U.S. patent application number 15/296680 was filed with the patent office on 2017-11-02 for fistula cannulation simulator.
The applicant listed for this patent is GREENVILLE HEALTH SYSTEM. Invention is credited to David L. Cull.
Application Number | 20170316719 15/296680 |
Document ID | / |
Family ID | 60159044 |
Filed Date | 2017-11-02 |
United States Patent
Application |
20170316719 |
Kind Code |
A1 |
Cull; David L. |
November 2, 2017 |
FISTULA CANNULATION SIMULATOR
Abstract
A cannulation simulation device and methods for using the device
are described. The device is designed to teach dialysis
technicians/nurses or patients to cannulate arteriovenous (AV)
fistulas for hemodialysis. The simulator includes one or more
artificial fistulas. The simulator includes a pad of simulated
flesh that can cover the artificial fistula(s). The pad can be
reversed, rotated, and replaced with thicker or thinner pads. A
personal simulation device for teaching self-cannulation can
include a sleeve for a limb that can carry an artificial fistula. A
clinical simulation device can include a plurality of artificial
fistulas held in a support. Optionally, the artificial fistulas can
vibrate to simulate an actual fistula.
Inventors: |
Cull; David L.; (Greenville,
SC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GREENVILLE HEALTH SYSTEM |
Greenville |
SC |
US |
|
|
Family ID: |
60159044 |
Appl. No.: |
15/296680 |
Filed: |
October 18, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62330404 |
May 2, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G09B 23/285 20130101;
G09B 23/30 20130101; G09B 23/34 20130101 |
International
Class: |
G09B 23/28 20060101
G09B023/28; G09B 23/34 20060101 G09B023/34 |
Claims
1. A cannulation simulation device comprising: a support; an
artificial fistula held in conjunction with the support, the
artificial fistula including an upper barrier having a radial
curvature and an axial length and further including a lower
barrier, the artificial fistula defining a lumen between the upper
barrier and the lower barrier; and a pad configured to be removably
located on an upper surface of the support such that the pad
overlays the upper barrier of the artificial fistula.
2. The cannulation simulation device of claim 1, further comprising
a vibration motor in mechanical communication with the upper
barrier.
3. The cannulation simulation device of claim 1, further comprising
a first sensor configured to detect the presence of a needle tip
within the lumen of the artificial fistula.
4. The cannulation simulation device of claim 1, further comprising
a second sensor configured to detect contact of a needle tip with
the lower barrier of the artificial fistula.
5. The cannulation simulation device of claim 1, wherein the
support defines a plurality of cut-outs and a plurality of the
artificial fistula, one of the plurality of the artificial fistulas
being retained in each of the plurality of cut-outs.
6. The cannulation simulation device of claim 1, further comprising
a plurality of pads.
7. The cannulation simulation device of claim 1, the pad defining a
cut-out configured to retain the artificial fistula.
9. The cannulation simulation device of claim 1, wherein a portion
of the support is the lower barrier.
10. The cannulation simulation device of claim 1, wherein the
support is in the form of a sleeve configured for temporary
attachment to a subject.
11. A method for cannulation training comprising: inserting a
dialysis needle through a pad, the pad overlying an artificial
fistula, the artificial fistula including an upper barrier having a
radial curvature and an axial length and further including a lower
barrier, the artificial fistula defining a lumen between the upper
barrier and the lower barrier; passing the dialysis needle through
the upper barrier; and detecting the presence of the dialysis
needle within the lumen of the fistula by use of a first sensor in
communication with the lumen.
12. The method of claim 11, wherein the first sensor is in optical
communication with the lumen.
13. The method of claim 11, the method further comprising detecting
contact of the dialysis needle with the lower barrier.
14. The method of claim 13, wherein the contact is detected by
formation of an electrical contact between the dialysis needle and
the lower barrier.
15. The method of claim 11, further comprising engaging a vibration
motor in communication with the artificial fistula such that the
upper barrier of the artificial fistula vibrates.
