U.S. patent application number 16/296959 was filed with the patent office on 2019-07-04 for cardiac simulation device.
The applicant listed for this patent is Vascular Simulations, Inc.. Invention is credited to Gary Bunch, David Jeffrey Carson, David Fiorella, Baruch B. Lieber, Michael Romeo, Chandramouli Sadasivan, Henry Woo.
Application Number | 20190206283 16/296959 |
Document ID | / |
Family ID | 55167173 |
Filed Date | 2019-07-04 |
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United States Patent
Application |
20190206283 |
Kind Code |
A1 |
Carson; David Jeffrey ; et
al. |
July 4, 2019 |
CARDIAC SIMULATION DEVICE
Abstract
The present invention describes a device and system for
simulating normal and disease state cardiovascular functioning,
including an anatomically accurate left cardiac simulator for
training and medical device testing. The system and device uses
pneumatically pressurized chambers to generate ventricle and atrium
contractions. In conjunction with the interaction of synthetic
valves which simulate mitral and aortic valves, the system is
designed to generate pumping action that produces accurate volume
fractions and pressure gradients of pulsatile flow, duplicating
that of a human heart. Through the use of a control unit and
sensors, one or more parameters such as flow rates, fluidic
pressure, and heart rate may be automatically controlled, using
feedback loop mechanisms to adjust parameters of the hydraulic
system to simulate a wide variety of cardiovascular conditions
including normal heart function, severely diseased or injured heart
conditions, and compressed vasculature, such as hardening of the
arteries.
Inventors: |
Carson; David Jeffrey;
(Stuart, FL) ; Lieber; Baruch B.; (Aventura,
FL) ; Sadasivan; Chandramouli; (Wilmington, DE)
; Fiorella; David; (East Setauket, NY) ; Woo;
Henry; (Setauket, NY) ; Romeo; Michael; (Port
St. Lucie, FL) ; Bunch; Gary; (Northport,
NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Vascular Simulations, Inc. |
Wilmington |
DE |
US |
|
|
Family ID: |
55167173 |
Appl. No.: |
16/296959 |
Filed: |
March 8, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14815629 |
Jul 31, 2015 |
10229615 |
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16296959 |
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13363251 |
Jan 31, 2012 |
9183763 |
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14815629 |
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62031628 |
Jul 31, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G09B 23/28 20130101;
G09B 23/288 20130101; G09B 23/32 20130101; G09B 23/30 20130101;
G09B 23/303 20130101 |
International
Class: |
G09B 23/30 20060101
G09B023/30; G09B 23/32 20060101 G09B023/32; G09B 23/28 20060101
G09B023/28 |
Claims
1. A cardiovascular simulator system comprising: a cardiac system
module for simulating cardiac functioning of a patient atrium
assembly for simulating blood flow through an atrium of a heart
comprising a rigid outer casing sized and shaped to house a
pressurized air delivery device therein and fluidly connected to a
flexible, fluid filled inner chamber, said flexible, fluid filled
inner chamber constructed and arranged to contract when a
pressurized fluid is exerted thereupon, thereby causing said fluid
stored within to be ejected out, and expand when said pressurized
fluid is removed, and a ventricle assembly for simulating blood
flow through a ventricle of a heart comprising an irregularly
shaped, flexible ventricle assembly inner member having said fluid
stored within and surrounded by a rigid ventricle assembly outer
member, said ventricle assembly inner member and said rigid
ventricle assembly outer member being separated by a space
therebetween, whereby pressurized fluid inserted within said space
exerts a force upon said flexible ventricle assembly inner member
causing said flexible ventricle assembly inner member to eject said
fluid stored within; a vasculature system module comprising at
least one tubing adapted to have characteristics of a human artery
or vein and fluidly connected to at least a portion of said cardiac
system module; a pneumatic supply system fluidly connected to at
least a portion of said atrium assembly and to at least a portion
of said ventricle assembly; a fluid reservoir configured to receive
said fluid therein; a compliance chamber; and a control unit
operatively coupled to at least one or more pressure sensors or
flow sensors operatively coupled to at least one component of said
cardiac system module, said vasculature system module, said
pneumatic supply system, said fluid reservoir, or said compliance
chamber; said control unit configured to control or modify one or
more operational parameters of said cardiovascular simulator system
via feedback loop systems; said cardiovascular simulator system
providing an anatomically and physiologically accurate
representation of a cardiovascular system in normal or diseased
states whereby said one or more operational parameters are
automatically controlled without the need for manual
adjustments.
2. The cardiovascular simulator system according to claim 1 further
including at least one resistance valve configured to adjust the
flow rate of a fluid within said system.
3. The cardiovascular simulator system according to claim 2 wherein
said at least one resistance valve is an electrically adjustable
fluid valve.
4. The cardiovascular simulator system according to according to
claim 1 wherein said control unit is configured to control the
timing or speed of generation of pressurized air within said
system.
5. The cardiovascular simulator system according to according to
claim 4 where said vasculature system module comprises at least one
tubing adapted to have characteristics of a human or other mammal
artery or vein and fluidly connected to at least a portion of said
cardiac system module.
6. The cardiovascular simulator system according to according to
claim 1 further including a head module, said head module
comprising a plurality of tubing suspended in a gel like material
and fluidly connected to said cardiac system module or vasculature
system module.
7. The cardiovascular simulator system according to according to
claim 6 further including at least one resistance valve configured
to adjust the flow rate of said fluid entering said head
module.
8. The cardiovascular simulator system according to claim 1 further
including at least one flow meter configured for converting
volumetric flow rate of a fluid not associated with a head region
to an electrical signal or at least one flow meter configured for
converting volumetric flow rate of fluid associated with said head
region to an electrical signal.
9. The cardiovascular simulator system according to claim 1 further
comprising a heating device configured to heat a fluid within said
system.
10. The cardiovascular simulator system according to claim 1
wherein said fluid is adapted to have characteristics of blood.
11. The cardiovascular simulator system according to claim 1
further comprising a computer device operatively connected to said
control unit.
12. The cardiovascular simulator system according to claim 11
wherein said computer device is wirelessly linked to said control
unit.
13. The cardiovascular simulator system according to claim 1
wherein said flexible atrium assembly inner member is anatomically
modeled after an atrium of a patient.
14. The cardiovascular simulator system according to claim 1
wherein said flexible ventricle assembly inner member is
anatomically modeled after a ventricle of a patient.
Description
FIELD OF THE INVENTION
[0001] In accordance with 37 C.F.R 1.76, a claim of priority is
included in an Application Data Sheet filed concurrently herewith.
Accordingly, the present application is a divisional to U.S. patent
application Ser. No. 14/815,629, filed on Jul. 31, 2015, entitled
"Cardiac Simulation Device" now U.S. Pat. No. 10,229,615, issued
Mar. 12, 2019, which claims priority as a continuation-in-part to
U.S. patent application Ser. No. 13/363,251, filed on Jan. 31,
2012, entitled, "CARDIAC SIMULATION DEVICE" now U.S. Pat. No.
9,183,763, issued Nov. 10, 2015, and claims priority to U.S.
