U.S. patent application number 10/222719 was filed with the patent office on 2002-12-12 for instrument for implanting sensors and solid materials in a subcutaneous location and method thereof.
Invention is credited to Bardy, Gust H..
Application Number | 20020188252 10/222719 |
Document ID | / |
Family ID | 24585873 |
Filed Date | 2002-12-12 |
United States Patent
Application |
20020188252 |
Kind Code |
A1 |
Bardy, Gust H. |
December 12, 2002 |
Instrument for implanting sensors and solid materials in a
subcutaneous location and method thereof
Abstract
An implantation instrument for implanting a substantially solid
material, including solid medication or drugs, in a subcutaneous
location and method are described. An incising shaft includes a
beveled tip with a cutting edge along a distal end. A syringe body
is affixed to a proximal end of the incising shaft. The syringe
body and the incising shaft each define a substantially
non-circular hollow bore extending continuously along a shared
longitudinal axis. The incising shaft bore does not exceed the
syringe body bore in girth. Both the incising shaft bore and the
syringe body bore are sized to receive the solid material. A
plunger is conformably shaped to the syringe body bore and has an
end piece facilitating deployment of the plunger assembly. The
plunger slidably fits within the syringe body bore and advances the
solid material through the syringe body bore and the incising shaft
bore into the subcutaneous location.
Inventors: |
Bardy, Gust H.; (Seattle,
WA) |
Correspondence
Address: |
PATRICK J S INOUYE P S
810 3RD AVENUE
SUITE 258
SEATTLE
WA
98104
US
|
Family ID: |
24585873 |
Appl. No.: |
10/222719 |
Filed: |
August 15, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10222719 |
Aug 15, 2002 |
|
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09644666 |
Aug 24, 2000 |
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6436068 |
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Current U.S.
Class: |
604/93.01 |
Current CPC
Class: |
A61M 37/0069 20130101;
A61B 2560/063 20130101 |
Class at
Publication: |
604/93.01 |
International
Class: |
A61M 031/00; A61M
037/00 |
Claims
What is claimed is:
1. An implantation instrument for implanting a substantially solid
material in a subcutaneous body location, comprising: an incising
shaft defining a substantially non-circular hollow bore extending
continuously along a longitudinal axis with a beveled tip forming a
cutting edge on a distal end thereof, the incising shaft bore being
sized to receive a substantially solid material for implant; and a
delivery mechanism receiving the incising shaft and comprising a
pushing device facilitating deployment of the substantially solid
material through the incising shaft bore and into an implantation
site.
2. An implantation instrument in accordance with claim 1, further
comprising: a syringe body defining a substantially non-circular
hollow bore extending continuously along a longitudinal axis and
sized to receive the solid material; and the pushing device
comprising a plunger slidably fitted within the syringe body bore,
the plunger conformably shaped to the syringe body bore with an end
piece facilitating deployment of the substantially solid material
into an implantation site.
3. An implantation instrument in accordance with claim 2, wherein
the incising shaft, the syringe body, and the pushing device are
formed with a substantially continuous curve along a commonly
shared ventral side.
4. An implantation instrument in accordance with claim 1, wherein
the delivery mechanism comprises at least one of a syringe and
plunger assembly, an automated compressed gas injection system, and
a mechanical injection system.
5. A subcutaneous implantation instrument for implanting a
substantially solid material, comprising: an incising body
comprising a syringe body and an incising shaft which each define a
substantially non-circular hollow bore extending continuously along
a shared longitudinal axis, the incising shaft comprising a beveled
tip with a cutting edge on a distal end, the incising shaft bore
and the syringe body bore both being sized to receive the solid
material; and a delivery assembly comprising a plunger slidably
fitted within the syringe body bore, the plunger conformably shaped
to the syringe body bore with an end piece facilitating deployment
of the substantially solid material into an implantation site.
