U.S. patent application number 10/604227 was filed with the patent office on 2004-06-03 for percutaneous needle alignment system.
This patent application is currently assigned to SDGI HOLDINGS, INC.. Invention is credited to Grossman, Jeffrey.
Application Number | 20040106934 10/604227 |
Document ID | / |
Family ID | 27395617 |
Filed Date | 2004-06-03 |
United States Patent
Application |
20040106934 |
Kind Code |
A1 |
Grossman, Jeffrey |
June 3, 2004 |
Percutaneous Needle Alignment System
Abstract
The present invention is an alignment system by which a needle
or other similar invasive device can be positioned for insertion so
as to have a real-time, predetermined trajectory to a targeted
tissue region, thereby reducing the need for repetitive needle
insertion and withdrawal to move the tip of the instrument
accurately to the target site.
Inventors: |
Grossman, Jeffrey; (Atlanta,
GA) |
Correspondence
Address: |
HAYNES AND BOONE, LLP
901 MAIN STREET, SUITE 3100
DALLAS
TX
75202
US
|
Assignee: |
SDGI HOLDINGS, INC.
300 Delaware Avenue Suite 508
Wilmington
DE
|
Family ID: |
27395617 |
Appl. No.: |
10/604227 |
Filed: |
July 2, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10604227 |
Jul 2, 2003 |
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09866238 |
May 25, 2001 |
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6605095 |
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60211279 |
Jun 13, 2000 |
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60216378 |
Jul 5, 2000 |
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Current U.S.
Class: |
606/130 |
Current CPC
Class: |
A61B 34/20 20160201;
A61B 2090/376 20160201; A61B 2090/3945 20160201; A61B 90/13
20160201; A61B 2017/3407 20130101; A61B 90/11 20160201; A61B
17/3403 20130101 |
Class at
Publication: |
606/130 |
International
Class: |
A61B 019/00 |
Claims
1. An insertion device trajectory system, comprising: a reflecting
element; and an energy source for producing an energy path in a
direction toward the reflecting element and away from an insertion
device wherein the reflecting element reflects the energy path
toward the energy source thereby indicating any trajectory
correction required for the insertion device.
2. A method of realigning a medical insertion device, the method
comprising: generating an energy path from an energy source located
on an insertion device; and reflecting the energy path so that a
proximity of the reflected energy path to the energy source
indicates a realignment for the insertion device.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No.
09/866,238, filed on May 25, 2001 which claims the benefit of U.S.
Provisional Application Serial No. 60/211,279 filed Jun. 13, 2000,
and No. 60/216,378 filed Jul. 5, 2000.
BACKGROUND OF INVENTION
[0002] The present invention generally relates to a trajectory
system for medical instruments, and more particularly to a
light-guided alignment system for a percutaneous needle.
[0003] Guidance methods are often used in conjunction with various
injection procedures. The most common guidance method for inserting
surgical instruments such as puncturing needles through the skin
and to a subsurface injection site is simply reliance on the
clinician's experience in visualizing a proper injection
trajectory, and then maintaining that trajectory throughout
insertion. One type of injection procedure is the spinal injection,
performed most often by a pain management specialist in which a
mixture of steroid and anesthetic is delivered to specific internal
structures of the body including, but not limited to, (i) a facet
joint, (ii) an area surrounding a spinal nerve root, (iii) a major
articulation, for example, a sacro iliac joint, and (iv) a
vertebral disk space (IDET, discography). The purpose of these
types of injections is to provide pain relief, as well as valuable
diagnostic information for identifying pain generators. Another
procedure is the use of a needle to obtain a biopsy sample. One
example of this procedure is the lumbar puncture. A lumbar puncture
is a commonly performed diagnostic, yet rarely therapeutic,
procedure. In a normal pressure hydrocephalus, a spinal needle is
guided into a patient's body in order to remove cerebrospinal fluid
for therapeutic purposes. The needle is passed into proximity of
spinal cord. Conventional guidance of the injection needle into the
patient is performed free-hand and with visual guidance by the
clinician performing the procedure. That is, the clinician
estimates the proper injection trajectory of the needle through the
skin and to a target site based on years of injection practice and
training. While skilled clinicians may perform the insertion
satisfactorily, a novice (or less experienced clinician) has
difficulty obtaining the requisite skill. Success in performing
puncture procedures requires knowledge of the patient's anatomy and
both good manual dexterity and eye-hand coordination. In the case
of performing a spinal tap, there exists a steep learning curve,
highly dependent on how many spinal taps the clinician has
performed during training. Much to the detriment of the patient,
puncture procedures such as the lumbar puncture commonly are
performed in emergent situations, frequently by the most junior