Provisional Patent Application No. 62/031,628, filed on Jul. 31,
2014, entitled, "CARDIAC SIMULATION DEVICE." The contents of each
of the above referenced applications or patents are herein
incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates to a surgical simulation system,
particularly to a cardiovascular simulation system; to a device and
system for simulating normal and disease state cardiac and
cardiovascular functioning, including an anatomically accurate left
cardiac simulator for training and medical device testing; and more
particularly to a device and system for simulating normal and
disease state cardiac and cardiovascular functioning which uses
sensors and other control mechanisms to automatically adjust
hydraulic and/or pneumatic components of the system to achieve
physiologically representative pressure and flow profiles through
the heart and major arteries.
BACKGROUND OF THE INVENTION
[0003] Cardiovascular disease, diseases affecting the heart and the
vasculature, and vascular disease, diseases affecting the
circulatory system, are prevalent conditions affecting millions of
individuals across the globe. While vasculature disease may
manifest in the hardening of arterial walls at a specific location,
such disease state affects every organ in the human body. Several
options exist to alleviate or minimize the risk associated with
prolonged vasculature disease states. Depending on the severity,
changes in life style, i.e. diet and increased exercise, or the use
of drugs may be helpful. Where these options will not work or where
the disease is severe, surgical intervention remains the primary
treatment tool. Traditional surgical procedures have been steadily
replaced with more minimally invasive endovascular techniques, and
such minimally invasive advances in endovascular technology are
altering the way surgeons treat vascular diseases.
[0004] While vascular surgical procedures are safer than ever,
complex vascular surgical procedures can result in collateral
damage to the patient. While no surgery is without risk, the level
of skill of the surgeon and his/her team, as well as the ability to
minimize unforeseen surprises when performing the surgical
procedure is paramount to preventing complications and/or death to
the patient. Experienced surgeons having performed numerous
vascular disease procedures are much more likely to complete such
surgical procedures with fewer complications than those surgeons
having less experience. While such experience is gained by training
and performing numerous procedures, the number of surgical
procedures available is a limiting factor. Accordingly, not every
surgeon will have the same opportunity to perform the number of
surgical procedures needed to obtain a skill level that minimizes
the risks of the procedures undertaken. Moreover, as new procedures
are developed, senior surgeons may find it difficult to obtain the
necessary experience needed.
[0005] Training devices for practicing various surgical procedures
have been used by surgeons to improve skills and are known in the
art. For example, U.S. Pat. Nos. 8,016,598, 7,976,313, and
7,976,312 describe patient simulator systems for teaching patient
care. U.S. Pat. No. 7,798,815 discloses an electromechanical
pumping system for simulating the beating of a heart in a cardiac
surgery training environment. U.S. Pat. No. 7,866,983 discloses a
surgical simulator for teaching, practicing, and evaluating
surgical techniques. The simulator is described as comprising a
cassette of organs, blood vessels, and tissues that may be
disposable.
[0006] U.S. Pat. No. 7,083,418 discloses a model for teaching or
illustrating surgical and/or medical technique. The system is
described as having a base component representing tissue or an
organ, and several components structured and arranged to be
coupleable to and detachable from the base component and/or to each
other, to illustrate different positions of the components with
respect to one another, representing different phases in surgical
and/or medical techniques.
[0007] U.S. Pat. No. 7,063,942 discloses a system for hemodynamic
simulation. The system is described as comprising a vessel having
properties of a blood vessel, a reservoir containing a quantity of
fluid, tubing connecting the vessel and reservoir, and at least one
pump for circulating the fluid within the system.
[0008] U.S. Pat. No. 6,843,145 discloses a cardiac phantom for
simulating a dynamic cardiac ventricle. The phantom is described as
comprising two concentrically-disposed, fluid-tight, flexible
membranes defining a closed space between the walls of the
membranes.
[0009] U.S. Pat. No. 6,685,481 discloses a training device for
cardiac surgery and other similar procedures. The device is
described as including an organ model such as a cardiac model, an
animation network adapted to impart to the model a motion similar
to the corresponding natural organ, and a control device used to
control the operation of the animation network. The cardiac model
is described as being made of two sections, an inner cast
simulating the myocardium and an external shell simulating the
pericardium.
[0010] U.S. Pat. No. 5,052,934 discloses an apparatus to serve as a
phantom for evaluation of prosthetic valves and cardiac ultrasound
procedures, wherein a controlled pulsatile flow of a
blood-mimicking fluid is passed through a multi-chambered region
into which are mounted mitral and aortic valves and adjustably
positionable ultrasound transducers.
[0011] While such training devices are known in the art, the device
and system for simulating normal and disease state
cardiovasculature functioning in accordance with the present
invention provides a training tool that is not only more
anatomically correct than prior art devices, but also provides
physiologically correct pressure and flow profiles in the major
arteries of the cardiovascular system; the profiles of which differ
at various arterial locations at the same instant throughout the
cardiovascular system as thought, for example, by Cooney
(Biomedical Engineering Principles--An Introduction to Fluid, Heat,
and Mass Transport Processes, by David Cooney, Marcel Dekker, Inc.
1976 pp. 76-80). To achieve correct physiological pressure and
flow, the heart and the vasculature have to work in unison
(Hemodynamics, William R. Milnor, Williams & Wilkins 1989 pp.
290-293); geometrical landmarks, such as major bifurcations, have
to be placed at appropriate distances from the pumping heart, and
the elasticity of the arteries has to represent that of the actual
vessels (Hemodynamics, William R. Milnor, Williams & Wilkins
1989 pp. 225-259). Furthermore, the implemented control mechanism
provides automatic adjustment of one or more functioning elements,
i.e. resistance valves or compliance chambers, to provide more
accurate and representative pressure and fluid flow profiles,
thereby providing a mechanism to reduce collateral damage
associated with cardiovasculature procedures.
SUMMARY OF THE INVENTION
[0012] The present invention describes a device and system for
simulating normal and disease state cardiac and vascular
functioning, including anatomically accurate elements, i.e. left
heart and blood vessels, for training and medical device testing.
The system and device uses pneumatically pressurized chambers to
generate ventricle and atrium contractions. In conjunction with the
interaction of synthetic mitral and aortic valves, the system is
designed to generate pumping action that produces accurate volume
fractions and pressure gradients of pulsatile flow, duplicating
that of a human heart. The present system further uses one or more
sensors or meters to monitor and/or change one or more
characteristics of the system. For example, various sensors are
used to control or provide proper representations of systolic
and/or diastolic pressures as desired. Flow meters for determining
and/or modifying flow rates throughout the system may be utilized
as well. As such, one or more feedback loops are used to adjust
such characteristics, thereby allowing for a more accurate
representation of the circulatory system. One or more control units
or components are provided for controlling the overall functioning
of the system. By providing a control unit that automatically
changes one or more functioning components of the system, pressure
and flow profiles can be generated without the need of manual
adjustment.
[0013] The cardiovasculature training and evaluation simulator
system and device suitable for training and testing medical devices
is adapted to provide an anatomically and physiologically accurate
representation of a cardiovasculature system in normal or diseased
states. In an illustrative embodiment, the system comprises a
pneumatically driven cardiac module for simulating cardiac
functioning of a patient, a vasculature system module fluidly
connected to the cardiac module and adapted for simulating the
vasculature of a patient, and a control component operatively
coupled to the cardiac module and the vasculature system module.
