U.S. patent application number 15/690574 was filed with the patent office on 2018-03-15 for simulated, representative high-fidelity organosilicate tissue models.
The applicant listed for this patent is Regents of the University of Minnesota. Invention is credited to Daniel M. Burke, Troy E. Reihsen, Robert M. Sweet.
Application Number | 20180075778 15/690574 |
Document ID | / |
Family ID | 47993402 |
Filed Date | 2018-03-15 |
United States Patent
Application |
20180075778 |
Kind Code |
A1 |
Reihsen; Troy E. ; et
al. |
March 15, 2018 |
SIMULATED, REPRESENTATIVE HIGH-FIDELITY ORGANOSILICATE TISSUE
MODELS
Abstract
A method of making a tissue model comprises determining one or
more material properties of a tissue, wherein the one or more
material properties include at least one of mechanical properties,
electroconductive properties, optical properties, thermoconductive
properties, chemical properties, and anisotropic properties,
creating an anatomical structure of the tissue, selecting an
artificial tissue material having one or more material properties
that substantially correspond to the one or more material
properties of the tissue, and coupling the artificial tissue
material to the anatomical structure.
Inventors: |
Reihsen; Troy E.; (Woodbury,
MN) ; Sweet; Robert M.; (Edina, MN) ; Burke;
Daniel M.; (Minneapolis, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Regents of the University of Minnesota |
Minneapolis |
MN |
US |
|
|
Family ID: |
47993402 |
Appl. No.: |
15/690574 |
Filed: |
August 30, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13630715 |
Sep 28, 2012 |
9805624 |
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15690574 |
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61541547 |
Sep 30, 2011 |
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61589463 |
Jan 23, 2012 |
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61642117 |
May 3, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B33Y 80/00 20141201;
G09B 23/28 20130101; G09B 23/30 20130101; B33Y 50/00 20141201; G16H
50/50 20180101 |
International
Class: |
G09B 23/30 20060101
G09B023/30; G09B 23/28 20060101 G09B023/28; G06F 19/00 20110101
G06F019/00 |
Claims
1. A method of making a tissue model, the method comprising:
determining one or more material properties of a tissue, wherein
the one or more material properties include at least one of
mechanical properties, electroconductive properties, optical
properties, thermoconductive properties, chemical properties, and
anisotropic properties; creating an anatomical structure of the
tissue; selecting an artificial tissue material having one or more
material properties that substantially correspond to the one or
more material properties of the tissue; and coupling the artificial
tissue material to the anatomical structure.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/630,715, filed Sep. 28, 2012, which the
subject matter of this application is related to Reihsen et al.,
U.S. Provisional Patent Application Ser. No. 61/541,547, entitled
"SIMULATED, REPRESENTATIVE HIGH-FIDELITY ORGANOSILICATE TISSUE
MODELS," filed on Sep. 30, 2011, to Reihsen et al., U.S.
Provisional Patent Application Ser. No. 61/589,463, entitled
"SIMULATED, REPRESENTATIVE HIGH-FIDELITY ORGANOSILICATE TISSUE
MODELS," filed on Jan. 23, 2012, and to Poniatowski et al., U.S.
Provisional Patent Application Ser. No. 61/642,117, entitled
"METHOD FOR ANALYZING SURGICAL TECHNIQUE USING ASSESMENT MARKERS
AND IMAGE ANALYSIS," filed on May 3, 2012, which are each
incorporated by reference herein in their entirety.
TECHNICAL FIELD
[0002] The present disclosure is directed to models used for
simulation of tissues, such as tissue models useful for providing
training of medical procedures for health care providers, and in
particular to human tissue models constructed with a base of organo
silicates. The present disclosure also relates to a method of
forming the models.
BACKGROUND ON THE INVENTION
[0003] Simulation of medical procedures is becoming a more
prominent part of medical training. Currently, animal tissues are
often used for simulation but are often anatomically different than
a human patient, have different mechanical properties than human
tissue with large amounts of variance between samples, are
difficult to obtain and store, and have ethical issues regarding
animal protection. Fresh, frozen, and fixed human cadaveric tissue
is also used for medical education and device development, and
training and offers better anatomical accuracy compared to animal
tissue. However, human cadaveric tissue often still has different
mechanical properties than live human tissue, is typically
expensive, and is difficult to obtain and store in sufficient
quantities for medical training. Cadaveric tissue also lacks the
constitutive properties of fresh or live human tissue. Neither
animal tissues nor cadaveric tissues meet the fidelity needs for
enhanced training, and in some cases their deficiencies can lead to
negative training transfer.
SUMMARY OF THE INVENTION
[0004] The present disclosure is directed to silicone-based
simulation materials and methods for making the same that can be
used to simulate tissue, such as human and animal tissue. The
simulation tissue can be used for training medical or veterinary
practitioners with a high-fidelity representative tissue model that
will closely and accurately simulate patient tissue. In some
examples, the tissue model can be patient-specific and designed for
a particular individual so that the practitioner can perform a
practice run of a procedure before actually working on the patient.
In an example, the tissue simulation material comprises
organosilicate materials.
[0005] In one example, the present disclosure is directed to a
method of making a tissue model. The method can include determining
one or more material properties of a tissue, wherein the one or
more material properties include at least one of mechanical
properties, electroconductive properties, optical properties,
thermoconductive properties, chemical properties, and anisotropic
properties, creating an anatomical structure of the tissue,
selecting an artificial tissue material having one or more material
properties that substantially correspond to the one or more
material properties of the tissue, and coupling the artificial
tissue material to the anatomical structure.
[0006] In another example, the present disclosure is directed to a
tissue model comprising a three-dimensional model and an artificial
tissue material coupled to the three-dimensional printed model. The
artificial tissue material is selected to have one or more material
properties that substantially corresponding to at least one of
mechanical properties, electroconductive properties, optical
properties, thermoconductive properties, chemical properties, and
anisotropic properties of a tissue.
[0007] In yet another example, the present disclosure is directed
to a tissue model comprising a three-dimensional model, an
artificial tissue material coupled to the three-dimensional printed
model, wherein the artificial tissue material is selected to have
one or more material properties that substantially correspond to
one or more material properties of a tissue, and an indicator
material applied to the artificial tissue material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a flow diagram illustrating a method for creating
desired artificial tissue models.
[0009] FIG. 2 is an illustration of a testing apparatus for
conducting uniaxial testing to determine viscoelastic mechanical
properties of specimens.
[0010] FIG. 3 is an illustration of overall process of creating a
three-dimensional physical mold from patient specific data
exemplifying pediatric airway.
[0011] FIG. 4 is a graph illustrating stress-strain relationship
for an artificial tissue.
[0012] FIG. 5 is a graph illustrating stress-strain relationship
for human renal artery.
[0013] FIG. 6A is an illustration of black light assessment of
surgical techniques (BLAST) skin Model with rare earth element
based coating under normal light.
[0014] FIG. 6B is an illustration of BLAST skin model with rare
earth element coating under UV black light.
[0015] FIG. 6C is an illustration of BLAST skin model with rare
earth element coating under IR light.
[0016] FIG. 7 is an illustration of animate renal artery training
model with blood.
[0017] FIG. 8 is an illustration of animate kidney training model
for endoscopy.
[0018] FIG. 9A is an illustration of BLAST face Model with rare
earth element based coating under normal light.
[0019] FIG. 9B is an illustration of BLAST face model with rare
earth element coating under black light.
