferrule into
physical contact with the transparent region of the primary seal.
The material comprising the window or lens may be selected from the
group consisting of: glass, fused silica, and sapphire. A second
lens subsequent to the primary seal may be configured focus light
onto the proximal face of the second optical fiber. The secondary
seal may comprise multiple individual axial seals along its length.
Electrical connections may be made within the secondary seal. The
first optical fiber may comprise a configuration selected from the
group consisting of: a step index fiber, a gradient index fiber,
and a hollow fiber. The second optical fiber may comprise a
configuration selected from the group consisting of: a step index
fiber, a gradient index fiber, and a hollow fiber. The lens used
may be configured to operate at unit magnification. The second lens
used may be configured to operate at unit magnification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 depicts an embodiment of the invention directed
towards use with an implantable medical system.
[0006] FIG. 2 depicts an embodiment of the invention directed
towards complementary use with the system of FIG. 1.
[0007] FIG. 3 depicts a further embodiment, wherein a spring force
is used to keep fiber ends in contact with each other.
[0008] FIG. 4 depicts a further embodiment of the invention
directed at the use of a focusing system for optical coupling.
[0009] FIG. 5 depicts a further embodiment, wherein a lens is used
to create a seal in the housing.
[0010] FIG. 6 depicts a further embodiment, wherein a recess in a
lens or window is used to align an optical fiber.
[0011] FIG. 7 depicts a further embodiment, wherein a raised
feature on a lens or window is used to align an optical fiber.
[0012] FIG. 8 depicts a further embodiment, wherein two lenses
allow for variable distances between two fibers being coupled.
DETAILED DESCRIPTION
[0013] FIG. 1 depicts an embodiment directed at use with an
implantable medical device, such that it may create a hermetic seal
without damaging optical properties of fiber or light guide with
temperature. Light from a light source (not shown for simplicity
and clarity) may be carried via optical fiber 2. The optical fiber
2 may be coupled to ferrule 4, which may be in turn coupled to
optical output module 6. As shown, optical fiber 8 is configured to
be concentric with the connector body. The connector body may be
comprised of a metallic, polymeric, or ceramic material such as
stainless steel, polycarbonate, or similar materials.
[0014] The type of optical fiber may depend upon the character of
the light being used and the nature of the therapy intended. For
example, in the case of visible light illuminating a peripheral
nerve or structures within the brain, 105 .mu.m silica core
diameter, 125 .mu.m silica cladding diameter, 250 .mu.m acrylate
buffer diameter 0.22 NA step index low-OH optical fiber such as
Thorlabs P/N FG105LCA, or Fiberguide P/N SFS105/125/250Y may be
used for optical fiber 8. A zirconia ferrule, such as the Precision
Fiber Products P/N MM-FER2030-2500 1.25 mm OD ceramic stick ferrule
may be used to construct ferrule 4 and/or ferrule 10. Ferrule 4 may
be brazed into optical output module 6. Leakage rates of less than
1.times.10.sup.-7 cc/sec Helium at 1 atmospheric differential
pressure may be achieved by utilizing Kryoflex Polycrystalline
Ceramic, manufactured by SOURIAU PA&E, as a brazing compound
between zirconia ferrules and metallic surfaces of optical output
module 6. Alternately, the elements may be gold plated and gold
brazed to create a hermetic seal. Optical output module 6 may be
subsequently laser welded to housing 12 to form a hermetic seal
about hermetic sealing surface 14, as shown, which may be
configured to be a titanium flange.
[0015] The proximal end of optical fiber 8 may stand proud of
sealing zone 16, for example, by approximately 1-4 mm. Axial
alignment of optical fiber 8 to optical fiber 2 via ferrule 10 and
ferrule 4, respectively, may be achieved by configuring the
connector to comprise an alignment sleeve 18, which may be
fabricated from zirconia to facilitate insertion, especially when
ferrule 10 and ferrule 4 are also fabricated from zirconia. The
wall thickness of alignment sleeve 18 may be made greater to
accommodate shorter engagement lengths of the ferrules 4 & 10
while providing uniform axial force to maintain concentricity
between their respective fibers. As an example, for a 3 mm exposure
for both ferrules 4 & 10, which may each be comprised of the
aforementioned 1.25 mm outer diameter zirconia ferrule, alignment
sleeve 18 may be configured to have a wall thickness of 150 .mu.m
and a finish smooth to within 0.5 .mu.m along the inner surface. An
optical coupling interface 20 may be configured to be a physical
contact coupling, such as is achieved using PC-, APC-, and
UPC-types of fiber termination.