The cardiac module comprises an atrium assembly for simulating an
atrium of a heart and a ventricle assembly for simulating a
ventricle of a heart. The cardiac module is adapted to operate by
air pressure, independently acting on components that represent the
left ventricle and atrium. Alternatively, the cardiac module may
simply contain one or more pumps. A control unit controls or
modifies one or more operational parameters of the system,
including heart rate, ejection fraction, systemic vascular
resistance and compliance and temperature. By modifying the systems
parameters, pathological hemodynamic states, including but not
limited to sepsis, hyperdynamic therapy with vasopressor agents, or
cardiac arrhythmias, such as atrial fibrillation or flutter, can be
recreated. The system may also contain replication of other body
components, preferably the cerebrovasculature.
[0014] The system and devices therefore provide a mechanism that
can be used to reduce collateral damage to patients undergoing
vascular surgeries resulting from surgeon inexperience or
inexperience with complex procedures. By providing a device that
replicates the heart and vasculature, the surgeon can perform
endovascular procedures prior to having to perform such procedures
on the actual patient. Device selection, placement, and
optimization can therefore be determined prior to actual surgery,
eliminating the risk associated with having to do such tasks during
a live procedure.
[0015] In one illustrative embodiment, a system for simulating the
cardiovascular system of a human or other mammal, in which one or
more operational parameters are automatically controlled without
the need for manual adjustments, comprises a control unit
operatively coupled to a closed loop pneumatic circuit configured
to simulate cardiovascular functioning of a human or other mammal
and a closed loop hydraulic circuit configured to simulate
cardiovascular functioning of a human or other mammal. The control
unit has one or more components configured to receive or process
data and cause at least one functional component to function based
on said data received or processed. At least one sensor is
configured to control one or more parameters of said closed loop
pneumatic circuit, or at least one sensor is configured to control
one or more parameters of the closed loop hydraulic circuit. The
control unit is configured to provide physiologically accurate
representation of a cardiovasculature system in normal or diseased
states whereby one or more operational parameters are automatically
controlled without the need for manual adjustments. The system may
also include a cardiac system module comprising an atrial actuator
and a ventricle actuator, a vasculature system module comprising at
least one tubing adapted to have characteristics of a human or
other mammal artery or vein and fluidly connected to at least a
portion of said cardiac system module, and a head region. A fluid
reservoir and compliance chamber may also be utilized.
[0016] Accordingly, it is a primary objective of the present
invention to provide a device and system for simulating normal and
disease state cardiac and cardiovascular functioning.
[0017] It is a further objective of the present invention to
provide a device and system for simulating normal and disease state
cardiovascular functioning including an anatomically accurate
cardiac and cardiovascular simulator for training and medical
device testing.
[0018] It is yet another objective of the present invention to
provide a device and system for simulating normal and disease state
cardiovascular functioning designed to generate pumping action that
produces accurate volume fractions duplicating that of a heart.
[0019] It is a further objective of the present invention to
provide a device and system for simulating normal and disease state
cardiovascular functioning designed to provide pressure gradients
of pulsatile flow that duplicates that of a heart and/or vascular
elements.
[0020] It is yet another objective of the present invention to
provide a device and system for simulating normal and disease state
cardiovascular function which controls air pressure level, fluid
pressure, and heart rate, thereby inducing contractions that
simulate a wide variety of heart conditions.
[0021] It is a still further objective of the invention to provide
a device and system for simulating normal cardiovascular
functioning which controls air pressure level, fluid pressure, and
heart rate to induce contractions that simulate a wide variety of
heart conditions having normal heart functions.
[0022] It is a further objective of the present invention to
provide a device and system for simulating disease state
cardiovascular functioning which controls air pressure level, fluid
pressure, and heart rate to induce contractions that simulate a
wide variety of heart conditions having diseased or injured heart
conditions.
[0023] It is a further objective of the present invention to
provide a training and evaluation simulator system and device
suitable for training and testing medical devices which is adapted
to provide an anatomically and physiologically accurate
representation of a cardiovasculature system in normal or diseased
states.
[0024] It is yet another objective of the present invention to
provide a training and evaluation simulator system and device
having a control module adapted for controlling or modifying one or
more operational parameters of the system, including heart rate,
temperature of the fluid such as a blood analog fluid, ejection
fraction, systemic vascular resistance and compliance.
[0025] It is a still further objective of the invention to provide
a training and evaluation simulator system and device in which
pathological hemodynamic states, including but not limited to
sepsis, hyperdynamic therapy with vasopressor agents, or cardiac
arrhythmias, such as atrial fibrillation or flutter can be
recreated.
[0026] It is a further objective of the present invention to
provide a training and evaluation simulator system and device which
allows a surgeon to perform endovascular procedures prior to having
to perform such procedures on the actual patient.
[0027] It is yet another objective of the present invention to
provide a training and evaluation simulator system and device which
allows a surgeon to determine device selection, placement, and
optimization prior to actual surgery, eliminating the risk
associated with having to do so during a live procedure.
[0028] It is a further objective of the present invention to
provide a device and system for simulating normal and disease state
cardiovascular function which utilizes feedback control mechanisms
to achieve physiological representative biological profiles.
[0029] It is a further objective of the present invention to
provide a device and system for simulating normal and disease state
cardiovascular function which utilizes systems to automatically
adjust fluidic elements to achieve physiological representative
biological profiles.
[0030] It is a further objective of the present invention to
provide a device and system for simulating normal and disease state
cardiovascular function which utilizes systems to automatically
control flow of fluid via pumping mechanisms to achieve
physiological representative biological profiles.
[0031] It is a further objective of the present invention to
provide a device and system for simulating normal and disease state
cardiovascular function which utilizes feedback control and
automatic adjustment of fluidic elements and pump control to
achieve physiologically representative temperature, pressure and
flow profiles.
[0032] It is a further objective of the present invention to
provide a control unit for controlling a cardiovascular simulation
device using closed loop pneumatic and hydraulic circuits.
[0033] It is a further objective of the present invention to
provide a control unit operatively coupled to a closed loop
pneumatic circuit configured to simulate cardiovascular functioning
of a human or other mammal and a closed loop hydraulic circuit
configured to simulate cardiovascular functioning of a human or
other mammal, where the control unit contains one or more
components for receiving or processing data and for causing at
least one functional component of a cardiovascular simulation
device or system to function based on said data received or
processed.
[0034] It is a further objective of the present invention to
provide a system or device for simulating the cardiovascular system
of a human in which one or more operational parameters are
automatically controlled without the need for manual
adjustments
[0035] Other objectives and advantages of this invention will
become apparent from the following description taken in conjunction
with any accompanying drawings wherein are set forth, by way of
illustration and example, certain embodiments of this invention.
