U.S. patent application number 17/122823 was filed with the patent office on 2021-06-10 for injection site training system.
The applicant listed for this patent is Truinject Corp.. Invention is credited to Bruce A. Christie, Clark B. Foster, Gabrielle A. Rios, Khoi Turner.
Application Number | 20210174706 17/122823 |
Document ID | / |
Family ID | 1000005413281 |
Filed Date | 2021-06-10 |
United States Patent
Application |
20210174706 |
Kind Code |
A1 |
Foster; Clark B. ; et
al. |
June 10, 2021 |
INJECTION SITE TRAINING SYSTEM
Abstract
An injection apparatus and training system for prophylactic,
curative, therapeutic, acupuncture, or cosmetic injection training
and certification. In an embodiment, an injection training system
is described that includes a testing tool having a needle and a
position sensor, where the position sensor is configured to obtain
position information of the testing tool. The system also includes
an injection apparatus configured to receive a simulated injection
by the testing tool. The system includes a display device
configured to receive the position information and to display
position data reflective of the position information.
Inventors: |
Foster; Clark B.; (Mission
Viejo, CA) ; Rios; Gabrielle A.; (Newport Beach,
CA) ; Christie; Bruce A.; (Claremont, CA) ;
Turner; Khoi; (Tustin, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Truinject Corp. |
Irvine |
CA |
US |
|
|
Family ID: |
1000005413281 |
Appl. No.: |
17/122823 |
Filed: |
December 15, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15886363 |
Feb 1, 2018 |
10896627 |
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17122823 |
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14598614 |
Jan 16, 2015 |
9922578 |
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15886363 |
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61928915 |
Jan 17, 2014 |
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61939093 |
Feb 12, 2014 |
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62066792 |
Oct 21, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 2205/332 20130101;
A61M 2205/3306 20130101; A61M 2205/8206 20130101; A61M 2205/50
20130101; G09B 23/30 20130101; G09B 23/285 20130101; G09B 23/28
20130101; A61M 2205/33 20130101; A61M 5/31 20130101 |
International
Class: |
G09B 23/28 20060101
G09B023/28; G09B 23/30 20060101 G09B023/30; A61M 5/31 20060101
A61M005/31 |
Claims
1.-160. (canceled)
161. An injection training system, the system comprising: a signal
processing and display interface comprising one or more processors;
and a display device in communication with the signal processing
and display interface, the display device configured to visually
display a three-dimensional likeness of an anatomical structure as
a stereoscopic representation, wherein the display device is
configured to display one or more layers of the anatomical
structure being peeled back.
162. The injection training system of claim 161, wherein the
anatomical structure is an injection site.
163. The injection training system of claim 161, wherein the
three-dimensional likeness of the anatomical structure comprises a
face.
164. The injection training system of claim 161, wherein the signal
processing and display interface is configured to retrieve one or
more models of physiological information from a database.
165. The injection training system of claim 164, wherein the one or
more models include three-dimensional information indicating
location(s) of certain anatomical or physiological features of the
anatomical structure.
166. The injection training system of claim 161, wherein the
three-dimensional likeness of the anatomical structure on the
display device is configured to be displayed with a plurality of
different views.
167. The injection training system of claim 166, wherein the
plurality of different views comprise rotated, zoomed in, zoomed
out, cross-sectional, or time-lapsed views.
168. The injection training system of claim 161, wherein the
three-dimensional likeness of the anatomical structure includes
muscles.
169. The injection training system of claim 161, wherein the
three-dimensional likeness of the anatomical structure comprises
arteries, veins, nerves, and skeletal portions that are to be
avoided or accommodated during an injection.
170. The injection training system of claim 161, wherein the one or
more layers of the anatomical structures are labeled.
171. The injection training system of claim 161, wherein different
layers of the one or more layers of the anatomical structures are
displayed with different colors, different textures, or both.
172. The injection training system of claim 161, further comprising
an injection tool, the injection tool comprising a
three-dimensional position sensor, the three-dimensional position
sensor in communication with the signal processing and display
interface.
173. The injection training system of claim 172, wherein the signal
processing and display interface is configured to map
three-dimensional position information of the three-dimensional
position sensor to the three-dimensional likeness of the anatomical
structure on the display device.
174. The injection training system of claim 161, wherein the
display device is configured to display the one or more layers of
the anatomical structure being peeled back as a new layer is
penetrated during a training injection.
175. An injection training system, the system comprising: a signal
processing and display interface comprising one or more processors;
and a display device in communication with the signal processing
and display interface, the display device configured to visually
display a three-dimensional likeness of an anatomical structure as
a stereoscopic representation, wherein the display device is
configured to further display labels of one or more layers of the
anatomical structure.
176. The injection training system of claim 175, wherein the
anatomical structure is an injection site.
177. The injection training system of claim 175, wherein different
layers of the one or more layers of the anatomical structures are
displayed with different colors, different textures, or both.
178. The injection training system of claim 175, wherein the signal
processing and display interface is configured to retrieve one or
more models of physiological information from a database.
179. The injection training system of claim 178, wherein the one or
more models include three-dimensional information indicating
location(s) of certain anatomical or physiological features of the
anatomical structure.
180. The injection training system of claim 175, wherein the
three-dimensional likeness of the anatomical structure on the
display device is configured to be displayed with a plurality of
different views.
181. The injection training system of claim 175, wherein the
plurality of different views comprise rotated, zoomed in, zoomed
out, cross-sectional, or time-lapsed views.
Description
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/886,363, filed Feb. 1, 2018, which is a
continuation of U.S. patent application Ser. No. 14/598,614, filed
Jan. 16, 2015, which claims the benefit of U.S. Provisional
Application No 61/928,915, filed on Jan. 17, 2014, U.S. Provisional
Application No 61/939,093, filed on Feb. 12, 2014, and U.S.
Provisional Application No. 62/066,792, filed on Oct. 21, 2014, the
entirety of each of which is hereby incorporated herein by
reference.
[0002] Any and all applications for which a foreign or domestic
priority claim is identified in the Application Data Sheet as filed
with the present application are hereby incorporated by reference
under 37 CFR 1.57.
BACKGROUND
[0003] A variety of medical injection procedures are often
performed in prophylactic, curative, therapeutic, or cosmetic
treatments. Injections may be administered in various locations on
the body, such as under the conjunctiva, into arteries, bone
marrow, the spine, the sternum, the pleural space of the chest
region, the peritoneal cavity, joint spaces, and internal organs.
Injections can also be helpful in administering medication directly
into anatomic locations that are generating pain. These injections
may be administered intravenously (through the vein),
intramuscularly (into the muscle), intradermally (beneath the
skin), subcutaneously (into the fatty layer of skin), or
intraperitoneally (into the body cavity). Injections can be
performed on humans as well as on animals. The methods of
administering injections typically vary for different procedures
and may depend on the substance being injected, needle size, or
area of injection.
[0004] Injections are not limited to treating medical conditions,
but may be expanded to treating aesthetic imperfections or
restorative cosmetic procedures. Many of these procedures are
performed through injections of various products into different
parts of the body. The aesthetics and therapeutic industry
comprises two main categories of injectable products:
neuromodulators and dermal fillers. The neuromodulator industry
commonly uses nerve-inhibiting products such as Botox.RTM.,
Dysport.RTM., and Xeomin.RTM.. The dermal filler industry uses
products administered by providers to patients for both cosmetic
and therapeutic reasons, such as, for example, Juvederm.RTM.,
Restylane.RTM., Belotero.RTM., Sculptra.RTM., Artefill.RTM., and
others. These providers or injectors may include plastic surgeons,
facial plastic surgeons, oculoplastic surgeons, dermatologists,
nurse practitioners, dentists and nurses.
[0005] A problem in the administration of injections is that there
is no official certification or training process. Anyone with a
minimal medically-related license may inject a patient. These
"injectors" may include primary care physicians, dentists,
veterinarians, nurse practitioners, nurses, physician's assistants,
or aesthetic spa physicians. However, the qualifications and
training requirements for injectors vary by country, state, and
county. For example, in most states in the United States, the only
requirement to be permitted to inject patients with neuromodulators
and/or fillers is to have a nursing degree or medical degree.
Accordingly, there is a lack of uniformity and expertise in
administering such injections. The drawbacks with this lack of
uniformity in training and expertise are widespread throughout the
medical industry. Doctors and practitioners often are not
well-trained in administering injections of diagnostic,
therapeutic, and cosmetic chemical substances. This lack of
training has led to instances of chronic pain, headaches, bruising,
swelling, or bleeding in patients.
[0006] Current injection training options are classroom-based, with
hands-on training performed on live models. The availability of
models is limited. Moreover, even when available, live models are
limited in the number and types of injections they may receive. The
need for live models is restrictive because injectors are unable to
be exposed to a wide and diverse range of situations and anatomies
in which to practice. For example, it may be difficult to find live
models with different skin tones or densities. This makes the
training process less effective because patients have diverse
anatomical features as well as varying prophylactic, curative,
therapeutic, or cosmetic needs. Live models are also restrictive
because injectors are unable to practice injection methods on the
internal organs of a live model due to safety and health
considerations.
[0007] As a result of these limited training scenarios, individuals
seeking treatments involving injections have a much higher risk of
being treated by an inexperienced injector. This may result in low
patient satisfaction with the results, or in failed procedures. In
many instances, patients have experienced lumpiness from incorrect
dermal filler injections. Some failed procedures may result in
irreversible problems and permanent damage to a patient's body. For
example, patients have experienced vision loss, direct injury to
the globe of the eye, and brain infarctions where injectors have
incorrectly performed dermal filler procedures. Additional examples
of side effects include inflammatory granuloma, skin necrosis,
endophthalmitis, injectable-related vascular compromise,
cellulitis, biofilm formation, subcutaneous nodules, fibrotic
nodules, and other infections.
[0008] As a result of the varying qualifications and training
requirements for injectors, there is currently no standard to
train, educate, and certify providers on the proper and accurate
process of various injection techniques. Patients seeking
injections also have few resources for determining the
qualifications or experience of a care practitioner.
SUMMARY
[0009] The present disclosure generally relates to an injection
apparatus and training system for prophylactic, curative,
therapeutic, acupuncture, or cosmetic injection training and
certification. The training system eliminates the need to find live
models for hands-on training sessions. The training system provides
feedback on trainees and the accuracy of injection procedures
performed. In an embodiment, feedback is provided in real time. The
training system can be used as a measurement on how the "trainee"
is doing prior to receiving actual product by the manufacturing
company as a measure of qualification. The training system reduces
the risks associated with inexperienced and uncertified medical
personnel performing injection procedures.
[0010] The training system can be used to educate, train, and
certify medical personnel for injection procedures. It can also be
utilized as a testing program for certifying medical personnel. The
system will enable users to practice a variety of injections,
ranging from on label to off label product injections. In some
embodiments, the system may allow users to train for therapeutic
treatments. In other embodiments, the system may allow users to
train for injections into arteries, bone marrow, the spine, the
sternum, the pleural space of the chest region, the peritoneal
cavity, joint spaces, internal organs, or any other injection
sites. The system may be used for any type of injection, including,
but not limited to those involving prophylactic, curative,
therapeutic, or cosmetic treatments in both humans and animals.
Illustratively, by way of non-limiting example, the disclosed
system may be used to simulate a cosmetic application of filling of
a wrinkle with a dermal filler. In other applications, the systems
disclosed herein can be used for dental application and training
for dental procedures.
[0011] In an aspect of the present disclosure, an injection
training system is described that includes a testing tool having a
needle and a position sensor, where the position sensor is
configured to obtain position information of the testing tool. The
system also includes an injection apparatus configured to receive a
simulated injection by the testing tool. The system includes a
display device configured to receive the position information and
to display position data reflective of the position information,
wherein the display device includes a processor and a memory
device.
[0012] In an embodiment of the disclosed injection training system,
a method of tracking the position of a testing tool used in an
injection training system is described. The method includes
obtaining position information of the testing tool from one or more
sensors; determining an estimate of the position of the testing
tool; transmitting, to a display device, data reflective of the
estimate of the position of the testing tool; and displaying, on
the display device, the data reflective of the estimate of the
position of the testing tool.
[0013] In an embodiment, an injection training system is disclosed.
The injection training system includes a testing tool having a
needle, a plunger, and a marker configured to reflect
electromagnetic waves. The system also includes an injection
apparatus configured to receive a simulated injection by the
testing tool. The injection apparatus also has a marker configured
to reflect electromagnetic waves. The system includes an optical
tracking system having a field of view, where the optical tracking
system is positioned such that the injection apparatus is in the
field of view. The optical tracking system is configured to obtain
position information of the testing tool and the injection
apparatus and to transmit the position information to a display
device. The display device is configured to receive the position
information and to display position data reflective of the position
information.
