U.S. patent application number 12/779562 was filed with the patent office on 2010-09-02 for medical patient simulator.
This patent application is currently assigned to LAERDAL MEDICAL AS. Invention is credited to Oystein Gomo.
Application Number | 20100221689 12/779562 |
Document ID | / |
Family ID | 29417585 |
Filed Date | 2010-09-02 |
United States Patent
Application |
20100221689 |
Kind Code |
A1 |
Gomo; Oystein |
September 2, 2010 |
Medical Patient Simulator
Abstract
Medical patient simulator comprising a torso that contains an
artificial lung, a chest skin and means for pulling the chest skin
downward in an area corresponding with an area where such
retractions occur on a human being. The simulator also provides for
changes in the compliance of the lung. The lung is situated between
two plates, the spacing of which can be adjusted. The torso has one
actuator on each side of the back to simulate muscular activity. It
includes a system for control of pneumatic functions by measuring a
representative pressure for each actuator and stopping the filling
when a pre-set pressure is reached. It also includes a head with
one or more air cushions in a fontanelle area on the head, which
may be filled with air to simulate an increased pressure in the
brain.
Inventors: |
Gomo; Oystein; (Hundvag,
NO) |
Correspondence
Address: |
BROOKS KUSHMAN P.C.
1000 TOWN CENTER, TWENTY-SECOND FLOOR
SOUTHFIELD
MI
48075
US
|
Assignee: |
LAERDAL MEDICAL AS
Stavanger
NO
|
Family ID: |
29417585 |
Appl. No.: |
12/779562 |
Filed: |
May 13, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10595306 |
Nov 17, 2006 |
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PCT/NO2004/000298 |
Oct 6, 2004 |
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12779562 |
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Current U.S.
Class: |
434/262 |
Current CPC
Class: |
G09B 23/30 20130101;
G09B 23/28 20130101 |
Class at
Publication: |
434/262 |
International
Class: |
G09B 23/28 20060101
G09B023/28 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 6, 2003 |
NO |
20034465 |
Claims
1. A medical patient simulator for simulation of subcostal
retractions of an infant, comprising: a torso containing at least
one artificial lung adapted for inflation by external air supply
and a sternum; a chest skin placed at least partially on the
outside of the torso; a means for pulling down the chest skin
providing an external visible depression of the skin below the
sternum of the torso; where the means includes a mechanism adapted
to pull the chest skin in a synchronous fashion with the at least
one lung raising and lowering the chest, said means further
including an elastic pulling strap attached to the inside of the
skin approximately in the middle of the area where subcostal
retractions occur; said means and said artificial lung being
coupled so that when said means are actuated to pull in the chest
skin, said means and said artificial lung are adapted to move
synchronously.
2. A medical patient simulator according to claim 1, wherein the
mechanism is a pneumatic mechanism including a bellows.
3. A medical patient simulator according to claim 1, further
comprising a chest plate disposed against said bellows of said
pneumatic mechanism and said artificial lung, a lever being hinged
to said chest plate and being coupled to said elastic strap, said
bellows being situated between said lever and said chest plate, and
said chest plate, said bellows and said lever being adapted to move
with inflation and deflation of said artificial lung.
4. A medical patient simulator, in particular a simulator for
simulation of an infant, comprising; a torso containing at least
one lung, with the option of altering the compliance of the at
least one lung, where the at least one lung is disposed between a
first and second plate in the torso, the spacing of the plates
being adjustable, the second plate being fixed relative to the
torso, and the first plate being movable relative to the torso; a
pneumatically driven mechanism being adapted to force the first
plate towards the second plate, the pneumatically driven mechanism
including a bellows; and a flexible means connecting the
pneumatically driven mechanism to the second plate to provide the
force between the first and second plate, said flexible means
having an initial slack so that the first plate is free to move
relative to the second plate when the pneumatically driven
mechanism is inactive.
5. The medical patient simulator of claim 4 further comprising a
third and fourth plate in the torso, and the bellows arranged
between the third and fourth plate.
6. The medical patient simulator of claim 5, wherein one of the
third and fourth plates is the first plate and is arranged over the
lung.
7. The medical patient simulator of claim 4, wherein the flexible
means is an elastic strap.
8. A medical patient simulator of claim 4 further comprising a
strap for pulling down the chest skin providing an external visible
depression of the chest skin below the sternum of the torso,
wherein the strap is attached to the chest skin from inside the
torso, and wherein the strap and the lung are coupled to move
synchronously.