[0020] FIG. 9C is an illustration of BLAST face model with rare
earth element coating under UV light.
[0021] FIG. 9D is an illustration of BLAST face model with rare
earth element coating under IR light.
[0022] FIG. 10 is an illustration of animate ureter training model
for endoscopy.
[0023] FIG. 11 is an illustration of animate hand training model
for endoscopy.
[0024] FIG. 12 is an illustration of animate face skin training
model for endoscopy.
[0025] FIGS. 13A-13B are illustrations of indicator material in
between tissue layers.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The present disclosure is directed to silicone-based
simulation materials and methods for making the same that can be
used to simulate tissue, such as human or animal tissue. The
simulation tissue can be used for training medical or veterinary
practitioners with a high-fidelity representative tissue model that
will closely and accurately simulate patient tissue. In some
examples, the tissue model can be patient-specific and designed for
a particular individual so that the practitioner can perform a
practice run of a procedure before actually working on the
patient.
[0027] As described above, animal tissue models and frozen human
cadaveric tissue can be used to simulate human tissue. However,
fidelity issues with animal and cadaveric tissue, as well as high
cost and ethical issues often make animal tissue and cadaveric
tissue models a poor simulation for living tissue. The factors that
contribute to the variation in constitutive properties amongst
fresh or live human tissue have been hypothesized but poorly
documented. Fresh human tissue models are logistically difficult to
obtain, store, process and lack embedded assessment methods for
formative and summative feedback.
[0028] The discrepancies between current simulator materials and
actual human tissue can lead to reduced efficacy when the trainee
moves from simulation to actual patient care. Training on
inaccurate and unrealistic models has the potential for negative
training transfer. Even if the training model material provides a
good model for live tissue generally, differences in a particular
patient can still provide for training difficulties that are
preferably experienced on non-living tissue. Therefore, efforts
have been made toward developing tissue models that can be a
functional analogue of living tissue. In some examples,
patient-specific tissue models with representative mechanical
physiology based on tissue elasticity and modulus can be made.
[0029] FIG. 1 shows a flow diagram of an example method for forming
a representative tissue model. In an example, a method of making or
developing a tissue model can include determining one or more
material properties of a tissue, such as a mammalian tissue, for
example human tissue. The tissue can be a specific type of tissue
upon which training is desired (e.g., fat, connective tissue,
nerve, artery, vein, muscle, tendon, ligaments, renal artery
tissue, kidney tissue, ureter tissue, bladder tissue, prostate
tissue, urethra tissue, bleeding aorta tissue, pyeloplasty tissue,
Y/V plasty tissue, airway tissue, tongue tissue, hand tissue,
general skin tissue, specific face skin tissue, eye tissue, brain
tissue, vaginal wall tissue, breast tissue, nasal tissue,
cartilage, colon tissue, stomach tissue, liver tissue, rectal
tissue, heart tissue, bowel tissue, pancreas tissue, gallbladder
tissue, liver tissue, inferior vena cava tissue, aortic tissue,
lung tissue, bronchial tissue, soft palate tissue, larynx tissue,
pharynx tissue, epidermis tissue, dermis tissue, lip tissue,
mucosal membrane tissue, or adhesion tissue, just to name a few).
The material property of the tissue can include mechanical
properties (such as viscoelastic properties, nanoindentive
properties, strain rate insensitivity, compressibility,
stress-strain curves, Young's modulus, yield stress, tear point,
deformability, and the like), electroconductive properties,
thermoconductive properties, optical properties, chemical
properties, or anisotropic properties. Methods of testing tissue
and determining specific material properties can be according to
methods known in the art. For example, mechanical properties can be
determiend by the viscoelastic mechanical properties are determined
by uniaxial, biaxial, nano-indentation, relaxation, creep, or shear
testing of the native tissue. FIG. 2 shows an example of a uniaxial
testing apparatus for determining viscoelastic mechanical
properties of a tissue or a tissue model.
[0030] After determining the one or more material properties of the
tissue, such as one or more constitutive properties of the tissue,
the method can include creating an anatomical structure of the
tissue, followed by coupling an artificial tissue material to the
anatomical structure. The anatomical structure can include a base
structure having a geometry that is representative of a
corresponding anatomical structure, such as within a mammalian
body. For example, if a model of the human hand is desired for
training regarding treatment of a skin wound, than the anatomical
structure that is formed can simulate the bones and underlying
musculature, ligaments, and cartilage of the hand. The artificial
tissue material can simulate one or more skin layers of the skin of
the hand. The anatomical structure and the artificial tissue
material can include more or less of the underlying structure,
depending on how much of the tissue is desired to be simulated. For
example, if only the skin need be simulated in order to allow a
trainee experience with stitching of simple wounds, then the
artificial tissue material can simulate only the skin tissue (e.g.,
the dermis and the epidermis). However, if it is desired to
simulate a portion of the muscle tissue as well, such as to train
on more advance tissue repair, the artificial tissue material can
simulate at least a portion of muscle tissue as well.
[0031] In an example, the material of the tissue model can be
selected or made to have material properties that substantially
correspond to the corresponding material properties of the tissue
being simulated. By "substantially correspond," as used herein, can
refer to a particular material property being within 10% of the
value of the same material property in the native tissue, such as
within 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1%. In an example, each
of the material properties being simulated is within about 2% to
about 4% of the corresponding material property of the native
tissue.
[0032] The material property or properties of the tissue model that
substantially correspond to the same material property of the
native tissue can depend on the purpose for the simulation. In most
examples, the tissue model can be designed to simulate native
tissue for a particular medical procedure where the tissue is to be
physically manipulated by a user, such as a surgical procedure. In
these examples, at least one or more mechanical properties of the
tissue model substantially correspond to the same mechanical
property in the native tissue being simulated. For example, the
tissue model might have a viscoelasticity, a compressibility, and a
tear stress that substantially corresponds to a viscoelasticity, a
compressibility, and a tear stress of the native tissue or tissues.
Additional mechanical properties may be included to substantially
correspond to those of the native tissue so that the tissue model
will feel and behave substantially the same as the native tissue,
particularly in the view of an expert in the procedure being
simulated. Because the specific material properties that may be
selected to be
[0033] Other types of material properties can be included, in
addition to mechanical properties, to increase the fidelity of the
tissue model for the procedure being simulated. If the procedure
being simulated includes cauterizing or some other thermal
manipulation of the native tissue, then the tissue model can also
include one or more thermoconductive properties that substantially
correspond to thermoconductive properties of the native tissue.
Similarly, if the procedure being simulated includes the use of
optical inspection, such as imaging of the native tissue, then one
or more optical properties, such as reflectivity, light
transmission of a particular wavelength or range of wavelengths, or
light absorption of a particular wavelength of range of
wavelengths, can substantially correspond to the same one or more
optical properties of the native tissue. Similar considerations can
be made for electroconductive properties, nano-indentive
properties, chemical properties, or anisotropic properties (e.g.,
the value of a particular property, including mechanical,
electrical, thermal, optical, or chemical, in one direction versus
another direction).
[0034] In some examples, two or more of the material properties,
such as three or more, four or more, five or more, six or more,
seven or more, and so on, of the material properties listed above,
substantially correspond to the corresponding material properties
of the native tissue.
[0035] The physical properties that can be considered for soft
tissues include homogeneity, nonlinear large deformation,
anisotropy, viscoelasticity, strain rate insensitivity and
compressibility. A human tissue database can include tissue
characteristics data that provide values for comparison with
simulator materials.