[0014] In one embodiment, there are three main components of the
training system: (1) a training apparatus (also referred to
interchangeably as an injection apparatus throughout the present
disclosure) which features an anatomically accurate model of a
human or human body part necessary for injection training, (2) a
light detection device, such as, for example, a camera, associated
with the training apparatus, and (3) a testing tool with light
emitting capabilities. In an embodiment, a fourth component of the
training system can include an output device that can run an
application which receives communications from the training
apparatus or light detection device and generates information
regarding injection parameters based on the communications from the
injection apparatus or light detection device. In an embodiment,
the images captured by the camera are processed by a processor
included either in the injection apparatus or in the light
detection device before being communicated to the output device.
This processing can include, for example, determining an indication
of one or more injection parameters. In an embodiment, the
anatomical model can include various injection conditions, such as,
for example, layered skin, available in multiple tones and textures
to mimic a diverse span of age, race, and skin texture. In an
embodiment, the layered skin can be removable and/or replaceable.
The injection apparatus can simulate any human or animal part, such
as, for example, the face, head, brain, neck, back, chest, spine,
torso, arms, legs, hands, feet, mouth, or any other body part or
portion of the body of interest. In an embodiment, the testing tool
can be, for example a syringe or hypodermic needle. In an
embodiment, the injection apparatus is reusable. In an embodiment,
the injection apparatus is disposable.
[0015] In an embodiment a syringe for simulating injection is
disclosed. The syringe can include a barrel having a portal at a
distal end, and an electronics assembly having a light source at a
distal end of the electronics assembly. The electronics assembly
can be configured to fit inside the barrel with the light source
positioned at the portal of the barrel. A needle can be attached to
the barrel. The needle can have a fiber bundle extending axially
through it such that the fiber bundle is in close-fitting relation
with the light source.
[0016] In some embodiments a testing tool for use in an injection
training system includes a barrel having a fitting at a distal end
of the barrel. The fitting can have a portal, and the barrel can
have an opening and a finger grip at a proximal end of the barrel.
A plunger can be configured to fit in the opening of the barrel to
apply a force directed axially toward the distal end of the barrel.
The testing tool can include an electronics assembly that has a
light source at its distal end and a force sensor at its proximal
end. The electronics assembly can be configured to fit inside the
barrel with the light source positioned at the portal of the
fitting, and the force sensor positioned near the proximal end of
the barrel. The force sensor can be configured to sense the force
applied by the plunger. The testing tool can include a needle
assembly attached to the fitting of the barrel. The needle assembly
can have a hollow needle, a fiber bundle extending axially through
the hollow needle, and a hub configured to secure the hollow needle
and to attach the needle assembly to the fitting of the barrel. The
needle assembly can be attached to the barrel such that the fiber
bundle within the hollow needle is in close-fitting relation with
the light source of the electronics assembly.
[0017] In an embodiment, a method of simulating an injection into a
synthetic anatomical structure is disclosed. The synthetic
anatomical structure can be configured to attenuate light emitted
into it and to detect the attenuated light. The method can include
providing a testing tool to simulate a syringe. The testing tool
can be configured to emit light through a needle at a distal end of
the testing tool. The method can also include inserting the needle
into the synthetic anatomical structure such that the light emitted
through the needle is attenuated and detected by the synthetic
anatomical structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 illustrates an injection training system comprising
an injection apparatus, a testing tool and an output device in
accordance with an embodiment of the present disclosure.
[0019] FIG. 2A is a perspective view of an embodiment of an
assembled testing tool.
[0020] FIG. 2B is an exploded perspective view of an embodiment of
a testing tool.
[0021] FIG. 2C is a perspective view of an embodiment of a barrel
of a testing tool.
[0022] FIG. 2D is a perspective view of an embodiment of a label of
a testing tool.
[0023] FIG. 2E is a perspective view of an embodiment of a needle
assembly of a testing tool.
[0024] FIG. 2F is an exploded perspective view of an embodiment of
a needle assembly of a testing tool.
[0025] FIG. 2G is a top view of the distal end of an embodiment of
the needle assembly of a testing tool.
[0026] FIG. 3A is a simplified block diagram of an embodiment of an
electronics assembly of a testing tool.
[0027] FIG. 3B is a perspective view of an embodiment of an
electronics assembly of a testing tool.
[0028] FIG. 3C is an exploded perspective view of an embodiment of
a force sensor sub-assembly of an electronics assembly of a testing
tool.
[0029] FIG. 4A is a perspective view of an embodiment of a testing
tool docked in an embodiment of a docking station.
[0030] FIG. 4B is a perspective view of an embodiment of a docking
station.
[0031] FIG. 4C is a perspective view of an embodiment of a docking
station with its cover removed.
[0032] FIG. 5 illustrates an embodiment of the injection training
system.
[0033] FIGS. 6A and 6B are two perspective views of an example
trajectory for an injection.
[0034] FIG. 7 illustrates an example embodiment of a
three-dimensional (3D) injection detection sensor.
[0035] FIG. 8 illustrates an example embodiment of a 3D injection
detection sensor.
[0036] FIG. 9 illustrates a side view of one embodiment of the
injection apparatus including a 3D injection detection sensor.
[0037] FIG. 10 is a process flow diagram of a method of
manufacturing an anatomically shaped injection apparatus including
a 3D tracking system.
[0038] FIG. 11 is a process flow diagram for a method of 3D
injection training.
[0039] FIG. 12 illustrates an embodiment of an injection training
system comprising an injection apparatus, a testing tool, and a
resting cradle in which the testing tool follows a sequence of
motion (A through D) from the resting cradle to an injection site
of the injection apparatus.
[0040] FIG. 13A illustrates a process flow diagram of a process to
determine the position and orientation of a testing tool according
to an embodiment of the disclosed injection training system.
[0041] FIGS. 13B, 13B1, and 13B2, collectively, illustrate a
process flow diagram of a process to determine the position and
orientation of a testing tool according to an embodiment of the
disclosed injection training system.
[0042] FIG. 14A is simplified perspective view of an exemplary
optical tracking system illuminating a testing tool according to an
embodiment of the disclosed injection training system.
[0043] FIG. 14B is simplified perspective view of an exemplary
optical tracking system sensing reflected light from testing tool
according to an embodiment of the disclosed injection training
system.
[0044] FIG. 14C illustrates a testing tool configured with multiple
markers according to an embodiment of the disclosed injection
training system.
[0045] FIG. 14D illustrates aspects of the user interface/display
device according to an embodiment of the disclosed injection
training system.
[0046] FIG. 15A illustrates an embodiment of an injection training
system comprising an injection apparatus, a testing tool, an output
device and an optical tracking system, in accordance with an
embodiment of the present disclosure.
[0047] FIG. 15B illustrates an embodiment of an injection training
system comprising an injection apparatus, a testing tool, an output
device and a plurality of optical tracking systems, in accordance
with an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0048] Embodiments will now be described with reference to the
accompanying figures. The following description is merely
illustrative in nature and is in no way intended to limit the
disclosure, its application, or its uses. For purposes of clarity,
the same reference numbers will be used in the drawings to identify
similar elements. The terminology used in the description presented
herein is not intended to be interpreted in any limited or
restrictive manner, simply because it is being used in conjunction
with a detailed description of certain specific embodiments of the
disclosure. Furthermore, embodiments of the disclosure may include
several novel features, no single one of which is solely
responsible for its desirable attributes or which is essential to
practicing the present disclosure. It should be understood that
steps within a method may be executed in different order without
altering the principles of the present disclosure.
[0049] FIG. 1 depicts an embodiment of an injection training system
100. An injection apparatus 105, comprising a synthetic anatomical
structure, can be used for any type of injection training involved
with administering diagnostic and therapeutic chemical substances.
For example, injection training can be provided for epidural
techniques and for intra-cardiac injections. In one embodiment, the
injection apparatus 105 can anatomically model the face, neck, and
head of a human or animal. Although not shown in the accompanying
drawings, the injection apparatus 105 can model other injection
sites including the chest, arms, mouth, back, buttocks, etc. The
injection apparatus 105 may also represent any body part of a human
or animal, including internal organs. In some embodiments, the
injection apparatus 105 may include a simulated skull and layers of
muscle and skin. The injection apparatus 105 can be positioned on a
base 108 to facilitate use on flat surfaces, such as a table or
desk.
[0050] A testing tool 110 is also illustrated which can be used
with the injection apparatus 105 and in conjunction with a
camera/light detector 120 located within the injection apparatus
105. The testing tool 110 may simulate any type of equipment used
in connection with an injection or minimally invasive procedure,
such as a needle, catheter or cannula. As described in further
detail below, the camera/light detector 120 can capture visual
indications of the user's injection using the testing tool 110. The
visual indications provide an operator or user with information
regarding the location, depth, pressure, or angle of the injection.
In an embodiment, the testing tool 110 contains a light source that
emits light through the needle portion of the testing tool 110
which is used to aid in obtaining the visual indications detectable
by a camera/light detector 120. The light source can emit visible
light. In an embodiment, a gradient of white light is emitted
through the needle portion of the testing tool. Other colors of
visible light can also be used, such as green, blue, red, yellow or
any combination of those colors. In an alternative embodiment, the
light source may emit light along a spectrum of visible or
non-visible light, such as fluorescent, ultraviolet, or infrared
light. In some embodiments, the light emitted from the light source
is attenuated differently depending on which layer of simulated
skin, muscle, or tissue the injection apparatus 105 is penetrated.
Different colors, directions, graph lines, visual patterns,
polarization, fluorescence, or intensities of light can be captured
by the camera/light detector 120 as the testing tool 110 is
inserted through the different layers of material surrounding the
injection apparatus 105. The resulting light detected by the
camera/light detector 120 can be used to determine the location of
the injection, the pressure exerted by the user, the angle of
injection, and/or the depth of the injection. This information can
be detected, for example by a camera/light detector 120, and
communicated to a user interface/display device 140 for training,
testing, and/or certification purposes. In some embodiments,
information used to determine the location of the injection, the
pressure exerted by the user, the angle of injection, and/or the
depth of the injection can be collected by the testing tool 110 and
communicated to a user interface/display device 140 and/or a
camera/light detector 120 for training, testing and certification
purposes.
[0051] The camera/light detector 120 within the simulated skull of
the injection apparatus 105 captures the attenuated light emitted
by the testing tool 110, simulating an injection, through video
recording and/or photographic images. The camera/light detector 120
can include a processor and can communicate output from the
camera/light detector 120 to a user interface/display device 140.
The information gathered from the camera/light detector 120 and
testing tool 110 may be communicated to a user interface/display
device 140 for data collection, testing or certification purposes.
Output from the camera/light detector 120 can be raw or processed
video or images obtained from the camera/light detector 120. The
processor of the camera/light detector 120 can include software
configured to interpret the visual indications for testing purposes
or can merely pass images to the user interface/display device 140
for further processing. In an embodiment, the user
interface/display device 140 can also communicate instructions to
the camera/light detector 120 and/or to the testing tool 110.
[0052] Attention is now directed to embodiments of the testing tool
110. Although disclosed with reference to particular embodiments of
the testing tool 110, an artisan will recognize from the disclosure
herein that there is a large number and wide variety of embodiments
and configurations that may be used to perform the functions of a
testing tool 110 as described herein.
[0053] FIGS. 2A and 2B illustrate (in assembled and exploded views,
respectively) an embodiment of the testing tool 110 adapted for use
to train individuals to inject materials with a syringe. In an
embodiment the testing tool 110 includes a plunger 210, a barrel
220, a needle assembly 230, and an electronics assembly 240. Also
illustrated are fasteners 221, such as screws, to secure portions
of the electronics assembly 240 to the barrel 220.
[0054] For purposes of this description, the end of the test tool
110 toward the needle assembly 230 is referred to as the "distal
end," and motion or direction toward the distal end is described as
being "distal." The end of the test tool 110 longitudinally
opposite the distal end is referred to as "the proximal end," and
motion or direction toward the proximal end is described as being
"proximal."
[0055] The plunger 210 can be manufactured by using many types of
materials including polypropylene, glass, and other materials known
to skilled artisans. The plunger 210 includes a top portion 212 at
the proximal end of the plunger 210. The plunger 210 also includes
a shaft 214 which, in an embodiment, is x-shaped. In some
embodiments the plunger shaft 214 can be cylindrical or any other
shape suitable to perform the function of a plunger 210. In some
embodiments, the plunger 210 is collapsible to simulate the process
of injecting material into a patient. In some embodiments the
plunger 210 is configured to house the electronics assembly 240. In
some embodiments the plunger 210 is collapsible and configured to
measure the plunger's 210 motion of contraction to determine a
volume of material that would have been injected under the
simulated circumstances and conditions of use of the testing tool
110. The collapsible plunger 210 can be reset by pulling it back to
its original, un-collapsed (or extended) position. In some
embodiments data reflecting the position of the plunger 210 is
collected and communicated to, for example, the user
interface/display device 140 and/or to the camera/light detector
120. In an embodiment the testing tool 110 includes a hydraulic
and/or a friction-based device, acting against the plunger 210, to
simulate the force of resistance that a liquid material with
certain properties of viscosity, would exert against the plunger
210 as it is injected into a patient.