Any drawings contained herein constitute a part of this
specification and include exemplary embodiments of the present
invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE FIGURES
[0036] FIG. 1 is a block diagram of the hydraulic circuit of the
simulator system in accordance with an illustrative example of the
present invention;
[0037] FIG. 2 is a block diagram as shown in FIG. 1 including the
pneumatic circuit of the simulator system in accordance with an
illustrative example of the present invention;
[0038] FIG. 3A is a block diagram as shown in FIG. 2 including the
electronic circuitry of the simulator system in accordance with an
illustrative example of the present invention;
[0039] FIG. 3B is a block diagram showing an illustrative example
of the present invention using a pump to represent the cardiac
module;
[0040] FIG. 4 is a partial perspective view of the cardiac
simulator module and ventricular module;
[0041] FIG. 5 is a partial cross-sectional view taken along lines
5A-5A of FIG. 4, showing an aortic valve and aortic arch;
[0042] FIG. 6 is a partial cross-sectional view taken along lines
6A-6A of FIG. 4 showing the atrial compression mechanism, the
atrial chamber, and the mitral valve;
[0043] FIG. 7 is a back view of the cardiac simulator module
illustrating the ventricular compression chamber, the aortic arch,
and the atrial compression mechanism;
[0044] FIG. 8 is an exploded view of the cardiac simulator
module;
[0045] FIG. 9 is a side view of one embodiment of the ventricle and
ventricle compression chamber;
[0046] FIG. 10 is an alternative embodiment of the ventricular
chamber and ventricle compression chamber;
[0047] FIG. 11 is a perspective view of an illustrative example of
the head unit;
[0048] FIG. 12 is a perspective view of the head unit shown in FIG.
11, shown with cerebrovasculature;
[0049] FIG. 13 illustrates a gas charged accumulator;
[0050] FIG. 14 illustrates a gas charged piston accumulator;
[0051] FIG. 15 illustrates a spring-loaded piston accumulator;
and
[0052] FIG. 16 illustrates an embodiment of the cardiovascular
simulator system.
DETAILED DESCRIPTION OF THE INVENTION
[0053] Referring to FIGS. 1-3, schematic block diagrams of the
simulator system, generally referred to as a cardiovascular
simulator system 10, are illustrated. The cardiovascular simulator
system 10 is illustrated and described as a cardiovascular system.
However, the simulator system is not limited to the cardiovascular
system and can be adapted to replicate other systems. The
cardiovascular simulator system 10 comprises one or more modules,
including a hardware component module and an anatomical component
module. The hardware component module and the anatomical component
module interact in a manner to provide a system which is an
anatomically and functionally accurate replication of a body
system, i.e. a cardiac and/or vasculature system. Providing such an
anatomically correct system provides the user a unique tool to
practice and train for various surgical procedures and/or
techniques prior to having to perform such actions on a living
system. While such system will be described using human anatomy and
systems, the vascular simulator system in accordance with the
instant invention can be adapted to replicate or model other
organism systems such as other mammals, including domesticated
animals such as dogs and cats, rodents such as mice and rats,
livestock such as cattle, horses, sheep, swine/porcine, or wild
animals such as lions or tigers.
[0054] Both the hardware component module, referred to generally as
1000 and the anatomical module, referred to generally as 2000,
further contain sub-modules. The sub-modules comprise individual
components that drive the system and/or provide accurate structural
and functional replication of a living system. As will be described
in greater detail, the hardware component module 1000 contains one
or more sub-modules including a pneumatics component, a hydraulics
component, and a control/electronics component. The cardiovascular
simulator system 10 is designed to include one or more feedback
loops configured to provide accurate and automatic representation
of several important components or characteristics of the system,
i.e. physiologically representative operation of the
cardiovasculature and cerebrovasculature, including flow rate and
valve operations. The control unit contains the necessary hardware
and monitoring devices to provide automatic manipulation of the
system to provide predetermined characteristics of blood flow or
pressure. The control unit may include pressure sensors, to
represent arterial and venous pressure, and/or flow sensors to
represents cephalic and thoracic flow in order to monitor and
provide physiological values of pressure and flow within the
system. Information obtained from the pressure and flow sensors are
used as part of feedback control mechanisms to achieve
physiologically representative characteristics. One or more valves
may also be used to provide control of fluid flow in the system.
The anatomical module 2000, illustrated herein as a
cardiovasculature system, is primarily made up of three
sub-modules, including a cardiac simulator module 2100, a
vasculature simulator module 2200, and one or more peripheral
organ/systems simulator module 2300.
[0055] The cardiac module 2100 is configured to be a replica of the
left half of the human heart. Air pressure drives the functioning
of the components of the cardiac module 2100. In this aspect, fluid
flow within and out of the cardiac module 2100 may be controlled,
using the control unit 130, by the timing of air pressure
application and by the speed of a pressurized air generating
device, such as an air compressor. Control and/or manipulation of
the air pressure application timing and the speed of a pressurized
air generating device is a result of measuring and monitoring
values as part of a feedback system. Feedback control loops may
also be used for other functional aspects of the cardiovascular
simulator system 10. For example, fluid pumps, such as motor driven
pumps, used to drive fluid flow within the system can be
manipulated, i.e. speed profiles modified, in response to feedback
information from any sensors or other monitoring devices.
[0056] As illustrated in FIGS. 1-3, and 16, the system is a closed
loop system designed to replicate the closed loop circulatory
system of a human or other animal. The cardiovascular simulator
system 10 includes a fluid reservoir (also known as a venous
chamber) 12 which is fluidly connected to a first portion of the
anatomical module 2000, a cardiac simulator module 2100. The fluid
reservoir or venous chamber 12 comprises a housing unit 14 which is
sized and shaped to receive and hold a fluid. Within the housing
unit 14, the fluid reservoir or venous chamber 12 may contain one
or more heating mechanisms, such as heating coils 15 that allow for
the fluid within the cardiovascular simulator system 10 to be
warmed to a predetermined temperature which corresponds to the
physiological fluid temperatures within a body. The fluid may be
any liquid that simulates blood. In an illustrative embodiment, the
fluid is a clear blood analog having properties which duplicate the
viscosity of human blood and mimics the friction coefficients as
endovascular devices, wires, and catheters traverse the vasculature
system. Alternatively, the fluid can be whole blood, or may simply
utilize water. Accordingly, any fluid can be used and modified to
have the viscosity and/or flow rate that is the same as or
approximates that of blood flow through veins or arteries. The
fluid could be clear, or may include a dye so that the fluid flow
can be visualized throughout the system. A fill cap 16 is used to
add a fluid, such as water, to the cardiovascular simulator system
10. The fluid reservoir or venous chamber 12 can be sealed and
pressurized to provide a baseline pressure, replicating the venous
pressure, to affect passive filling of the cardiac simulator module
2100. The top fluid reservoir or venous chamber 12 may contain
indictors, such as a gauge (not illustrated), or a window may be
utilized to provide visual confirmation of flow level.
Alternatively, a sensor may be used and coupled to the control unit
(control unit described later) to provide indications of high, low,
or appropriate fluid levels.