[0036] The creation of a human tissue property database can provide
for accurate constitutive computer simulation models of structures,
injury and disease. The primary components affecting the creation
of artificial tissue models are material costs and supplies,
accurate anatomical modeling, knowledge of the mechanical
properties of the represented tissues, choosing the right
materials, assemblage of the models in an accurate representation
of human anatomy, and model development based on educational
principals and "backwards-design" with an embedded-assessment
strategy to maximize the learning.
[0037] In an example, data regarding material properties of tissue
to be simulated is determined by harvesting soft-tissue specimens
within 24 hours of death of a subject. The specimens are warmed to
body temperature and then subjected to uniaxial or biaxial testing
to determine viscoelastic mechanical properties. In addition,
electroconductive, thermoconductive, and indentation experiments
can be performed on a plurality of different tissue types. The data
is then stratified according to gender, age, and body mass index
(BMI).
[0038] In an example, data from the testing of the tissue samples
is used to form a tissue database, such as a human tissue database,
which can be used to guide the formulation of organo silicate base
material with the objective of tailoring the recipes of artificial
tissues to match the properties of fresh human tissue.
[0039] In an example, analyzing the similarities between human
tissue materials and simulation materials is to compare
characteristics of their stress-strain curves. The stress-strain
curves can be generated by a preprogrammed routine in Excel on an
MTS computer based on inputted width, thickness, and initial
displacement values and load vs. extension data.
[0040] Engineering stress is defined as a force per unit area:
.sigma. = F A [ 1 ] ##EQU00001##
where F is the applied force and A is the cross sectional area.
Green strain is defined as:
G = 1 2 ( L o - L 2 ) L 2 [ 2 ] ##EQU00002##
where L.sub.0 is the original length of the sample and L is the
final length of the sample. The Young's modulus can be found by
taking the slope of the stress-strain curve at the initial linear
portion of the graph. Yield stress is defined as the stress at
which the material begins to break and can be found on the
stress-strain curve as the maximum stress value on the
stress-strain curve. The corresponding strain value is defined as
the strain at yield.
[0041] The data from the human tissue database allows tailoring of
the organosilicate base material. Simulator models can be produced
using commercially available off-the-shelf (COTS) organosilicate
materials. The base material can undergo modifications to change
cross-linking, electrical conductivity, thermal conductivity,
reflectivity, indentation, odor, and color. Pigments and dyes can
be added to the organosilicate material to create anatomically
accurate color mapping of the simulator model.
[0042] The materials used to create human tissue analogues need to
meet many specifications in order to successfully emulate actual
human tissues. In some examples, organosilicate materials are used
as the base material for creating artificial tissues. Commerical
off the shelf (COTS) organosilicate materials can undergo repeated
cycles of revision by continually comparing testing data of the
artificial tissue to the human tissue database.
[0043] Organosilicate materials are stable and do not require
specialized storage or shipping. These materials are cost effective
and are less expensive as compared to animal and cadaveric models.
The material is durable and can often be reused which also adds to
cost-effectiveness.
[0044] The organosilicate polymer base material is mostly clear in
color and is capable of being cured in room air or within a mold.
The polymer base material is mixed thoroughly with additives,
resins, or indicators to allow for equal distribution of the base
throughout the combined mixture. The mixture is placed in a mold to
form a molded sample layer by layer. Once fully cured, the mold is
de-cast, and the the molded sample is coated with a talcum powder
and is washed with cold water to remove excess talcum powder.
[0045] Reflectivity is a factor in ultrasound and fluoroscopy
procedures. The organosilicate materials of the tissue models of
the present disclosure have demonstrated useful reflectivity
properties with respect to ultrasound and fluoroscopy. This
reflectivity allows the materials to be used in simulated
procedures such as ultrasound and fluoroscopy.
[0046] Possible modifications affecting viscoelastic properties
include ratio changes, chemical additives and ultraviolet (UV)
light exposure. For example, organosilicate films that are exposed
to an ultraviolet light source have at least a 10% or greater
improvement in their mechanical properties (i.e., material hardness
and elastic modulus) compared to the as-deposited film (U.S. Pat.
No. 7,468,290). The UV light has been shown to cause increased
cross-linking in the material, which can increase the modulus and
decrease the elasticity (Crowe-Willoughby et al., 2009). In some
examples, the intensity and duration of UV exposure can be
modulated to provide for fine-tuning of desired mechanical
properties.
[0047] In an example, silicone-based materials are useful in
simulation and biomedical applications. Silicon is an element that
is rarely found in its elemental form but can be found as oxides or
as silicates. Silica is an oxide with formula SiO.sub.2 that can
have amorphous or crystalline structure. Silicates are salts or
esters of silicic acid (general formula
(SiO.sub.x(OH).sub.4-2x).sub.n) that contain silicon, oxygen, and
metal elements. Silicones are polymers made of silicon, oxygen,
carbon, and hydrogen with repeating Si--O backbone (Colas, 2005).
These polymers are created synthetically with the addition of
organic groups to the backbone via silicon-carbon bonds. A common
silicone is polydimethylsiloxane (PDMS) with monomeric repeat unit
(e.g., SiO(CH.sub.3).sub.2). The number of repeat units and degree
of cross-linking within the silicone polymer can account for the
different types of silicone materials available for different
applications. Silicones have been used in biomedical applications
because of their high biocompatibility, their chemical inertness,
and their resistance to oxidation.
[0048] In an example, the material of the tissue model can comprise
platinum based silicone-rubbers, tin cured silicone rubbers or
urethane rubbers. The sources and trade names of these materials
are presented in Table 1. Table 2 provides the foams and additives
used in the present application.
[0049] In an example, the organosilicate base can be a soft, room
temperature vulcanized (RTV) silicone rubber with a hardness of
less than 30 shores. The two-part component can be addition cured
and platinum catalyzed to result in high tear strength and flexible
mold compounds. The organosilicate base can bond to plastics. The
percentage of mixing of A and B change depending on the application
of the tissue model.
[0050] In an example, a platinum salt in portion B (OSHA PEL and
ACGIH threshold limit value 0.002 mg/m.sup.3 (as Pt)) has the
following technical specifications.
TABLE-US-00001 a. Mix ratio, by weight 1A:1B b. Hardness, Shore A
10 .+-. 2 c. Pour time, minimum 6 min d. Demould time @ 25.degree.
C. (77.degree. F.) 30 min e. Color off white translucent/Colorless
f. Viscosity, mixed 15,000 cP g. Specific volume (in.sup.3/lb) 25
h. Specific gravity @ 25.degree. C. (77.degree. F.) 1.10 i.
Shrinkage upon cure Nil j. Flash point >350.degree. F.
[0051] In an example, a tissue-specific organosilicate base
material is formed onto the three-dimensional model, such as by
painted layering, casting, depositing, molding, printing and the
like. The organosilicate base material conforms to the details of
the model to create an exact replica of the patient specific
anatomy.
[0052] In an example, organosilicate material is added in precise
layers to imitate the physiologically distinct layers found in skin
and other human tissues. In an example, a first layer of a first
organosilicate material is applied to the three-dimensional printed
model and allowed to cure to simulate a first layer of tissue. A
second layer of a second organosilicate material is applied to the
first layer, wherein the second organosilicate material can be
different than or the same as the first organosilicate material and
allowed to cure to simulate a second layer of tissue. Subsequent
layers (e.g., a third, fourth, and fifth layer, etc.) can be added
over the second layer. The layers might not all be cured in between
if the layers are to be inseparable. However, substances, devices,
sensors can be added between or within each layer.