[0056] At the distal end of the plunger 210 is a seal 216, which is
made of rubber in an embodiment. A skilled artisan will appreciate
that in some embodiments the plunger seal 216 may be made from any
material suitable for creating a seal between the plunger 210 and
the inside walls of the barrel 220, such as various types of
elastomers and/or polymers. In some embodiments the plunger 210
lacks a seal 216 because the testing tool 110 is not used to
deliver liquid, chemical substances, thereby lacking a need to form
a seal.
[0057] FIG. 2C is a perspective view of an embodiment of a barrel
220 of a testing tool 110. The barrel 220 can be made from many
types of materials including polypropylene, glass, and other
materials known to skilled artisans. The barrel 220 includes a grip
222 and an opening 223 at the barrel's proximal end. The grip 222
provides finger support for reciprocation of the plunger 210
relative to the barrel 220 during use for training. At the distal
end of the barrel 220 is a threaded portion 224 configured to
receive a fitting 226. The fitting has a portal 225 through which
light passes from a light source (on the electronics assembly 240)
to a fiber bundle housed within a hollow needle (in the needle
assembly 230). In some embodiments the fitting 226 can be a Luer
fitting, a standardized set of fittings used to make leak-free
mechanical connections between a male-taper fitting and a mating
female part on medical and laboratory instruments, including
hypodermic syringe tips and needles. In some embodiments the
fitting 226 is not tapered. Advantageously, in some embodiments,
the fitting 226 can accommodate numerous configurations of needle
assemblies 230 corresponding to various injection indications and
applications. In some embodiments a customized fitting 226 includes
a thread with no taper component to facilitate intimate contact
between a light source and a fiber bundle that transmits the
emitted light into the injection apparatus 105. In an embodiment
the barrel 220 includes bores 228 configured to receive connector
pins attached to the electronics assembly 240 to enable charging of
a battery when, for example, the testing tool 110 is housed in a
docking station. The barrel 220 also includes holes 229 through
which fasteners, such as screws, can be used to secure the
electronics assembly 240 to the barrel 220.
[0058] FIG. 2D is a perspective view of an embodiment of a label
250 of a testing tool 110. In an embodiment, the label 250 is
configured to fit inside the barrel 220 in close-fitting relation
with an inner wall of the barrel 220. In an embodiment the label
250 is configured to fit outside the barrel 220 in close-fitting
relation with an outer wall of the barrel 220. The label 250 can be
configured to present any type of information including, among
other things, branding and/or instructional information.
[0059] FIGS. 2E-2F are perspective views (assembled and exploded,
respectively) of an embodiment of a needle assembly 230 of a
testing tool 110, including a hollow needle 232, a needle hub 234,
an adapter 236, and a fiber bundle 238 positioned centrally along
the longitudinal axis of the needle assembly 230 and configured to
transmit light at the distal end of the testing tool 110. In some
embodiments a needle hub 234 is configured to connect directly to
the fitting 226 of the barrel 220, thereby eliminating the need for
an adapter 236. The fiber bundle 238 is housed within the hollow
needle 232. In an embodiment the hollow needle 232 is made from
hypodermic tubing. A wide variety of hollow needles 232 used for,
among other things, hypodermic applications, have outer diameters
described by gauge numbers ranging from 7 to 34. Hollow needles 232
within this gauge range can be used in various embodiments of the
disclosed needle assembly 230. Smaller gauge numbers indicate
larger outer diameters. The inner diameters of such hollow needles
232 depend on both gauge and wall thickness. Thin-wall needles have
identical outer diameters, but larger inner diameters, for a given
gauge. Thin-wall needles can also be used in various embodiments of
the needle assembly 230. In an embodiment the hollow needle 232 is
made of stainless steel and has a gauge size of 23RW. A skilled
artisan will appreciate that the hollow needle 232 can be of many
different gauge sizes without departing from the scope of the
disclosure herein. Free space between the fiber bundle 238 and the
inner wall of the hollow needle 232 can be potted with optical
epoxy. The proximal and distal ends of the hollow needle 232,
having the fiber bundle 238 secured inside it, can be polished
flat. The hollow needle 232 can be epoxy-bonded to the needle hub
234, which attaches to the fitting 226 on the barrel 220. FIG. 2G
is a top view of the distal end of the needle assembly 230
illustrating the fiber bundle 238 housed and secured with optical
epoxy within the hollow needle 232.
[0060] FIG. 3A is a simplified block diagram of an embodiment of
the electronics assembly 240 of the testing tool 110. Functionally,
among other things, the electronics assembly 240 emits light from a
light source 320, measures the electronic assembly's 240 physical
position and/or orientation with a position sensor 308, and
measures force applied to the plunger 210 by a force sensor 312.
The electronics assembly 240 communicates the measured position
information and the measured force information to, for example, an
external user interface/display device 140, and/or to a
camera/light detector 120, by way of a communications protocol. In
some embodiments the electronics assembly 240 communicates data by
way of a USB port 322 using a cable that has a minimal diameter and
is highly compliant. In some embodiments the electronics assembly
240 communicates data by way of a radio 310 employing, for example,
a Bluetooth wireless communications protocol.
[0061] As illustrated in FIG. 3A, an embodiment of the electronics
assembly 240 includes a battery 302, a power management controller
304, a voltage regulator 306, a position sensor 308, a radio 310, a
force sensor 312, a data acquisition system 314, one or more
processors 316, a light source driver 318, a light source 320 and
one or more power/communication ports 322. In some embodiments the
battery 302 is rechargeable, and the power management controller
304 is configured to communicate with an external battery-charging
power/communication port 322, such as, for example, a universal
serial bus (USB) port. The battery 302 can supply power to the
components and circuitry of the electronics assembly 240. In an
embodiment the battery 302 is an ultrathin, rechargeable, lithium
polymer cell. A skilled artisan will appreciate that numerous other
batteries can be used in the disclosed electronics assembly
240.
[0062] According to an embodiment, the electronics assembly 240
comprises a battery 302 and a light source 320, where the
electronics assembly 240 is configured to emit light through the
hollow needle 232 to achieve basic functionality of the disclosed
testing tool 110. In an embodiment, the electronics assembly 240
comprises a light source 320 and a port 322 through which an
external power source may be electrically connected to energize the
light source 320 to achieve basic functionality of the testing tool
110. One skilled in the art will appreciate that various functional
capabilities described in connection with embodiments of the
electronics assembly 240 can be implemented in numerous ways. To
illustrate this point, illustrative components, blocks, modules,
and circuits have been described generally in terms of their
functionality. The manner by which such functionality is
implemented can depend upon the particular application and design
constraints imposed on the overall system. The described
functionality can be implemented in varying ways for each
particular application, but such embodiment decisions should not be
interpreted as causing a departure from the scope of the present
disclosure.
[0063] To operate effectively in the injection training system 100,
the light source 320 must be sensed by the camera/light detector
120. In an embodiment the camera/light detector 120 is configured
to sense visible light and infrared light. In an embodiment the
light source is a light emitting diode (LED) that emits low,
infrared light at a wavelength of 810 nanometers (nm). In an
embodiment the light source 320 is a laser that emits low infrared
light at a wavelength of 850 nm. In an embodiment the light source
320 has a narrow emission angle of twenty degrees or less. In an
embodiment, the light source 320 is an LED that has its dome
removed and is polished flat to facilitate intimate contact with
the proximal end of the fiber bundle 238 and the light source 320
when the testing tool 110 is assembled. In some embodiments lenses,
reflectors, and/or fiber optic tapers are coupled to the light
source 320 to focus and/or to intensify the emitted light in the
direction of the fiber bundle 238. In some embodiments the
intensity of the light emitted by the testing tool 110 is
proportional to the amount of pressure applied to a plunger 210 of
the testing tool 110, thereby simulating a process by which liquid
material is injected through the testing tool 110. A skilled
artisan will appreciate that many other light sources 320 and light
ranges of various wavelengths can be used in the disclosed training
system 100 without departing from the scope of the disclosure
herein.
[0064] In an embodiment the force sensor 312 is configured to sense
up to twenty pounds (20 lbs.) of force with a 2 percent accuracy
factor. In an embodiment the position sensor 308 is a three-axis
digital gyroscope with angle resolution of two degrees and with a
sensor drift adjustment capability (pitch, yaw and roll) of one
degree. A skilled artisan will appreciate that numerous other
position sensors 308 and force sensors 312 can be used in the
disclosed electronics assembly 240 without departing from the scope
of the disclosure herein. In an embodiment the electronics assembly
includes a power conditioning component, such as a voltage
regulator 306, to enable operation of the position sensor 308 and
the force sensor 312. In an embodiment the position sensor 308
senses the position of the testing tool 110 in three-dimensional
space, and the sensed position information is communicated to the
user interface/display device 140 and/or to the camera/light
detector 120.
[0065] FIG. 3B is a perspective view of an embodiment of the
electronics assembly 240. Advantageously, the electronics assembly
240 is configured to fit within the barrel 220 of the testing tool
110. A rectangular circuit board 324 comprises a substrate onto
which several components of the assembly 240 are attached. In an
embodiment the electronics assembly includes the battery 302, the
power management controller 304, the voltage regulator 306, the
light source driver 318 and the light source 320. When the
electronics assembly 240 is configured in the testing tool 110, it
is positioned such that the light source 320 is located at the
distal end of the testing tool 110, within the fitting 226 so as to
make intimate contact with the proximal end of the fiber bundle
238, which is secured to the needle assembly 230.
[0066] In an embodiment the electronics assembly 240 also includes
a force sensor sub-assembly 360 illustrated in FIG. 3B and in FIG.
3C, in assembled and exploded views, respectively. The force sensor
sub-assembly 360 has a circular printed circuit board 326
comprising a substrate to which several components of the force
sensor sub-assembly 360 are attached, including a force sensor 312,
backstops 328, and connector pins 330. The backstops 328 provide
structural support for the force sensor sub-assembly 360 and serve
as a mechanism by which to secure the force sensor sub-assembly 360
to the barrel 220. The circular printed circuit board 326 is
attached to the two backstops 328 with fasteners 329. The connector
pins 330 are used to couple to an external power source to charge
the battery 302. In an embodiment, the connector pins 330 are
spring-loaded contacts that are soldered to the circular printed
circuit board 326 and configured to fit through the bores 228 in
the barrel 220. By protruding through the bores 228 the connector
pins 330 are able to make electrical connection with an external
power source to enable charging of the battery 302.
[0067] When positioned within the testing tool 110, the force
sensor sub-assembly 360 is oriented substantially perpendicular to
the rectangular printed circuit board 324 such that the force
sensor 312 is configured to sense axial force applied in the distal
direction by the plunger 210. The force sensor sub-assembly 360 is
secured to the barrel 220 by fasteners 221 (shown in FIG. 2B), such
as flat head screws, that are inserted through the holes 229 of the
barrel 220 and secured into threaded screw holes 362 located
centrally on the backstops 328. In this manner the force sensor
sub-assembly 360 resists being deflected in response to force
applied to the force sensor 312 by the plunger 210.
[0068] In an embodiment the circular printed circuit board 326 is
electrically coupled to the proximal end of the rectangular printed
circuit board 324 to enable electrical communication between the
force sensor 312 and the processor 316, and between the connector
pins 330 and the power management controller 304.
[0069] An artisan will recognize from the disclosure herein that
the functionality of the electronics assembly 240 may be
accomplished in many different ways, using many different
electronic components and organized in a large number of ways
without departing from the scope of the disclosure herein.
[0070] Referring back to FIGS. 2A-2B, assembly of the testing tool
110, for some embodiments, is accomplished by securing the needle
assembly 230 to the fitting 226, and by securing the electronics
assembly 240 into the barrel 220. Spring-loaded connector pins 330
retract inward to permit the electronics assembly 240 to move to
the distal end of the inside of the barrel 220, such that the light
source 320 is in close intimate relation with the proximal end of
the fiber bundle 238 of the needle assembly 230. The electronics
assembly 240 may be rotated axially such that the spring-loaded
connector pins 330 are aligned with bore holes 228, at which point
the spring-loaded connector pins will expand to lock into position.
Fasteners 221 are then used to secure the electronics assembly 240
to the barrel 220. The plunger 210 is inserted into the proximal
end of the barrel 220.