9. A medical patient simulator, in particular a simulator for
simulation of an infant, comprising: a torso, for simulation of
muscle activity in a patient; the torso having at least two
actuators, the first and second actuator being arranged on the
right and left sides, respectively, of the backside of the torso;
wherein the at least two actuators are being designed to be
operated in at least the following modes: a mode for simulation of
normal muscle movement, alternate and regular activation of the at
least two actuators on the left and right sides; a mode for
simulation of muscle spasms, rapid and irregular activation of the
at least two actuators on the left and right sides; and a mode for
simulation of defibrillation, rapid activation of the at least two
actuators simultaneously, once for each defibrillation, wherein the
at least two actuators are air cushions situated near the outer
surface of the simulator to act between a rigid part of the
simulator and a surface upon which the simulator is placed.
10. A medical patient simulator, in particular a simulator for
simulation of an infant, comprising: a head having a rigid part
covered with a skin; where one or more air cushions are arranged
between said rigid part and said skin in at least one fontanelle
area on the head of the simulator, and where the one or more air
cushions are designed to be filled with air in order to simulate an
increased pressure in the brain and provide a swelling in the
fontanelle area that can be detected by palpation.
11. A medical patient simulator according to claim 10, wherein said
one or more air cushions are disposed in a recess defined by said
rigid part.
12. A medical patient simulator according to claim 11, further
comprising a flexible body disposed between said one or more air
cushions and said skin.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 10/595,306, filed Nov. 17, 2006, which is a 371 of U.S.
national phase application PCT/NO2004/000298, filed Oct. 6, 2004,
which, in turn, claims the benefit of Norwegian patent application
2003 4465, filed Oct. 6, 2003.
TECHNICAL FIELD
[0002] The present invention regards a medical patient simulator,
in particular a simulator for simulating an infant and its
physiological responses.
BACKGROUND
[0003] The background for a first aspect of the invention is a
request from the market for a simulation of the breathing pattern
called sub-costal retractions, so as to provide a basis for
diagnosing breathing problems in the patient. Today there are no
patient simulators in existence that mimic this particular
breathing pattern.
[0004] Chest retractions occur when a patient has difficulties
breathing due to an obstruction of the respiratory passage or
severe asthma and the lungs use a great amount of force in order to
get the air through. The retractions are visible as a cavity in the
diaphragm (the skin is "sucked" in between the ribs and at the
lower edge of the ribs, i.e. below the sternum).
SUMMARY
[0005] The above mentioned object is achieved by using means that
pull the chest skin down in an area that corresponds to an area
where such retractions would occur on a human being.
[0006] Preferably this can be done by attaching or integrating an
elastic strap to the inside of the chest skin in the middle of the
area where retractions occur.
[0007] The invention concerns systems intended for patient
simulators (particularly manikins) used for medical teaching and
training. It is an object for the manikin to exhibit various signs
of illness as well as both normal and abnormal bodily functions in
order to allow the users to make a diagnosis and take corrective
measures.
[0008] In a preferred embodiment a pneumatic mechanism pulls this
strap in a manner which is synchronized with the lungs' raising and
lowering of the chest, giving the desired cavity in the skin over
the diaphragm.
[0009] This makes it possible to practice the diagnosing and
treating of a respiratory problem in a way which is currently not
possible with any other patient simulator. Preferably the function
can be switched on and off from the instructor's PC or via remote
control.
[0010] In alternative embodiments the strap may be glued or welded
to the chest skin. Most preferably the strap is moulded integrally
with the rest of the skin. The latter allows for more efficient
production.
[0011] Preferably the skin can be pulled down by pneumatics and a
lever mechanism.
[0012] Alternatively the skin can be pulled down by en
electro-mechanical mechanism, e.g. an electric motor or a
solenoid.
[0013] As an alternative to a strap magnetic material may be fixed
to or moulded to the relevant area of the chest skin. Pull-down is
carried out by activating an electromagnet placed a distance under
the skin.