[0053] In an example, one thick layer of a first organosilicate
material or a plurality of thin layers of the first organosilicate
material can be applied to the three-dimensional model in order to
simulate a substantially uniform tissue structure or layer. Once
the material layer or layers have been added to the desired
thickness, the outer material can be separated from the mold and
sealed.
[0054] The simulator materials can also be implemented with
indicators that can provide for evaluation of the proficiency of a
trainee to perform certain skills. Synthetic, photochromic,
thermochromic, solvatochromic, or piezochromic materials can allow
for color change based on light that the material is exposed to,
heat that the material is exposed to, chemicals that the material
is exposed to, or pressure applied to the material. FIGS. 6A to 6C
successfully demonstrate black light assessment of surgical
technology (also referred to as "BLAST") for embedding performance
assessment in a model. Similarly, FIG. 9D demonstrates infrared
light assessment of surgical technology (IRAST) for embedding
performance in a model. In this case, lines invisible to the user
(FIG. 6A) can be assessed after a tissue approximation exercise
allowing his or her ability to perform a desired task. In an
example, photochromatic materials that change color based on
contact or pressure can provide a non UV-based goal for
measurement. A thermochromatic material exposed to heat can also be
used, and would produce a similar effect. Chemical indicators can
also be used using a steam, or chemical acid/base interaction and
can provide similar results.
[0055] In an example, an indicator material can be added within or
in between one or more layers of the organosilicate tissue model in
order to provide for skill proficiency training and evaluation. The
indicator material can be added as lines, dots, or other indicating
patters that can be used to indicate or determine proper
performance of a particular task. In an example, the indicator
material can be applied on an outer surface of the tissue model
with a predetermined pattern that can be compared to an ideal
pattern for a particular procedure. In another example, the
indicator material can be embedded within the tissue model material
so that the indicator material is only exposed if and when it is
exposed by cutting or removing a portion of the artificial tissue
model. The indicator material can be configured to be exposed when
a procedure is performed correctly, e.g., when an incision or
dissection is performed properly, or the indicator material can be
configured to be exposed when a procedure is performed incorrectly,
e.g., when a portion of the tissue model is incorrectly removed or
exposed, or both.
[0056] In an example, the indicator material can be visible to a
user, e.g., a trainee, to indicate the proper position for a
particular portion of a procedure, e.g., the location where a
trainee should perform a particular action, such as clipping,
cutting, or suturing the tissue model. The amount of indicator used
can depend on an application, depth that the indicator layer is
placed, and the color of substrates and layers as shown in FIGS.
13A and 13B.
[0057] In an example, the indicator material is selected to be
undetectable by a user of the tissue model, such as a trainee using
the tissue model. In an example, the indicator material can be
undetectable by being transparent or substantially transparent, so
that the trainee will be unaware of the location of the indicator
material. The indicator material can then be made to be visible to
the trainee or an evaluator after completion of the procedure to
determine the effectiveness of the procedure. The indicator
material can also be used as a real-time indicator.
[0058] In an example, the indicator material can comprise an
ultraviolet light or infrared light sensitive coating that can be
added onto or into the simulated tissue, for example on one
organosilicate layer or between the organosilicate tissue layers,
at predetermined locations.
[0059] In an example, a polymer resin coating is applied to one or
more organosilicate layers of the simulator model in lines, dots,
or other patterns. While performing a specified task, such as a
surgical procedure, the user (e.g., a trainee) is unaware of the
polymer resin based coating patterns on the simulator due to the
transparent nature under normal light (See FIG. 6A). Following
completion of a task by the user, an evaluation of his or her
ability to perform the task can be made by viewing the tissue model
under UV light where the UV-sensitive coating pattern will appear
(FIG. 6B).
[0060] In an example, UV-sensitive coatings can be applied to
fluoresce in more than one color when exposed to UV light, such as
a first color for a first pattern of UV-sensitive indicator
coating, and a second color for a second pattern of UV-sensitive
indicator coating. Indicator coatings can be especially useful in
skill assessment involving matching or aligning tissues, such as
for suturing or grafting.
[0061] A polymer resin can be created from UV pigments that are
natural or synthetic minerals, and added to one part of the
organosilicate base. The base is then agitated to ensure a complete
homogenous mixture.
[0062] The pigments can be in powder form. Examples of pigments
which make up the colors of blue, red, white, yellow, orange, or
green may be selected from the following list of minerals: adamite,
agate, albite, alunite, amber, amblygonite, analcime andersonite,
anglesite, anthrophyllite, apatite, aphthitalite, apoplyllite,
aragonite, autunite, axinite, barite, becquerelite, boltwoodite,
brucite, cahnite, calcite, caloimel, celestite, cerrusite,
chondrodite, clinohedrite, corundrum, cowlesite, datolite, dioside,
dypinite, espertite, eucryptite, fluorite, foshagite, gaylusite,
gowerite, gypsum, halite, hanksite, hemimorphite, hydroboracite,
idrialite, laumontite, magnesite, margarosanite, melanophlogite,
mesolite, meta-autunite, meyerofferite, montebrasite, nahcolite,
natrolite, norbergite, opal, pectolite, phosphuranylite,
pirssonite, plombierite, powelite, pyrophylite, quartz, scapolite,
scheelinte, smithsonite, sodalite, soddylite, sphalerite,
spodumene, stilbite, strontianite, talc, thaumasite, thomsonite,
tirodite, tremolite, trona, ulexite, uralolite, urannopilite,
uranocirite, walstromite, wavellite, whewellite, willemite,
witherite, wollastonite, wulfenite, wurtziste, xonotlite, zincite,
zippeite, zircon.
[0063] Fluorescent pigments may be combined to create custom
colors, that can match the tissue, or contrast based on need.
Embedment of COTS indicators can also be used. An example would be
of Clear Neon Black Light Paint.
[0064] In an example, the simulator models are produced by hand.
The process for including the indicator material, such as a
UV-sensitive material, on a tissue layer, in a tissue layer, or
between tissue layers can be by hand painting or by spraying. Each
type of rare earth element powder can be mixed separately or within
some parts or with any of the additives such as thinners or
thixotropic agents.
[0065] In an example, the ultraviolet light used to activate a
UV-sensitive indicator material comprises UV A light having a
wavelength of from about 340 nanometers to about 380 nanometers,
such as about 365 nm. In some examples, the coating cannot be used
in direct sunlight.
[0066] In an example, long wave fluorescent minerals, powders, or
chemicals can be used to achieve a desired color, although short
wave fluorescence or phosphorescence can show different colors.
[0067] In an example, household products such as cornstarch, tonic
water (quinine), vitamin B.sub.12, Woolight, Triethylamine, water
based paints or fabric dyes can also be used. Some examples of
colors and compositions of fabric dyes include, but are not limited
to, white (agate, magnesium carbonate, or hydrated sodium calcium
aluminum silicate); red (calcite, barium sulfate, halite, zinc iron
sulfide, calcium fluoride, or quartz); orange (calcium fluoride, or
zircon); yellow (calcium fluoride, or powellite); blue (calcium
fluoride, fluorite, or calcite); green (calcium fluoride, zinc
silicates, adamite, quartz, agate, or willemite); or purple
(apatite or kunzite).