[0016] Connection between electrical connection surfaces 22 within
delivery segment 24 and the electrical connections within the
housing connector portion 26 of housing 12 may be configured such
as those in the BalSeal Sygnus device, as is described in detail in
U.S. Pat. No. 6,835,084 by Poon and Balsells, which is hereby
incorporated by reference in its entirety. Housing connector
portion 26 may comprise an epoxy overmould, for example, of the
components described above. The electrical connections may be made
of wires fabricated from stainless steel, platinum-iridium, or
similar materials as described in the abovementioned reference.
[0017] The sealing of the distal seal zone 28 and boot zone 30 need
not be as tight as that of the seals within the connector
comprising seal 32 and sealing surface 34, and may be of greater ID
than those same elements. As such, distal seal zone 28 and boot
zone 30 may provide for easier insertion of sealing zone 16 of
delivery segment 24 into housing connector portion 26.
[0018] FIG. 2 shows an exemplary embodiment of a delivery segment
24 configured for use with the invention, and comprising an
applicator 36 operationally coupled to delivery segment 24 via
undulations 38. Delivery segment 24 may further comprise an optical
fiber 8 to conduct light to applicator 36 and the target tissue via
applicator 36, electrical wires 44 operationally coupled to
electrical contact surfaces 40, jacket 42 configured to enclose and
protect electrical wires 44 and fiber 8 from the implantation
environment, sealing surfaces 46, distal seal 48, and boot 50 may
serve to further isolate the implantation environment from the
electrical connections of electrical connection surfaces 40, and
provide a means for connecting the delivery segment to a housing,
not shown, utilizing sealing zone 52. Sealing zone 52 may be
fabricated by moulding (or overmoulding) the entire assembly of the
connector and boot 50 and incorporating the proximal end of jacket
42 such that it forms a contiguous enclosed segment. Jacket 42 may
be made from a biocompatible tubing, such as, by way of nonlimiting
example; polyethylene, silicone, PTFE, ePTFE, and/or PEEK. The
sealing zone 52 constituting a portion of the connector may be made
of similar materials. Electrical connection surfaces 40 may be made
of platinum or stainless steel, for example. In the exemplary
configuration shown, a 500 .mu.m ID 700 .mu.m OD silicone tube may
serve as jacket 42, and be made to enclose as many as 19 100 .mu.m
OD electrical wires 44. The optical fiber 8 comprises a proximal
end 54, and a distal end 56. The distal end of optical fiber 8
provides light to (and possibly from when optical feedback is
desired) applicator 36, while the proximal end of optical fiber 8
may serve to couple light from one or more light sources to
delivery segment 24.
[0019] Alternately, the applicator 36 may be eliminated to provide
a delivery segment comprised of a single end-emitting optical
fiber. Such a configuration may lend itself to implantation within
the brain of a patient for treatment of the CNS, for example.
[0020] FIG. 3 shows an exemplary embodiment of a coupling interface
configured for use with the invention, and comprising a
spring-loaded ferrule used to maintain contact between the two
fibers being coupled. Stainless steel may be used to construct the
spring cover 58. The spring cover 58 may be retained in place
within the housing connector portion, not shown, by means of a ball
end spring plunger (e.g. part number 3408A65 from McMaster-Carr) or
a similar feature within the housing connector portion. The spring
60 acts against the spring cover 58 and applies force against the
delivery segment ferrule 10 via the delivery segment ferrule
housing 62, keeping the proximal end of the optical fiber 8 in
contact with the distal end of the optical fiber 2 and minimizing
the amount of light/energy lost at the interface. Alternately, the
spring cover 58 may not actually cover the spring 60 and instead be
a simple flange that prevents the spring 60 from moving in the
distal direction. In the exemplary configuration shown, a spring 60
is applying force to the delivery segment ferrule 10 via the
delivery segment ferrule housing 62. An alternate embodiment may
apply spring force directly to the delivery segment ferrule 10. An
alternate embodiment may instead incorporate a spring 60 to apply
force directly or indirectly to the light source ferrule 4, or two
springs 60 may be used to apply force directly or indirectly to
both ferrules 4 & 10.