[0014] In a further alternative embodiment the retractions may
occur as a result of suction on the underside of the area in
question. Such a solution may also be used to simulate intercostal
and mid-clavicular retractions. In practice the suction effect can
be produced by forming a closed space underneath the skin through:
[0015] Moulding vertical walls as a continuous "skirt" around the
relevant area, sealed with a rigid "lid" at the bottom. The lid at
the bottom is equipped with a nipple for evacuation of air and is
prevented from being pulled up when the air is sucked from the
space. [0016] Welding a foil against the underside of the skin so
as to form a funnel down towards a central air nipple. The nipple
is prevented from being pulled up when the air is sucked from the
space. [0017] Leave the skin placed across a sealed "cup" shaped
according to the anatomy of the area in question. The brim of the
cup seals against the skin. The air can be evacuated through
pumping or by the walls of the cup acting as a cylinder in which a
piston is pulled down to create the vacuum.
[0018] In a second aspect of the present invention the aim is to
achieve a patient simulator that allows for a change in the
compliance of the lungs, i.e. the resistance offered by the lungs
when ventilated (artificial respiration). This provides an
opportunity for practicing diagnosis and treatment of a respiratory
problem, which today does not exist in any other patient simulator.
Preferably the function can be switched on and off from the
instructor's PC or via remote control.
[0019] There is no other patient simulator in existence today which
can offer different degrees of lung compliance.
[0020] Different compliance of the lungs can according to the
invention be simulated by placing the lung or lungs between two
plates in the chest. The spacing between the plates or their
resistance against moving apart can be altered, so that it becomes
more difficult to inflate the lungs.
[0021] As an example, the lower plate may be fixed while the upper
plate is movable. The upper is forced up when the lung is inflated
through artificial respiration, simulating lifting of the chest.
The normal resistance against this ventilation is caused by the
chest skin stretching when the chest lifts. In order to initiate an
increase in the inflexibility of the lungs an actuator is
activated, which pulls the upper chest plate down towards the lower
plate. This applies a pressure to the lung sack and makes it more
difficult for the user to blow air into the lungs. The actuator may
include e.g. a pneumatically operated mechanism.
[0022] In an embodiment of the invention the tightening of the
plates enclosing the lung sack can be carried out by an
electromechanical mechanism.
[0023] The elastic body may be an elastic strap, band or a tension
spring.
[0024] Optionally the force may be inverted so that a compression
spring or a soft compressible body provides the resistance against
lung expansion.
[0025] In the case of pneumatic operation of the actuator for
moving the upper plate the elastic body may be replaced by a rigid
locking mechanism. The air cushion tensioning the locking mechanism
will then provide the required resilience. Alternatively, variable
compliance of the lungs may also be achieved by varying the
tightening of the chest skin. This may be done e.g. by a pneumatic
or electromechanical mechanism pulling at the attachment points of
the skin at the sides or back of the manikin, causing the skin to
tighten across the chest, thus offering increased resistance
against expansion of the lung sack.
[0026] A third aspect of the present invention provides a patient
simulator that is capable of simulating muscular activity in the
patient.
[0027] The background for this is an idea of increasing the realism
of the simulator by using the electropneumatic control system
already present in the simulator to simulate muscular activity in
the patient and also simulate a physical response to the electric
shock to which a patient is subjected during defibrillation of the
heart.
[0028] A simulator is known in which an arm can be moved to
simulate muscular activity. A BLS manikin was previously on the
market, which through an electromechanical solution could provide a
physical reaction to defibrillation. The reason why this manikin is
no longer available is unknown; neither is it known whether the
chosen technical solution was satisfactory.
[0029] However there are no simulator manikins that can move the
actual torso in order to simulate spasm or the first signs of
consciousness upon waking up from general anaesthesia and similar.
Movement of the actual torso in order to give signs of life is not
known from any other patient simulator.
[0030] A system has therefore been developed to simulate both
normal and abnormal body movements and reactions to defibrillation.
According to the invention this is solved by the torso comprising
at least two actuators arranged on the right and left sides,
respectively, of the backside of the torso, which actuators are
arranged to be operated in the following modes: [0031] for
simulation of normal muscle movement, alternate and regular
activation of the actuators on the left and right sides, [0032] for
simulation of muscle spasms; rapid and irregular activation of the
actuators on the left and right sides, [0033] for simulation of
defibrillation; rapid activation of both actuators simultaneously,
once for each defibrillation.
[0034] Preferably the actuators are air cushions.
[0035] Preferably there is one air cushion disposed on the right
side and one on the left side. When air is injected into these the
manikin will lift slightly from the surface on which it has been
placed. Initiating rapid and irregular actuation of the air
cushions creates random spasmodic reactions. More regular and more
complete filling and emptying of the air cushions, alternating
between the right and left sides, simulates normal body movements
in a patient regaining consciousness.