[0071] In some embodiments the plunger 210 is configured to move
distally through the barrel 220 when force is applied to the
plunger 210, thereby simulating the plunger motion associated with
injecting material into a patient. In an embodiment, the plunger
shaft 214 is cylindrical, having an outer diameter slightly less
than the inner diameter of the barrel 220. As the cylindrical
plunger shaft 214 moves through the barrel 220 in the distal
direction, the plunger shaft 214 slides around and envelops the
electronics assembly 240. In an embodiment, a resistance device
offers a resistive force in response to the force applied to the
plunger 210, corresponding to a resistive force experienced when
injecting liquid materials into a patient. In an embodiment the
resistive device is a friction-based device. In an embodiment the
resistive device is a fluid-based device. In an embodiment the
resistive device includes a spring configured to apply a resistive
force to the plunger 210. One skilled in the art will readily
appreciate that there are many ways by which to achieve the
functionality of the resistive device. In an embodiment, the force
applied by the plunger 210 and the force applied by the resistive
device are sensed and communicated to a user interface/display
device 140 and/or to a camera/light detector 120.
[0072] In some embodiments the plunger shaft 214 is configured to
collapse telescopically to simulate plunger motion associated with
injecting material into a patient. In some embodiments, the
collapsible plunger shaft 214 is configured to sense positional
displacement of the plunger shaft 214 and to communicate the
plunger shaft 214 displacement coordinates to a user
interface/display device 140 and/or to a camera/light detector 120.
In some embodiments measurements of the position of a movable,
collapsible or telescoping plunger 210 are communicated to a user
interface/display device 140 and/or to a camera/light detector 120
and used to determine whether proper doses are being delivered.
[0073] In some embodiments, the electronics assembly 240 is
positioned within the plunger shaft 214, and is configured to move
distally and proximally through the barrel 220, along with the
plunger 210. Placing the electronics assembly 240 in a hollowed
shaft 214 of the plunger 210 makes the barrel 220 available to hold
a therapeutic agent that can be injected during the training into
the injection apparatus 105. The position sensor 308 is configured
to obtain position and orientation information of the testing tool
110 and of the plunger 210, and to wirelessly transmit the
information to the user interface/display device 140. In an
embodiment, the force sensor sub-assembly 360 can be positioned
within the shaft 214 of the plunger 210 to measure the resistive
force of the therapeutic agent in the barrel 220, as the injection
is applied. The measured force information can be wirelessly
transmitted to the user interface/display device 140.
Illustratively, in such an embodiment the testing tool 110 operates
in a manner similar to a syringe in that the testing tool 110 is
configured to deliver a therapeutic agent through the needle 232
into the injection apparatus 105. In some embodiments the
electronics assembly 240 is positioned within the plunger shaft 214
and is configured to move distally and proximally through the
barrel 220, along with the plunger 210. The light source 320 is
positioned at the distal end of the barrel 220, and a flexible
connector connects the light source 320 to the electronics assembly
240. In some embodiments the flexible connector connecting the
light source 320 to the electronics assembly is extendable and
retractable. Accordingly, the plunger 210 is able to move axially
into and out of the barrel 220, while the light source is
configured to emit light through the tip 233 of the hollow needle
232.
[0074] FIG. 4A illustrates an embodiment of a testing tool 110
docked in a docking station 400. The docking station 400 includes a
dock cover 402, a USB port 404, and two indicator lights 406. The
docking station 400 is contoured to accommodate the testing tool
110 such that the connector pins 330 of the testing tool 110 are in
contact with contact pins 408 to facilitate charging of the battery
302. FIG. 4B provides a view of a contact pin 408 of the docking
station 400. FIG. 4C illustrates the docking station 400 with its
cover 402 removed revealing a dock circuit board 410 electrically
coupled to the USB port 404 and to the indicator lights 406. The
dock circuit board 410 is also electrically coupled to contact pins
408 such that when a connection is made from, for example, a
standard power outlet to the USB port 404, the contact pins are
configured to support charging of the battery 302 of the testing
tool 110 when the testing tool is docked in the docking station
400. Standoff elements 412 are employed to provide appropriate
spacing within the structure of the docking station 400.
[0075] In some embodiments of the injection training system 100, an
injection training apparatus 105 or method can use one or more
three-dimensional (3D) position sensors to determine a position of
a testing tool 110, such as a syringe and/or needle, in an
artificial patient injection site (such as, for example, an
artificial face). One or more 3D position sensors can also be used
for training caregivers on performing injections where accurate
positioning is important, such as in facial injections (e.g.,
Botox.RTM.), spinal injections, and/or the additional injections
described above.
[0076] By integrating one or more 3D sensors, the injection
training apparatus and method may provide enhanced accuracy when
tracking the trainee's injection technique. Increased training
accuracy can facilitate increased detail on the feedback provided
to the trainee. The features discussed below with reference to
FIGS. 5-11 may be included, in whole or part, with the training
systems, methods, and devices described herein.
[0077] FIG. 5 illustrates an embodiment of the injection apparatus
105, testing tool 110 and user interface/display device 140. The
injection apparatus 105 shown forms a head bust with realistic look
and feel of human flesh. The external surface of the injection
apparatus 105 may be a substantially synthetic or simulated skin.
The synthetic or simulated skin can be an opaque rubber or other
material which simulates skin and facial features of real patients.
Underlying the skin may be a layer of substantially clear rubber
(and/or any suitable elastomer) which simulates the viscosity,
elasticity, and feel of skin, muscle, nerve, and bone tissue of a
patient. The opaque skin and clear underlay may be capable of being
pierced by a needle. It should be noted that the injection
apparatus 105 need not include colored underlying skin to attenuate
light.
[0078] The injection apparatus 105 is hollow and includes, within
the cavity, a three-dimensional (3D) sensor 502. The 3D sensor 502
may include a camera, an array of light detectors or other
sensor(s) capable of detecting a location of an object in three
dimensions. The 3D sensor 502 is configured to detect a position of
a needle and/or to view the interior surface of the injection
apparatus 105. A field of view 504 is established in front of the
3D sensor 502. The field of view 504 represents an area in which
the 3D sensor 502 may detect light.
[0079] A testing tool 110 is also shown. The testing tool 110 may
be implemented as a syringe equipped with a light emitting needle,
for example, as described in greater detail above. The light
emitted by the testing tool 110 may be detected by the 3D sensor
502.
[0080] As shown in FIG. 5, the 3D sensor 502 and the testing tool
110 are coupled with a signal processing and display interface 555
via cables 560 and 570. The signal processing and display interface
555 can include one or more processors configured to receive and
process information, provided from the 3D sensor 502 and/or from
the testing tool 110 that corresponds to the position of the
testing tool 110 relative to the injection apparatus 105.
Illustratively, the processing and display interface 555 processes
the received information from the 3D sensor 502 and from the
testing tool 110 to determine the testing tool's 110 position
relative to the injection apparatus 105. Although illustrated in
FIG. 5 as being coupled by wires, coupling between the 3D sensor
502, the testing tool 110, and the user interface/display 140 can
be accomplished via wired, wireless, or a combination of wired and
wireless configurations. Moreover, the processing and interface 555
can be incorporated into the user interface/display 140. The method
of coupling the 3D sensor 502 need not be identical to the method
of coupling used for the testing tool 110.
[0081] In use, as illustrated in FIG. 5, a trainee punctures the
face of the injection apparatus 105 with the testing tool 110 which
is emitting light from a tip 233 of the hollow needle 232. When the
tip 233 passes through the opaque skin layer of the injection
apparatus 105, the 3D sensor 502 is configured to detect the light
emitted from the tip 233 and to determine the three-dimensional
position, in space, of the tip 233. The three-dimensional position
information is transmitted to the signal processing and display
interface 555, which is configured to communicate the
three-dimensional position information to the user
interface/display device 140. The user interface/display device 140
integrates the communicated position information into a digital
model of the head bust injection apparatus 105. The user
interface/display device 140 may be configured to present a visual
representation of the position of the needle tip 233 relative to
the injection site on the injection apparatus 105. The user
interface/display device 140 allows the trainee to evaluate the
actual needle position, as represented on the user
interface/display device 140, in comparison to the ideal position,
which is also represented on the user interface/display device 140.
The user interface/display device 140, shown in FIG. 5, is coupled
with the signal processing and display interface 555 by a cable
580. The coupling may be via wired, wireless, or a combination of
wired and wireless configurations.
[0082] The three-dimensional position information relative to the
3D sensor 502 is mapped in software to a graphical representation
of the injection site on the user interface/display device 140.
This mapping is performed by determining accurate three-dimensional
coordinates corresponding to the position of the injection
apparatus 105 in the world. The position of the 3D sensor 502
relative to the injection apparatus 105 is also determined with a
high degree of precision. This precision allows a very accurate
mapping of the detected three-dimensional position information of
the hollow needle 232 and its tip 233 to be accurately detected by
the 3D sensor 502 and accurately mapped in software to recreate the
position of the needle 232 and the needle tip 233 of the testing
tool 110. This information is then used to determine both the
accuracy of the injection relative to a predetermined injection
site accuracy goal, as well as to provide a graphical illustration
of the injection, again relative to the injection site goal. This
mapping and display can be provided substantially in real time so
that a user can adjust the trajectory of injection during the
training.
[0083] FIGS. 6A and 6B illustrate two views of a trajectory for an
injection. FIG. 6A illustrates a view from the perspective of the
3D sensor 502, positioned inside the injection apparatus 105 and
directed at the inner surface of the injection apparatus 105. To
orient the reader, an eye 602 and a nose 604 have been labeled. An
injection starting point 610 is detected by the 3D sensor 502. As
the needle tip 233 proceeds into the injection apparatus 105, the
changing positions of the light emitted from the needle tip 233 are
measured by the 3D sensor 502. In some implementations, the
measurement may be a video capture of the injection. In some
implementations, the measurement may be a sampled capture at, for
example, predetermined intervals. A trajectory path 630, from the
starting point 610 to an ending point 620, is thus obtained. As
shown in FIG. 6A, the trajectory path 630 takes the form of an
irregular injection path, which may, in some circumstances,
indicate the need for additional training.
[0084] The trajectory path 630 may be presented via the user
interface/display device 140. The presentation may include
providing a line tracking the injection path. The presentation may
include providing an animated depiction of the injection. In some
implementations, the presentation may be augmented with additional
information such as identifying and showing which muscles, skin,
body parts, etc. the injection is coming in contact with or is
penetrating. The augmentation of the presentation may retrieve one
or more models of the desired physiological information from a data
store. The models include three-dimensional information indicating
the location(s) of certain anatomical or physiological features.
The feature information, along with the three-dimensional injection
location information, is mapped onto the presentation of the
injection apparatus 105.
[0085] Because three-dimensions of information are being obtained,
multiple views of the injection trajectory may be provided. FIG. 6B
provides a second view of the injection trajectory shown in FIG.
6A. FIG. 6B illustrates a view taken from an overhead perspective
of a horizontal cross-section of the injection apparatus 105. The
cross-section is taken at a point on the injection apparatus 105
which allows the viewer to see a horizontal injection trajectory
path 660 of the needle. As in FIG. 6A, to orient the reader, the
eye 602 and the nose 604 have been labeled.
[0086] The horizontal injection trajectory path 660 begins at the
starting point 610 and ends at the ending point 620. However,
because the perspective has changed, the shape of the path 660 is
different than that shown in FIG. 6A. This provides another view of
the injection result. It will be understood that the presentation
model may be arbitrarily rotated, and a representation of the
trajectory path for the representational model, as rotated, may be
generated. The rotation may be provided to the system as a display
point of view identifying the location in space from which to view
the trajectory path. Because the injection apparatus digital model
is combined with the three-dimensional injection information and,
in some instances, anatomical or physiological information, the
injection training may provide a wide variety of views, depending
on the technique needed for the injection. The views may be
provided as animated depictions, such as video or reconstructed
animations. For example, in some embodiments, historical
trajectories for the same type of injection can be shown in a 3D
overlap view which illustrates historical injection trajectories to
a current injection trajectory. In this way, a care provider can
visually compare trajectory information for improvement progression
analysis and general accuracy analysis. Different historical
trajectories can be shown in different colors, shades, and/or
highlights in order to illustrate age and/or accuracy of the
trajectories.
[0087] The aspects shown in FIG. 5 allow a trainee to adjust his or
her technique and monitor his or her progress toward the ideal
injection technique. For example, the user interface/display device
140 may provide a view selector (not shown) to allow the trainee to
see the injection site from a variety of views, such as rotated,
zoomed in, zoomed out, cross-sectional, time-lapsed, and the like,
both in real time and after the injection has occurred. As shown in
FIG. 5, a cross-sectional view is displayed on the user
interface/display device 140 whereby the trainee can see how far
through an opaque skin layer 590 into a clear material layer 592
the testing tool has passed.
[0088] In some implementations, the three-dimensional position
information received from the 3D sensor 502 may be converted before
integration into the digital model of the injection apparatus 105.