16. The method of claim 11, wherein the pad overlays a plurality of
artificial fistulas, the method further comprising reorienting the
pad from a prior orientation prior to inserting the dialysis
needle.
17. The method of claim 11, the artificial fistula being retained
on a sleeve, the method further comprising temporarily attaching
the sleeve to a subject.
18. The method of claim 11, further comprising prior to inserting
the dialysis needle, assembling the artificial fistula with the
pad.
19. The method of claim 18, wherein the artificial fistula is
assembled on a support with an orientation to mimic the fistula of
a subject.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims filing benefit of U.S. Provisional
Patent Application Ser. No. 62/330,404 having a filing date of May
2, 2016, which is incorporated herein by reference in its
entirety.
BACKGROUND
[0002] To cannulate an arteriovenous (AV) fistula for hemodialysis,
it is necessary to insert two large gauge (usually 15 g to 17 g)
needles through a patient's skin and into a vessel having high
blood flow rate. AV fistula cannulation is an almost entirely
tactile skill that requires locating the AV fistula in the
subcutaneous tissue and proper assessment of the fistula
orientation and depth followed by accurate placement of the needle
end within the lumen of the vessel. Fistulas are identified in
practice by the tactile pressure difference of the vessel longitude
and circumference and by local area vibration caused by the mixed
venous and arterial blood flow. The procedure is performed in
clinical settings by dialysis nurses and technicians and requires
great skill in correctly identifying the proper location and
orientation of the fistula as well as obtaining proper needle
insertion into the vessel lumen. Patients who opt for home dialysis
treatment must learn how to perform this skill themselves,
generally without any prior experience in vascular access.
[0003] To improve the dialysis capabilities of medical personnel,
nurses and technicians are trained on simulators. Unfortunately, no
such simulators exist that have been designed for patients to train
for self-cannulation. Moreover, even existing simulators offer only
limited training effectiveness. Typical existing cannulation
simulators are formed in shapes that mimic human or animal body
parts (e.g., arms) and include a fixed artificial fistula covered
with an artificial flesh material. While the anatomical form of the
simulators can add to the perceived realism of the devices, the
fixed placement and materials of the components decreases realism.
Repeated piercing of the surface material to access the artificial
fistula fixed beneath the surface material can reveal previous
students' attempt locations and decrease effectiveness of the
training. Movement or replacement of the surface material can be
carried out at added expense, but the gel-like artificial flesh can
be difficult to replace and the replacement procedure can be messy
if the simulator includes synthetic blood.
[0004] Due to such issues, the skills gained by use of existing
simulators provide fairly limited proficiency in real-world
application. Difficulties can arise following training not only due
to the fixed, static nature of existing simulators but also because
it is difficult to capture in existing training simulators the
large degree of variation in fistula depth, orientation, skin
thickness and size between patients that will be faced by
clinicians.
[0005] Patients wishing to self-cannulate away from the clinical
setting may have the opportunity to use existing simulators, but
the insufficiencies described for clinical settings still apply.
Currently, estimates show that only 0.8% of hemodialysis patients
choose to engage in home treatment. However, it is commonly held
that outcomes are better when patients choose home treatment and
nephrologists prefer patients be on home dialysis. The major
barrier to home dialysis is patient fear of needle sticks, but
proper training could alleviate such fears. As technology improves
and the pool of hemodialysis patients expands, this market is
expected to grow, as will the need for better training options.
[0006] What is needed in the art are cannulation simulators that
more closely mimic an AV fistula cannulation experience. For
instance, a cannulation simulator that addresses the real-world
variables that may be encountered by health-care workers during
actual dialysis practice such as little or no visual cues as to the
location of the fistula could be of great benefit. A cannulation
simulator that provides for patients to safely train for
self-cannulation that can closely represent an actual AV fistula
cannulation experience would also be of great benefit.