[0068] In an example, luminescent minerals such as petrolatum in
fluorite can be used. In an example, phosphorescent minerals or
chemicals can also be used.
[0069] In an example, the indicator material can be sprayed, hand
painted, printed, silkscreened, or drawn in patterns that can be
used for measurement or evaluation of performance, such as in a
curricular or educational setting.
[0070] In an example, Smooth-On thinners are used and such thinners
are applicable to all platinum cured silicones. The thinner can be
composed of 100% dimethylsiloxane (CAS number 63148-62-9). Adding
the thinner to the organosilicates can decrease the viscosity and
durometer of the final material. The ultimate tear strength and
tensile stress can also be reduced in proportion to the amount of
thinner added. In an example, the maximum amount of thinner that
can be added to a recipe is 15% of the weight of part A.
[0071] Additives can be added to reduce tackiness, decrease cross
linking of the polymers (which makes them more fragile), increase
lubricity (for a more viscous "feeling"), or increase the
electrical conductive nature of the materials. In an example, the
additives can include a silicone oil such as Dow Corning 200.RTM.
fluid, 1 CST (01013092) or octamethlytrisiloxanes (>60%). In an
example, the additives can be at least one of petroleum jelly,
glycerin, baby oil, talcum powder, colors, tints, dyes, metal
wires, metal powders, nanotubules, theromochromatic pigments,
slurries, water, and ink. Further, the additives can also be at
least one of germanium wires, copper powders, nickel powders,
dielectric inks, and dielectric coatings.
[0072] In an example, one or more sensors can be positioned on or
between a layer or layers of the organo silicate tissue model or
imbedded within one or more layers of the tissue model for
measuring deformation of the tissue model, or force or pressure
exerted on the tissue model, such as due to contact or collision
with objects such as surgical instruments, hands of a medical
practitioner, or other organs such as bones. In an example, the one
or more sensors can be configured to perform an operation when a
predetermined deformation, force, or pressure is sensed. For
example, the sensor can be configured to record if and when a
deformation, force, or pressure is exerted on the tissue model that
corresponds to damage to the native tissue that the tissue model
material is simulating. For example, if a particular native tissue
is known to result in inflammation upon the exertion of a
particular deformation, force, or pressure on the native tissue,
than the sensor can be configured to record instances when that
deformation, force, or pressure is reached. The sensor can also be
configured to trigger an alarm or other notification that the
predetermined deformation, force, or pressure had been experienced
by the tissue model.
[0073] In an example, a piezoelectric film that can detect pressure
or deformation can be used, such as the pressure or force sensing
films sold by Tekscan, Inc. (South Boston, Mass. USA).
[0074] In an example, at least one of a strain gauge, a capacitive
diaphragm, an electromagnetic inductance diaphragm, an optical
strain detection sensor, a potentiometer mechanism, a vibration
sensor, an accelerometer, a dynamic switch element, and a
piezoelectric sensor can be positioned on or between or imbedded
within any layer of the tissue model. In an example, the sensor can
produce a voltage signal in proportion to a compression force, or a
tensile mechanical stress or strain. Piezoelectric sensors, such as
a piezoeelectric film or fabric can also be well suited for high
fidelity tissues with audio in the high frequency (e.g., greather
than about 1 kHz) and ultrasound frequency (e.g., up to 100 MHz)
ranges, such as for ultrasound detection. Piezoelectric sensors can
be in the form of cables, films, sheets, switches, and can be
amplified in a laboratory setting.
[0075] In an example, a piezoresistive sensor can be used to
measure deformation of the tissue model material at a particular
location. In an example, a piezoresistive fabric can be imbedded
on, within, or between layers of the tissue model to provide
contact and deformation detection with minimal delay in response or
recovery time (over 400 Hz). A small delay in response or recovery
time allows for haptic data of the interactions to be collected and
for a dynamic response to be performed.
[0076] In an example, EeonTex flexible fabric (also known as
e-fabric), sold by Eeonyx Corporation (Pinole, Calif. USA) can be
used as a piezoelectric sensor that can conform with
three-dimensional surfaces can be used.
[0077] In an example, a sensor can be located at an expected
collision site. For example, while intubating the airway of an
artificial tissue analogue, one or more sensors can be placed in at
least one of an artificial tongue, an artificial larynx, an
artificial pharynx, artificial vocal cords, and an artificial
bronchii because these locations are known as collision sites where
damage has occurred by improper technical or procedural technique.
In an example, a sensor or sensors can be located near an incision
site for the tissue model in order to measure the depth, pressure,
and forces (with direction) of any movement of the tissue.
[0078] In an example, flow sensors can be imbedded into the tissue
in order to measure flow rate, for example of a simulated blood
flowing through the tissue model.
[0079] In an example, leak testing pressure sensors can be used to
send the decay of pressure in an closed loop artificial artery or
vein due to an accidental or purposeful cut, incision, or needle
stick of the wall of the model. Quantifying the amount of fluid
loss can be associated with blood loss in a patient during
procedures, which can be related to outcomes and safety
metrics.
[0080] In an example, determining the physical shape that the
tissue model will take comprises creating a patient specific
three-dimensional physical model via life casting, computer
tomography (CT scan), or magnetic resonance imaging (MRI) datasets.
In an example, DICOM imaging stacks are processed through
compositing software (e.g., After Effects.RTM.) to identify and
isolate the specific anatomical structure. The refined stack data
can be processed through image segmentation software (e.g.,
Mimics.RTM.) to create a coarse three-dimensional model of the
selected anatomy. The coarse model can be brought into a
three-dimensional development package (e.g., Maya.RTM.) and used as
a reference so that a new, clean model can be built over the
previous model. The model can be further refined to the desired
level of detail. The process can be guided by a physician or a
subject matter expert. The subject matter experts include but not
limited to engineers, physicians, anatomists, physiologists or
biochemists.
[0081] In an example, forming the tissue model comprises sending
the finalized virtual three-dimensional model to a
three-dimensional printer that utilizes stereolithographic
techniques to produce a three-dimensional printed model prototype
or negative which is cast, created, or molded using the
organosilicate base material determined from the tissue database.
FIG. 3 shows an example process of forming a three-dimensional
model of a patient's airway from an image take of the patient, such
as an X-ray, CT scan, or MRI scan. The three-dimensional model can
be used to form a mold. The base material, e.g., an organosilicate
base material, can be applied to the mold, such as via painting,
casting, molding, or printing, to form the final artificial tissue
model.
[0082] The completed model can undergo face and content validation
studies and testing by clinical and/or anatomy subject matter
experts in the training environment to inspect any possible
anatomical deviations. The anatomical deviations can include poor
color mapping, visible seams or extra material pieces. Any
abnormalities can be noted and corrections can be made to the
protocol regarding the building of future models. As part of a
curriculum, the models are assessed for their ability to provide
face, construct, content, discriminate, concurrent, convergent, and
predictive validity.
[0083] Comparisons between the stress-strain relationships of the
organosilicate based recipes and human renal artery have shown
similarities in modulus, yield stress, and yield strain. FIG. 4 is
an example of stress-strain graphs for an artificial renal artery
tissue and FIG. 5 is an example of a stress-strain graph for actual
human renal artery tissue. By comparing mechanical data obtained
from these graphs, further improvement in human tissue to
artificial tissue recipe matching can be made.