medical person on staff. If not in the case of an emergency, spinal
injections are performed and practiced by medical students in
teaching hospitals, wherein the student is under the supervision of
a more experienced physician. In such settings, there are limited
options for the mentor or teacher to convey to the trainee just
what the intended trajectory should be based on the years of
experience of the mentor. The mentor often is reluctant to "talk"
the trainee through the procedure, as this can make the awake
patient who is listening quite uncomfortable. Yet, this lack of
oral communication often results in a miscalculated pass of the
spinal needle by the trainee. The free-hand, visual guidance
approach to aligning spinal injections can be supplemented with
fluoroscopic assistance in radiology suites or in the operating
room where sophisticated imaging devices are available. The imaging
device commonly available in the operating room involves uniplanar
fluoroscopy provided by a "C-arm" imaging device. In computer
tomography or fluoroscopically guided procedures, imaging is used
to localize and determine the position of a subsurface target
requiring treatment or medical investigation. Once the position of
the subsurface target is determined, a clinician then uses the
imaging equipment to select the desired path of access to the
subsurface target with invasive instruments such as needles,
drainage catheters, localization wires or other tools to perform
necessary procedures. After the desired path is selected, the
clinician guides the invasive instrument along the path to the
target by maintaining the invasive instrument in alignment with
that selected path. The disadvantages of this type of needle
guidance are apparent and well understood both by those in the art
and those unfortunate patients that require repeated insertions
with misguided needle insertions. The process of inserting the
needle from an initial stage (prior to puncture when the needle
point is resting on the patient's skin at the insertion site and in
proper alignment as viewed by the clinician in the monitor) to a
final stage (when the medication has been delivered to the target
site) takes steady hands and repeated views back to the monitor to
ensure the insertion trajectory is followed throughout the
procedure. Even assuming this conventional needle guidance is
successful in just one pass, repeated fluoroscopy is still
necessary during the one pass, all the while exposing the patient
to numerous doses of radiation. The inability of the clinician to
ensure, in real-time, the correct trajectory of the needle from the
insertion site to the target site may cause significant patient
discomfort. Even when guided by free-hand with C-arm assistance,
the clinician typically must insert and withdraw the needle
multiple times to reach a sufficient confidence level that the
target site has be reached. One technique used in overcoming a few
of the disadvantages of fluoroscopically guided free-hand insertion
of a needle is the use of a light beam serving as a visible guide
for accessing the subsurface target with the needle, the needle
being maintained in an aligned position with the light beam during
insertion. Light emitting diodes "LEDs" are frequently used in
medicine with percutaneous insertion of spinal needles or other
instruments such as pedicle screws. Typically, the light emitted by
the LEDs identifies for the clinician the needle point of entry on
the patient's skin. For example, U.S. Pat. No. 6,041,249 to Rein
discloses a device for making a guide path for an instrument. A
light source located on a rail of a computed tomography apparatus
emits a light beam toward the patient. When the light beam,
insertion site and the target site are aligned, a needle is placed
in the path of the beam and inserted into the body. The angle of
the needle is adjusted during insertion to maintain the light beam
in contact with the top end of the needle. Other applications are
known utilizing LEDs, including U.S. Pat. No. 6,096,049 to
McNeirney et al., to identify trajectories for the insertion
instrument. However, these devices are not very efficient. The beam
of light is used to indicate the spot on the patient's skin through
which the needle will puncture. Yet, if the patient moves
thereafter, the true insertion site moves as well, and the
procedure for identifying the spot on the body must be administered
again. Thus, with the McNeirney et al. system, when a patient
moves, the technician then must reposition the C-arm so as to
redefine a new point of entry on the skin to adjust for the
patient's movement. Repositioning the C-arm repeatedly in response
to patient movement can be so time consuming as to render the
McNeirney et al. system impractical. Another problem that can arise
with free-hand needle insertion primarily is due to the flexibility
inherent in puncture needles in view of a needle's small diameter
relative to its length. Typically the clinician holds the needle
from only the distal end (with the clinician fingers), the proximal
end of the needle resting on the patient's skin. This leaves the
length of the needle unsupported, thus facilitating needle
deflection under the insertion force of the clinician's fingers.