SUMMARY
[0007] A cannulation simulation device is disclosed. The
cannulation simulation device includes an artificial fistula that
can include an upper barrier, a lower barrier, and an opening there
between that simulates the lumen of a fistula blood vessel. The
upper barrier can define a radial curvature and an axial length
that can simulate the radial curvature and longitudinal length of a
blood vessel. The lower barrier can include a conductive material,
e.g., a metal. During use, the conductive material can be utilized
to register the passage of the conductive tip of a needle tip and
provide information with regard to the exit of the needle tip out
of the fistula opening and through the lower barrier. This feature
can be used to register to a trainee that the needle has passed out
of the fistula opening.
[0008] An artificial fistula can be associated with a vibration
motor and a controller. The controller can be utilized to vibrate
an artificial fistula via the associated vibration motor. An
artificial fistula can optionally include a sensor that can be in
communication with the open lumen area of the artificial fistula
and function to register and communicate the presence of a needle
tip within the opening of the artificial fistula.
[0009] In one embodiment, a device can include a support surface
that defines a plurality of cut-outs in the surface, and each
cut-out can retain an artificial fistula therein.
[0010] A device can also include a pad that can be removably
located over the upper barrier of an artificial fistula. For
instance, in one embodiment a pad can be removably located on a
support surface that defines a plurality of cut-outs in the
surface. In this embodiment, the pad can cover all of the cut-outs
and the artificial fistulas retained therein and can function as an
artificial flesh over the fistulas. Optionally, a device can
include several different pads of different thickness, compression
characteristics, etc. so as to provide a different "feel" to the
simulator surface and provide for cannulation simulations of a
variety of difficulties.
[0011] In one embodiment, a support surface and a pad can both have
a same surface area shape and size, such as a circle. As such, the
pad can be removed, rotated and/or reversed, and replaced on the
support surface to again fully cover the support surface and
artificial fistulas. This can minimize the presence of visual and
tactile cues on the pad that could designate the locations of the
underlying fistulas and can extend the useful life of the pad.
[0012] In one embodiment, the support surface can rotate about an
axis, which can be utilized to vary the location of the artificial
fistulas underneath the pad and prevent memorization by trainees of
fistula locations on a simulator.
[0013] According to another embodiment, a personal cannulation
simulation device is disclosed. A personal cannulation simulation
device can include a sleeve that is configured for temporary
attachment to a subject, for instance by having a shape that
generally conforms to a human arm. In one embodiment, the sleeve
can be of a closed and substantially cylindrical construction and
can be configured to be slipped over the hand and onto the arm. In
another embodiment the sleeve can include an opening along a length
of the sleeve and can include a closure. In this embodiment, a
sleeve can be configured to wrap around an arm and optionally be
held in place by use of the closure. A sleeve can be impenetrable
to a needle (e.g. include a metal or a hard plastic) and can
protect a wearer from accidental needle puncture during
training.
[0014] A personal cannulation simulation device can also include an
artificial fistula and a pad as described above. The artificial
fistula can be between the sleeve and the pad, and can be separable
from the pad and/or sleeve or of unitary construction with the pad
and/or sleeve.
[0015] In one embodiment, a personal cannulation simulation device
can include multiple removably attachable components so as to be
assembled to mimic an individual's fistula depth, orientation,
size, etc.
[0016] A cannulation simulation device can also include a flesh
simulant material located on either side of the artificial fistula.
The flesh simulant material can be a unitary component of a pad
(e.g., the pad can include one or more channels of the flesh
simulant material for location of the artificial fistula), or may
be removably attachable to the pad, a sleeve, and/or the artificial
fistula.
[0017] Also disclosed are methods for utilizing the cannulation
simulation devices. For instance, following assembly of a device, a
vibration motor can be turned on causing an artificial fistula to
vibrate. A trainee (either a clinician or a patient) can then use
tactile interaction to explore the upper surface of the pad and
locate this vibrating artificial fistula. The trainee can then
insert a dialysis needle into the fistula opening following
determination of the direction and side edges of the fistula.