6. An implantation instrument for implanting a substantially solid
material in a subcutaneous location, comprising: an incising shaft
comprising a beveled tip with a cutting edge along a distal end
thereof; a syringe body affixed to a proximal end of the incising
shaft, the syringe body and the incising shaft each defining a
substantially non-circular hollow bore extending continuously along
a shared longitudinal axis, the incising shaft bore not exceeding
the syringe body bore in girth, both the incising shaft bore and
the syringe body bore being sized to receive the solid material;
and a plunger conformably shaped to the syringe body bore and
having an end piece facilitating deployment of the plunger
assembly, the plunger slidably fitting within the syringe body bore
and advancing the solid material through the syringe body bore and
the incising shaft bore into the subcutaneous location.
7. An implantation instrument in accordance with claim 6, wherein
the non-circular bore has a cross-sectional shape selected from the
group comprising, and which is substantially shaped as, an oval,
rectangle, square, pentagon, hexagon, heptagon, octagon, and
similar equilateral or non-equilateral shapes.
8. An implantation instrument in accordance with claim 6, wherein
the solid material comprises at least one of a data transmitter and
a sensor collecting at least one of physiological measures and
chemical measures.
9. An implantation instrument in accordance with claim 6, wherein
the solid material comprises a medication.
10. A method for implanting a substantially solid material in a
subcutaneous location, comprising: inserting a beveled tip of an
incising shaft with a cutting edge along a distal end thereof into
an implantation site, a proximal end of the incising shaft being
affixed to a distal end of a syringe body, the syringe body and the
incising shaft each defining a substantially non-circular hollow
bore extending continuously along a shared longitudinal axis, the
incising shaft bore not exceeding the syringe body bore in girth,
both the incising shaft bore and the syringe body bore being sized
to receive the solid material; advancing the solid material through
the syringe body bore and the incising shaft bore into the
subcutaneous location through deployment of a plunger conformably
shaped to the syringe body bore, the deployment being effected via
actuation of an end piece on a distal end of the plunger, the
plunger slidably fitting within the syringe body bore.
11. A method in accordance with claim 10, wherein the non-circular
bore has a cross-sectional shape selected from the group
comprising, and which is substantially shaped as, an oval,
rectangle, square, pentagon, hexagon, heptagon, octagon, and
similar equilateral or non-equilateral shapes.
12. A method in accordance with claim 10, wherein the solid
material comprises at least one of a data transmitter and a sensor
collecting at least one of physiological measures and chemical
measures.
13. A method in accordance with claim 10, wherein the solid
material comprises a medication.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a continuation of U.S. patent
application Ser. No. 09/644,666, filed Aug. 24, 2000, pending, the
priority date of which is claimed and the disclosure of which is
incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates in general to subcutaneous
implantation instruments and methods and, in particular, to an
instrument for implanting sensors and solid materials in a
subcutaneous location and method thereof.
BACKGROUND OF THE INVENTION
[0003] A major part of health care assessment involves the review
and analysis of physiological measurements collected and recorded
by electronic data sensors. In addition to vital signs,
physiological measures can include detailed measurements of organ
functions, body fluid chemistry and rates, activity levels, and
similar measures, both measured directly and derived.
[0004] The type and quality of physiological measures depends
greatly on the type and location of the sensor employed. External
sensors, such as thermometers, blood pressure cuffs, heart rate
monitors, and the like, constitute the most common, and least
invasive, form of sensors. However, these sensors are extremely
limited in the kinds of information which they are able to collect
and encumber the patient with wearing and maintaining an external
sensor. On the other extreme, implantable in situ sensors provide
the most accurate and continuous data stream through immediate
proximity to organs and tissue of interest. However, implantable
sensors are invasive and generally require surgery for
implantation.
[0005] Recent advances in microchip technology have created a new
generation of highly integrated, implantable sensors. For instance,
PCT Application Nos. PCT/GB99/02389, to Habib et al., filed Jul.
22, 1998, pending, and PCT/GB99/02393, to Habib et al., filed Jul.
22, 1998, pending, respectively describe an implantable sensor chip
and treatment regiment, the disclosures of which are incorporated
herein by reference. The sensor chip is adapted to receive and
rectify incoming electromagnetic signals and to transmit data
relating to treatment parameters by wireless telemetry to a
receiver external to a body. Similarly, the emerging Bluetooth
wireless communication standard, described at
http://www.bluetooth.com/developer/specification/specificati-
on.asp, proposes a low cost, small form factor solution to short
range data communications, potentially suitable for use in
implantable sensor technology.