[0057] The cardiovascular simulator system 10 is designed to
replicate the blood flow from the left side of the heart out to
other parts of the body. As such, the cardiac simulator module 2100
could include pumps which are designed to push fluid out of the
module and into other components of the cardiovascular simulator
system 10, thereby replicating the flow of blood through the left
atrium and the left ventricle. Alternative to the use of simple
pumps, an embodiment of the cardiac simulator module 2100 which
includes replicas of the anatomy of the heart may be used, see
FIGS. 4-10. As illustrated in the figures, the cardiac simulator
module 2100 comprises several chambers representing the left side
of the heart, and includes an atrial actuator, illustrated herein
as a left atrium assembly 2108, and a ventricle actuator,
illustrated herein as a left ventricle assembly 2110. The atrium
and the ventricle may be molded using a standard size and shape.
Preferably, the present invention uses an atrium and a ventricle
that have been molded using Computer Tomography (CT Scan) imagery
of a heart as well as its vasculature. The left atrium assembly
2108 and left ventricle assembly 2110 can be molded to represent
the exact size and shape analogous to that of individual
patients.
[0058] The left atrium assembly 2108 pneumatically connects to the
pneumatics module, illustrated as a compressor 100 through tubing
17 and 19 (see FIG. 2). The pneumatics module contains the
necessary components to provide one or more modules of the
cardiovascular simulator system 10 with compressed air. The
compressed air generated allows one or more of the components of
the cardiac simulator module 2100, which is pneumatically connected
to the compressor 100, to compress and forcibly expel any
substance, such as liquid contained therein, out, as will be
described later. Accordingly, the air compressor acts to provide
the cardiac simulator module 2100 with accurate simulation of
cardio dynamic functions.
[0059] Pressurized air enters the left atrium assembly 2108 through
the atrium pneumatic-in connector 2111 which is coupled to an elbow
connection 2112 to tube barb 2114 for fitting to a tube, see FIG. 6
and FIG. 7. The left atrium assembly 2108 contains an outer air
pneumatic support structure 2116 which is preferably fabricated
from a hard, firm, clear cast plastic, such as urethane. Inside of
the outer air pneumatic support structure 2116 is a flexible bellow
assembly 2120, which is pneumatically connected to connection 2112
to tube barb 2114. Pneumatic pressure generated from the pneumatic
modules, i.e. compressor 100, and pneumatically connected to the
atrium pneumatic-in connector 2111 inflates the bellows. Additional
injection ports may be included to provide a mechanism to inject
dyes or representative medicine into various places within the
cardiovascular simulator system 10. As the bellow assembly 2120
expands, it compresses a left atrium chamber 2122. The bottom ends
2124 and 2126 of the atrium outer air pneumatic support structure
2116 connect to plates 2228 and 2230, see FIG. 8.
[0060] The left atrium chamber 2122 is preferably made of a soft,
flexible, clear silicone which is capable of contracting and
expanding. To allow fluid flow into the left ventricle at the
appropriate time, i.e. when the left atrium contracts, without
fluid flowing back into the left atrium upon relaxation, the left
atrium assembly 2108 contains a one way valve, illustrated herein
as a synthetic valve 2129, see FIG. 6. The valve 2129 represents a
mitral valve, and as an illustrative example, could be a synthetic
replication. Alternatively, the valve may be a transplant of an
actual mammalian mitral valve, such as a swine, or a human mitral
valve.
[0061] The left ventricle module assembly 2110 is composed of a
left ventricle pneumatic chamber 2130 which surrounds the left
ventricle chamber 2132, see FIGS. 4, 6, and 8. The left ventricle
pneumatic chamber 2130 is preferably fabricated from a hard, firm,
clear cast plastic, such as urethane. The left ventricle chamber
2132 is preferably made of a soft, flexible clear plastic, such as
silicone. A first end 2134 of the left ventricle pneumatic chamber
2130 contains a flange 2136 for connection to the left atrium
assembly 2108, preferably to a cardiac support structure 2137. The
second end 2138 of the left ventricle pneumatic chamber 2130
contains a second flange 2140. The second flange 2140 connects to a
ring 2141 sized and shaped to encircle an apex 2142 of the left
ventricle chamber 2132. In this embodiment, apex 2142 does not
contract with the rest of the left ventricle chamber 2132. In an
alternative embodiment, the apex 2142 is fully enclosed by the left
ventricle pneumatic chamber 2130, see FIG. 10.
[0062] As illustrated in FIG. 9, the left ventricle chamber 2132
does not include any vasculature. In an alternative embodiment,
FIG. 10, the left ventricle chamber 2132 includes anatomically
correct vasculature 2144, such as the left coronary artery, the
left circumflex artery, the left marginal artery, the left anterior
descending artery, and the diagonal branch of the left ventricle
chamber 2132. The vasculature can be "normal" vasculature, or can
be that of disease state vasculature. In addition, the normal or
the disease state vasculature can be adapted to represent the exact
vasculature of individual patients (through use of CT scans, MRI
and/or rotational angiography) or can be designed to represent
normal/disease states of non-patient specifically. Moreover,
sections of the left ventricle chamber 2132 may include thick
sections 2146 (simulating ventricular hypertrophy) and/or thinner
sections 2148 (simulating ventricular hypotrophy) to simulate
differing resistance of the heart to contraction and expansion, see
FIG. 10. While not illustrated, such features may apply to the left
atrium chamber 2122 as well. The left ventricle module 2110 is
fluidly connected to one or more parts of the vasculature module
2200 through various connectors. For example, fluid flows out of
the left ventricle into the vasculature module 2200 through a
valve, illustrated herein as a synthetic aortic valve 2150, see
FIG. 5. The synthetic aortic valve 2150 may be constructed from a
synthetic plastic or from an animal, such as a swine/pig or human
aortic valve. In either case, the valve 2150 is designed to allow
fluid flow at the proper time in one direction, i.e. out of the
left ventricle chamber 2132 and into the vasculature module
2200.
[0063] The vasculature module 2200 is made of a plurality of
members, such as synthetic tubing, that provide fluid flow into and
away from the cardiac simulator module 2100. Similar to the atrium
and ventricle, the vasculature module 2200 tubing can be made to
replicate the size, shape, and tonometry of the vasculature of
specific patients. Preferably, the tubing is made of clear medical
grade plastics having flexural modules, or stiffness, which
corresponds to a desired need. Referring to FIGS. 4 and 7, fluid
flows out of the left ventricle chamber 2132 and into tubing
representing the aorta 2202 and aortic arch 2203. One or more aorta
connectors, such as but not limited to, 2204 (subclavian artery),
2206 (right common carotid artery), and 2208 (brachiocephalic
artery), are used to fluidly attach to other components of the
vasculature module 2200, such as tubing representing the vertebral
arteries 2210, and fluidly connect to the periphery organ/system
module 2300 using tubing that represents the left common carotid
artery and the right common carotid artery. Fluid further flows
into the descending aorta 2216 and connects to tubing representing
the right Iliac artery 2218 and the left Iliac artery 2220. Fluid
flow out of the cardiac simulator module 2100 is directed through
additional tubing depending on which part of the system the fluid
is traveling.
[0064] Referring to FIGS. 11 and 12, the periphery organ/system
module 2300 is shown as a head 2302. The head 2302 contains a
bottom portion 2304 connected to a board 2305 and/or a top portion
2306 through fastening members 2308, such as screws or nuts. Such
arrangement allows for the top portion 2306 to be removed and
replaced. The bottom portion 2304 contains one or more fluid
connectors 2310 and 2312 which are adapted to fluidly connect the
head 2302 to one or more components of the vasculature module 2200.