[0036] These patterns of movement can be activated from the
instructor's PC or via remote control. In addition the simulator
may be equipped with a sensor to detect defibrillation. Upon
receiving such an electric shock both air cushions are immediately
filled to a maximum level of fill, then to deflate completely
again. This results in a rapid lifting and lowering of the body,
simulating a human body in which the muscles are tensed by the
electric shock.
[0037] A fourth aspect of the present invention provides a system
for controlling various pneumatic functions in patient simulators
(manikins) used in medical education and training. It is important
to be able to set many of these functions to various levels, e.g.
depth of breathing (degree of lung inflation), degree of swelling
of the oral cavity and respiratory passages and the extent of body
movements. It must also be possible to limit the maximum pressure
to which the actuators are subjected, due to the risk of ruptures
and leakage.
[0038] Thus it is desirable to achieve control of the actual air
pressure in each actuator (air cushion) and then use this actively
to control the different functions.
[0039] In a currently used technique the pressure in each actuator
appears as a function of the fill-up time. The functions are
programmed individually based on empirical data for pressure
build-up as a function of fill-up time. The problem with this
solution is that it requires complete deflation of the individual
actuator prior to re-filling. If this is not done the next filling
(which takes place over the same period of time as the previous)
will come in addition to the air remaining from the previous
filling, thus creating an excessive pressure. This problem arises
upon repeated activation at a high frequency (e.g. when simulating
rapid breathing). As this system includes no pressure feedback,
repeated filling without sufficient time for complete deflation
will lead to an increased build-up of pressure. In many cases this
has caused actuators (air cushions) to rupture as a result of
overpressure.
[0040] The present invention therefore proposes to measure the
pressure of each actuator and use the pressure values to set a
limit for the degree of fill. In order to avoid having to use a
double set of air hoses (one for air into and out of the actuator
and one for pressure measurements) in manikins where there may
already be many hoses and little room, the pressure is measured
closer to the pressure source (the valve) for the individual
actuator. In order to minimize the effect of a pressure overshoot
immediately after opening the valve, the pressure is measured after
a nozzle that restricts the air flow and provides pressure
measurements that are approximately equal to the pressure in the
actuator. For functions where fast filling (i.e. high air flow) is
important a throttle-free system may be used. The pressure in the
air bladder is then measured by the pressure sensor being connected
directly to the bladder via a separate hose.
[0041] A fifth aspect of the present invention aims to provide
variable fontanelles in an infant simulator.
[0042] According to the invention this is provided by arranging one
or more air cushions in at least one fontanelle area on the head of
the simulator, which air cushion (s) can be inflated with air in
order to simulate an increased pressure in the brain.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] The various aspect of the invention will now be described in
greater detail through examples of embodiments and with reference
to the accompanying drawings, in which:
[0044] FIG. 1 is a longitudinal section through a patient
simulator;
[0045] FIG. 2 is a longitudinal section through a patient
simulator;
[0046] FIG. 3 is a cross section through a patient simulator;
[0047] FIG. 4 is a schematic diagram showing an air control system
according to the invention;
[0048] FIG. 5 is a longitudinal section through the head of a
patient simulator; and
[0049] FIG. 6 is a longitudinal section through a patient
simulator.
DETAILED DESCRIPTION OF ONE OR MORE EMBODIMENTS
[0050] When in the following the orientational terms "over" and
"under" are employed, this should be understood to be in relation
to the figures, in which the patient simulator is depicted as lying
on its back. Other orientational terms used are "below" and
"above". These relate to the manikin in the upright position. The
use of these terms is purely practical and is intended to simplify
the description of the invention, and shall in no way be taken to
impose any limitations on the positions in which the invention may
be used.
[0051] FIG. 1 is a longitudinal section through a patient
simulator, showing part of a head 1 and part of a torso 2. The
torso 2 comprises a chest skin 3. Under the chest skin is a shell 4
to represent ribs and sternum. Under this shell is a first plate 5,
which may also be termed an upper plate. Under the plate 5 is one
or preferably two lungs 6, one on the right side and one on the
left side of the rib cage. Under the lung (s) 6 is a second or
lower plate 7.
[0052] An area of the chest skin 3 below the shell has a strap 8
attached to it or integrated into the chest skin. Preferably this
is done by moulding the chest skin 3 and the strap 8 at the same
stage.