Successful entrance of the needle tip into the fistula opening can
be ascertained by use of sensors within the fistula openings.
Should the trainee pass the needle tip through the fistula opening
and out of a lower barrier of the artificial fistula, contact
between the needle tip and a conductive surface on the lower
barrier can be registered to signify that the needle tip has gone
too far.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] A full and enabling disclosure of the present invention,
including the best mode thereof, directed to one of ordinary skill
in the art, is set forth in the specification, which makes
reference to the appended figure, in which:
[0019] FIG. 1 is a top view of a support surface.
[0020] FIG. 2 is a perspective view of a support surface.
[0021] FIG. 3 is a side view of components of a cannulation
simulator.
[0022] FIG. 4 is a top view of an opening of a support surface and
an artificial fistula retained therein.
[0023] FIG. 5 is an end view of an artificial fistula.
[0024] FIG. 6 illustrates several components of an artificial
fistula.
[0025] FIG. 7 illustrates a fistula needle and hub.
[0026] FIG. 8 illustrates a method of utilizing a cannulation
simulator.
[0027] FIG. 9 illustrates a personal cannulation simulator in cross
section.
[0028] FIG. 10 illustrates a personal cannulation simulator located
on an arm.
DETAILED DESCRIPTION
[0029] It is to be understood by one of ordinary skill in the art
that the present discussion is a description of exemplary
embodiments only, and is not intended as limiting the broader
aspects of the present disclosure. Each example is provided by way
of explanation of the invention, not limitation of the invention.
In fact, it will be apparent to those skilled in the art that
various modifications and variations can be made in the present
invention without departing from the scope or spirit of the
invention. For instance, features illustrated or described as part
of one embodiment can be used with another embodiment to yield a
still further embodiment. Thus, it is intended that the present
invention covers such modifications and variations as come within
the scope of the appended claims and their equivalents.
[0030] A cannulation simulation device and methods for using the
device are disclosed herein. The device can be used as an
instructive instrument designed to teach dialysis
technicians/nurses/patients to cannulate arteriovenous (AV)
fistulas for hemodialysis. The simulator facilitates cannulation
training by use of a more realistic experience as compared to
existing cannulation simulators and can include real-time feedback
to the trainee to indicate successful as well as unsuccessful
cannulation of the lumen of the artificial fistula. Moreover, the
simulator has been designed to provide for long life without
development of visual or eidetic indicators as to the location of
the artificial fistulas, so as to improve the capabilities of
individuals trained by use of the device. While the present
disclosure is primarily directed to description of arteriovenous
cannulation, it will be readily understood by the person skilled in
the art that the invention is not so limited but extends to
techniques such as cannulation of arteriovenous grafts for
hemodialysis.
[0031] In one embodiment, the simulator comprises a support,
multiple artificial fistulas held in various locations in
conjunction with the support, and a removable pad of synthetic
flesh overlaying the upper surface of the support and the
artificial fistulas. By way of example, FIG. 1 illustrates a top
view of a support 10 and FIG. 2 illustrates a perspective view of a
support 10. The support 10 includes a series of cut-outs 12 within
the support 10. The cut-outs 12 can generally have a
cross-sectional dimension 14 of about 0.5 inches, for instance from
about 0.25 inches to about 1 inch. In addition, the cut-outs 12 can
have a length 15 of several inches, for instance from about 5
inches to about 12 inches or from about 7 inches to about 10 inches
in some embodiments. As shown, the cut-outs 12 can define
curvature(s) or can be generally straight along the length 15.
[0032] As shown in FIG. 2, the support 10 can be supported by legs
16. The legs 16 can be of any suitable length. For instance, the
legs 16 can be designed such that the device can be held on a table
or bench top, in which case the legs 16 can be relatively short,
e.g., about 8 inches to about 14 inches, or about 12 inches in one
embodiment. Alternatively, the device can be self-standing, in
which case the legs 16 can be long enough (e.g., about 24 inches to
about 40 inches) to locate the upper surface 18 of support 10 at a
convenient height for use. In any case, the legs 16 can be of a
height such that device components, e.g., wiring, controllers,
motors, etc. can be retained beneath the support 10.