[0084] Stereolithography is advantageous due to the ability to
rapidly create prototypes (typically less than one day). The
resulting prototypes are durable and reusable as a positive or
negative for tissue castings, adding to the cost-effectiveness of
using stereolithography. The patient specific prototypes can also
be made with as little as one datasets that are already collected
for clinical purposes, expanding on the current use of medical
technology and existing testing.
[0085] Prototypes created using stereolithography are anatomically
accurate because of the detailed layer-by-layer process used to
print the prototype. A stereolithography printer can be configured
with high resolution that allows precise anatomical structures to
be depicted in the printed prototype. A three-dimensional printed
model can be made to be patient specific based on the original
computer tomography (CT) or magnetic resonance imaging (MRI) images
used. The models can also be used as a functional base for
anatomical deviations and pathophysiology. One approach is to add a
layer of wax over the three-dimensional printed model, which is
sculpted to create bumps, detailing, or other deviations that can
be desired for a specific training model.
[0086] The uses for physiologically accurate tissue simulators are
widespread. Organosilicate based materials can be subjected to
extremes such as cuts, burns, gun shots, and blast pressures. They
can then be repaired by the trainee as part of a simulated
procedure. They can also be repaired via exposure to UV lighting,
reducing their cost, and increasing their usage.
[0087] The tissue simulators can be used independently or as hybrid
models attached to standardized patients or confederates in
training environments. The trainee is able to perform tasks such as
needle sticks and suturing on the attached analogue tissues without
harming the volunteer. The combination of patient interaction and
accurate tissue simulation provides for an ideal training
environment.
[0088] The completed tissue models can be used in combination with
other substances in order to replicate a clinical situation. The
organosilicate based tissue models can be used in the absence of
silicone spray and can instead be implemented with inexpensive
clinical substitutive artificial blood, saliva, urine, or
vomit.
[0089] Examples of types of tissues that can be formed using the
organosilicate base materials of the present disclosure include,
but are not limited to: fat, connective tissues, nerve, artery,
vein, muscle, tendon, ligaments, renal artery tissue, kidney
tissue, ureter tissue, bladder tissue, prostate tissue, urethra
tissue, bleeding aorta tissue, pyeloplasty tissue, Y/V plasty
tissue, airway tissue, tongue tissue, complete hand tissue, general
skin tissue, specific face skin tissue, eye tissue, brain tissue,
vaginal wall, breast tissue, nasal tissue, cartilage, colon tissue,
stomach tissue, liver tissue, rectum, and heart tissue.
[0090] Examples of types of tissues that can be formed using the
organosilicate base materials of the present disclosure include,
but are not limited to: bowel tissue, pancreas tissue, gallbladder
tissue, liver tissue, Inferior Vena Cava, Aorta, Lung Tissue,
bronchial tissue, soft palate tissue, larynx tissue, pharynx
tissue, epidermis tissue, dermis tissue, lip tissue, mucosal
membrane tissue, adhesion tissue. The present application
benchmarked any inclusive tissues of the human tissue database.
[0091] FIGS. 9-12 show examples of specific artificial tissue
training models in accordance with the present disclosure. The
artificial tissue training model has been created for a human face
as shown in FIGS. 9A-9D. FIGS. 9A-9D also show an indicator
material that has been placed on or within the artificial tissue
that can be seen under various light sources, such as under an
ultraviolet, or "black" light (FIGS. 9A, 9B, and 9C) or under an
infrared light (FIG. 9D). FIG. 10 is an illustration of animate
ureter training model for endoscopy. FIG. 11 is an illustration of
animate hand training model for endoscopy. FIG. 12 is an
illustration of animate face skin training model for endoscopy.
[0092] An entire segment of the body that has emulated physiology
and accurate anatomical representation can be re-created relative
to literature, data, studies, and testing. For example, for skin
tissue, epidermis, demis, fat along with nerves, arteries, and
veins, bones, muscle, and connective tissues can be created. The
tissue models developed have the capability to define or create
subtle differentiation of the stratum corneum, stratum lucidum,
stratum granulo sum, stratum spinosum, and stratum basale.
EXAMPLES
Example 1
Renal Artery Simulator
[0093] Using an organosilicate base material, the successful
creation of an artificial tissue training model has been created
for a human renal artery (FIG. 7) in order to meet the
specifications of the American Urological Association for
laparoscopic and robotic clip applying (Syverson, et al., 2011).
The simulator tissue was color mapped to mimic human renal artery
and filled with artificial blood to a mean arterial pressure (MAP)
of 80.+-.2 mmHG. Solid black pigment lines and dotted black pigment
lines were added for training purposes to indicate areas for
clipping and cutting respectively. The model was fitted into a
mechanical apparatus to mimic a beating motion.
Example 2
Kidney Simulator
[0094] A kidney simulator (FIG. 8) was also developed using the
techniques described above. The simulator utilizes renal tissue
properties, e.g., from a human tissue database, accurate human
anatomical modeling (stereolithographic prototyping) and color
mapping to create realistic internal features such as the
endoluminal ureter and the calyceal kidney collecting system. The
model can be used in combination with artificial kidney stones and
fluid to simulate procedures such as a ureteroscopy (FIG. 9),
retrograde pyelography, ureteral stent placement, nephro-lithotomy,
laser and extracorporeal lithotripsy and kidney stone
extraction.
[0095] In conclusion, the overall method for developing artificial
tissue simulators for training purposes provides accurate
anatomical modeling and matching of tissue properties. The
materials and fabrication techniques are cost-effective and allow
for the integration of indicators to properly evaluate trainee
skill acquisition. The resulting tissue simulators can be applied
to countless tissue types and training strategies to improve
patient care through better procedural practice and assessment.
