U.S. patent number 3,659,593 [Application Number 05/030,136] was granted by the patent office on 1972-05-02 for cardiovascular assist device.
Invention is credited to Edwin G. Vail.
United States Patent |
3,659,593 |
Vail |
May 2, 1972 |
CARDIOVASCULAR ASSIST DEVICE
Abstract
A cardiovascular assist device for producing an inwardly
orienting pulsating pressure circumferentially to the entire length
of each extremity of a patient, including a main body portion
surrounding the extremity and a lateral body portion being
inflatable to tightly constrict the main body portion about the
extremity before pulsation. The lateral body portion includes a
single inflatable tube having connecting tapes extending
substantially entirely circumferentially therearound and oppositely
circumferentially at least partially around said main body portion
to terminal ends secured to the main body portion. The main body
portion includes an outer restraint material reinforced by a
plurality of circumferentially extending and a plurality of
longitudinally extending restraint tapes, two sheets of resilient
material circumferentially bonded together at longitudinal
intervals and longitudinally along seams to produce a plurality of
overlapping circumferentially extending inflatable bladders, which
are longitudinally spaced from each other, an inner pouch material
and a plurality of fluid couplings communicating with each bladder
and inflatable tube. Mittens are provided to close one end of each
main body portion and similarly constructed to provide an inwardly
pulsating pressure to the respective hand or foot of the patient.
The main body portions and mittens may be donned and doffed by
means of respective longitudinally extending fasteners, and
thereafter manually circumferentially constricted by means of
longitudinally extending lacings prior to the pressure constriction
caused by inflating the lateral body portion.
Inventors: |
Vail; Edwin G. (Simsbury,
CT) |
Family
ID: |
21852693 |
Appl.
No.: |
05/030,136 |
Filed: |
April 20, 1970 |
Current U.S.
Class: |
601/151; 601/152;
128/DIG.15 |
Current CPC
Class: |
A61H
9/0078 (20130101); A61H 2230/04 (20130101); Y10S
128/15 (20130101) |
Current International
Class: |
A61H
23/04 (20060101); A61h 007/00 () |
Field of
Search: |
;128/24,64,87,DIG.20 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
483,111 |
|
Apr 1938 |
|
GB |
|
1,171,361 |
|
Nov 1969 |
|
GB |
|
Primary Examiner: Trapp; L. W.
Claims
I claim:
1. A cardiovascular assist device, comprising: a main body portion
adapted to be assembled around the extremity of a patient, and
having a longitudinal extent with opposite ends; fluid expandable
bladder means within said main body portion for exerting an inward
pulsating pressure to the patient corresponding to pulsating fluid
pressure supplied to the bladder means; separate fluid expandable
chamber means adjacent to and parallel to the longitudinal extent
of said main body portion for expansion in response to fluid
pressure supplied thereto to constrict said bladder means around
the extremity of the patient, closure means attached to at least
one end of said longitudinal extent of said main body portion, said
closure means including a rigid plate longitudinally extending
along one side and adapted to receive the sole or palm of the
patient, and bladder means extending around the entire
circumference of the closure means, said bladder means being
positioned inwardly of said rigid plate.
2. The device of claim 1, wherein said main body portion is adapted
to extend substantially the full longitudinal length of the
patient's corresponding extremity; said expandable chamber means
extending substantially the entire longitudinal length of said main
body portion.
3. The device of claim 1, including a plurality of separate
connecting tapes, each secured at their opposite ends to said main
body portion, to extend from one end partially around said main
body portion, between said main body portion and said expandable
chamber, reversely around said expandable chamber, between said
main body portion and said expandable chamber and partially around
said main body portion to its other end.
4. The device of claim 1, including releasable fastener means
extending for substantially the full length of said main body
portion to permit opening and closing of said main body portion
along one entire longitudinal side for donning and doffing by the
patient.
5. The device of claim 1, wherein said main body portion includes
lacing means extending for substantially its full longitudinal
length to permit manual constriction and expansion of said main
body portion bladder means.
6. The device of claim 1, including a plurality of said cuff
assemblies adapted to be attached to each extremity of the
patient.
7. The device of claim 1, wherein said main body portion has an
outer layer of restraint material being substantially more
dimensionally stable than said bladder means and extending for the
full longitudinal length and full circumference of said main body
portion; and a pouch material forming the inside surface of said
main body portion and extending for the full longitudinal length
and circumference of said main body portion.
8. The device of claim 7, including a plurality of restraint tapes
longitudinally spaced with respect to each other and extending
circumferentially around said main body portion; and a plurality of
additional restraint tapes circumferentially spaced from each other
and extending for the full longitudinal length of said main body
portion.
9. The device of claim 1, including slot means permitting the
passage of a catheter radially through said main body portion to
the arm area of the patient opposite from the elbow; said slot
means being a narrow longitudinally aligned slot extending
completely through said main body portion.
10. The device of claim 9, including reinforcing means extending
externally completely around said slot; and binding means extending
completely externally around said slot, along all the inner walls
of said slot and continuously internally around said slot.
11. The device of claim 1, wherein said closure means includes a
mitten-type body forming a closure for one end of said body.