[0033] In general, the device can be portable. As such, the support
10 can generally be about 36 inches or less in width as measured
from one side to an opposite side of the upper surface 18 of the
support 10, e.g., from about 15 inches to about 24 inches in some
embodiments. In addition, the support 10 and legs 16 can be formed
of any suitable material, e.g., wood, plastic, or combinations of
materials.
[0034] In the embodiment of FIG. 1 and FIG. 2, the support 10 has a
generally round upper surface 18. The round surface 18 can be of
benefit in some embodiments as by placing the artificial fistulas
in conjunction with a round support 10, there can be few or no
spatial reference points for students, ensuring that students will
rely on tactile sensing to determine the location and the size of
the target fistula held in conjunction with the support 10. A round
upper surface 18 can also enable instructors to rotate and flip a
flesh-simulation pad (described further herein) that is held on the
upper surface 18 of the support 10 and has a size and shape that
corresponds to the upper surface 18 of the support 10 while
maintaining alignment between the upper surface 18 of the support
10 and the pad held thereon. This can prevent the formation of
visual cues on the flesh-simulator pad that could indicate
underlying fistula locations and can also extend the life of the
flesh-simulator pad.
[0035] FIG. 3 presents a side-view of components of a device
including a support 10 an artificial fistula 20 held in conjunction
with the support 10 and a flesh-simulation pad 22 that can be
removably located so as to align with the upper surface 18 of
support 10 and can cover the artificial fistula 20.
[0036] The pad 22 can be a flesh-simulation material as is
generally known in the art. For instance, the pad 22 can include an
opaque gel-like or foam filler to simulate subcutaneous tissue and
an outer cover to simulate skin. The pad 22 can generally be from
about 0.5 inches to about 1 inch in total thickness. In one
embodiment, the device can include multiple pads of varying
thicknesses or various degrees of hardness (e.g., Shore A hardness)
that can provide varying degrees of difficulty to a trainee. For
instance, a relatively thin pad of about 0.5 inches can be used in
an easier or beginning training session and a higher degree of
difficulty can be obtained by substituting a thicker pad, e.g.,
about 1 inch, on the support 10. Alternatively, multiple thin pads
can be combined to provide a more difficult simulation
experience.
[0037] As mentioned previously, the temporary fixation of the pad
22 on the upper surface 18 of the support 10 can also be used to
extend the life of the pad 22 and prevent the formation of visual
cues on the pad 22 with regard to the location of the underlying
fistula 20. In particular, the pad 22 can be lifted, rotated and/or
flipped and replaced on the upper surface 18 of the support 10.
Beneficially, such changes can be carried out without creating a
mess as the device need not include an artificial blood in the
simulated flesh, as is the case for previously known cannulation
simulators (though inclusion of an artificial blood in the device
is certainly not prohibited). By changing the orientation of the
gel pad the previous attempts at cannulation are obfuscated,
preventing students from following needle marks to find a fistula.
Further, the difficulty of the cannulation can be increased by
increasing the thickness, density, and/or hardness of the pad 22,
simulating difference in the depth and tenacity of the flesh.
[0038] An artificial fistula 20 can be held in conjunction with
each of the openings 12 in the support 10. FIG. 4 presents a top
view of an artificial fistula 20 held in a cut-out 12. Each fistula
20 is suspended within a cut-out 12, for instance by use of rubber
bushings 24 and the like. The suspension mechanism can at least
partially isolate the fistula 20 from the support 10 that surrounds
the cut-out 12. As such, vibration of the fistula 20 can be better
confined to the fistula and minimal vibration can transfer to the
support 10. Partial isolation of the vibrations of the fistula 20
can better simulate the vibrations of an actual fistula in
real-world practice.