In such implementations, the received three-dimensional position
information may be calibrated, adjusted, or otherwise converted
such that the position information of the testing tool 110 may be
correlated with a position on the digital model of the injection
apparatus 105.
[0089] As discussed, one or more sensors may be provided within the
training apparatus 105 which provide three-dimensional position
information for the testing tool 110. FIG. 7 illustrates an example
embodiment of a 3D sensor 502. A dimensional legend 799 is provided
to indicate the three axes (e.g., X, Y and Z) of detection. This
dimensional legend 799 is logical and may not physically be
included in an embodiment of the injection training systems
described. The names attributed to each axis may differ, but each
axis should represent one unique dimension.
[0090] The 3D sensor 502 is shown receiving light from a testing
tool 110 at a first position 702, and then at a second position
704. These positions are not simultaneous, but rather represent the
sequential movement of the testing tool 110 over time. The light
emitted from the testing tool 110 is received by the 3D sensor 502.
The light is emitted from the tip 233 of the testing tool 110 and
disperses on its way to the 3D sensor 502. As shown in FIG. 7, a
first area of light 710 is generated when the testing tool is
located at the first position 702. A second area of light 712 is
generated at a second time when the testing tool 110 is located at
the second position 704. The 3D sensor 502 may be configured to
measure one or more characteristics of the received light and
generate information corresponding to the three-dimensional
position of the testing tool 110 based on the characteristics
detected. Illustratively, the characteristics may include angle,
intensity, brightness, color, dispersion, and/or duration of the
light.
[0091] In one implementation, the 3D sensor 502 may include an
array of light sensors. As light is emitted from the needle tip
233, one or more of the sensors in the array may receive light. By
aggregating the information about which sensors received light and
characteristics of the light received at each sensor,
three-dimensional information about the position of the light
source may be determined. Some 3D sensors 502 may be housed in a
recess and, based on the light pattern cast on the sensor,
determine the location of the light source. In generating the 3D
location information, the 3D sensor 502 may also obtain calibration
information for the needle tip 233 of the testing tool 110 to
account for variability, such as in manufacturing, wear-and-tear,
and power. Further calibration information may be used to specify
the field of view 504 for the 3D sensor 502. The calibration
information may be received, for example, through an initialization
sequence whereby the testing tool 110 is placed at a predetermined
location on the injection apparatus.
[0092] Because the 3D sensor 502 knows the light source and its
particular location vis-a-vis the light source, the 3D sensor 502
can generate accurate and, in some implementations, real-time 3D
location information for the testing tool 110.
[0093] FIG. 8 illustrates another embodiment of a 3D sensor 502. It
may be desirable to implement the 3D sensor 502 as a stereoscopic
sensor pair. A dimensional legend 899 is provided indicate the
three axes (e.g., X, Y and Z) of detection. This dimensional legend
899 is logical and may not physically be included in an embodiment
of the injection training systems described. The names attributed
to each axis may differ, but each axis should represent one unique
dimension.
[0094] The 3D sensor pair includes a first 3D sensor 502A and a
second 3D sensor 502B. The first 3D sensor 502A and the second 3D
sensor 502B are configured to receive, at substantially the same
time, light from a testing tool 110. The testing tool 110 may be
located at different positions at different times. FIG. 8 shows a
first position 810 at a first time, and a second position 812 at a
second time, for the testing tool 110.
[0095] Each 3D sensor 502A and 502B is configured to measure one or
more characteristics of the light transmitted from the testing
tool's 110 position and to generate three-dimensional location
information corresponding to the position of the testing tool 110,
based in the detected characteristics. The characteristics may
include angle, intensity, dispersion, brightness, color, or
duration of the sensed light. Combining the characteristic data
received from the first 3D sensor 502A and the second 3D sensor
502B, three-dimensional information for the testing tool 110 may be
generated. The combination may be performed by one of the 3D
sensors 502A and 502B, or by the signal processing and display
interface 555. In an embodiment the combination can be performed in
the user interface/display device 140.
[0096] In generating the 3D location information, the generation of
the three-dimensional information may also include obtaining
calibration information for the needle tip 233 to account for
variability such as in manufacturing, wear-and-tear, and power. The
calibration information may be received, for example, through an
initialization sequence whereby the testing tool 110 is placed at a
predetermined location on the injection apparatus 105.
[0097] FIG. 9 depicts a side view of one embodiment of the
injection apparatus 105, including a 3D sensor 502. The injection
apparatus 105 is formed as a human head. A testing tool 110 is
shown inserted into the injection apparatus 105. The testing tool
110 may be implemented as described above, such as in reference to
FIGS. 2A-G, 3A-C and 4A-C. To minimize diffraction of the light
emitted from the testing tool 110, a surface of clear elastomer 910
may be made substantially perpendicular to the direction of light
travel. Accordingly, in an embodiment the inner surface of the
clear elastomer 910 is formed as a spherical surface with the
center facing a 3D sensor 502. The 3D sensor 502 may be implemented
as described above such as in reference to FIGS. 5, 7 and 8. The 3D
sensor 502 is configured to detect light emitted by the testing
tool 110 within a field of view 504.
[0098] Rather than utilize a light emitting testing tool 110 in
combination with a single two-dimensional (2D) camera that detects
a two-dimensional position of the light emitting needle tip 233,
the injection training system 100 may include one or more 3D
sensors 502 and/or tracking equipment. With a single 2D camera, a
position with respect to a third dimension may be determined, for
example, by tinting the clear elastomer surface 910, causing a
color of the light to change as the needle tip 233 transitions
through the tinted layer. Illustratively, the color may trend
toward white light as the needle tip 233 moves closer to the inner
surface of the clear elastomer surface 910.
[0099] It may be desirable to avoid tinting the clear elastomer
surface 910 and allow the use of 3D tracking equipment, such as 3D
sensors 502 (which may be cameras or other types of sensors),
examples of which are shown in FIGS. 7 and 8 above. Further
examples of 3D tracking equipment include equipment sold by
Personal Space Technologies B.V. (available at
http://ps-tech.com/). An additional example of 3D tracking
equipment is described in a Centre Suisse d'Electronique et
Microtechnique SA (CSEM) Scientific & Technical Report entitled
"spaceCoder: a Nanometric 3D Position Sensing Device," which is
incorporated by reference herein in its entirety.
[0100] As the testing tool 110 penetrates an opaque skin layer 590
and enters the internal clear elastomer layer 592, the 3D sensor
502 detects characteristics of the light which can be used to
generate a three-dimensional location of the testing tool 110. For
example, it may be desirable to track a desired range 912 of needle
penetration. In some implementations, the depth information is
displayed on a display, such as the user interface/display device
140, as the testing tool 110 is inserted. This allows a trainee to
visualize the location of the injection in near real-time. The
signal processing and display interface 555 may provide the
location information to facilitate such displays. In some
implementations, the feedback may be provided in audio form such as
a beep or an alert.
[0101] FIG. 10 shows a process flow diagram of a method of
manufacturing an anatomically shaped injection apparatus 105
including a 3D sensor 502, such as that shown in FIG. 9. The method
includes, at block 1002, forming an at least partially hollow base
configured to provide structural support for a target injection
test area. The method includes, at block 1004, coating at least a
portion of the base with a clear layer of elastomer. The method
also includes, at block 1006, coating at least a portion of the
clear layer with an opaque layer. The base, clear layer, and opaque
layer form an anatomical shape such as a skull. The method further
includes, at block 1008, affixing a three-dimensional (3D) tracking
system (which can include one or more 3D sensors 502) within the
hollowed portion of the base, wherein the three-dimensional
tracking system provides a field of view of the clear layer
covering the target injection test area. The three-dimensional
tracking system may be a 3D camera such as that shown in FIG. 7 or
a stereoscopic camera pair such as those shown in FIG. 8. In some
implementations, the method may also include coupling the 3D
tracking system with a location processor configured to provide
location information for a light source inserted into the clear
layer. The location information identifies a three-dimensional
location of the light source relative to the injection apparatus
105. The location processor may be implemented in the signal
processing and display interface 555 shown in FIG. 5.
[0102] FIG. 11 illustrates a process flow diagram for a method of
three-dimensional (3D) injection training. The method may be
performed in whole or in part by one or more of the devices
described herein such as the training apparatuses described
above.
[0103] The method includes, at block 1102, calibrating at least one
of a light source and a three-dimensional tracking system. The
light source may be a light emitter located at the tip 233 of a
testing tool 110. The three-dimensional tracking system may include
a 3D camera, a stereoscopic camera pair, or other sensor configured
to provide three-dimensional location information for the light
source. The method also includes, at block 1104, detecting, by the
three-dimensional tracking system, a characteristic of light
emitted from the light source for an injection. The characteristic
may include intensity, angle, dispersion, brightness, color, or
duration of the light. In some implementations, an array of sensors
may be used to detect light. In such implementations, the
characteristic may include which sensors in the array of sensors
received light. The method further includes, at block 1106,
generating three-dimensional location information of the light
source based on the detected characteristics and said
calibrating.
[0104] In some embodiments, the testing tool 110 is configured to
determine its position and orientation in three-dimensional space
relative to the injection apparatus 105. The testing tool 110 is
also configured to communicate its position and orientation
information to other components of the injection training system
100, such as, for example, the user interface/display device 140.
The user interface/display device 140 can display, in near real
time, the testing tool's 110 position relative to the injection
apparatus 105, as injection training is performed. The testing tool
110 can also communicate its position and orientation information
to the 3D sensor 502 and/or to the signal processing and display
interface 555.
[0105] In an embodiment, the position sensor 308 collects nine
dimensions of sensed information to determine the 3D position and
orientation of the testing tool 110 in space with adequate
accuracy. This is because processing sensed three-dimensional
angular velocity provided by a 3D gyroscope leads to an
accumulating error in the calculated position and orientation of
the testing tool 110. To compensate for this error accumulation,
measurements from a 3D accelerometer and from a 3D magnetometer can
be used. The 3D accelerometer measures the earth's gravitational
field, and the 3D magnetometer measures the earth's magnetic field.
Together, the sensed information from the 3D accelerometer and 3D
magnetometer can provide an absolute reference of orientation that
can be used to compensate for the progressively accumulating error
of the sensed and processed angular velocity data provided by the
3D gyroscope. A method for sensor fusion includes processing the
measured nine dimensions of sensed information (from the 3D
gyroscope, the 3D accelerometer, and the 3D magnetometer) to
determine a single estimate of position and orientation of the
testing tool 110, in three-dimensional world coordinates.
[0106] In an embodiment, the position sensor 308 of the testing
tool 110 comprises a inertial measurement unit (IMU) that includes
one or more accelerometers, one or more gyroscopes, one or more
magnetometers to provide, in near real time, information describing
the 3D position and orientation of the testing tool 110. In some
embodiments, the position sensor 308 can also include an embedded
processor that handles, among other things, signal sampling,
buffering, sensor calibration, and sensor fusion processing of the
sensed inertial data. The position sensor 308 can also include a
wireless network protocol for data transmission to external
components, such as, for example, the user interface/display device
140, the 3D sensor 502, and the signal processing and display
interface 555. Illustratively, the position sensor 308 senses,
processes and transmits sensed position and orientation data of the
testing tool 110 to a sensor fusion processing component that can
be configured to operate on, for example, the user
interface/display device 140. In an embodiment, the position sensor
308 transmits already-processed position and orientation
information, delivered in three-dimensional, world coordinates, to
the user interface/display device 140 which graphically displays
the position of the testing tool 110 relative to the injection
apparatus 105 in near real time as the injecting training occurs.
The position sensor 308 can provide calibrated 3D linear
acceleration, 3D angular velocity, 3D magnetic field, and
optionally, atmospheric pressure data, to the sensor fusion
processing component which processes the data to deliver precise
position and orientation information of the testing tool 110. In an
embodiment, the sensor fusion processing component employs a Kalman
filter to provide three degrees-of-freedom position and orientation
information of the testing tool 110 relative to the injection
apparatus 105. The sensor fusion processing component uses data
collected from the gyroscopes, accelerometers and magnetometers to
compute a statistical, optimal 3D position and orientation
estimate, of high accuracy and with no drift, for movements of the
testing tool 110.
[0107] Illustratively, the sensor fusion processing component
comprises an algorithm in which the measurement of gravity (by the
3D accelerometers) and the earth's magnetic north (by the 3D
magnetometers) compensate for otherwise slowly, but steadily
increasing drift errors from the processing (using mathematical
integration) of rate-of-turn data (angular velocity) measured from
the rate gyroscopes. The described approach for compensating for
drift can be referred to as attitude and heading referenced, and a
system that employs this approach can be referred to as an Attitude
and Heading Reference System (AHRS).