[0006] Even though implantable sensor technology is trending
towards smaller and more specialized microchip sensors, in humans,
these sensors must still be implanted via surgical procedure.
Minimally invasive implantation using large bore needles is
impracticable because sensors, particularly when embodied using
microchip technology, favor a prismatic shape with substantially
rectangular cross sections. A large bore needle can cause a core of
flesh or skin (or hide, when used in domesticated animals) to form
in the pointed tip as the needle is inserted. Cylindrical needles
also severely limit solid sensor sizes, shapes and dimensions to
only those that can be inserted through a circular bore.
[0007] Although current surgical approaches attempt to minimize the
size of incision and decree of invasion, implantation is, at best,
costly, time-consuming, traumatic, requires multiple instruments
and maneuvers, and potentially risky to the patient. Subcutaneous
implantable sensors offer the best compromise between in situ
sensors and external sensors and are potentially insertable with a
simple injection. These sensors are typically implanted below the
dermis in the layer of subcutaneous fat. The subcutaneous
implantation of solid materials has been described in the prior art
as follows.
[0008] An insertion and tunneling tool for a subcutaneous wire
patch electrode is described in U.S. Pat. No. 5,300,106, to Dahl et
al., issued Apr. 5, 1994. The tunneling tool includes a stylet and
a peel-away sheath. The tunneling tool is inserted into an incision
and the stylet is withdrawn once the tunneling tool reaches a
desired position. An electrode segment is inserted into the
subcutaneous tunnel and the peel-away sheath is removed. Although
providing a tool for subcutaneous implantation, the Dahl device
requires an incision into the subcutaneous fat layer and forms an
implantation site larger than the minimum sized required by the
electrode segment. Further more, the cylindrical bore precludes the
injection of non-conforming solid sensors or materials.
[0009] An implant system for animal identification that includes a
device for implanting an identification pellet in a fat layer
beneath the hide or skin of an animal is described in U.S. Pat. No.
4,909,250, to Smith, issued Mar. 20, 1990. The device includes a
curved needle-like tube that terminates at a tapered, sharpened
point. An elongated, flexible plunger is slidably received within
the needle-like tube. The pointed tip is inserted through the hide
or skin and the plunger is actuated to drive the identification
pellet from the tip into the fat layer. However, the Smith device
uses an oversized open bore which can cause coring of the hide or
flesh.
[0010] A trocar for inserting implants is described in PCT
Application No. PCT/US99/08353, to Clarke et al., filed Oct. 29,
1999, pending. An implant retention trocar includes a cannula for
puncturing the skin of an animal and an obturator for delivering
the implant. A spring element received within the cannula prevents
an implant from falling out during the implant process. The cannula
has a distal tip design which causes a minimum of trauma and
tearing of tissue during implant insertion. However, the distal tip
design is specifically directed to cannulas having a substantially
circular bore and thereby limits the size and shape of implant
which can be inserted through the Clarke trocar.
[0011] An instrument for injecting implants through animal hide is
described in U.S. Pat. No. 5,304,119, to Balaban et al., issued
Apr. 19, 1994. The instrument includes an injector having a tubular
body divided into two adjacent segments with a hollow interior
bore. A pair of laterally adjacent tines extend longitudinally from
the first segment to the distal end of the tubular body. A plunger
rod has an exterior diameter just slightly larger than the interior
diameter of the tubular body. With the second segment inserted
beneath the animal hide, the push rod is advanced longitudinally
through the tubular body, thereby pushing the implant through the
bore. As the implant and rod pass through the second segment, the
tines are forced radially away from each other, thereby dilating or
expanding the incision, and facilitating implant. The instrument is
removed from the incision following implantation. Though avoiding
the coring of animal hide or flesh, the instrument forms an
implantation site larger than the minimum sized required by the
implant and causes potentially damaging compaction of the implant
against the laterally adjacent times during implant delivery.