TABLE-US-00002 TABLE 1 Organosilicate base materials Type Category
Company Product Trade Name Bases Tin Smooth ON Mold Max Series
Cured Smooth on Mold Max T-series Silicone Smooth on Mold Max
STROKE Rubber Smooth on Mold Max XLS II Smooth on OOMOO Series
Polytek TinSil 70& 80 Series, Dow Corning Silastic Series
Silicones, Inc. Gl-650, 384, 1000, 1032, 1040, 1100, 1120, 1210,
1220, 184 Silicones, Inc. XT 153, 177, 314, 385, 386, 426, 464,
475, 479, 493, 585 Platinum Smooth on Mold Star 15, 16, and 30
Based Smooth on Smooth-Sil Silicon Smooth on Dragon Skin Series
(incl Fx Pro) Rubbers Smooth on Ecoflex Series Smooth on Rebound 25
and 40 Smooth on Sorta Clear Smooth on Body Double Smooth on Skin
Tite Smooth on Psycho Paint Polytek Platsil Series 71, 73, and Gels
Dow Corning Silastic Series Dow Corning Xiameter Series Silicones,
Inc. P series (incl.656, FDA, 157, 125, 100, 90, 70, 60, 50, 45,
44, 20, 17, 15, 4, 10, 1 49, 163, 268, 288) Silicones, Inc. XP
series (incl.149, 163, 288, 344, 368, 378, 382, 429, 450, 536, 541,
549, 550, 573, 657) NuSil LSR elastomers (Med 4805, 4810, 4815,
4820, 4830, 4840, 4842, 4714, 4905, 4900 Series, 50/5800 series)
NuSil VersaSil (Med4032) NuSil Optical Elastomers (LS-1200 and
LS-3200/3300series) Artmolds.com LifeRite Series Artmolds.com
MoldRite Series (25) Artmolds.com SkinRite Series (10 Renew
Silicone (00-30/50, 5, 10, 20 replicator) Primasil Sil 100 &
400 series Alumilite High Strength 2 & 3 3M Impregum,
Soft/DuoSoft Polyethers 3M Imprint 3, Express 2 VPS, (3M ESPE
series) Urethane Smooth on Clear Flex 50 & 95 Rubber Smooth on
Renew UR 40, 60, 80, 90
TABLE-US-00003 TABLE 2 Additives Foams Rigid and Smooth on Foam-it
3, 5, 8, 10, 15, 26 Flexible Smooth on Foam-iT III,, V, X, 17, 25
Foam Smooth on Soma Foama-15 Renew Rigid Foam 10, Flexible foam 10,
25 Additives Silicone Smooth on Ti-Vex Silicone Thickener Rubber
& Smoothon Silicone Thinner Urethane Smooth on Cryptolyte
Accessories Smooth on Slacker - deadener Smooth on URE-FIL 9
Polytek TinThix Polytek PolyFiber II Polytek Fumed Silica Polytek
Polyfil ND Artmolds.com ThickRITE Coloring Smooth on So-Strong
Color Tints Smooth on Ignite - Flourescent Pigments Smooth on
Sil-Pig - Silicone Pigments Artmolds.com Cirius Paint Series
Artmolds.com Cirius Pigment Series NuSil Med Series (4102, 4502,
4800, 4900) through Gayson Silicon Dispersions, Inc. (GSDI)
[0096] To illustrate the methods and tissue models disclosed in the
present application, a non-limiting list of example Embodiments is
provided here:
[0097] Embodiment 1 can include subject matter (such as an
apparatus, a device, a method, or one or more means for performing
acts), such as can include a method of developing a tissue model.
The subject matter can include determining material properties of a
tissue, wherein the material properties include at least one of
viscoelastic mechanical properties, electroconductive properties,
anisotropic, thermoconductive properties, reflectivity, and color
of the tissue, creating an anatomical structure of the tissue, and
coupling an artificial tissue material to the anatomical structure,
wherein the artificial tissue material has properties corresponding
to the material properties of the tissue.
[0098] Embodiment 2 can include, or can optionally be combined with
the subject matter of Embodiment 1, to optionally include the
material properties being determined from a tissue database.
[0099] Embodiment 3 can include, or can optionally be combined with
the subject matter of one or any combination of Embodiments 1 or 2,
to optionally include the tissue database being a human tissue
database.
[0100] Embodiment 4 can include, or can optionally be combined with
the subject matter of one or any combination of Embodiments 1-3, to
optionally include the human tissue database being generated by
harvesting soft tissue specimens from a human, determining at least
one of viscoelastic mechanical properties, electroconductive
properties, and thermoconductive properties of the soft tissue, and
stratifying data according to gender, age, and body mass index.
[0101] Embodiment 5 can include, or can optionally be combined with
the subject matter of one or any combination of Embodiments 1-4, to
optionally include the harvesting the soft tissue specimens from a
human comprises harvesting the soft tissue within 24 hours of the
death of a deceased human.
[0102] Embodiment 6 can include, or can optionally be combined with
the subject matter of one or any combination of Embodiments 1-5, to
optionally include the viscoelastic mechanical properties being
determined by a uniaxial or a biaxial testing of the soft
tissue.
[0103] Embodiment 7 can include, or can optionally be combined with
the subject matter of one or any combination of Embodiments 1-6, to
optionally include the creating of the anatomical structure
comprising forming a three-dimensional model of the tissue.
[0104] Embodiment 8 can include, or can optionally be combined with
the subject matter of one or any combination of Embodiments 1-7, to
optionally include the forming of the three-dimensional model
comprising three-dimensional printing of the three-dimensional
model.
[0105] Embodiment 9 can include, or can optionally be combined with
the subject matter of one or any combination of Embodiments 1-8, to
optionally include the creating of the anatomical structure
comprising casting the anatomical structure.
[0106] Embodiment 10 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-9, to optionally include the creating of the anatomical structure
comprising collecting computer tomography or magnetic resonance
imaging datasets of the tissue.
[0107] Embodiment 11 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-10, to optionally include the creating of the anatomical
structure comprising processing at least one of computer tomography
or magnetic resonance imaging images of the tissue through a
composite software to generate imaging stack data, refining the
stack data through image segmentation software, creating a virtual
three-dimensional anatomical structure of the tissue based on the
refined stack data, and printing the virtual three-dimensional
anatomical structure using stereolithographic techniques to produce
a three-dimensional printed model of the anatomical structure.
[0108] Embodiment 12 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-11, to optionally include the creating of the virtual
three-dimensional anatomical structure comprising creating a coarse
three-dimensional model of the anatomical structure based on the
refined stack data, and refining the coarse three-dimensional model
to generate the virtual three-dimensional anatomical structure of
the tissue.
[0109] Embodiment 13 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-12, to optionally include the coupling of the artificial tissue
material comprising applying a base material of the artificial
tissue material on the anatomical structure.
[0110] Embodiment 14 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-13, to optionally include the applying of the base material
comprising at least one of casting, machining or molding of the
base material onto the anatomical structure.
[0111] Embodiment 15 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-14, to optionally include the base material being an
organosilicate.
[0112] Embodiment 16 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-15, to optionally include the applying of the base material
comprising applying a plurality of layers of the base material.
[0113] Embodiment 17 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-16, to optionally include applying an indicator material to the
base material.
[0114] Embodiment 18 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-17, to optionally include the indicator material comprising an
ultraviolet sensitive material.
[0115] Embodiment 19 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-18, to optionally include the ultraviolent sensitive material
being transparent under normal light.
[0116] Embodiment 20 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-19, to optionally include the ultraviolet sensitive coating
comprising at least one of a polyurethane or a silicone.
[0117] Embodiment 21 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-20, to optionally include the applying of the indicator material
comprising applying the indicator material in at least one of a
line, a dot or a pattern.
[0118] Embodiment 22 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-21, to optionally include positioning a sensor on or within at
least one layer of the base material or between two or more layers
of the base material.
[0119] Embodiment 23 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-22, to optionally include the sensor comprising at least one of a
strain gauge, a capacitive diaphragm, an electromagnetic inductance
diaphragm, an optical strain detection sensor, a potentiometer
mechanism, a vibration sensor, an accelerometer, a dynamic switch
element, a piezoelectric sensor, a flow sensor, and a leak testing
pressure sensor.
[0120] Embodiment 24 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-23, to optionally include the sensor comprising a piezoresistive
fabric, the piezoelectric fabric being capable of detecting
deformation of the tissue model in response on contact with an
object.
[0121] Embodiment 25 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-24, to optionally include the sensor being configured to measure
tactile pressure on the tissue model with an object.
[0122] Embodiment 26 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-25, wherein the object is a surgical instrument or an organ.
[0123] Embodiment 27 can include, or can optionally be combined
with the subject matter of one or any combination of Examples 1-26,
to include subject matter (such as an apparatus, a device, a
method, or one or more means for performing acts), such as can
include a method of making an artificial tissue material. The
subject matter can include adding an additive to an organosilicate
material to form a mixture, and placing the mixture in a mold to
form a molded sample.