The needle will bend/deflect as force is applied to the distal end
to commence needle insertion. Injection procedures also suffer from
the problem of insufficient needle point friction control at the
insertion site on the skin when beginning the insertion procedure.
Prior to insertion, and even slightly after insertion, the needle
can easily swivel off trajectory. In an unaided needle procedure,
an on-phase insertion will be completely dependent on the
steadiness of the clinician's hands. Thus, repeatable on-phase
insertions can not be guaranteed even with the same clinician.
Further, once the insertion site has been identified on the
patient's skin, the needle point is rested on the skin site, and
the distal end of the needle is brought into a proper trajectory
prior to insertion. During this phase of needle positioning, if too
much pressure is exerted on the skin by the proximal end of the
needle, the needle will puncture the skin prior to aligning the
needle. Yet, if too little contact is brought against the skin and
proximal end of the needle, the needle point can float above the
insertion site, making the alignment procedure more difficult. In
view of the foregoing limitations in the prior art, it would be
desirable to provide an alignment system by which a needle or other
similar invasive device could be positioned for insertion so as to
have a real-time, predetermined trajectory to a targeted tissue
region, thereby reducing the need for repetitive needle insertion
and withdrawal to move the tip of the instrument accurately to the
target site. It also would be desirable to provide an alignment
system that minimizes or eliminates the need for repositioning the
fluoroscopic device in response to each and every patient movement.
It would further be desirable to provide an alignment system
incorporating a needle driver supporting the needle in its proper
trajectory, the driver limiting the amount of needle deflection
during insertion. It also would be beneficial to provide an
alignment system that provides needle point friction control during
the alignment phase of the needle. It is believed the prior art
neither teaches nor suggests an alignment system that combines the
beneficial features of those identified. Accordingly, there is a
need in the art for such a needle alignment system, and it is to
the provision of such a system that the present invention is
primarily directed.
SUMMARY OF INVENTION
[0004] Briefly described, in a preferred form, the present
invention is an alignment and guidance system for a puncture device
used to deliver injection material such as medicine to a subsurface
target region or site within a patient's body. Alternatively, the
puncture device can be used to receive injection material, such as
removing biopsy fluid, from the subsurface target site. The present
alignment system provides a clinician with precise guidance for the
puncture device.
[0005] The present alignment system comprises an insertion device,
an energy source and a reflecting element. The insertion device
preferably is a needle, however the alignment system can be used
with other puncture devices such as pedicle screws, heat probes and
other inserted instruments. The needle has a proximal end for
puncturing the skin and a distal end. The distal end of the needle
can include a hub.
[0006] The energy source preferably is a light source being, for
example, a lightbulb or LED. Alternatively, the energy source can
be a non-visible source coupled with a sound-emitting device to
indicate on-phase alignment. The light source is housed in the hub
at the distal end of the needle, aligned parallel to the radial
axis of the needle, and shining in the direction away from the
proximal end of the needle.
[0007] The reflecting element is capable of reflecting the light
emanating from the distal end of the needle back onto the hub.
Preferably, the reflecting element comprises a reflective piece of
radiolucent material adhered to the undersurface of a C-arm. The
reflective element lies in a perpendicular plane from the radial
axis on the needle.
[0008] When the light source is energized, the clinician can
visualize the spot of reflected light on the hub and note how far
the needle is off optimal alignment. The clinician then swivels the
injection element accordingly until the reflected light is aligned
with the shined light. The needle can then be advanced along the
optimal injection trajectory so long as the reflected light is kept
on the hub of the needle.
[0009] A process for aligning a puncture device according to the
present invention is also disclosed. A similar process can be used
to retrieve biopsy material from a subsurface target region.
[0010] The present invention can further comprise a needle driver
for supporting the length of the needle in a proper trajectory. The
needle driver is designed to prevent bending of the needle. In such
an embodiment, the energy source can be communicative with the
driver, instead of the needle, and the driver properly aligned as
previously discussed. Once the driver trajectory is equivalent with
the injection trajectory, the needle can be passed through the
needle driver, and the injection be assured of alignment.