[0012] Therefore, there is need for a non-surgical instrument and
method for subcutaneous implantation of sensors and solid materials
that preferably does not require an incision preparatory to
instrument insertion.
[0013] There is a further need for a subcutaneous implantation
instrument and method capable of implanting sensors and other solid
materials that are not readily disposed to implantation through a
substantially circular bore.
[0014] Moreover, there is a further need for a subcutaneous
implantation instrument and method which is minimally invasive,
preferably creating the smallest needed implantation site, and
capable of implantation without exposing the implant to
longitudinal stresses.
SUMMARY OF THE INVENTION
[0015] The present invention provides an implantation instrument
and method of use for implanting sensors and other solid materials
in a subcutaneous or other site. As used herein, "subcutaneous"
refers generally to those implantation sites located within a body
below the skin. The implantation instrument consists of an incising
shaft attached to a syringe body. The syringe body and incising
shaft both define a substantially non-circular hollow bore for
accommodating the sensor or solid material. The subcutaneous site
is formed by a cutting edge on the distal end of the incising
shaft. The subcutaneous site can be cleared using a clearing trocar
slidably received within the hollow bore. The sensor or solid
material is advanced through the hollow bore and delivered into the
subcutaneous site. The depth of the subcutaneous site can be
limited using a penetration limiting mechanism.
[0016] An embodiment of the present invention is an implantation
instrument for implanting a substantially solid material in a
subcutaneous body location. An incising shaft defines a
substantially non-circular hollow bore extending continuously along
a longitudinal axis. The incising shaft has a beveled tip forming a
cutting edge on a distal end thereof and is sized to receive a
substantially solid material for implant. The solid material, which
can include a sensor, is preferably protected against damage by
encasement within, for example, a mannitol pellet or similar
carrier. The solid material can also be encased in titanium,
silicone, epoxy, or other similar, functionally inert protective
material. A delivery mechanism receives the incising shaft and
includes a pushing device facilitating deployment of the
substantially solid material through the incising shaft bore and
into an implantation site.
[0017] A further embodiment of the present invention is a
subcutaneous implantation instrument for implanting a substantially
solid material. An incising body includes a syringe body and an
incising shaft. The syringe body and the incising shaft each define
a substantially non-circular hollow bore extending continuously
along a shared longitudinal axis. The incising shaft includes a
beveled tip with a cutting edge on a distal end. Several prismatic
or non-cylindrical bore shapes are possible. The incising shaft
bore and the syringe body bore both are sized to receive the solid
material. A delivery assembly includes a plunger slidably fitted
within the syringe body bore. The plunger is conformably shaped to
the syringe body bore with an end piece facilitating deployment of
the substantially solid material into an implantation site.
[0018] A still further embodiment of the present invention is an
implantation instrument for implanting a substantially solid
material in a subcutaneous location. An incising shaft includes a
beveled tip with a cutting edge along a distal end thereof. A
syringe body is affixed to a proximal end of the incising shaft.
The syringe body and the incising shaft each define a substantially
noncircular hollow bore extending continuously along a shared
longitudinal axis. The incising shaft bore does not exceed the
syringe body bore in girth. Both the incising shaft bore and the
syringe body bore are sized to receive the solid material. A
plunger is conformably shaped to the syringe body bore and has an
end piece facilitating deployment of the plunger assembly, the
plunger slidably fits within the syringe body bore and advances the
solid material through the syringe body bore and the incising shaft
bore into the subcutaneous location.
[0019] A still further embodiment of the present invention is a
method for implanting a substantially solid material in a
subcutaneous location. A beveled tip of an incising shaft with a
cutting edge along a distal end thereof is inserted into an
implantation site. A proximal end of the incising shaft is affixed
to a distal end of a syringe body. The syringe body and the
incising shaft each define a substantially non-circular hollow bore
extending continuously along a shared longitudinal axis. The
incising shaft bore do not exceed the syringe body bore in girth.