[0124] Embodiment 28 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-27, to optionally include coating the molded sample with a talcum
powder, and washing the sample with cold water to remove excess
talcum powder.
[0125] Embodiment 29 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-28, to optionally include the adding of an additive comprising
adding at least one of a silicone oil, petroleum jelly, glycerine,
baby oil, talcum powder, a color, a tint, a dye, a metal wire, a
dielectric wire, metal powders, a dielectric ink and a dielectric
coating.
[0126] Embodiment 30 can include, or can optionally be combined
with the subject matter of one or any combination of Examples 1-29,
to include subject matter (such as an apparatus, a device, a
method, or one or more means for performing acts), such as can
include a tissue model. The subject matter can include a
three-dimensional printed model, and an artificial tissue material
coupled to the three-dimensional printed model, wherein the
artificial tissue has properties corresponding to at least one of
viscoelastic mechanical properties of a tissue, electroconductive
properties of the tissue, and thermoconductive properties of the
tissue.
[0127] Embodiment 31 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-30, to optionally include the artificial tissue material
comprising an organosilicate base material.
[0128] Embodiment 32 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-31, to optionally include an indicator material applied to the
organosilicate base material.
[0129] Embodiment 33 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-32, to optionally include the indicator material comprising an
ultraviolet light sensitive material.
[0130] Embodiment 34 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-33, to optionally include the ultraviolet light sensitive
material being transparent under normal light.
[0131] Embodiment 35 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-34, to optionally include the tissue comprising at least one of
fat, connective tissues, nerve, artery, vein, muscle, tendon,
ligaments, renal artery tissue, kidney tissue, ureter tissue,
bladder tissue, prostate tissue, urethra tissue, bleeding aorta
tissue, pyeloplasty tissue, Y/V plasty tissue, airway tissue,
tongue tissue, complete hand tissue, general skin tissue, specific
face skin tissue, eye tissue, brain tissue, vaginal wall, breast
tissue, nasal tissue, cartilage, colon tissue, stomach tissue,
liver tissue, rectum, and heart tissue, bowel tissue, pancreas
tissue, gallbladder tissue, liver tissue, inferior vena cava,
aorta, lung tissue, bronchial tissue, soft palate tissue, larynx
tissue, pharynx tissue, epidermis tissue, dermis tissue, lip
tissue, mucosal membrane tissue and adhesion tissue.
[0132] Embodiment 36 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-35, to optionally include at least one sensor configured to
measure a deformation of the artificial tissue material.
[0133] Embodiment 37 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-36, to optionally include the at least one sensor comprising at
least one of a strain gauge, a capacitive diaphragm, an
electromagnetic inductance diaphragm, an optical strain detection
sensor, a potentiometer mechanism, a vibration sensor, an
accelerometer, a dynamic switch element, and a piezoelectric
sensor.
[0134] Embodiment 38 can include, or can optionally be combined
with the subject matter of one or any combination of Examples 1-37,
to include subject matter (such as an apparatus, a device, a
method, or one or more means for performing acts), such as can
include a tissue model. The subject matter can include a
three-dimensional printed model, an artificial tissue material
coupled to the three-dimensional printed model, wherein the
artificial tissue has properties corresponding to at least one of
viscoelastic mechanical properties of a tissue, electroconductive
properties of the tissue, and thermoconductive properties of the
tissue, and an indicator material applied to the artificial tissue
material.
[0135] Embodiment 39 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-38, to optionally include the indicator material comprising at
least one of a photochromic material, a thermochromic material, a
solvatochromic material, or a piezochromic material.
[0136] Embodiment 40 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-39, to optionally include the indicator material comprising a
light-sensitive material that changes color under light having a
first wavelength range.
[0137] Embodiment 41 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-40, to optionally include the light-sensitive material being
transparent under light having a wavelength in a visible-light
range.
[0138] Embodiment 42 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-41, to optionally include the first wavelength range being in an
ultraviolet wavelength range.
[0139] Embodiment 43 can include, or can optionally be combined
with the subject matter of one or any combination of Embodiments
1-42, to optionally include the indicator material being applied in
a pattern configured to indicate or determine performance of a
predetermined task.
[0140] The above detailed description includes references to the
accompanying drawings, which form a part of the detailed
description. The drawings show, by way of illustration, specific
embodiments in which the invention can be practiced. These
embodiments are also referred to herein as "examples." Such
examples can include elements in addition to those shown or
described. However, the present inventors also contemplate examples
in which only those elements shown or described are provided.
Moreover, the present inventors also contemplate examples using any
combination or permutation of those elements shown or described (or
one or more aspects thereof), either with respect to a particular
example (or one or more aspects thereof), or with respect to other
examples (or one or more aspects thereof) shown or described
herein.
[0141] In the event of inconsistent usages between this document
and any documents so incorporated by reference, the usage in this
document controls.
[0142] In this document, the terms "a" or "an" are used, as is
common in patent documents, to include one or more than one,
independent of any other instances or usages of "at least one" or
"one or more." In this document, the term "or" is used to refer to
a nonexclusive or, such that "A or B" includes "A but not B," "B
but not A," and "A and B," unless otherwise indicated. In this
document, the terms "including" and "in which" are used as the
plain-English equivalents of the respective terms "comprising" and
"wherein." Also, in the following claims, the terms "including" and
"comprising" are open-ended, that is, a system, device, article,
composition, formulation, or process that includes elements in
addition to those listed after such a term in a claim are still
deemed to fall within the scope of that claim. Moreover, in the
following claims, the terms "first," "second," and "third," etc.
are used merely as labels, and are not intended to impose numerical
requirements on their objects.
[0143] Method examples described herein can be machine or
computer-implemented at least in part. Some examples can include a
computer-readable medium or machine-readable medium encoded with
instructions operable to configure an electronic device to perform
methods as described in the above examples. An implementation of
such methods can include code, such as microcode, assembly language
code, a higher-level language code, or the like. Such code can
include computer readable instructions for performing various
methods. The code may form portions of computer program products.
Further, in an example, the code can be tangibly stored on one or
more volatile, non-transitory, or non-volatile tangible
computer-readable media, such as during execution or at other
times. Examples of these tangible computer-readable media can
include, but are not limited to, hard disks, removable magnetic
disks, removable optical disks (e.g., compact disks and digital
video disks), magnetic cassettes, memory cards or sticks, random
access memories (RAMS), read only memories (ROMs), and the
like.
[0144] The above description is intended to be illustrative, and
not restrictive. For example, the above-described examples (or one
or more aspects thereof) may be used in combination with each
other. Other embodiments can be used, such as by one of ordinary
skill in the art upon reviewing the above description. The Abstract
is provided to comply with 37 C.F.R. .sctn. 1.72(b), to allow the
reader to quickly ascertain the nature of the technical disclosure.
It is submitted with the understanding that it will not be used to
interpret or limit the scope or meaning of the claims. Also, in the
above Detailed Description, various features may be grouped
together to streamline the disclosure. This should not be
interpreted as intending that an unclaimed disclosed feature is
essential to any claim. Rather, inventive subject matter may lie in
less than all features of a particular disclosed embodiment. Thus,
the following claims are hereby incorporated into the Detailed
Description as examples or embodiments, with each claim standing on
its own as a separate embodiment, and it is contemplated that such
embodiments can be combined with each other in various combinations
or permutations. The scope of the invention should be determined
with reference to the appended claims, along with the full scope of
equivalents to which such claims are entitled.
* * * * *