Alternatively, the needle driver can itself be advanced
percutaneously in some insertion techniques.
[0011] While the energy source can produce a single beam of light,
the energy source used with the needle driver can alternatively
produce a ring of light such that the energy source does not impede
the travel of the needle through the needle driver. Further,
although the energy source can be located on the distal end of the
insertion element or needle driver, the energy source may
alternatively be located at other sites along the needle and
driver. However, the light source is aligned parallel to the radial
axis of the needle, and shone in the direction away from the
proximal end of the needle.
[0012] The present invention can further include a method and
apparatus for stabilizing the proximal end of the needle, or
proximal end of the needle driver, against excessive movement both
during the aligning procedure and during needle insertion.
[0013] There are many advantages of the present invention. The
present invention limits the amount of time and effort to align the
needle into the optimal injection trajectory, and limits the amount
of punctures correspondingly decreasing the amount of infusion of
local anesthetic. The present device is further advantageous as it
can be used in conjunction with the injection of local anesthetic
so the anesthetized areas of tissue are located in proximity to
(the same path of) the injection trajectory. Additionally, by
having a more accurate insertion of the needle there will be less
risk of injuring nearby structures due to the incorrect passage of
an instrument along an undesired trajectory.
[0014] The present device also decreases fluoroscopy time and
simplifies the identification of the insertion site. For example,
to identify the needle insertion point according to the present
invention, a radio-opaque object such as a hemostat is moved across
the patient's skin. When the tip of the radio-opaque instrument is
positioned within the line determined by the anatomic structure of
interest and the perpendicular axis of the undersurface of the
C-arm, an eclipse forms on the monitor such that the anatomic
structure of interest and the tip of the radio-opaque object appear
superimposed. Assuming the clinician is then comfortable that the
fluoroscopic image indicates a proper path, the clinician marks a
spot on the skin surface under the tip of the radio-opaque
instrument. If by accident the patient slightly moves, the marked
spot remains on the patient's skin and in most circumstances will
still illustrate the proper insertion point. The spot of entry may
change slightly and can be easily remarked by moving a radio-opaque
object. Yet, the clinician will not need to reposition the C-arm to
have the light hit the new entry point as the light is shining from
the needle. However, with prior art trajectory systems that utilize
light shone on the patient to identify the insertion site, if the
patient subsequently moves, then the C-arm and attending machinery
must be realigned. This can be quite a common problem, since the
patients are rarely heavily sedated to such an extent that they do
not move.
[0015] Placing the light on the needle itself is a dramatic
improvement over the prior art injection procedures that have a
light on the x-ray source, or have a light at a distant source from
the patient. Utilizing a light directed from the needle and
reflecting back from the reflective surface on the x-ray machine
also is beneficial. The light shining from the needle, to the
reflecting surface, and back travels twice as far than if only
shining from the machine. Thus, when the clinician views the
reflection of the light back on the emitting instrument, the light
has traveled twice as far and is twice as sensitive for alignment
purposes. Additionally prior art devices are very expensive,
cumbersome and are not cost effective or time efficient.
[0016] Further, prior art guidance devices provide the clinician
only two discrete settings, on or off alignment. The present
invention provides the clinician an almost infinite range of on or
off alignment information so the clinician can make a quantitative
judgment based on how close the reflected light is from the energy
source from where it came.
[0017] The present invention limits excessive x-ray exposure to the
patient. The clinician using the present invention directs the
light at the C-arm and looks for the reflection back toward a
sheath as the technician can adjust the machine or move the C-arm
around until it is centered over the instrument itself. For
example, this could be 30.degree. to the oblique and 20.degree. to
the cephalad and the technician will move the machine until the
light source is directed back at the energy source itself. This
provides an advantage as less fluoroscopic pictures are taken and
less fluoroscopy exposure is needed. Fluoroscopy machines will last
longer and more importantly the clinician and others, as well as
the patient, will receive less radiation exposure.
[0018] Additionally, it is important to have the insertion site and
target site aligned in the center of the C-arm. This reduces
parallax which can be a source of error. Parallax may cause the
image visualized on the x-ray machine not to be actually
representative of space and the target area. Also, images in the
center of the screen are more accurate than are the images off to
the side of the screen. Therefore, it is advantageous for the
clinician to place the anatomic structure of interest in the center
of the screen even though frequently many operators are satisfied
with having the anatomic structure of interested located towards
the periphery of the machine. With prior art devices, it is too
time consuming to continually take fluoroscopic pictures until the
anatomic structure of interest is in the center of the screen.