Both the incising shaft bore and the syringe body bore are sized to
receive the solid material. The solid material is advanced through
the syringe body bore and the incising shaft bore into the
subcutaneous location through deployment of a plunger conformably
shaped to the syringe body bore. The deployment is effected via
actuation of an end piece on a distal end of the plunger. The
plunger slidably fits within the syringe body bore.
[0020] Still other embodiments of the present invention will become
readily apparent to those skilled in the art from the following
detailed description, wherein is described embodiments of the
invention by way of illustrating the best mode contemplated for
carrying out the invention. As will be realized, the invention is
capable of other and different embodiments and its several details
are capable of modifications in various obvious respects, all
without departing from the spirit and the scope of the present
invention. Accordingly, the drawings and detailed description are
to be regarded as illustrative in nature and not as
restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a perspective view of an instrument for implanting
sensors or solid materials in a subcutaneous or other tissue
location in accordance with the present invention;
[0022] FIG. 2A is a longitudinal cross-sectional view of the
implantation instrument with a straight incising shaft;
[0023] FIG. 2B is a longitudinal cross-sectional view of the
implantation instrument with a curved incising shaft;
[0024] FIG. 3 is a diagrammatic view illustrating the implantation
of a sensor or solid material into a subcutaneous site;
[0025] FIG. 4A is a diagrammatic view illustrating the clearing of
a subcutaneous site using the implantation instrument fitted with a
clearing trocar in accordance with a further embodiment;
[0026] FIG. 4B is a diagrammatic view illustrating the subcutaneous
implantation of a sensor using the implantation instrument fitted
with a pushing stylet in accordance with a further embodiment;
[0027] FIGS. 5A-D are transverse cross-sectional views of the
implantation instrument illustrating, by way of example, various
bore configurations;
[0028] FIG. 6 is a segmented side view of a clearing trocar;
[0029] FIG. 7 is a segmented side view of a pushing stylet; and
[0030] FIGS. 8A-8B are section views illustrating penetration
limiting mechanisms for use with the implantation instrument;
and
[0031] FIG. 9 is a perspective view of an instrument for implanting
sensors or solid materials in a subcutaneous or other tissue
location in accordance with a further embodiment of the present
invention.
DETAILED DESCRIPTION
[0032] FIG. 1 is a perspective view of an instrument 10 for
implanting sensors or solid materials in a subcutaneous or other
tissue location in accordance with the present invention. The
implantation instrument 10 consists of two principal groups of
components, an incising body consisting of an incising shaft 11 and
a syringe body 15, and a delivery assembly consisting of a plunger
assembly 20. The delivery assembly is received into the syringe
body bore by sliding the plunger assembly 20 through proximal bore
opening 19.
[0033] The incising shaft 11 is formed with a beveled and rounded
tip 12 that tapers into a surgically sharp cutting edge 13 formed
on a distal edge. The beveled tip 12 includes a distal bore opening
14 through which the sensor or solid material is delivered into the
implantation site.
[0034] In the described embodiment, the sensor or solid material
(implant) has approximate dimensions of 5 mm by 10 mm by 20 mm. The
critical dimension is the cross-sectional profile, that is, the
height and width, of the implant which must conform to passage
through the syringe body and incising shaft bores. Other nonlinear,
prismatic shapes are equally usable provided the implant can fit
within the confines of the syringe body and incising shaft bores.
The implant could also be folded or compacted to minimize the
cross-sectional profile with the implant unfolding or expanding
upon implantation. As well, the implant is preferably protected
against damage by encasement within, for example, a mannitol pellet
in the case of a solid drug delivery system or epoxy in the case of
an implantable sensor.
[0035] An implantable sensor microchip suitable for use in the
present invention is described in PCT Application No.
PCT/GB99/02389, to Habib et al., filed Jul. 22, 1998, pending, the
disclosure of which is incorporated herein by reference. Such a
sensor could be used for monitoring and collecting physiological or
chemical measures. Similar devices for therapeutic uses, including
treating cancer, and for health care giving, including
administering solid medication in the form of boluses, are
possible. As well, the present invention has equal applicability to
implantation of sensors, including location and identification
sensors, and solid materials in domesticated animals. The sensor
could also constitute or include a data transmitter with which to
exchange information and telemetered signals.