Such fluid connection allows the user to evaluate the effects of
surgical techniques or procedures with peripheral organs or
systems.
[0065] FIG. 12 shows an illustrative example of the head unit 2302
with a plurality of tubing, 2312 and 2314, representing the
cerebrovasculature. The cerebrovasculature is placed within a gel
like material 2316 in order to mimic the compliance of the vessels
in the subarachnoid space and surrounding brain. The vasculature
system, from the carotid bifurcation to the intracranial
circulation, as well as any pathology can be replicated. The head
unit 2302 may also contain additional tubing 2318 connectable to
other parts of the cardiovascular simulator system 10.
[0066] The cardiovascular simulator system 10 may use one or more
compliance chamber modules. The compliance chamber modules act as
system fluid storage devices and are adapted to functionally
provide compensation for the fact that the entire vasculature
system is not modeled. Accordingly, the compliance chamber provides
an anatomically correct range of cardiac system compliance and
compensation, given that the cardiovascular simulator system 10
does not replicate all vasculature vessels contained within the
entire human cardiovasculature system. For example, vasculature to
the lower extremities, particularly the legs, is generally not
included as part of the vasculature module 2200. To replicate
accurate cardio dynamics with anatomically accurate cardiac
physiology while pumping into an incomplete modeled vascular
system, the compliance chamber is used. The compliance chamber
simulates the vascular volume and tonometry of the non-molded parts
of the system. The vascular tonometry simulates arterial tension
and can be changed by adding or removing air from the compliance
chamber. Depending on the amount of air, the conditions of
hypertension or hypotension can be simulated.
[0067] Referring to FIGS. 1-3B, the compliance module is
illustrated as an accumulator and referred to as the arterial
compliance chamber 18. FIGS. 13-15 illustrate several embodiments
of accumulators. FIG. 13 illustrates a gas charged accumulator 18A.
Accumulator 18A comprises a housing unit 20 enclosing an internal
cavity 22. Within the internal cavity 22 is a rubber bladder 24 for
separating gas 26 (inserted through gas inlet 25) and any liquid
stored within the internal cavity 22. A valve may be placed within
the discharge port 30. FIG. 14 illustrates a gas charged
accumulator using a piston, referred to as 18B. The accumulator 18B
also has a housing unit 32 having an internal cavity 34. A piston
36 separates the gas 38 and a liquid within the internal cavity 34.
FIG. 15 illustrates a spring loaded piston accumulator 18C. The
spring loaded piston accumulator 18C also contains a housing unit
40 having an internal cavity 42. A piston 44 with a spring 46
operates similar to the gas charged piston, except that the spring
46 forces the piston against stored liquid. Although not
illustrated, alternative accumulator types, such as an accumulator
that uses a diaphragm, known to one of skill in the art, may be
used as well. The fluid reservoir 12 may be configured as an
accumulator as well.
[0068] Referring back to FIG. 1, fluid from the cardiac module
2100, directly, or if diverted to and returned from the arterial
compliance chamber 18, is directed towards the anatomical module,
including the vasculature simulator module 2200, and/or one or more
peripheral organ/systems simulator module 2300 of the anatomical
module 2000. Adjustment of flow rate can be accomplished by control
mechanisms. For example, the flow rate for fluid entering the
vasculature simulator module 2200 can be controlled by first
resistance valve 48, also referred to as body resistance valve.
Preferably, the resistance valve 48 is an electrically adjustable
fluid resistance valve which includes a linear stepper motor and a
globe valve. The resistance valve 48 can be automatically adjusted
in order to achieve the desired flow rate to the body. The flow
rate for fluid entering the one or more peripheral organ/systems
simulator module, i.e. the head, can be controlled by a second
resistance valve 50, also referred to as a head resistance valve.
The second resistance valve 50 is preferably an electrically
adjustable fluid resistance valve which includes a linear stepper
motor and a globe valve. The resistance valve 50 can be
automatically adjusted in order to achieve the desired flow rate to
the head.
[0069] Each pathway, i.e. the vasculature pathway and the one or
more peripheral organ/systems pathway, contains one or more
monitoring or detecting mechanisms. As show in FIG. 1, the
vasculature pathway includes a first flow meter 52, also referred
to as a body flow meter. The body flow meter 52 may be, for
example, a paddle wheel flow meter, configured to convert
volumetric flow rate to an electrical signal. The signal is used by
the system controller (to be described later) to determine when
changes to the flow resistance valve 48 settings are required in
order to achieve the desired flow. The one or more peripheral
organ/systems may include a second flow meter 54, also referred to
as a head flow meter. The head flow meter 54 may also be a paddle
wheel flow meter configured to convert volumetric flow rate to an
electrical signal. The signal is used by the system controller to
determine when changes to the second flow resistance valve 50
settings are required in order to achieve the desired flow. Fluid
is then transported back to fluid reservoir 12. A check valve 56
ensures that the returning fluid flow enters into the fluid
reservoir 12 while preventing backflow, i.e. reverse flow out of
the fluid reservoir 12, replicating the actions of the anatomical
veins.
[0070] Fluid may be drained from the cardiovascular simulator
system 10 via a drain connector, such as a Schrader type quick
disconnect valve 58. The valve 58 may be connected to a drainage
hose or tubing (not shown) attached during the draining cycle
operation. The fluid is preferably drained into a container, shown
as a fluid holding container or jug 60.
[0071] Referring to FIG. 2, the cardiovascular simulator system 10
is shown with the pneumatics components. Air compressor 100 is
responsible for several functions within the cardiovascular
simulator system 10. Air compressor 100 provides pressurized air
flow to the cardiac module 2100 through tubing 110 or 112.
Specifically, pressurized air is supplied to the left atrium
assembly 2108 and the left ventricle assembly 2110. Control of air
flow into the cardiac simulator 2100, i.e. into the left atrium
assembly 2108 or left ventricle assembly 2110 so as to allow each
component to simulate a beating heart, is provided by one or more
control mechanisms. Control of the left atrium assembly 2108 can be
accomplished using a valve, illustrated on FIG. 2 as an actuation
solenoid valve 114, also referred to as an atrium actuation
solenoid valve. When the atrium actuation solenoid valve 114 is
energized, pressurized air from compressor 100 is admitted into the
bellows 2120 (FIG. 6). Such action compresses the left atrium
assembly 2108. When the atrium actuation solenoid valve 114 is
de-energized, pressure is released from the bellows, allowing the
left atrium assembly 2108 to relax. A second actuation solenoid,
referred to as a ventricle actuation solenoid valve 116 controls
air into the left ventricle 2110. When the ventricle actuation
solenoid valve 116 is energized, pressurized air from the
compressor 100 is admitted into the left ventricle pneumatic
chamber 2130 (FIGS. 4-10) that surrounds the left ventricle 2110.
This action allows the left atrium 2110 to compress and push out
any fluid within the left ventricle chamber 2132. When the
ventricle actuation solenoid valve 116 is de-energized, pressure
from the left ventricle pneumatic chamber 2130 is released,
allowing the left ventricle 2110 to relax. Such actions simulate
physiological contractions, and thus heartbeat, of the left side of
the heart. The pressurized air may also cause one or more portions
of the cardiac module, such as the left ventricle chamber 2132, to
partially move about its axis to more accurately simulate the
heartbeat.