However, if one is able to simply locate the anatomic structure of
interest on the screen, one can mark the insertion site on the skin
and the present invention will allow the clinician to place the
insertion site in the center of the screen without taking anymore
images simply by activating the light and directing it to the
center of the undersurface of the C-arm. In this way the technician
can simply move the machine until the light which is reflecting
back at the present device hits the reflective surface in the very
center of the undersurface of the C-arm or in the very center of
the reflective surface.
[0019] The present invention need not necessarily be used with
fluoroscopy, but can also be used as a teaching tool for lumbar
punctures and other biopsy procedures. The lumbar puncture is often
performed by third-year medical students and is based on known
anatomy. With the present invention, the correct trajectory can be
presented to the student by having a light on the end of the needle
and watching and using this light as a reference point. For
example, if a supervising physician in the room is aware of the
correct trajectory based on his/her experience and knowledge and is
trying to convey this to the medical student performing the
injection of a needle, the present invention is a nice teaching
tool to convey to the medical student the correct trajectory for
insertion. Rather than using terms of "move the needle tip" or
"move the needle hub right, left, up or down", the supervising
physician can simply take hold of the needle without advancing it,
and show the medical student the correct trajectory without
advancing the needle and the medical student can take notice of
where the light, which is added to the hub of the spinal needle,
appears relative to a reference point within the room. In this way
the medical student can pass the needle as the supervising
physician intended the medical student to do by assuring that the
student's light path shines upon the mark indicated by the
supervisor.
[0020] These and other objects, features and advantages of the
present invention will become more apparent upon reading the
following specification in conjunction with the accompanying
drawing figures.
BRIEF DESCRIPTION OF DRAWINGS
[0021] FIG. 1 illustrates a preferred embodiment of the present
needle alignment system.
[0022] FIG. 2 is a schematic of the trajectories and directions
referred to herein.
[0023] FIG. 3 shows a perspective view of the insertion device of
the present invention.
[0024] FIG. 4 is an interior view of the energy source housing of
the present invention.
[0025] FIG. 5 illustrates one embodiment of the reflecting surface
of the present invention.
[0026] FIG. 6 shows an "on-phase" operation of the present
invention.
[0027] FIG. 7 is a perspective view of another preferred embodiment
of the insertion device and energy source of the present
invention.
[0028] FIG. 8 is a perspective view of a reusable light source
embodiment of the present invention.
[0029] FIG. 9 is view of yet another preferred embodiment of the
light source of the present invention.
[0030] FIG. 10 is an exploded view of a needle driver of the
present invention.
[0031] FIG. 11 illustrates a stabilizing element according to a
preferred embodiment of the present invention.
[0032] FIG. 12 illustrates one way to mark the insertion site on a
patient.
DETAILED DESCRIPTION
[0033] Referring now in detail to the drawing figures, wherein like
reference numerals represent like parts throughout the several
views, FIG. 1 illustrates the present alignment system 100
comprising a insertion device 20, an energy source 40 and a
reflecting element 60. The alignment system 100 is located in an
injection trajectory T.sub.INJ aligning an insertion site X on the
skin of a patient 12, and a target site 14 below the skin.
[0034] As shown in FIG. 2 and as used herein, the term "injection
trajectory" T.sub.INJ is defined as the trajectory passing through
the insertion site X on the skin and the target site 14 within the
body, and the term "injection direction" D.sub.INJ is defined as
the direction lying on the injection trajectory T.sub.INJ from the
insertion site X to the target site 14.
[0035] As distinguished from the injection trajectory T.sub.INJ and
the injection direction D.sub.INJ, the insertion device 20 has a
device trajectory T.sub.DEV (or sometimes needle trajectory) and a
device direction D.sub.DEV (or sometimes needle direction). "Device
trajectory" T.sub.DEV is defined as the trajectory of alignment of
the proximal 22 and distal ends 24 of the insertion device 20, and
the "device direction" D.sub.DEV is the direction lying on the
device trajectory T.sub.DEV from the distal end 24 to the proximal
end 22 of the insertion device 20. It will become apparent that the
present invention preferably is used to position the device
trajectory T.sub.DEV equivalent to the injection trajectory
T.sub.INJ.