[0039] FIG. 5 presents an end-view of an artificial fistula 20. The
fistula 20 includes an upper barrier 26 and a lower barrier 28 that
define a cannulation opening 27 there between. In the illustrated
embodiment, the upper barrier 26 and the lower barrier 28 can be
formed of different materials, but this is not a requirement of the
devices. For instance, the upper barrier 26 can be a portion of a
rubber or silicone tube that has a cross sectional width w similar
to that of a typical fistula. For instance, the side-to-side width
(e.g., diameter) of the upper barrier 26 can be from about 6
millimeters to about 10 millimeters, or about 8 millimeters in one
embodiment. The semi-circular cross-sectional shape of upper
barrier 26 defining a radial curvature can also be beneficial as it
can more closely resemble the shape of a natural fistula for the
trainee. A fistula 20 can be held in a cut-out 12 such that a
portion of the upper barrier 26 extends above the upper surface 18
of the support 10. For instance the upper barrier 26 of a fistula
20 can protrude above the upper surface 18 of the support 10 by a
distance of from about 2 millimeters to about 4 millimeters.
[0040] The lower barrier 28 can be of any suitable shape and
material. In one embodiment, the lower barrier 28 can be formed of
an electrically conductive material, such as a metal mesh. In this
embodiment penetration of the lower barrier 28 of the fistula 20
can be noted by a closed electrical circuit created between the
conductive material of the lower barrier 28 and a conductive
material of the needle tip. A signal (e.g., visual and/or auditory)
can then be generated when the needle passes through the fistula
opening 27 and makes physical contact with the charged mesh on the
other side. Of course, alternatively, the electric signal generator
and detector may be reversed, with the needle providing an electric
potential and the mesh acting as a detector. As illustrated in FIG.
8, if the tip of the needle 42 passes through the opening 27 and
through the lower barrier 28, a signal (e.g., an optical and/or
auditory sound) can be emitted; signifying cannulation failure
because the lower barrier 28 of the fistula 20 has been penetrated.
For instance, the signal can be generated when the metal tip of the
needle 42 contacts the charged wire mesh forming the lower barrier
28 of the fistula 20.
[0041] Referring again to FIG. 5, the fistula 20 can include a
cradle 25 that can be utilized to suspend the fistula 20 in a
cut-out 12 of a support 10 and to support the other components of
the fistula 20, including the upper barrier 26 and the lower
barrier 28, as shown.
[0042] The cradle 25 can also support a component of a sensor 30
that can be utilized to detect successful penetration of the tip of
a needle 42 into the opening 27. By way of example, the cradle 25
can support a strip 34 of IR-light emitting diodes (LEDs) 30 spaced
along the length 15 of the fistula 20 that radiate emission within
the opening 27. Proper positioning of a cannulation needle 42 with
the tip within the opening 27 of the simulated fistula 20 can be
determined by an infrared (IR) detector 40 (FIG. 7) attached to the
needle 42 that can detect emission from the IR-LEDs 30 placed
beneath the fistula opening 27 in the cradle 25. The emission from
the IR-LEDs 30 cannot permeate beyond the fistula opening 27 as the
upper barrier 26 and the overlying pad 22 can be opaque. When the
tip of the needle 42 pierces the upper barrier 26, the detector 40
can create a signal upon detection of the IR emission from the
IR-LEDs 30. For example, the detector 40 in the end of the
cannulation needle 42 can create a signal 44 (e.g., optical and/or
auditory signal) when the student successfully inserts the needle
tip within the cannulation opening 27 of the fistula 20.
[0043] Of course, the detection method is not limited to IR and
other optical or other detection systems may be utilized. Moreover
the location of the various sensor components may be reversed. For
instance an IR-LED can be attached to the tip of a fistula needle,
and an IR detector can be located under or within the fistula
opening. Missed cannulations of the fistula can thus be noted by
the absence of a signal generation by the IR detector.