[0108] FIG. 12 illustrates an embodiment of an injection training
system 100 comprising an injection apparatus 105, a testing tool
110, and a resting cradle 1202 in which the testing tool 110
follows a sequence of motion (A through D) from the resting cradle
1202 to an injection site of the injection apparatus 105. In FIG.
12, the injector's hand is not shown to better illustrate the
motion of the testing tool 110. At position A, the testing tool 110
sits in the resting cradle 1202. The resting cradle 1202 is in a
known, fixed position relative to the injection apparatus 105. This
can serve to calibrate the injection training system 100 to know
where the testing tool 110 is located relative to the injection
apparatus 105 at the initiation of the injection training. In an
embodiment, the resting cradle 1202 is attached to the base 108 of
the injection apparatus 105. In an embodiment, the injection
apparatus 105 has calibration points 1204 that can be used to
establish an initial position of the testing tool 110 relative to
the injection apparatus 105.
[0109] Starting from the known position relative to the injection
apparatus 105, such as from the resting cradle 1202, the movement
of the testing tool 110 can be determined, even as the needle tip
233 penetrates the material of the artificial face. By way of
non-limiting illustration, the testing tool is lifted from the
resting cradle 1202 to position B. The testing tool 110 is rotated
to position C, where the needle tip 233 is directed toward the
injection apparatus 105. At position D, the needle tip 233 of the
testing tool 110 is inserted into the injection apparatus 105.
Position information corresponding to the testing tool 110,
including the needle tip 233, can be conveyed to a digital model of
the injection apparatus 105. The digital model includes target
tissue (individual muscles) and details of vital structures (VS,
which is also referred to as vital tissue, VT), such as, for
example, arteries, veins, nerves, and skeletal portions, that are
to be avoided or accommodated. By comparing the position of the
needle tip 233, based on the determined position of the testing
tool 110, to the target tissues and the vital structures
illustrated on the user interface/display device 140, proximity to
a desired injection target can be established. This proximity to
target and to vital structures can serve as the basis for
evaluating the skill of the injection trainee.
[0110] Various manufacturers offer for sale inertial measurement
systems, devices, and methods, including sensor fusion processing
components, for incorporation into products and systems. Such
manufacturers include Xsens Technologies, B.V., of Enschede, the
Netherlands; InvenSense, Inc. of Sunnyvale, California, USA; and
Synopsys, Inc., of Mountain View, California, USA. Examples of
systems, devices and/or methods for inertial measurement of objects
in three-dimensional space are disclosed in U.S. Pat. No.
7,725,279B2, issued on May 25, 2010; U.S. Pat. No. 8,165,844B2,
issued on Apr. 24, 2012; U.S. Pat. No. 8,203,487B2; issued on Jun.
19, 2012; U.S. Pat. No. 8,250,921B2, issued on Aug. 28, 2012; U.S.
Pat. No. 8,351,773B2, issued on Jan. 8, 2013; and in U.S. Patent
Application Publication Numbers 2009/0278791A1, published on Nov.
12, 2009; and 2009/0265671A1, published on Oct. 22, 2009, each of
which is incorporated by reference herein in its entirety.
[0111] Computation of the position and orientation of an object in
three-dimensional space is a task that can process inputs from
several sensors to achieve accurate estimates of the position and
orientation of the object. The method can be referred to generally
as a fusion of sensor inputs. A sensor fusion process can reduce
the impact of, and/or compensate for, inaccuracies of senor
measurements and/or processing approximations. Disclosed herein is
a system and method to implement a fusion process that is
computationally efficient and that includes nine dimensions of
sensor input. In an embodiment, the system includes a processor
that can be supplemented with hardware accelerators to help reduce
power consumption. An example of a system, device and method to
compute the 3D orientation of an object by processing nine
dimensions of data using a sensor fusion process is described in a
paper entitled "Ultra Low-Power 9D Fusion Implementation: A Case
Study," by Pieter Struik, which is incorporated by reference herein
in its entirety.
[0112] The disclosed system and method to fuse sensor information
is one among many possible sensor fusion approaches. One skilled in
the art will appreciate that there are numerous systems and methods
for fusing sensor input to derive accurate position and orientation
information of an object in three-dimensional space without
departing from the spirit of the present disclosure. The disclosed
system and method offers effective tracking performance while
executing computations that are similar to those used by other
sensor fusion processes. Performance optimization for this
embodiment is based on an analysis of processing-intensive
activities. One approach to optimization is to employ a fixed point
processing implementation. Another approach to optimization can
include the use of one or more hardware accelerators to execute
certain computations efficiently. Such optimization approaches are
directed at reducing the number of processing cycles required to
determine accurate estimates of the position and orientation of an
object in three-dimensional space.
[0113] Described herein is a system and method to calculate
three-dimensional (3D) position and orientation of an object
derived from inputs from three motion sensors attached to the
object: an accelerometer configured to measure linear acceleration
along three axes; a gyroscope configured to measure angular
velocity around three axes; and a magnetometer configured to
measure the strength of a magnetic field (such as the earth's
magnetic field) along three axes. In an embodiment, the three
motion sensors are attached to the testing tool 110. In an
embodiment the three motion sensors are integrated into a single
position sensor 308, as reflected in FIG. 3A. In an embodiment, the
sensors are sampled at a rate of 50 Hz; however, one skilled in the
art will appreciate that the sensors can be sampled at different
rates without deviating from the scope of the present disclosure.
The sampled data from the three motion sensors, which provide nine
sensor inputs, are processed to describe the testing tool's 110
position and orientation in three-dimensional space. The testing
tool's position and orientation are described in terms of Euler
angles as a set of rotations around a set of X-Y-Z axes of the
testing tool 110.
[0114] Theoretically, the method to determine orientation angles
around the three axes of the testing tool 110 is a straightforward
process that includes mathematically integrating the three angular
velocity measurements provided by the 3D gyroscope sensor. However,
when implemented, sensor drift and/or processing approximations can
lead to a steadily increasing set of errors that affect the
accuracy of such determinations. A method to compensate for the
inaccuracy of the processed angular velocity measurements includes
processing accelerometer data and magnetometer (or compass) data,
in a sensor fusion process. The disclosed system and method to fuse
sensor input applies principles that are comparable in accuracy to
systems and methods that employ techniques of linear quadratic
estimation, such as Kalman filtering, which may also be used to
fuse sensor input data in some embodiments.
[0115] The disclosed system and method to fuse sensor input uses
quaternion algebra to determine a present position and orientation
of the testing tool 110. In practical application, quaternions can
be used in conjunction with other processing methods, such as Euler
angles and rotation matrices, to calculate rotations of objects in
three-dimensional space. Illustratively, a quaternion, where Q=[q0
q1 q2 q3], can define a three-by-three rotation matrix "R" that
translates each coordinate x=(x,y,z) of the initial testing tool's
110 orientation into its current position, Rx. A product (known as
the Hamilton product in quaternion algebra, which is represented by
the symbol "") of two quaternions, such as Q0Q1, delivers another
quaternion that describes a compound rotation performed by a first
rotation, described by Q0, which is followed by a second rotation,
described by Q1. Use of quaternion algebra can reduce computational
processing requirements because most of the computations used to
perform quaternion algebra do not employ computationally-intensive
trigonometric functions.
[0116] FIG. 13A illustrates a process flow diagram of a process
1300 to determine the position and orientation of a testing tool
110 according to an embodiment of the disclosed injection training
system 100. One skilled in the art will appreciate that there are
numerous ways by which the position and orientation of the testing
tool 110 can be determined without departing from the scope of the
present disclosure. At block 1302, the process begins by collecting
measured data from the 3D gyroscope, the 3D accelerometer, and the
3D magnetometer. The sampling rate can vary, depending on the
components used to implement the process.
[0117] At block 1304, the present orientation of the testing tool
110 is represented by a quaternion "Q" which represents the
currently measured angular acceleration data from the 3D gyroscope.
This quaternion is an initial estimate of the position and
orientation of the testing tool 110. The present orientation can be
updated with information provided by the gyroscope sensor which may
be represented as (gx, gy, gz). Additional rotation of the testing
tool 110 that occurred since the most recent measurement can be
represented by a quaternion [1 (gx/f) (gy/f) (gz/f)], where f is
defined as a sampling frequency used to execute the sensor fusion
process. This representation may be expressed as quaternion [C gx
gy gz ], with "C" being a constant that is proportional to the
sampling frequency, f.
[0118] At block 1306, information provided by an accelerometer
sensor is used to help compensate for accuracy errors in the
angular velocity data provided by the gyroscope sensor. An
acceleration vector (ax, ay, az), measured by the accelerometer,
will equal the acceleration of gravity when the testing tool 110 is
not in motion. When the testing tool 110 is in motion, its rotation
can be characterized by rotation R, and the vector corresponding to
gravity is directed towards the earth's center. When viewed
relative to the motion of the sensors attached to the testing tool
110, the gravity vector will have been rotated by the same rotation
R. Accordingly, the initial gravity vector v becomes Rv, relative
to the testing tool 110, after rotation has taken place. If the
testing tool 110 is not moving, the computed gravity vector, Rv,
will be aligned with the measured accelerometer information (ax,
ay, az). When Rv and (ax, ay, az) are pointing in different
directions, we determine that rotation R is inaccurate and,
therefore, the coordinates representing the present orientation, Q,
must be adjusted based on the vector cross product Rv.times.(ax,
ay, az).
[0119] At block 1308, fusion with information sensed by the
magnetometer can also be applied. It is assumed that the testing
tool 110 is subject to the earth's magnetic field. It is also
assumed that the testing tool 110 is not subject to interference
from a separate magnetic field, such as, for example, the field of
a permanent magnet. Under these assumed conditions, the magnetic
field measured by the 3D magnetometer (mx, my, mz) can be related
to the initial orientation of the testing tool 110 by applying a
reverse rotation R*, where the vector w=R*(mx, my, mz). It is also
assumed that the earth's magnetic north is aligned in the direction
of the X axis. Accordingly, an alignment error can be determined by
comparing the vector w to a vector w', which is obtained by
rotating the vector w onto the plane of the testing tool 110. An
alignment error vector c can be calculated. The alignment error
vector, c, is proportional to the vector cross product
c=w.times.w'. As c is related to the initial orientation of the
testing tool 110, Rc corresponds to the adjustment that can be
applied to the testing tool's 110 present position and orientation,
represented by quaternion Q.
[0120] At block 1310, the adjusted quaternion Q is converted into
three Euler angles. Euler angles are a way of representing the
spatial orientation of a coordinate system as a composition of
three elemental rotations, starting from a known, standard
orientation. The relation between the quaternion Q and the
converted Euler angles includes calculations that use inverse sine
and inverse tangent functions. Illustratively, the rotation angle
around the Y axis is determined with the following conversion
equation: Y=-asin(2*q1*q3+2*q0*q2), where the quaternion Q=[q0 q1
q2 q3].
[0121] In an embodiment, the method 1300 to determine the position
and orientation of a testing tool 110 updates the position and
orientation of the testing tool 110 at the sampling rate of the
sensors. Accordingly, at block 1312, the process 1300 determines
whether the present injection training is continuing or whether it
has ended. When the present injection training is continuing, the
method 1300 returns to block 1302 to update the position and
orientation information of the testing tool 110. When the present
injection training is completed, the process 1300 terminates at
block 1314.
[0122] FIGS. 13B, 13B1, and 13B2, collectively, illustrates a
process flow diagram of a process 1340 to determine the position
and orientation of a testing tool 110 according to an embodiment of
the disclosed injection training system 100. Illustratively,
process 1340 discloses one approach to implementing process 1300,
described above. One skilled in the art will appreciate that there
are numerous ways by which process 1300 can be implemented without
departing from the scope of the present disclosure.
[0123] At block 1350, the process begins by collecting measured
data from the 3D gyroscope (providing angular momentum
information), the 3D accelerometer (providing linear accelerations
information), and the 3D magnetometer (providing magnetic field
information). The present position and orientation of the testing
tool 110 is represented by a quaternion, based on the measured
angular acceleration data from the 3D gyroscope. Blocks 1352
through 1358 illustrate computation actions implemented to
compensate for inaccuracies in the angular velocity data, provided
by the 3D gyroscope, based on the linear acceleration information
provided by the 3D accelerometer. This methodology uses the earth's
gravitational field to identify inaccuracies in the measured
angular momentum data and to compensate for those inaccuracies. At
block 1352, the measured 3D accelerometer data is compared with a
rotated initial gravity vector. At block 1354, the accelerator data
is inverted and normalized. At block 1356, a vector cross product
of the normalized accelerator data and the rotated gravity vector
is computed. And at block 1358, a compensation for gyroscope data
inaccuracies is made, using a constant acceleration compensation
factor.