[0053] The strap 8 is connected to a lever 9 designed to pull on
the strap 8. One end of the lever 9 is supported in a hinge 10.
Between the lever 9 and the upper plate 5 is an air cushion 11. The
air cushion 11 is connected via a hose 12 to a source of compressed
air (not shown). The lung 6 is connected to a source of compressed
air (not shown) via a hose 13.
[0054] In the case of simulated breathing with retractions air is
repeatedly pumped into the lung (s) 6 and then released. The
filling of the air cushion 11 takes place in time with this
inflation and deflation of the lung (s) 6. This filling takes place
at the specific point during the lung inflation which best
corresponds to the time of retraction in a human being.
[0055] When the air cushion 11 is filled, the lever 9 rotates about
the hinge, and the outer end of the lever 9 moves down (in FIG. 2),
as indicated by the dotted line. This pulls the strap 8, pulling
the chest skin 3 down in the area around the strap 8, as indicated
by the dotted line.
[0056] When the retraction function is not in use, the mechanism
will have no visible effect on the chest skin. This is due to the
fact that the lever 9 is attached to the upper plate 5, moving
entirely with this.
[0057] FIG. 2 is a longitudinal section similar to FIG. 1. However,
FIG. 2 also shows a mechanism for reducing the plate's 5 mobility.
This comprises a lever 14, one end of which is supported at a hinge
15. The opposite end of the lever 14 is connected to a flexible
body 16.
[0058] The flexible body 16 is functionally engaged with the lower
plate 7. To make sure the elastic strap does not prevent the plate
5 from moving in the case of normal lung compliance, the strap has
some slack with respect to the plate 7, indicated at 17. The strap
16 may be an endless elastic band, as shown.
[0059] An air cushion 18 is arranged between the plate 5 and the
lever 14. This is connected to a source of compressed air (not
shown) via a hose 19. When the air cushion fills with air the lever
14 is lifted to the position indicated by the dotted line at 14'.
Thus the slack between the strap 16 and the plate 7 is reduced or
eliminated. Upon subsequent filling of the lung 6 the strap 16,
which acts between the lever 14 and the lower plate 7, will
counteract the movement of the upper plate 5 away from the lower
plate 7. This will make the lungs feel less compliant, as it
becomes more difficult to fill them with air.
[0060] FIG. 3 is a cross section through the torso 2 of a patient
simulator, illustrating a back shell 20. The back shell serves to
reinforce the torso. On the outside of the back shell 20 are two
recesses 21 and 22, on the left and right sides of the torso,
respectively. In each recess 21,22 is an air cushion 23 and 24,
respectively. The air cushions 23,24 are connected to a source of
compressed air (not shown) via respective hoses 25,26.
[0061] Preferably rapid deflation of the air cushions is achieved
by using a three-way valve (not shown) both for filling and
emptying the air cushions. Filling and emptying takes place through
the same hose 25,26. Upon activation of the valve it opens for
compressed air from the compressed-air source, and the air cushions
are inflated. As soon as the valve is deactivated it closes to
compressed air, and the air in the air cushion passes back through
the valve and out into the atmosphere.
[0062] As an alternative but suboptimal solution the air cushions
can be provided with an orifice which allows rapid deflation after
inflation. The orifice is shaped so as to be too small to allow
rapid inflation of the air cushion with a fast flow of compressed
air, but large enough to give a rapid deflation when the flow of
compressed air stops.
[0063] The air cushions 23,24 can be used in the following
modes:
[0064] Simulation of normal muscle movements: Alternate and regular
filling and emptying of air on the left and right sides.
[0065] Simulation of muscle spasms: Rapid and irregular (arbitrary)
filling and emptying (inflation and deflation) of the right and
left air cushions. The inflation and deflation may in some cases be
complete and in some cases incomplete.
[0066] Simulation of defibrillation: Rapid filling of both air
cushions simultaneously, once for each defibrillation.
[0067] In the case of defibrillation the electrical current from
the defibrillator is detected, and the control system of the
patient simulator is set to defibrillation mode. Consequently the
cushions will be filled rapidly and simultaneously when the
electric shock is triggered.
[0068] FIG. 4 is a schematic view of a control system for
regulating the filling of air cushions and/or lungs in a patient
simulator.