12. The device of claim 11, including fluid expandable bladder
means extending at least partially circumferentially around said
mitten and longitudinally thereof for exerting an inward pulsating
pressure to the patient in response to being supplied pulsating
fluid under pressure.
13. The device of claim 11, wherein said mitten has releasable
fastener means extending for substantially its full longitudinal
length.
14. The device of claim 13, wherein said mitten includes lacing
means extending for substantially the full longitudinal length of
said mitten and on each side of said releasable fastener means, for
manually constricting said mitten in the circumferential
direction.
15. The device of claim 11, wherein said mitten includes a rigid
plate longitudinally extending along one side and adapted to
receive the sole or palm of the patient.
16. The device of claim 1, wherein said main body portion bladder
means includes a plurality of separate inflatable bags
longitudinally spaced with respect to each other and each
circumferentially extending around the full circumference of the
main body portion.
17. The device of claim 16, wherein each of said inflatable bags
has opposed overlapping ends, with the corresponding ends of all
inflatable bags being longitudinally aligned; and releasable
fastener means for completely opening one longitudinal side of said
main body portion radially opposite from said overlapping ends of
said inflatable bags.
18. The device of claim 16, wherein each inflatable bag includes a
separate fluid coupling; and said expandable chamber means
including a separate fluid coupling.
19. The device of claim 16, including a plurality of longitudinally
spaced and circumferentially extending restraint tapes, with each
tape longitudinally alternating with said inflatable bags.
20. The device of claim 16, including restraint material
circumferentially extending completely around and longitudinally
along said main body portion to form its outer surface; pouch
material circumferentially extending around and longitudinally
along said main body portion to form its inner surface; a plurality
of restraint tapes, each extending circumferentially along the
outer surface of said restraint material immediately radially
opposite the division between longitudinally adjacent inflatable
bags; a plurality of binding tapes circumferentially extending
around the inner surface of said pouch material directly radially
opposite the division between longitudinally adjacent inflatable
bags; each of said inflatable bags being formed of two resilient
sheets; respective ones of said restraint tapes, said restraint
material, said resilient sheets, said pouch material, and
respective ones of said binding tapes being circumferentially
bonded one to the other at least along a common radially extending
plane.
21. The device of claim 16, wherein each of said inflatable bags is
constructed of only two resilient sheets bonded together along
circumferential lines forming the division between longitudinally
adjacent bags and together along two longitudinal lines forming
said overlapping ends.
22. The device of claim 21, including restraint material
circumferentially and longitudinally surrounding and forming the
outer layer of said main body portion; a plurality of anchor tabs,
each having one end secured to the inner surface of said restraint
material and an opposite end secured to a respective one of said
inflatable bags; a pouch material circumferentially extending and
longitudinally extending to form the inner surface of said main
body portion; a plurality of anchor tabs each having one end
secured to a respective one of said inflatable bags and an opposite
end secured to said pouch material; all of said anchor tabs being
located immediately radially of the division between longitudinally
adjacent inflatable bags.
23. The device of claim 22, including a restraint tape
circumferentially extending around said main body portion radially
opposite each division between longitudinally adjacent inflatable
bags.
Description
BACKGROUND OF THE INVENTION
In the past, various devices have been conceived to compress a
single extremity of the human body as a means of treating varicose
veins, skin ulcers, flaccid muscles, and the like. None of these
devices has been configured and integrated in a manner which is
considerate of the total body physiology and body surface area
required to effectively mechanically pump blood to reduce the work
of the heart of sequentially compressing the arteries and veins of
all the extremities, concurrently. It is one thing to apply
pressure and suddenly release it on part of an extremity, but to be
effective, an external cardiovascular assist device must be
sequence pulsated over all extremities, concurrently, with each
pulse sequence being keyed by the patient's electrocardiogram to
effectively augment the arterial pulse wave in the arterial system.
Further, none of the past devices considered the integrated
structural means, using textile-type materials, essential in
assuring pulsating pressures high enough to increase the aortic
pulse pressure while concurrently augmenting arterial and venous
blood flow.
SUMMARY
It is the purpose of this invention to describe the means for the
structural integration of pressure zones required in an external
cardiovascular assist device for reducing the work of the heart and
which is easily operable by physicians, nurses, ambulance
technicians, and the like.
The structural means for this device are capable of transferring
high pressure (up to 10 p.s.i. or more) to the human extremities
with a minimum loss of mechanical advantage within the pressurizing
materials of the cuff assemblies. The sequence pulsating cuff
assemblies encompass, concurrently, all extremities of the human
body, extending from the arm pits to enclose the tips of the
fingers, and from the groins to enclose the tips of the toes.
Another objective of this invention is to utilize the human
physiological responses to eternal mechanical stimulation in the
pressure receptors located in the aortic arch and the resulting
sequences of autonomic reflex action which, when stimulated by an
increase in aortic pressure, reflexively slow the heart rate and
reduce the strength of contraction of heart muscle. It is known
that if the work of the heart is reduced by 25-30 percent,
collateral blood vessels will open within cardiac muscle and will
fill with blood during an increase in the resting phase of the
cardiac cycle. The establishment of this collateral cardiac
circulation can prevent or reduce cardiac infarction which may
result from an occlusion of a coronary artery.