[0044] In the real-world cannulation of a fistula, the proper
alignment of a needle in a vessel is evidenced by the "flashback"
of blood within the IV tubing of the cannulation set that includes
a large gauge needle, IV tubing with connectors, and flow arrestor.
Previously known simulation systems include tubes filled with
simulated blood that are connected to external reservoirs, allowing
the simulator to "bleed". Cannulated synthetic veins in such
systems can continue to leak between simulations and can lead to
wet, messy simulators as the artificial blood will not coagulate a
puncture as would living tissue. The presently disclosed systems
can avoid such problems as proper cannulation of a fistula can be
determined by signal generation without the need for synthetic
blood.
[0045] Signals generated or received by the cannulation needle can
be used to generate an indication for immediate user feedback, an
indication only revealed to the instructor, and/or a recording of
the trainee's attempts. These indications can be of any type, e.g.,
visual, tactile, and/or auditory, and recordings can be catalogued
by computer program.
[0046] In addition to other components, a device can include
vibration motors 32 in communication with each of the artificial
fistulas 20. For example, one or more vibration motors 32 can be in
mechanical communication with a cradle 25 or some other component
of each fistula 20 so as to vibrate the upper barrier 26 of the
fistula 20 and provide a tactile cue through the pad 22 to a
trainee of the location, width, and direction of the underlying
fistula 20.
[0047] Any suitable vibration motor 32 is encompassed, such as
those commonly found in cell phones that can be used to mimic the
vibrations of fistula. The vibration motor(s) 32 can be in
communication with a control system (not shown) as is known in the
art. Each motor 32 can be separately controlled or alternatively
multiple motors 32 can be in communication with a single
controller. For instance multiple vibration motors 32 of a single
fistula 20 can be controlled together. As shown in FIG. 8, in one
embodiment a series of vibration motors 32 can be located beneath
the fistula opening 27, for instance in mechanical communication
with the cradle 25 of a fistula 20. During use, the vibration
motor(s) 32 of only one fistula 20 of the device can be activated
at a time to denote a single fistula that the trainee will then
attempt to locate and cannulate. This is not a requirement,
however, and in other embodiments, multiple fistulas can be
activated at one time.
[0048] According to one embodiment, a simulator can be designed as
a personal simulation device for use in training a patient for
self-cannulation. According to this embodiment, a simulator can
include a support in the form of a removable sleeve that is held in
conjunction with a single artificial fistula. Similar to the
multiple-fistula device described above, a personal simulation
device can also include a pad of synthetic flesh overlaying the
upper surface of the sleeve and the artificial fistula.
[0049] One embodiment of a personal simulation device 101 is
illustrated in FIG. 9. As shown, a simulation device 101 can
include a sleeve 128 as a support for the artificial fistula. In
one embodiment, a portion of the sleeve 128 can function as a lower
barrier for the artificial fistula 120. In other embodiments, the
lower barrier can be applied to the sleeve 128 during assembly. In
the cross sectional view of FIG. 9, the device is illustrated as
covering a portion of a patient's limb 130, e.g., a forearm, leg,
etc.
[0050] The sleeve 128 can be of a material that can prevent
puncture by the trainee (generally a person wearing the device on
their limb 130) with the training needle. For instance, the sleeve
128 can include a metal or a relatively hard plastic (e.g., a
polyvinyl chloride, a polypropylene, etc.) The sleeve can be formed
so as to be pulled over or wrapped around a patient's limb. For
instance, one embodiment of a sleeve can be in the form of a
generally cylindrical tube that can slide over a wearer's hand and
into place on the limb. In another embodiment, the sleeve is not in
the form of a closed tube, but rather is open along the length of
the cylinder. In this embodiment, the sleeve can be wrapped around
the arm. Optionally, and depending upon the flexibility of the
sleeve material, etc., a sleeve can include a closure such as a
buckle, snap, button, or other commonly used securing techniques.