[0036] The incising shaft 11 is fixably attached to the syringe
body 15 through frictional, adhesive, or preformed constructive
means, as is known in the art. Both the incising shaft 11 and
syringe body 15 define a substantially non-circular hollow bore
extending continuously along a shared longitudinal axis, as further
described below with reference to FIGS. 5A-D.
[0037] The plunger assembly includes a plunger 16, an
interconnecting plunger shaft 17 and a plunger end piece 18. The
plunger 16 is conformably shaped to fit within the syringe body
bore. The plunger end piece 18 facilitates deployment of the
plunger assembly through the syringe body bore and is preferably
shaped to fit a thumb or palm impression.
[0038] In the described embodiment, the implantation instrument 10
is designed for inexpensive and disposable use utilizing low-cost,
sanitizable materials. The incising shaft 11 can be fashioned from
surgical grade stainless steel and has the approximate dimensions
of approximately 10 mm by 5 mm in cross section. The incising shaft
11 is approximately 50 mm long and the length can be varied to
accommodate different implantation depths. The plunger 16 is formed
from plastic and rubber and preferably forms a watertight seal
within the syringe body bore and has the approximate dimensions of
approximately 8 mm by 3 mm in cross section. The plunger shaft 17
and plunger end piece 18 are formed from plastic or similar
material. Other materials, as would be recognized by one skilled in
the art, could be substituted.
[0039] In a further embodiment, the syringe body 15 and plunger
assembly can be replaced by an automated injection system, such as
used with immunization injection guns or similar devices. These
devices typically employ compressed air or other inert gases to
administer medication in lieu of manual plungers. Other automated
variations include spring-loaded and similar mechanical injection
systems. The incising shaft 11 is fixably attached to the automated
injection system which functions as a delivery mechanism in place
of the syringe body 15 and plunger assembly. Thus, the implant
would be pushed through the incising shaft bore using the
compressed air or gas, or mechanical equivalent.
[0040] FIG. 2A is a longitudinal cross-sectional view of the
implantation instrument 10 with a straight incising shaft 11. The
hollow bore defined by both the incising shaft 11 and the syringe
body 15 runs along a common shared axis. The incising shaft bore 22
is sized to allow the implant to advance smoothly into the
implantation site under the forward lateral urging of the plunger
assembly 20. The syringe body bore 23 must be at least as large as
the incising shaft bore 22, but can be slightly larger to
accommodate lubricants, anesthetizing agents, or similar coatings,
such as mannitol, applied over the sensor or solid material.
[0041] The syringe body 15 preferably includes a circular collar
21, pair of winglets, ears, or eyelets, or similar structure,
optionally formed on a proximal end of the syringe body 15 to
assist a user in depressing the plunger assembly 20.
[0042] FIG. 2B is a longitudinal cross-sectional view of the
implantation instrument with a curved incising shaft 24. The curved
incising shaft 24, as well as the syringe body 15 and related
components, are shaped into a substantially continuous curve along
the ventral side. The curvature helps regulate the penetration
depth of the incising shaft and, in the described embodiment, has
an arc of approximately 20 degrees.
[0043] FIG. 3 is a diagrammatic view illustrating the implantation
of a sensor 28 or solid material into a subcutaneous site. Prior to
delivery, the sensor 28 is fed through the proximal bore opening 19
of the syringe body 15 and then further advanced through the
syringe body bore 23. During operation, the incising shaft 11 is
inserted through the dermis 25 and guided into the layer of
subcutaneous fat 26, above the layer of muscle 27. The sensor 28 is
then advanced through the incising shaft bore 22 by the plunger 16
into the subcutaneous site. Note that although the foregoing view
illustrates an implant into the subcutaneous fat layer, one skilled
in the art would appreciate that subcutaneous implantation
locations are not strictly limited to the subcutaneous fat layer
and are generally termed as those implantation locations situated
within a body under the skin.
[0044] FIG. 4A is a diagrammatic view illustrating the clearing of
a subcutaneous site using the implantation instrument 10 fitted
with a clearing trocar 29 in accordance with a further embodiment.