[0036] The insertion device 20 illustrated in FIG. 3 comprises a
needle 26 having a proximate puncture end 22, an energy source
housing 28 located at the distal end 24, and a viewing surface or
hub 32 located on the housing 28.
[0037] A light source 42 of the energy source 40 can be located
within the energy source housing 28, the light source 42 being, for
example, a small lightbulb connected by wires W to a battery B.
FIG. 4. Alternatively, the light source 42 can comprise an LED. The
energy source 40 is arranged such that that light L from the light
source 42 is directed in an opposite direction than the
prior-defined device direction D.sub.DEV.
[0038] The reflecting element 60 can comprise a reflective piece of
radiolucent material 62 adhered to the undersurface of a C-arm 64,
as shown in FIG. 1. Alternatively, the reflecting element 60 can
comprise a swinging element 66 of radiolucent material pivotal
about a pivot 68 such that the element 66 can easily located in
proximity to the undersurface of the C-arm 64. FIG. 5. The
reflecting element 60 should adhere/align with the undersurface of
the C-arm 64 so that it is flat and flush with the undersurface of
the C-arm 64.
[0039] FIG. 6 illustrates that with the puncture end 22 of the
needle 26 in contact with the X mark, the light L from the energy
source 40 shines upon and reflects away from the reflective
covering 62 of the C-arm 64, which conventionally is a distance of
about 11/2 feet away from the patient 12. The light L is reflected
back towards the light source 42, wherein surface 32 indicates
whether the light L reflects directly back at the light source 42;
thus ensuring proper needle alignment and an "on-phase" indication.
The on-phase indication means the needle trajectory T.sub.DEV is
equivalent to the injection trajectory T.sub.INJ.
[0040] Another embodiment of the combination of the insertion
device 20 and energy source 40 of the present invention is shown in
FIG. 7, wherein the insertion device 20 comprises a needle 26 in
communication with an injection store 34 capable of storing
injection material M for delivery to the target site 14. A plunger
36 of the insertion device 20 can include the energy source 40.
[0041] Although the preferable construction of the present
invention incorporates an energy source 40 that is of such expense
that it can be thrown away after use; thus, enabling a fully
disposable unit, FIG. 8 illustrates one example of a light source
40 being capable of numerous uses. A self-contained light source 42
can be slipped into an energy source housing 28 that is sealable
and sterile, so that the removable light source 42 need not
necessarily be sterile. The energy source housing 28 has a cover 44
that provides for such a reusable light source 42.
[0042] FIG. 9 shows an alternate embodiment of the light source 42,
wherein the light source 42 need not be located directly on the
distal end 24 of the insertion device 20. Further, FIG. 9
illustrates that the light source 42 can be releasably secured to
the insertion device, for example, via clips 46. In such an
embodiment, it will be understood by those in the art that the
light L shining from this embodiment of the light source 42 will
have a have a trajectory parallel with that of the needle
trajectory T.sub.DEV.
[0043] The present invention 100 can further comprises a needle
driver 80 that includes the energy source 40, as shown in FIG. 10.
The needle driver 80 comprises a tubular member 82 of sufficient
strength and having an interior space which has a diameter slightly
greater than the diameter of the needle 26, such that the needle 26
can slip within the tubular member 82. The needle driver 80
supports the length of the needle in a proper trajectory, and is
designed to prevent bending of the needle 26. The energy source 40
as shown can be communicative with the needle driver 82, instead of
the needle 26, and the driver 82 itself aligned. Once the driver 82
is aligned equivalent with the injection trajectory T.sub.INJ, the
needle 26 can be passed through the needle driver 82, and the
injection be assured of alignment. Alternatively, the needle driver
82 can itself be advanced percutaneously in some insertion
techniques. As shown in this embodiment, while the energy source 40
can produce a single beam of light L, the energy source 40 can
alternatively produce a plurality of beams, for example a ring of
light, such that the energy source 40 does not impede the insertion
and travel of the needle 26 through the needle driver 80.
[0044] The present invention can further comprise a stabilizing
element 90, shown in FIG. 11. The stabilizing element 90 is
designed to restrain the proximal end 22 of the needle 26, or
proximal end of the needle driver 80, against excessive movement
both during the aligning procedure and during needle insertion.