[0021] As shown in the exemplary embodiment of FIG. 4, optical
coupling may also be achieved using an optically powered coupling,
such as reimaging the distal end of optical fiber 2 onto the
proximal end of optical fiber 8 through an optical window 66. This
may be achieved by substituting an optical window 66 in lieu of a
ferrule to define the outside surface of housing 12 and a lens 70
such as, by way of nonlimiting example, a 1.0 mm Dia..times.2.0 mm
focal length planoconvex lens (e.g. P/N 65-276 from Edmund Optical)
placed subsequent to distal end of optical fiber 2 and within
optical output module 6 within housing 12 that serves to direct
light into the proximal end of optical fiber 8, such as placing a
lens 70 two focal lengths away from optical fiber 2 to operate at
nominally unit magnification, wherein, distances d1 and d2 may not
be equal due to the difference in optical path length introduced by
the window. To relax the axial alignment constraints between
optical fibers 2 & 8, optical fiber 2 may be configured to have
a smaller core diameter than optical fiber 8, or, alternately, by
decreasing the magnification of the optical system to create a spot
nominally smaller that that of optical fiber 2 on the face of
optical fiber 8. To relax the angular alignment constraints between
optical fibers 2 & 8, optical fiber 2 may be configured to have
a smaller numerical aperture than optical fiber 8. The size of the
core for optical fiber 2 may be dictated by the brightness of the
light source, not shown. By way of nonlimiting example, the window
may be comprised of a 5 mm outer diameter and 1 mm thick sapphire
or glass plate and its edges metallized to allow for a brazed or
soldered seal to be created by the window.
[0022] FIG. 5 shows a further embodiment, similar to that of FIG.
4, the alteration of using lens 70 to both create the seal in the
housing and focus light from optical fiber 2 into optical fiber 8.
A spacer 68 has been added to dispose the input end of optical
fiber 8 at the correct distance from lens 70. Furthermore,
alignment features on or within the housing wall may be used to
dispose the input end of optical fiber 8 at the correct
location.
[0023] FIG. 6 shows a further embodiment, similar to that of FIGS.
4 & 5, with the addition of physical registration feature in
the form of a recess 72 in the surface of the lens or window 66 to
align the optical fiber 8. The recess may be sized to accept either
the proximal end of the ferrule 10 or the proximal end of the
optical fiber 8 if the optical fiber 8 is not covered by the
ferrule 10.
[0024] In a further embodiment, similar to that of FIGS. 4 & 5,
FIG. 7 shows the alteration of using a raised physical registration
feature 76 on the surface of the lens or window 66 to align the
optical fiber 8 by use of an alignment sleeve 68 which may fit
directly over, or engage with certain mechanical aspects of, raised
feature 76. The raised feature 76 and alignment sleeve 68 may be
sized to be compatible with different size optical fibers 8 and/or
ferrules 10, such as is done with respect to element 18 of FIG.
1.
[0025] FIG. 8 shows a further embodiment wherein two lenses are
used to produce/receive collimated light. The light exiting optical
fiber 2 enters lens 78 and exits nominally collimated. The
nominally collimated light then travels a distance before entering
lens 80. Since the light is nominally collimated, the distance d2
between lens 78 and lens 80 may vary without critically affecting
the transmission and/or optical coupling efficiency between fibers
2 and 8. After exiting lens 80, the light is focused onto the
proximal end of optical fiber 8. A spacer 68 with alignment
features 90 similar to those described above in FIG. 7 may be used
to position the lens 80 and/or optical fiber 8 with respect to the
optical output of lens 70. The distance d1 between fiber 2 and lens
70 may be the focal length of lens 70. Alignment feature 90 may be
configured to engage with a raised feature 76, as was described
regarding FIG. 7, and may be formed to create a frustoconical
segment (as shown) that engages the edge of raised feature 76. In
this collimated configuration, an angular misalignment with
translate to a lateral shift in the focused spot that is
proportional to the system magnification, thereby possibly
providing a degree of insensitivity to such imperfections and
produce a more clinically robust system. Of course, other such
mating schemes are considered to be within the scope of the present
invention. Spacer 68 may be also configured such that it contains
provisions to hold lens 80 and ferrule 10 within it, as shown.