The clearing trocar 29, as further described below with reference
to FIG. 6, is mounted to its own handle or plunger assembly and has
a sharp cutting tip 30 for optionally clearing a subcutaneous site
prior to delivery of the implant.
[0045] Prior to implantation, the clearing trocar 29 is slidably
received into the syringe body 15 and is advanced until the cutting
tip 30 is even with the proximal bore opening 19 of the incising
shaft 11. During operation, the incising shaft 11 and clearing
trocar 29 are inserted through the dermis 25 and guided into the
layer of subcutaneous fat 26, above the layer of muscle 27.
[0046] The cutting edge 13 of the beveled tip 12 makes an entry
incision through the dermis 25 and is laterally pushed into the
subcutaneous fat 26 until the cutting edge 13 is adjacent to the
subcutaneous site. The clearing trocar 29 is then urged through the
subcutaneous fat 26 by advancement of its handle or plunger
assembly to prepare the implantation site for delivery of the
sensor 28 or solid material. The clearing trocar 29 is then
withdrawn from the subcutaneous site and out of the implantation
instrument 10.
[0047] FIG. 4B is a diagrammatic view illustrating the subcutaneous
implantation of a sensor 28 using the implantation instrument 10
fitted with a pushing stylet 31 in accordance with a further
embodiment. The pushing stylet 31, as further described below with
reference to FIG. 7, has a blunt tip 32 for advancing the sensor 28
(or solid material) through the syringe body bore 23 and incising
shaft bore 22 and into the subcutaneous site. The cross section of
the pushing stylet 31 closely conforms to the incising shaft bore
22 while the plunger 16 closely conforms to the syringe body bore
23. The pushing stylet 31 thus extends the reach of the plunger
assembly 20 and allows the syringe body bore 23 to have a different
cross-section than the incising shaft bore 22.
[0048] The pushing stylet 31 is used while the incising shaft 11 is
in situ in the subcutaneous layer 26. Prior to delivery, the sensor
28 is fed through the proximal bore opening 19 of the syringe body
15 and further advanced within the syringe body bore 23 by contact
with the plunger 16. The pushing stylet 31 is slidably received
into the syringe body 15 and is advanced until the blunt tip 32
contacts the sensor 28. During operation, the sensor 28 is urged
through the incising shaft bore 22 by the pushing stylet 31 and
into the subcutaneous site by advancement of the plunger assembly.
Upon delivery of the sensor 28 into the subcutaneous site, the
incising shaft 11 and pushing stylet 31 are withdrawn.
[0049] Although operation of the implantation instrument 10 is
described with reference to the implantation of sensors or solid
materials into a subcutaneous site situated within the layer of
subcutaneous fat 26, implantations could also be effected in other
subcutaneous, intramuscular, intraperitoneal, intrathoracic,
intracranial, intrajoint, as well as other organ or
non-subcutaneous sites, as would be recognized by one skilled in
the art. In addition, the foregoing procedure could be modified to
forego the use of the clearing trocar 29 for small sensors 28 or
solid materials. The clearing effect of the clearing trocar 29 can
be approximated by use of the incising shaft 11 alone whereby the
incising shaft 11 is inserted into the subcutaneous site and then
withdrawn by reverse deployment, thereby forming a slightly
overwide implantation site.
[0050] The operations of subcutaneous implantation can be carried
out over a plurality of sites and with the same or different
sensors 28 and solid materials. Similarly, several sensors 28 and
solid materials could be implanted at the same subcutaneous site
during a single implantation operation.
[0051] FIGS. 5A-D are transverse cross-sectional views of the
implantation instrument 10 illustrating, by way of example, various
bore configurations. FIG. 5A illustrates an incising shaft 35 with
a substantially rectangular bore 36. FIG. 5B illustrates an
incising shaft 37 with a substantially square bore 38. FIG. 5C
illustrates an incising shaft 39 with a substantially oval bore 40.