This needle point friction control can be delivered by a
stabilizing element 90 in contact with the skin, which stabilizing
element 90 maintains the proximal end of the needle sufficiently
away from the skin to prevent a mistaken injection, but close
enough so that when proper alignment is established, the needle can
easily be injected into the insertion site at the insertion
trajectory. The stabilizing element also ensures that the needle
does not easily swivel off trajectory regardless of the steadiness
of the clinician's hands.
[0045] The stabilizing element 90 can incorporate indicia
representative of differing trajectories. Alternatively, the
stabilizing element 90 can be composed of a malleable radiolucent
putty which can form fit to the subjects skin contour.
[0046] Alignment Procedure. For a spinal injection, the patient
typically is positioned to lie face down. The C-arm 64 fluoroscopic
machine is moved about the patient 12 until the clinician has
visualized both a skin puncture site for the needle (the insertion
site X), and an internal anatomic body structure (the target site
14), to receive the injected medication. As illustrated in FIG. 12,
the clinician positions the reflective element 60 of radiolucent
material to the undersurface of a C-arm 64. The C-arm 64 can then
be initially positioned by the technician by centering the target
site 14 with the center of the undersurface of the C-arm 64. Then,
to identify the insertion site X, the clinician moves a
radio-opaque object 112 (such as a hemostat or scissors) on the
skin surface while watching a real time x-ray image on the
fluoroscopic monitor 114. For optimal alignment, the C-arm 64 is
positioned so the anatomic structure of interest 14 is visualized
in the center of the image recorded. The C-arm 64 and the
radio-opaque object 112 are moved iteratively until the
fluoroscopic image indicates that the tip of the radio-opaque
object 112 is aligned with the subsurface target site 14. The C-arm
can be rotated either obliquely (side to side), or cephalad (toward
the head), or caudad (toward the feet).
[0047] When the image illustrates that the tip of the radio-opaque
object 112 is aligned with the subsurface target site 14, the
undersurface of the C-arm 64 lies in a plane normal to the
injection trajectory T.sub.INJ. Once the injection trajectory
T.sub.INJ has been determined through the positioning of the C-arm
64, the C-arm 64 is locked against changing its orientation,
thereby resulting in an effective memorization of the injection
trajectory T.sub.INJ.
[0048] The insertion site X is marked on patient at that location
where the tip of the object 112 is aligned in the monitor 114 with
the subsurface target site 14. The clinician then places the
proximal end 22 of the needle 26 on the desired marked skin site X,
and energizes the light source 42 on the distal end 24 of the
needle 26 so as to produce a beam of light L in the device
trajectory T.sub.DEV and shining in the opposite direction of the
device direction D.sub.DEV. The light path L reflects from the
radiolucent material 62 back down toward the patient. The clinician
moves the distal end 24 of the needle 26 until the reflective path
of light shines back against the energy source 40. The clinician
can continually view the reflected light in the hub 32 and readjust
the position of the hub 32 until the reflected light and the shone
light interfere with one another. At this instance, the device
trajectory T.sub.DEV is spatially aligned and equivalent with the
injection trajectory T.sub.INJ, and the procedure can begin.
[0049] When this "on-phase" alignment occurs, the clinician
punctures the skin and advances the spinal needle 26 into the
patient 12 and can be confident that the advancing needle 26
remains in a trajectory which is in line with the path
predetermined by the x-ray image or "on phase". It may be necessary
to puncture the skin minimally and then establish "on-phase"
position before further advancing into the deeper and denser (less
forgiving) tissues.
[0050] When an x-ray is taken and shown in the fluoroscopic monitor
114, and the clinician has successfully aligned the present
invention 100, a "hubogram" will appear in the monitor 114. The
term hubogram is the optimal fluoroscopic image of a spinal needle
26 that has been advanced perfectly "on phase". This hubogram will
look like a small dot or will look like a picture of the hub 32 (or
that portion of the present invention which is radio-opaque). If
the device trajectory is off by just a few degrees of the injection
trajectory, the size of the dot in the image will grow.
[0051] While the invention has been disclosed in its preferred
forms, it will be apparent to those skilled in the art that many
modifications, additions, and deletions can be made therein without
departing from the spirit and scope of the invention and its
equivalents as set forth in the following claims.
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