[0124] Blocks 1360 through 1368 illustrate actions implemented to
compensate for inaccuracies in the angular velocity data, provided
by the 3D gyroscope, based on the magnetic field information
provided by the 3D magnetometer. This methodology uses the earth's
magnetic field to identify inaccuracies in the measured angular
momentum data and to compensate for those inaccuracies. At block
1360, the measured 3D magnetometer data is normalized and inverted.
At block 1362, an inverse rotation of the normalized magnetometer
data is computed. At block 1364, the computed rotation is aligned
in orientation with the testing tool 110, based on earth's magnetic
north. At block 1366, the computed rotation is rotated back to the
original orientation, and an alignment error vector is computed by
computing a cross product of rotation vector with the measured
magnetometer data. At block 1370, a compensation for gyroscope data
inaccuracies is made, using a constant magnetic compensation
factor. At block 1370, the testing tool's position and orientation,
represented in a quaternion, is updated based on the adjusted
gyroscope data, and it is normalize at block 1372. At block 1374,
the updated position and orientation information of the testing
tool 110 is converted into Euler angles which can be used by, for
example, the user interface/display device 140 to graphically
display the position of the testing tool 110. At block 1376, the
process 1340 returns to block 1350, to begin another iteration when
the injection training is continuing. Alternatively, the process
terminates at block 1378 when the injection training is
finished.
[0125] Advantageously, the disclosed method for determining the
position and orientation of a testing tool 110 is robust, even when
assumptions are not held. For example, when the testing tool 110 is
moving, the measured accelerometer data (ax, ay, az) represents a
non-zero linear acceleration relative to gravity; however the
sensor fusion processing method nevertheless delivers accurate
position data. Moreover, fusion of magnetometer data proves to be
accurate in the presence of distortion in the gravitational
magnetic field.
[0126] In an embodiment, the disclosed method can be implemented in
a system of integrated hardware and software (or firmware) that can
be optimized to process data from digital and analog sensors and to
engage in power-efficient processing of the sensor data. The system
can include a processor (such as the ARC EM4 32-bit processor core
offered by Synopsys Inc.), a user-configurable set of serial
digital interfaces, analog-to-digital converter interfaces,
hardware accelerators, and a software library of digital signal
processor (DSP) functions and input/output (I/O) software drivers.
The system can take advantage of capabilities to implement tightly
coupled I/O peripherals and tightly coupled hardware accelerators,
which may be accessed directly from the processor pipeline without
the overhead of additional hardware infrastructure, such as, for
example, busses, bridges, and/or adapters.
[0127] In an embodiment, the system configuration contains one or
more Inter-Integrated Circuit (I2C) master peripheral ports, a
Serial Peripheral Interface (SPI) master peripheral port, and a
general purpose input/output (GPIO) port. The processor can be
configured to have a single-cycle 32-bit integer multiplier. The
system can be configured to include one or more fixed-point
hardware accelerators to perform computationally-intensive
operations, such as, for example, multiply-accumulate (MAC)
operations, trigonometric operations, and the square root
operation. Illustratively, use of hardware accelerators can reduce
processor cycle time with respect to computationally-intensive
operations such as the square root operation. A hardware
accelerator accepts a 32-bit fixed point number as input and
computes the square root in 31 cycles, evaluating one bit at a time
which is substantially faster than calculating a square root by use
of software delivered as part of a compiler's standard library.
[0128] Many of the required computations used in the disclosed
method are computationally-intensive when implemented using
standard software routines. For example, rotation and inverse
rotation operations are matrix-vector multiplications where the
(inverse) rotation matrix has coefficients that are based on the
quaternion Q. Illustratively, inverse rotation operations involve
many multiplications and additions. Similarly computing the inverse
norm of a vector or a quaternion requires the following operations:
multiplication, addition, square root, and division. Likewise,
computing a vector cross product requires multiplication operations
and addition operations. Computing the Hamilton product of two
quaternions takes many multiplications and additions. Computing
Euler angles involves trigonometric functions (atan 2 and asin),
where the arguments are expressions that are based on quaternion Q.
These expressions include multiplication operations and addition
operations. Use of one or more hardware accelerators to implement
such operations can reduce overall processing time and power
consumption.
[0129] To further improve performance and to reduce power
consumption the disclosed system, device and method can be
configured to be implemented using fixed point arithmetic as
opposed to using floating point arithmetic. Conversion of numerical
processing using floating point arithmetic to fixed point
arithmetic requires care with respect to overflow and underflow in
computations. However, after such conversion is performed
successfully, the processing workload can be reduced by replacing
floating point multiplication operations with single-cycle, 32-bit
multiplications, and floating point addition operations with
simple, 32-bit additions (or subtractions). Evaluation of the
resulting fixed-point version of the disclosed method shows that
the square root function, which is executed four times in each
cycle of the disclosed method, consumes many processing cycles.
Using a standard square root function call, which is typically
included in a library of digital signal processing (DSP) functions,
to apply the square root hardware accelerator can further reduce
processing cycle count. Another optimization can be to reduce the
cycle count of the Euler angles computation by applying a hardware
accelerator for the inverse sine function. Because the inverse
tangent function can be expressed in terms of the inverse sine and
square root operations, using the hardware accelerators for thee
computations reduces computational workload, power consumption, and
processing time per iteration. Thus the processing cycle count of
the disclosed nine-dimensional sensor fusion method can be reduced
by implementing a fixed point version of the process that takes
advantage of available hardware accelerators. Reduction of cycle
count leads to lower energy, as the energy that is used for
executing the algorithm is proportional to the required
performance.
[0130] In an embodiment, position sensors 308 are used in both the
barrel 220 of the testing tool 110 and in the plunger 210 of the
testing tool 110 to determine the position of the plunger 210
relative to the barrel 220 of the testing tool 110. This
information can be used to indicate distal travel movement of the
plunger 210 in the testing tool 110 during simulated injection. The
distal travel movement can represent a volume of fluid that would
be injected, and therefore the distal travel movement can be used
to determine a measure of the injection trainee's performance.
[0131] An embodiment of the disclosed system, device and method to
determine the position and orientation of the testing tool 110,
relative to the injection apparatus 105, during injection training
includes the use of one or more retro-reflectors attached to the
testing tool 110 in association with an optical tracking system. A
retro-reflector (sometimes called a retroflector or cataphote) is a
device or surface that reflects light back to its source with a
minimum of scattering. In a retro-reflector, an electromagnetic
wave front is reflected back along a vector that is parallel to,
but opposite in direction from, the wave's source. The angle of
incidence at which the device or surface reflects light in this way
is greater than zero, unlike a planar mirror, which reflects an
electromagnetic wave (such as light) only if the mirror is exactly
perpendicular to the wave front, having a zero angle of incidence.
The retro-reflectors are locatable by an optical tracking system
that can operate in, for example, the infrared (IR) range. The
retro-reflectors can be positioned on the external surface of the
testing tool 110 for use with optical tracking systems that operate
by use of infrared illumination. This type of optical tracking
allows for the triangulation of energy reflected from the
retro-reflectors to determine the testing tool's 110 position in
three-dimensional space. In an embodiment, alignment of the needle
tip 233 with the injection apparatus 105 can be accomplished by
touching the needle tip 233 to a known location on the injection
apparatus 105, such as calibration points 1204.
[0132] FIGS. 14A and 14B are perspective views of an exemplary
optical tracking system 1400. Optical tracking is a 3D localization
technology that monitors a defined measurement space using two or
more light sensors 1402, such as, by way of non-limiting example,
cameras. In an embodiment, each light sensor 1402 is equipped with
an infrared (IR) pass filter (not shown) in front of the lens, and
a ring of IR light emitting diodes (not shown) around the lens to
periodically illuminate the measurement space of the optical
tracking system 1400 with IR light, as illustrated in FIG. 14A.
Reflections from markers 1404 on the testing tool 110 are sensed by
the light sensors 1402, and the sensed information is processed by
the optical tracking system 1400 to determine the position and
orientation of the testing tool 110 in three-dimensional space.
Examples of optical tracking systems 1400 are described in a paper
entitled "PST iris: Instruction Manual," published by Personal
Space Technologies B.V, and in International Patent Application
Number PCT/NL2009/050607, having International Publication Number
WO 2011/043645A1, published on Apr. 14, 2011, which are
incorporated by reference herein in their entirety.
[0133] Computer stereo vision is the extraction of 3D information
from digital images, such as obtained by a charge-coupled device
camera. By comparing information about a scene from two vantage
points, 3D information can be extracted by examination of the
relative positions of objects in the two panels. In traditional
stereo vision, two cameras, displaced horizontally from one another
are used to obtain two differing views on a scene, in a manner
similar to human binocular vision. By comparing these two images,
the relative depth information can be obtained, in the form of
disparities, which are inversely proportional to the differences in
distance to the objects. To compare the images, the two views are
superimposed in a stereoscopic device. In camera systems, several
pre-processing steps are required. The image is removed of
distortions, such as barrel distortion to ensure that the observed
image is a pure projection. The image is projected back to a common
plane to allow comparison of the image pairs, known as image
rectification. An information measure which compares the two images
is minimized. This gives the best estimate of the position of
features in the two images, and creates a disparity map.
Optionally, the disparity as observed by the common projection, is
converted back to a height map by inversion. Using a correct
proportionality constant, the height map can be calibrated to
provide precise distances. Active stereo vision is a form of stereo
vision which actively employs a light, such as an infrared light
source, to simplify the stereo matching problem. An examples of a
stereo vision system and processing method is disclosed in U.S.
Pat. No. 8,208,716B2, issued on Jun. 26, 2012, which is
incorporated by reference herein in its entirety.
[0134] Objects to be tracked, such as the testing tool 110, can be
equipped with retro-reflective markers 1404 that reflect the
incoming IR light back to the light sensors 1402. The IR
reflections are detected by the light sensors 1402 and then
internally processed by the optical tracking system 1400. The
optical tracking system 1400 calculates the 2D marker position, in
image coordinates, with high precision. Using at least two light
sensors 1402, the 3D position of each marker 1404 can be derived,
as described above. The 3D position can be measured by using a
single marker 1404 in the measurement space; however, to be able to
also measure the orientation of an object (or to track multiple
objects simultaneously), multiple markers 1404 must be placed on
each object. Such a configuration can be created by affixing
markers 1404 randomly onto the object, making sure at least two
markers 1404 can be seen from each angle of the object that the
user desires to be detected. By establishing a model of the
configuration of each object, the optical tracking system 1400 can
distinguish between objects and can determine the 3D position and
orientation of each object.
[0135] Optical tracking systems 1400 offer some advantages over
other approaches to measure and determine the 3D position and
orientation of an object in three-dimensional space. For example,
optical tracking is less susceptible to noise from the environment,
such as, for instance, ferromagnetic metal in the environment which
can influence the accuracy of the measurements of magnetic tracking
systems. Additionally, optical tracking does not suffer from drift
problems experienced in, for instance, inertial sensors, which
cause measurements to slowly deviate from actual values, for which
compensation techniques must be applied. Optical tracking also
allows for many objects to be tracked simultaneously. Optically
tracked devices can be lightweight and they do not require wires or
power. As such, users are neither hampered by wires nor limited in
their manipulation of the object.
[0136] FIG. 14C illustrates a testing tool 110 configured with
multiple markers 1404, in accordance with an embodiment of the
present disclosure. In an embodiment, an optical tracking system
1400 measures the 3D positions of markers 1404, such as, for
example, retro-reflectors, affixed to the testing tool 110. The
markers 1404 can be active or passive. Using this information, the
optical tracking system 1400 can determine the position and
orientation of the marked testing tool 110 within a specific field
of view defined by the optical tracking system. The optical
tracking system 1400 can be a self-contained, integrated system
that does not require external processing or calibration
components. The optical tracking system 1400 can be connected to
the user interface/display device 140 via a wired or by a wireless
communication scheme. The optical tracking system 1400 can deliver
3D position and orientation measurement of the testing tool 110 to
the interface unit/display device 140. Advantageously, the
disclosed optical tracking system 1400 delivers fully-processed
position and orientation data to the user interface/display device
140, thereby freeing up the processing capability of the user
interface/display device 140 for other computationally-intensive
activities, such as, for example, processing and rendering of a
digital model representative of the injection apparatus 105 and the
testing tool 110 during injection training.
[0137] FIG. 14D illustrates, among other things, aspects of the
user interface/display device 140 according to an embodiment of the
disclosed injection training system 100. Shown in magnified
perspective are examples of how the user interface/display device
140 can graphically display, either during the injection training
or afterwards, the location of the needle tip 233 as it penetrates
the injection apparatus 105. The user interface/display device 140
illustrates portions of the anatomy in the vicinity of the
injection site. In particular, vital tissue (VT), and muscle are
represented digitally on the user interface/display device 140.