And FIG. 5D illustrates an incising shaft 41 with a substantially
hexagonal bore 42. Note the circumferential shape of the incising
shaft need not follow the internal shape of the incising shaft
bore. Other bore configurations, including variations on oval,
rectangular, square, pentagonal, hexagonal, heptagonal, octagonal,
and similar equilateral or non-equilateral shapes, are
feasible.
[0052] In the described embodiment, the rectangular bore 36 has the
dimensions of approximately 10 mm by 5 mm. The syringe body bore 23
has a length of approximately 5 cm.
[0053] FIG. 6 is a segmented side view of a clearing trocar 45. The
clearing trocar 45 consists of a beveled tip 47 on the distal end
of the clearing trocar 45 and a clearing trocar shaft 46 affixed,
either fixably or removably, to the distal end of a plunger 16.
[0054] During a clearing operation, the clearing trocar 45 is fully
extended from the distal bore opening 14 of the incising shaft 11.
The clearing trocar shaft 46 is only long enough to clear out the
subcutaneous site. The plunger 16 acts as a stop that limits the
extent of penetration of the clearing trocar 45, thereby preventing
the clearing trocar 29 from incising too deeply into the
subcutaneous fat 29. In addition, the clearing trocar 29 is sized
to approximate the girth of the incising shaft bore 22 and will
clear a subcutaneous site only as wide as minimally necessary to
facilitate implantation of the sensor or solid material. In the
described embodiment, the clearing trocar 45 has a length of
approximately 2 cm beyond the tip of the syringe body 15.
[0055] FIG. 7 is a segmented side view of a pushing stylet 50. The
pushing stylet 50 consists of a blunt tip 52 on the distal end of
the pushing stylet 50 and a pushing stylet shaft 51 affixed, either
fixably or removably, to the distal end of a plunger 16.
[0056] During a delivery operation, the pushing stylet 50 is
extended from the distal bore opening 14 of the incising shaft 11.
The pushing stylet shaft 51 is only long enough to clear the distal
bore opening 14. The plunger 16 acts as a stop that limits the
lateral travel of the pushing stylet 50. In the described
embodiment, the pushing stylet 50 has an additional length of
approximately 2 cm beyond the tip of the syringe body 15.
[0057] FIGS. 8A-8B are section views illustrating penetration
limiting mechanisms for use with the implantation instrument 10.
The penetration limiting mechanisms limit the depth of penetration
of the incising shaft 11 and help prevent excessive penetration.
FIG. 8A shows a fixed penetration limiting mechanism consisting of
a stopping flange 55 attached to the incising shaft 11. The
position of the stopping flange 55 along the incising shaft 11 can
be adjusted by loosening a hold-down screw 58 and sliding the
stopping flange 55 into the desired location. The lower edge of the
stopping flange 55 has a bend 57 with an angle .tau., preferably
between approximately 30.degree. and 60.degree., thereby forming an
elbow 56 which stops lateral travel upon contact with the skin.
[0058] FIG. 8B shows an adjustable penetration limiting mechanism
consisting of a stopping flange 60 attached a frictional collar 64.
The stopping flange 60 and frictional collar 64 are slidably
attached to the incising shaft 11. An adjustable collar 64,
preferably in threaded communication 65 with the frictional collar
64, manually stops deployment of the penetration limiting mechanism
by tightening the frictional collar 64 against the incising shaft
11. The lower edge of the stopping flange 60 has a bend 62 with an
angle, preferably between approximately 30.degree. and 60.degree.,
thereby forming an elbow 61 which stops lateral travel upon contact
with the skin.
[0059] FIG. 9 is a perspective view of an instrument for implanting
sensors or solid materials in a subcutaneous or other tissue
location in accordance with a further embodiment of the present
invention. The instrument is equipped with the stopping flange 55
shown in FIG. 8A. Other forms of penetration limiting mechanisms,
both fixed and adjustable, could be used, as would be readily
apparent to one skilled in the art.
[0060] While the invention has been particularly shown and
described as referenced to the embodiments thereof, those skilled
in the art will understand that the foregoing and other changes in
form and detail may be made therein without departing from the
spirit and scope of the invention.
* * * * *
References