[0069] A pneumatic actuator (e.g. air cushion or lung) 27 is
connected to a hose 28. The hose is connected to a purge valve 29
with an air outlet 30. The hose 28 is also connected to a first air
duct 31, which in turn is connected to a pressure sensor 32. The
air duct 31 is also connected to a second air duct 33, which in
turn is connected to a fill valve 34. The fill valve 34 is again
connected to a source of compressed air (not shown) via an inlet
36. The second air duct 33 includes a throttle regulator or nozzle
35.
[0070] Together, the fill valve 34, the purge valve 29, the nozzle
35, the pressure sensor 32 and the first and second air ducts 31,33
form a control unit 37 and are located in physical proximity to
each other and at a distance from the actuator 27.
[0071] When the actuator 27 is to be filled with air the fill valve
is manipulated to the open position. At this the air flows via the
second air duct 33 and the nozzle 35 into the first air duct 31 and
on to the hose 28 and the actuator 27. The nozzle 35 provides
pressure equalization to make the pressure in the first air duct 31
(which is the pressure sensed by the pressure sensor 32)
approximately equal to the pressure in the actuator 27. The nozzle
35 will delay the inflation of the actuator 27 slightly but not
significantly. Therefore the throttling of the nozzle 35 is a
compromise between rapid filling of the actuator 27 and pressure
equalization between the pressure sensor 32 and the actuator 27.
The arrangement of the nozzle 35 will therefore be dependent on the
function of the actuator 27. With actuators that require rapid
filling, e.g. the above air cushions 23 and 24, the throttling in
the nozzle 35 must only restrict the air flow to the actuator to a
small extent. In these cases the preferred solution is one in which
the pressure is measured in the actual actuator by connecting the
pressure sensor directly to the volume therein via a separate
hose.
[0072] With a lung 6 the inflation takes place over a longer time.
However, it is now even more crucial to control the pressure.
Therefore the pressure equalization requirements are stricter and
the throttling must to a greater extent slow the air flow.
[0073] The fill valve 34 closes when the pressure in the first air
duct 31 reaches a desired value. If the actuator 27 is to be
deflated again immediately (as in the case of a lung) the purge
valve 29 is opened and the air is released.
[0074] If the actuator 27 is not completely empty of air prior to
the commencement of the next inflation (which may easily happen
e.g. in the case of a simulation of rapid breathing) the pressure
in the actuator, hose 28 and the first air duct 31 will be higher
than it was at the commencement of the previous inflation. However
the pressure sensor will stop the inflation at the same pressure as
before. Overinflation of the actuator and any rupturing of this is
therefore prevented.
[0075] FIG. 5 is a longitudinal section through the head 1 of the
simulator. The head 1 comprises an inflexible inner shell 41
covered in a soft skin 40. In an area of the head corresponding to
where the greater or front fontanelle is found on an infant, is a
recess 45 in the inner shell 41. In this recess there is provided
an air cushion 43 connected to a source of compressed air (not
shown) via a hose 42. A flexible body 44 such as a block of foam
rubber is arranged between the air cushion 43 and the skin 40.
[0076] In order to simulate an increased pressure in the brain the
air cushion 43 is inflated from the air source via the hose 42,
pushing the flexible body 44 against the skin 40, causing this to
move outwards. This is indicated by the dotted line 40' and forms a
swelling in the head 1. The swelling in the head 1 will be visible
and feel soft and yielding, as will be the case with a real
patient. Releasing the air from the air cushion 43 will cause the
swelling to disappear, as the flexible body 44 returns to the
recess 45. If so desired, the manikin can also be provided with a
similar device in the area where the smaller or rear fontanelle is
found on an infant.
[0077] The above describes the use of pneumatic devices in the
present simulator in order to realize different illnesses together
with normal and abnormal bodily functions. It is also possible to
use other means that the above described pneumatic devices to
achieve the same effects. FIG. 6 shows an alternative solution for
visualising the refraction function, which is also described with
reference to FIG. 1. In the embodiment shown in FIG. 1 the
retraction function is achieved by attaching the lower end of the
strap 8 to a rotating wheel in an eccentric fashion. The rotating
wheel is driven by a motor (not shown) and is attached to the upper
plate 5 via a fastening stay 51. Upon rotation of the wheel 50 this
will produce a refraction of the chest skin 3, in the same manner
as described above. The frequency and timing of the retractions can
be controlled by adjusting the wheel 50 rotation. It would be
appropriate to replace the wheel 50 with a crank handle.
[0078] Other situations that are obvious to a person skilled in the
art can also be realized by means of mechanical devices.
* * * * *