[0026] Although the descriptions have been focused on embodiments
for implantable photomedical devices, as they are the most
strenuous, this does not preclude their use for other
applications.
[0027] Various exemplary embodiments of the invention are described
herein. Reference is made to these examples in a non-limiting
sense. They are provided to illustrate more broadly applicable
aspects of the invention. Various changes may be made to the
invention described and equivalents may be substituted without
departing from the true spirit and scope of the invention. In
addition, many modifications may be made to adapt a particular
situation, material, composition of matter, process, process act(s)
or step(s) to the objective(s), spirit or scope of the present
invention. Further, as will be appreciated by those with skill in
the art that each of the individual variations described and
illustrated herein has discrete components and features which may
be readily separated from or combined with the features of any of
the other several embodiments without departing from the scope or
spirit of the present inventions. All such modifications are
intended to be within the scope of claims associated with this
disclosure.
[0028] Any of the devices described for carrying out the subject
diagnostic or interventional procedures may be provided in packaged
combination for use in executing such interventions. These supply
"kits" may further include instructions for use and be packaged in
sterile trays or containers as commonly employed for such
purposes.
[0029] The invention includes methods that may be performed using
the subject devices. The methods may comprise the act of providing
such a suitable device. Such provision may be performed by the end
user. In other words, the "providing" act merely requires the end
user obtain, access, approach, position, set-up, activate, power-up
or otherwise act to provide the requisite device in the subject
method. Methods recited herein may be carried out in any order of
the recited events which is logically possible, as well as in the
recited order of events.
[0030] Exemplary aspects of the invention, together with details
regarding material selection and manufacture have been set forth
above. As for other details of the present invention, these may be
appreciated in connection with the above-referenced patents and
publications as well as generally known or appreciated by those
with skill in the art. For example, one with skill in the art will
appreciate that one or more lubricious coatings (e.g., hydrophilic
polymers such as polyvinylpyrrolidone-based compositions,
fluoropolymers such as tetrafluoroethylene, hydrophilic gel or
silicones) may be used in connection with various portions of the
devices, such as relatively large interfacial surfaces of movably
coupled parts, if desired, for example, to facilitate low friction
manipulation or advancement of such objects relative to other
portions of the instrumentation or nearby tissue structures. The
same may hold true with respect to method-based aspects of the
invention in terms of additional acts as commonly or logically
employed.
[0031] In addition, though the invention has been described in
reference to several examples optionally incorporating various
features, the invention is not to be limited to that which is
described or indicated as contemplated with respect to each
variation of the invention. Various changes may be made to the
invention described and equivalents (whether recited herein or not
included for the sake of some brevity) may be substituted without
departing from the true spirit and scope of the invention. In
addition, where a range of values is provided, it is understood
that every intervening value, between the upper and lower limit of
that range and any other stated or intervening value in that stated
range, is encompassed within the invention.
[0032] Also, it is contemplated that any optional feature of the
inventive variations described may be set forth and claimed
independently, or in combination with any one or more of the
features described herein. Reference to a singular item, includes
the possibility that there are plural of the same items present.
More specifically, as used herein and in claims associated hereto,
the singular forms "a," "an," "said," and "the" include plural
referents unless specifically stated otherwise. In other words, use
of the articles allow for "at least one" of the subject item in the
description above as well as claims associated with this
disclosure. It is further noted that such claims may be drafted to
exclude any optional element. As such, this statement is intended
to serve as antecedent basis for use of such exclusive terminology
as "solely," "only" and the like in connection with the recitation
of claim elements, or use of a "negative" limitation.
[0033] Without the use of such exclusive terminology, the term
"comprising" in claims associated with this disclosure shall allow
for the inclusion of any additional element--irrespective of
whether a given number of elements are enumerated in such claims,
or the addition of a feature could be regarded as transforming the
nature of an element set forth in such claims. Except as
specifically defined herein, all technical and scientific terms
used herein are to be given as broad a commonly understood meaning
as possible while maintaining claim validity.
[0034] The breadth of the present invention is not to be limited to
the examples provided and/or the subject specification, but rather
only by the scope of claim language associated with this
disclosure.
* * * * *