[0072] The air compressor 100 may be fluidly connected to the
arterial compliance chamber 18 via tubing 118 in order to reduce
the water level in the arterial compliance chamber 18. To aid in
draining fluid from within the cardiovascular simulator system 10,
compressor 100 may be fluidly connected to the fluid reservoir 12
via tubing 120. Fluid can be drained via drain disconnect valve 58
pumping pressurized air through the venous chamber 12, as well as
arterial chamber 18. Various control mechanisms for delivery of the
pressurized air from the compressor 100 is preferably utilized. A
valve, referred to as a venous chamber venting valve 122 is used to
control the amount of air, and therefore the pressure, to the
venous chamber 12. For example, manipulation of the venous chamber
venting valve 122 to release air pressure from the venous chamber
12 may be used when the average venous pressure is determined to be
too high. A second valve, referred to as a venous chamber
pressurization valve 124 can be used to admit pressurized air into
the venous chamber 12 in order to, for example, increase the
baseline venous pressure. Manipulation of the venous chamber
pressurization valve 124 may also be used during the drain cycle to
force pressurized air through the cardiovascular simulator system
10. The pressurized air that is forced through the cardiovascular
simulator system 10 drives the fluid out via the drain disconnect
valve 58.
[0073] On the other side, or the simulation of the arterial
chamber, various control mechanisms may be used as well. A valve,
referred to as an arterial chamber venting valve 126 is designed to
affect the hydraulics of the arterial compliance chamber 18.
Manipulation of the arterial chamber venting valve 126 releases air
pressure from the arterial compliance chamber 18. This has the
effect of allowing more water to enter into the chamber, thereby
reducing the air volume. This also has the effect of reducing the
hydraulic compliance of the arterial compliance chamber 18. A
second valve, the arterial chamber pressurization valve 128 can be
used to control air flow into the arterial compliance chamber 18.
Manipulation of the arterial chamber pressurization valve 128
admits pressurized air into the arterial compliance chamber 18.
Admission of the pressurized air drives any fluid out of the
arterial compliance chamber 18. As fluid is driven out, air volume
increases within the arterial compliance chamber 18 and increases
the compliance of the arterial compliance chamber 18. The arterial
chamber pressurization valve 128 may further be used in the drain
cycle to force pressurized air through the cardiovascular simulator
system 10. As the pressurized air moves throughout the
cardiovascular simulator system 10, any fluid within the
cardiovascular system 10 is driven out through the drain disconnect
valve 58.
[0074] The cardiovascular simulator system 10 is designed to allow
for control of various parameters to be run automatically. Such
control allows the cardiovascular system to function more
efficiently and accurately in order to represent blood flow and/or
other physical characteristics as required. Referring to FIG. 3A, a
control unit 130 is electronically connected to various components
of the cardiac system through connector members 132A-132M, referred
to generally as connector member 132. The connector member 132 may
be wireless connection using, for example, blue tooth technology,
or may be hardwired, such as computer cables using USB (Universal
Serial Bus) connection. The control unit is preferably a computer
having the necessary hardware for processing capability, storage
capability and any necessary software to drive or control the
functioning of various components, and may include, for example,
logic boards such as printed circuit boards with the necessary
integrated circuitry, central processing units, RAM, ROM, and/or
hard drives. The control unit 130 must be designed to process
various system parameters measured by the body flow meter 52 and
the head flow meter 54. Additionally, the cardiovascular simulator
system 10 may contain sensors 134 and 136. Sensor 134, also
referred to as the venous pressure sensor, is a pressure sensor
configured to convert gauge pressure reading of the fluid chamber
12 into an electrical signal. The signal can be transmitted to the
system control unit 130 where a determination of adjustment to the
fluid chamber 12 pressurization can be made. Sensor 136, also
referred to as the arterial pressure sensor, is a pressure sensor
configured to convert the gauge pressure reading of the arterial
compliance chamber 18 into an electrical signal. The signal can be
transmitted to the system control unit 130 where adjustment to the
pumping action of the cardiac module 2100 to achieve various system
pressures, i.e. to represent a predetermined systolic and diastolic
pressure can be determined and/or made. The control unit 130 may
further be configured to use command values to affect other system
operations through, for example, control of 1) body flow resistance
valve 48 settings, 2) head flow resistance valve 50 settings, 3)
the speed profile of the compressor 100, 4) the timing and
actuation of the atrium actuation solenoid valve 114 and the
ventricle actuation solenoid valve 116. In addition, the control
unit 130 may be programmed to control the use of the compressor 100
in conjunction with the arterial chamber venting valve 126 and the
arterial chamber pressurization valve 128 to modify levels of fluid
in the arterial compliance chamber 18, thereby modifying the
compliance. The control unit 130 may contain an information
display, such as an LCD screen, to provide an interface with the
user to allow for manipulation of one or more parameters.
[0075] A second computer device, illustrated as a tablet computer
138, may be used in conjunction with the control unit 130. The
tablet computer 138 may contain the necessary hardware, such as a
processor and memory, as well as the necessary software to provide
a user interface to monitor one or more operations of the system
and to adjust any settings. The tablet computer 138 may be
electronically connected to the control unit 130 by wireless or
hardwire connection 140. Preferably, the connection 140 is
wireless, using, for example, blue tooth technology. However, the
connection 140 may be via cable connections, such as cables using
USB connection.
[0076] FIG. 3B illustrates the cardiovascular simulator system 10
in which the cardiac module 2100 uses an electrically driven pump
141. The pump 141 provides similar pulsatile flow characteristics
as that of the anatomical heart model previously described. Such an
embodiment could provide similar physiological pressure and flow
characteristics with potentially lower cost, smaller size, higher
reliability, or more controllable flow characteristics.
[0077] Referring to FIG. 16 (as well as FIGS. 4-10 when referring
to specific components of the cardiac or vasculature modules), an
illustrative embodiment of the cardiovascular simulator system 10
is shown. The cardiovascular simulator system 10 may include a
support structure 142 which may be used to support the various
components of the cardiovascular simulator system 10. Each of the
components may be secured to the support structure using, for
example, screws, nuts and bolts or may be secured using chemical
fastening, such as an adhesive. Fluid stored within the fluid
reservoir module 12 is passed through the system using the
compressor 100 to push pressurized air into the fluid reservoir
module 12. The action of the pressurized air allows the cardiac
simulator module 2100 to function like a heart muscle of an human
or animal by contracting and expanding, forcing fluid representing
blood flow to travel within the vasculature simulator module 2300.
The control unit 130 is designed to supply pulses of pressurized
air to the cardiac module 2100. Fluid pressures and fluid
dynamics/flows are created by the pumping action of the cardiac
module itself. The fluid is pushed out of fluid reservoir module 12
and enters the anatomical module 2000 which represents oxygenated
blood returning from the lungs, not used in the presently described
system, and flows into the left atrium assembly 2108 through tubing
that represents the left and right pulmonary veins.