Advantageously, the user can view a target site, a proximity to the
target site, and nearby vital tissues or structures. In some
embodiments, visual and/or aural signals are delivered to the
trainee as indications of the needle tip's 233 proximity to the
target site. During an injection, for example, the display can
graphically illustrate the different skin and tissue layers as the
needle tip 233 penetrates each layer. For example, this can be done
by graphically peeling back the layers as a new layer is
penetrated. For training purposes, the different layers can be
labeled or provided with different textures or colors to indicate a
new layer is shown.
[0138] In an embodiment, a single optical tacking system 1400 can
track the testing tool 110 in an injection training environment, as
illustrated in FIG. 15A. In an embodiment, multiple optical
tracking systems 1400 can be coupled together to extend the
workspace environment or to reduce issues due to the line-of-sight
requirement of the optical tracking system 1400, as illustrated in
FIG. 15B. In an embodiment, the optical tracking system 1400 can be
configured with different optics configurations to adapt the field
of view and the performance characteristics of the optical tracking
system 1400 to the intended environment and application.
Illustratively, optics with a higher field of view result in a
wider tracking area closer to the system, whereas optics with a
lower field of view provide a narrower, but longer, tracking
area.
[0139] The optical tracking system 1400 can use tangible, wireless
devices for 3D interaction and 3D measurement, such as the testing
tool 110. In an embodiment, the position and orientation (sometimes
referred to as the "pose") of the testing tool 110 can be
reconstructed with millimeter accuracy. Advantageously, the optical
tracking system 1400 can be based on infrared lighting, which can
reduce the interference of visible light sources from the
environment. This allows the optical tracking system 1400 to be
used under normal, ambient working conditions without requiring
controlled lighting. The testing tool 110, and the injection
apparatus 105, can be tracked by applying retro-reflective markers
1404 to their external surfaces. The optical tracking system 1400
employs these markers to recognize different objects and to
reconstruct their poses. In an embodiment, and by way of
non-limiting illustration, the optical tracking system 1400
reconstructs the pose of the testing tool 110, and optionally, of
the injection apparatus 105, at an adjustable sampling frequency
with a maximum of 120 times per second. One skilled in the art will
appreciate that other sampling frequencies can be used without
departing from the scope of the present disclosure. The optical
tracking system 1400 can be triggered externally, such that it can
be synchronized to external clock sources. This can, for instance,
be used to prevent interference between the internal infrared flash
and shutter glasses that are synchronized to a 3D monitor, such as
the user interface/display device 140, using an infrared
signal.
[0140] In an embodiment, tracking devices comprise physical
objects, such as the testing tool 110 and the injection apparatus
105, that can be recognized by the optical tracking system 1400 and
of which the 3D position and orientation can be measured. In an
embodiment, such devices can be used to measure the spatial
coordinates of objects, or for instance, to interact with virtual
3D objects in an application. Illustratively, just as a mouse can
be used to position a pointer in two-dimensional space, so too can
a tracking device be used to position an object in
three-dimensional space, with six degrees of freedom. The 3D
position and orientation (pose) of a tracking device, such as the
testing tool 110, is optically tracked, ensuring wireless
operation. Retro-reflective markers 1404 can be applied to objects,
such as the testing tool 110 and the injection apparatus 105, to
transform them into tracking devices. The tracking system uses
these markers 1404 to recognize devices and to reconstruct each
pose. In order for the optical tracking system 1400 to be able to
determine the position and orientation of a tracking device, at
least four markers 1404 need to be applied. The size of the markers
1404 helps to determine the optimal tracking distance. The optical
tracking system 1400 supports flat retro-reflective markers 1404
for the construction of tracking devices. Such flat
retro-reflective markers 1402 do not hamper manipulation.
[0141] In an embodiment, the markers 1404 are locatable by tracking
systems, devices, and methods that can operate in the radio
frequency (RF) range. The markers 1404 can be positioned on the
interior of the testing tool 110 for tracking systems 1400 that
operate through use of RF illumination, such as the technology
known as radio-frequency identification (RFID). Advantageously, the
RF energy is able to be transmitted through the tissue of the
injector's hand, arm and other portions of the injector's body that
may obstruct the required line-of-site view between an optical
tracking system 1400 and the testing tool 110 during injection
training, when implemented using optical tracking systems 1400
based on infrared illumination.
[0142] In an embodiment, the reflective markers 1404 comprise
corner reflectors. Corner reflectors can operate in a wide range of
electromagnetic frequencies including the infrared and the radio
spectrums. A corner reflector is a retro-reflector comprising three
mutually perpendicular, intersecting flat surfaces. The corner
reflector reflects waves back directly towards the source, but
shifted (translated). The three intersecting surfaces often have
square shapes. Optical corner reflectors, called corner cubes, made
of three-sided glass prisms, are used in surveying and laser
range-finding. The incoming ray is reflected three times, once by
each surface, which results in a reversal of direction. The three
corresponding normal vectors of the corner's perpendicular sides
can be considered to form a basis (a rectangular coordinate system)
(x, y, z) in which to represent the direction of an arbitrary
incoming ray, [a, b, c]. When the ray reflects from the first side,
say x, the ray's x component, a, is reversed to -a while the y and
z components are unchanged, resulting in a direction of [-a, b, c].
Similarly, when reflected from side y and finally from side z, the
b and c components are reversed. So the ray direction goes from [a,
b, c] to [--a, b, c] to [--a, --b, c] to [--a, --b, --c] and it
leaves the corner reflector with all three components of direction
exactly reversed. The distance traveled, relative to a plane normal
to the direction of the rays, is also equal for any ray entering
the reflector, regardless of the location where it first
reflects.
[0143] In an embodiment, the optical tracking system 1400 views the
testing tool 110 and the needle tip 233 as it approaches and
penetrates the injection apparatus 105. The optical tracking system
1400 can operate in the visual and infrared spectrums. For optical
tracking systems 1400 using the infrared spectrum, an improvement
in resolution and differentiation is available by altering the
temperature of the testing tool 110 and/or the needle tip 233 to be
different (hotter or colder) than ambient temperature. Infrared
thermography (IRT), thermal imaging, and thermal video are examples
of infrared imaging science. Thermographic cameras detect radiation
in the infrared range of the electromagnetic spectrum (roughly
9,000-14,000 nanometers or 9-14 .mu.m) and produce images of that
radiation, called thermograms. Since infrared radiation is emitted
by all objects above absolute zero according to the black body
radiation law, thermography makes it possible to see one's
environment with or without visible illumination. The amount of
radiation emitted by an object increases with temperature;
therefore, thermography allows one to see variations in
temperature. When viewed through a thermal imaging camera, warm
objects stand out well against cooler backgrounds.
[0144] The testing tool 110 and needle tip 233 can be clearly
resolved against the ambient temperature background when using
thermal imaging. In an embodiment, the 3D sensor(s) 502 from the
interior of the injection apparatus 105 can be configured to sense
both light emitting from the testing tool 110 and thermal energy
emitted from the testing tool 110 and/or needle tip 233 by use of
infrared, or other forms of thermal imaging. Multiple methods for
achieving temperature variation of the testing tool 110 relative to
ambient temperature can be used, including, without limitation,
resistive heating on the testing tool 110 interior with conductive
heat transfer to the hollow needle 232, and routing gas of a
controlled temperature through a tube into the testing tool 110
interior and exhausting the gas through the needle tip 233. In an
embodiment, thermal imaging is available by including temperature
markers on the injection apparatus 105 to be viewable by a the
optical tracking system 1400, which can support accurate resolution
of the testing tool's 110 position relative to the injection
apparatus 105. In an embodiment, the depth of penetration of the
needle tip 233 into the injection apparatus 105 can be determined
by measuring the length of the needle 232 remaining exterior to the
injection apparatus 105, thereby exposed to the view of the optical
tracking system 1400. By knowing the orientation and position of
the testing tool 110 relative to the injection apparatus 105, along
with the measured length of the needle 232 remaining exterior to
the injection apparatus 105, the depth of penetration of the needle
tip 233 in the injection apparatus 105 may be determined.
[0145] In an embodiment, position information provided by the 3D
sensor(s) 502 and the optical tracking system 1400 can be combined
to determine the position and orientation of the testing tool 110
and the needle tip 233 relative to the injection apparatus 105
during injection training. Combination of position data
corresponding to the light emitting needle tip 233 as the needle
tip 233 passes through the opaque layer of artificial skin, as
sensed by the 3D sensor(s) 502 from the interior of the injection
apparatus 105, with the length of the needle 232 remaining exterior
to the injection apparatus 105, as sensed by the optical tracking
system 1400, can be combined to determine the position and
orientation of the testing tool 110 and the needle tip 233 relative
to the injection apparatus 105.
[0146] An injection training system has been disclosed in detail in
connection with various embodiments. These embodiments are
disclosed by way of examples only and are not to limit the scope of
the claims that follow. One of ordinary skill in the art will
appreciate from the disclosure herein any variations and
modifications.
Terminology/Additional Embodiments
[0147] The term "injection" as used herein includes it usual and
customary meaning of an injection, but is also to be interpreted
broad enough to encompass, for example, the insertion of a catheter
device or the use of simple needles, such as would be used in an
acupuncture therapy. The techniques involved, particularly a camera
embedded in a model of a living subject and a tool with a light
emitter can be applied to any therapeutic procedure. For example,
the tool can be a catheter and the procedure can be a minimally
invasive procedure requiring the catheter to be located in a
particular location.
[0148] Conditional language used herein, such as, among others,
"can," "could," "might," "may," "e.g.," and the like, unless
specifically stated otherwise, or otherwise understood within the
context as used, is generally intended to convey that certain
embodiments include, while other embodiments do not include,
certain features, elements and/or states. Thus, such conditional
language is not generally intended to imply that features, elements
and/or states are in any way required for one or more embodiments
or that one or more embodiments necessarily include logic for
deciding, with or without author input or prompting, whether these
features, elements and/or states are included or are to be
performed in any particular embodiment.
[0149] Depending on the embodiment, certain acts, events, or
functions of any of the methods described herein can be performed
in a different sequence, can be added, merged, or left out
altogether (e.g., not all described acts or events are necessary
for the practice of the method). Moreover, in certain embodiments,
acts or events can be performed concurrently, e.g., through
multi-threaded processing, interrupt processing, or multiple
processors or processor cores, rather than sequentially.
[0150] The various illustrative logical blocks, modules, circuits,
and algorithm steps described in connection with the embodiments
disclosed herein can be implemented as electronic hardware,
computer software, or combinations of both. To clearly illustrate
this interchangeability of hardware and software, various
illustrative components, blocks, modules, circuits, and steps have
been described above generally in terms of their functionality.
Whether such functionality is implemented as hardware or software
depends upon the particular application and design constraints
imposed on the overall system. The described functionality can be
implemented in varying ways for each particular application, but
such embodiment decisions should not be interpreted as causing a
departure from the scope of the disclosure.
[0151] The various illustrative logical blocks, modules, and
circuits described in connection with the embodiments disclosed
herein can be implemented or performed with a general purpose
processor, a digital signal processor (DSP), an application
specific integrated circuit (ASIC), a field programmable gate array
(FPGA) or other programmable logic device, discrete gate or
transistor logic, discrete hardware components, or any combination
thereof designed to perform the functions described herein. A
general purpose processor can be a microprocessor, but in the
alternative, the processor can be any conventional processor,
controller, microcontroller, or state machine. A processor can also
be implemented as a combination of computing devices, e.g., a
combination of a DSP and a microprocessor, a plurality of
microprocessors, one or more microprocessors in conjunction with a
DSP core, or any other such configuration.
[0152] The blocks of the methods and algorithms described in
connection with the embodiments disclosed herein can be embodied
directly in hardware, in a software module executed by a processor,
or in a combination of the two. A software module can reside in RAM
memory, flash memory, ROM memory, EPROM memory, EEPROM memory,
registers, a hard disk, a removable disk, a CD-ROM, or any other
form of computer-readable storage medium known in the art. An
exemplary storage medium is coupled to a processor such that the
processor can read information from, and write information to, the
storage medium. In the alternative, the storage medium can be
integral to the processor. The processor and the storage medium can
reside in an ASIC. The ASIC can reside in a user terminal. In the
alternative, the processor and the storage medium can reside as
discrete components in a user terminal.
[0153] While the above detailed description has shown, described,
and pointed out novel features as applied to various embodiments,
it will be understood that various omissions, substitutions, and
changes in the form and details of the devices or algorithms
illustrated can be made without departing from the spirit of the
disclosure. As will be recognized, certain embodiments of the
disclosures described herein can be embodied within a form that
does not provide all of the features and benefits set forth herein,
as some features can be used or practiced separately from others.
The scope of certain disclosures disclosed herein is indicated by
the appended claims rather than by the foregoing description. All
changes which come within the meaning and range of equivalency of
the claims are to be embraced within their scope.
* * * * *
References