As such, following location around a patient's limb, the sleeve can
be secured in place. Currently available products on the market may
also be used as a sleeve of a simulation device such as, without
limitation, the Needle Resistant Arm Sleeves AG8TW by
HexArmor.RTM.. Optionally, the sleeve 128 can include a conductive
material, such as a metal mesh as described above for the lower
barrier so as to aid in training when a portion of the sleeve
serves as the lower barrier of the artificial fistula.
[0051] A personal fistula cannulation simulation device 101 can
include an artificial fistula 120 that includes an upper barrier
126 as described previously and a portion of the sleeve 128 as a
lower barrier that define a cannulation opening 127 there between.
Alternatively, the lower barrier can be formed of a different
material that is applied to the sleeve. For instance, in one
embodiment, the upper and lower barriers can be formed from a
unitary tube that is assembled on the sleeve 128. The artificial
fistula 120 can generally be of a size and shape as described
previously.
[0052] A personal simulation device 101 can optionally include
penetration sensors and vibrational components as described above
for a larger, clinical-type device. For instance, a device 101 can
be electrically connectable to a motor as described above that can
vibrate all or a portion of the upper barrier 126 or a portion of
the sleeve 128 so as to provide a vibration in the area of the
artificial fistula 120 similar to what will be encountered by the
patient during self-cannulation.
[0053] In one embodiment a personal simulation device can include
separable components that can provide for the device to be
personalized for a user. For instance, the artificial fistula 120
can be separable from the sleeve 128 so as to be securable thereto
in a variety of orientations. During formation, a technician that
is familiar with a patient's fistula can locate the artificial
fistula 120 on the sleeve 128 so as to mimic the orientation of the
patient's actual fistula. Placement can be carried out with
temporary attachment, for instance by use of a temporary adhesive
or hook and pile attachments (e.g., Velcro.RTM.) or alternatively
by use of a more permanent adhesive.
[0054] The personal device 101 can also include a pad 122 that can
cover the artificial fistula and function as a flesh simulation.
For instance, the pad can have a thickness of from about 0.25
inches to about 1 inch and be formed of materials as discussed
previously.
[0055] In order to create a generally uniform upper surface on the
device 101 and thereby offer minimal tactile cues as to the
location of the fistula below the flesh simulant pad, a device can
provide for the artificial fistula 120 to be generally surrounded
on the top and sides with an artificial flesh such as the pad 122.
For instance, the pad 122 can be formed with a channel or cavity
within which the artificial fistula 122 can be located.
Alternatively, multiple pieces of pad materials can be located on
the sleeve 128 so as to surround the artificial fistula 120 and
provide a uniform upper surface with little or no visual cues as to
the location of the underlying fistula 120.
[0056] The channel or cavity formed in a pad 122 that can be
adjacent to the top and sides of the fistula 120 may be formed by
the manufacturer or may be custom designed by a nurse/technician
removing material from a pad 122 to mimic a patient's specific
fistula orientation. The pad 122 with imbedded artificial fistula
120 can then be located on the sleeve 128.
[0057] FIG. 10 illustrates a perspective view of a personal
simulation device 101 following location on a patient's limb 130.
As can be seen, in this embodiment, the sleeve 128 can be formed so
as to be wrapped around the limb 128, following which it can be
secured with buckles, snap closures, buttons, hook and loop
closure, or other commonly-used temporary securing techniques. A
sleeve 128 that is open along the side and includes a closure can
be preferred in some embodiments, as this can provide for a device
with a variable cross sectional size.
[0058] As shown, during use, a trainee can target a needle 142 to
the artificial fistula 120. In the illustrated embodiment, the pad
122 is not shown. In one embodiment, during use a trainee can
locate the device on their own limb and over their own fistula. The
trainee can then be taught to locate the artificial fistula 120
that lies beneath the pad by tactile exploration of the pad
following which the trainee can be taught to penetrate the pad with
a needle 142 and successfully locate the tip of the needle within
the lumen 127 of the artificial fistula 120.
[0059] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other examples are intended to be within the scope
of the claims if they include structural elements that do not
differ from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal languages of the claims.
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