[0078] The atrium chamber 2122 fills with fluid and the pressure of
the fluid, measured at the systolic side of the circuit, is
controlled by the control unit 130 to be in the minimal normal
range for diastolic pressure of a human heart (50-80 mm HG). The
actual blood pressure of 120/80 (systolic/diastolic) obtained by
the system is a combination function of the fluid flow volume
(simulated by manipulation of the control unit 130 in relationship
to the cardiac simulator module), the cardiac simulated heart rate,
arterial compression, ventricular compression (or ejection
fraction, simulated as the amount of fluid ejected out of the
atrium chamber or ventricle chamber), the capillary resistance
(simulated effects by the manipulation of the compliance chamber
18) and the vascular tonometry or tension (simulated effects by the
manipulation of the compliance chamber 18).
[0079] The cardiovascular simulator system 10 is designed to
independently adjust for systolic and diastolic values using
various combinations of parameters which affect the systolic and
diastolic numbers to varying degrees. The value of the diastolic
pressure can be manipulated to above or below the normal ranges to
simulate various disease states using the control module. In
addition to any of the components described previously, the control
unit 130 is shown having one or more circuit boards, illustrated
herein as a control printed circuit board (PCB) 144 and a second
PCB 146 for control of voltage sensing. A power source 148, which
may include a battery, powers the entire cardiac simulator system
10. Initiated by the control module 130, the left atrium is
contracted. Contraction of the left atrium is controlled by the
compressor 100 which controls when and how much pressurized air is
forced into the left atrium chamber 2128. The pressurized air
generated flows through tubing and enters the outer air pneumatic
support structure 2116 of the left atrium chamber 2122. The air
causes the atrium bellows 2120 to compress against the left atrium
chamber 2122, reducing the volume within the left atrium chamber
2122. Reduction of the volume results in fluid being expelled
through the mitral valve 2129 and into the left ventricle pneumatic
chamber 2130.
[0080] The pressurized air generated travels through the tubing of
the vasculature module into the left ventricle pneumatic chamber
2130. The pressurized fluid causes a reduction of volume within the
left ventricle chamber 2132, resulting in the expulsion of fluid
through the synthetic aortic valve 2150 and into the aortic arch
2203. Because of the feedback systems utilized, the cardiovascular
simulator system 10 is configured to regulate various physiological
parameters. The pressure of the fluid can be set, for example,
within the range of normal physiological representative
systolic/diastolic pressures. For example, the cardiovascular
simulator system 10 may include set points of: 1) default 120 mmHg
representing systolic pressure, 2) default 80 mmHg, representing
diastolic pressure, 3) default 10 mmHg, representing venous pool
pressure, 4) blood flow of, default 12 mL/second, representing the
average cephalic flow (total head flow), 5) blood flow, default 20
mL/second, representing the average thoracic flow (abdominal aorta,
no internal organs), and 6) fluid temperature, default 98.6 degrees
Fahrenheit. These values or set points may also be changed to
represent non-normal values. The physiological parameter set points
are adjustable by a user. In addition, the system uses the feedback
controls to automatically compensate for changes in the set
points.
[0081] The conditions can be manipulated by the control unit 130 to
change the corresponding pressure, volume flow rate, ejection
fraction, or combinations thereof as the fluid moves through the
entire system. The fluid ejected from the left ventricle chamber is
under pressure and flows through tubing which represents or
simulates various portions of the ventricle anatomy, such as the
vertebral arteries, the left common carotid artery, and the right
common carotid artery. Fluid also flows down to the descending
aorta and into the right iliac artery and the left iliac artery. As
such, cardiovascular simulator system 10 is configured to regulate
the average of systolic and diastolic pressure by adjusting the
volume of pressurized air produced by the compressor 100 and used
to compress the atrium and ventricle. Time varying air flow rates
within a cycle (as opposed to constant flow) is preferably
generated. Regulation of the pressure difference between
representative systolic and diastolic pressures are accomplished by
adjusting the volume of air (and thus the hydraulic compliance) of
the arterial compliance chamber 18. Adjusting the resistance valves
provides regulation of the representative cephalic and thoracic
flow. The flow meters are preferably positioned in the
representative venous portion of the system rather than the
representative arterial portion. Therefore, flows are more
continuous than pulsatile at that point and adjustments to average
flow rates, rather than ejection fractions and peak flow rates, can
be used. With regards to the heating of the fluid, heater surface
temperature and replicator fluid temperature can be determined and
controlled via the control unit 130 to heat the fluid to the
desired temperature, while ensuring that the heater surface
temperature does not exceed a predefined limit.
[0082] Eventually all fluid is directed back to the fluid reservoir
12 in which the flow rate is adjusted. Vascular tension can be
simulated and adjusted through several mechanisms, such as through
the use of compliance and resistance valves, and through the molded
vasculature simulator module representing the arteries having
various durometer values. Although not illustrated, fluid flow may
be directed to the periphery organ/system module, i.e. the head
2302 and its representative vasculature tubing. If used as part of
the cardiac simulator system 10, the head 2302 may be secured to
the support structure frame 142 through the head support structure
150. The head 2302 may contain a quick connect connector to quickly
and easily connect/disconcert to/from the support structure frame
142 and can be capable of angular translation. Fluid is then
returned to the tubing representing the pulmonary anatomy and
eventually back into cardiac module 2100 to start a new cycle.
[0083] The body resistance valve 48, the head resistance valve 50,
the body flow meter 52 and the head flow meter 54 may be housed in
housing structures 152, 154, 156, and 158. The compliance adjusting
valves, such as the venous chamber venting valve 122, the venous
chamber pressurization valve 124, the arterial chamber venting
valve 126, and/or the arterial chamber pressurization valve 128 may
be stored in housing structure 160.
[0084] As described previously, abnormal heart conditions can be
simulated by varying the force, duration, and frequency of the air
burst generated by the atrium/ventricle assemblies through commands
sent from the control unit and adjustments to various structures
within the system to cause such changes to occur.
[0085] All patents and publications mentioned in this specification
are indicative of the levels of those skilled in the art to which
the invention pertains. All patents and publications are herein
incorporated by reference to the same extent as if each individual
publication was specifically and individually indicated to be
incorporated by reference.
[0086] It is to be understood that while a certain form of the
invention is illustrated, it is not to be limited to the specific
form or arrangement herein described and shown. It will be apparent
to those skilled in the art that various changes may be made
without departing from the scope of the invention and the invention
is not to be considered limited to what is shown and described in
the specification and any drawings/figures included herein.
[0087] One skilled in the art will readily appreciate that the
present invention is well adapted to carry out the objectives and
obtain the ends and advantages mentioned, as well as those inherent
therein. The embodiments, methods, procedures and techniques
described herein are presently representative of the preferred
embodiments, are intended to be exemplary and are not intended as
limitations on the scope. Changes therein and other uses will occur
to those skilled in the art which are encompassed within the spirit
of the invention and are defined by the scope of the appended
claims. Although the invention has been described in connection
with specific preferred embodiments, it should be understood that
the invention as claimed should not be unduly limited to such
specific embodiments. Indeed, various modifications of the
described modes for carrying out the invention which are obvious to
those skilled in the art are intended to be within the scope of the
following claims.
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