High external mechanical pressure is applied, concurrently and
sequentially, to all the extremities of the human body in proper
sequence with the patient's electrocardiogram and cardiac cycle to
raise the aortic pulse pressure after the aortic valves have
closed. This mechanical increase in the aortic pulse pressure
stimulates the aortic pressure receptors, which in turn reflexively
activate the autonomic reflex arch through the autonomic nervous
system and thence to the heart to slow the heart rate, reduce the
strength of heart muscle contraction, and increase the relaxation
phase of each cardiac cycle. Concurrently, with each sequence
pulsation of the cuff assemblies there is an increase of venous
blood flow back to the heart.
The fully integrated parts will increase the mechanical advantage
of cuff assemblies constructed of textile-type materials. The
integrated structure described herein has been developed to
overcome the stretch (8-19 percent of nominal length) inherent in
various textile-type fabric materials when acted upon by high
applied pressures. This structural integration is essential and a
novel feature of this invention since no industry has as yet
produced a non-elastic flexible fabric of a strength which won't
stretch under high pressure loads. The failure of past concepts to
be effective has been due to a disregard of the losses of
mechanical advantage in force transfer which results from a loose
unsupported construction and a lack of integration of all component
parts in each cuff assembly. A laterally located tube is connected
to the restraint material by interlapping tapes so that expansion
of the lateral tube on inflation fully stretches the outer
restraint material to its maximum stretch to increase the effective
transfer of force from the pulsating pressure, inwardly, applied
within each pressure bladder zone of each cuff assembly,
concurrently, during operation on all extremities of the human
body. Positive control of the bladder volume in each pressure
compartment of each zone is obtained while maintaining a maximum of
applied force from pulsating pressures applied to the arteries and
veins within each bladder zone of each cuff assembly, concurrently,
during operation on all extremities of the human body.
Circumferential structural support is attained adjacent to each
pressure zone of each bladder compartment of each cuff assembly,
concurrently, during operation on all extremities of the human
body.
Means are provided for removing all slack from the restraint cloth
by establishing a pre-stretch condition throughout the entire
length of each cuff assembly prior to the application of pressure
in the laterally located tubes to assure that all restraint
materials will be fully pre-stretched, before maximum stretch is
accomplished on pressurization of the lateral tubes and prior to
sequential pulsation operation on all extremities of the human
body. Rapid donning and doffing of each cuff assembly is obtained
by the proper structural integration of zippers, Velcro, or similar
type closures without affecting the pressure integrity or
mechanical efficiency of operation (restraining force pressures up
to 10 p.s.i. or more) of each cuff assembly in maintaining the
restraint cloth in a fully stretched condition, and maintaining
structural and mechanical function during sequential pulsation
operation on all extremities of the human body.
Means are provided for introducing high pressures (up to 10 p.s.i.
or more) into the bladder compartments for each zone of each cuff
assembly, concurrently and sequentially, while maintaining the
structural integrity of the adjacent restraint cloth and bladder
material during sequential pulsation operation on all extremities
of the human body.
The structural arrangement of the bladder compartments of each zone
of the cuff assembly includes an overlapping segment of sufficient
area to assure that the pressure compartments of each zone fully
encompass the circumferential dimensions of all extremities of the
human body and that the said extensions of each bladder compartment
fully underlie the entire length of the closure device, thereby
assuring that all pulsating pressures are equally applied to the
entire circumferential area of all extremities of the human body,
concurrently, throughout the entire length of each cuff assembly.
An independent compartment in each bladder zone of each cuff
assembly is provided in a proper relationship with the restraint
cloth and of sufficient extent and area to encompass the entire
circumference and underlie the entire length of the closure device,
while concurrently maintaining a minimum bladder volume, yet
assuring a maximum of applied force inwardly to the arteries and
veins within each bladder zone of each cuff assembly, concurrently,
during operation on all extremities the human body.
Sequence pulsation pressure is applied concurrently to the hands
and feet in proper sequence as a functional zone with each cuff
assembly for all extremities of the human body. The slack from the
restraint cloth is removed throughout the entire length of each
mitten assembly prior to the application of pulsation pressure to
assure that all restraint material of the mitten assemblies is
fully pre-stretched prior to the application of pressure loads. The
pressurizable mittens have positive means for controlling the
bladder volume and a means for providing a rigidized integral
support structure to the palm, while maintaining a maximum of
applied force (up to 10 p.s.i. or more) from pulsating pressure to
the arteries and veins of the hand, concurrently, during operation
on all upper extremities of the human body. Rapid donning and
doffing of the mittens is provided by a proper structural
integration of zipper, Velcro, or similar type closures without
affecting the pressure integrity or mechanical efficiency of
operation of each mitten of each upper extremity cuff assembly in
maintaining the restraint cloth in a pre-stretched condition and
maintaining structural and mechanical function during sequence
pulsation operation on all upper extremities of the human body.
High pressure (up to 10 p.s.i. or more) is introduced into the
mitten bladder compartment, concurrently and sequentially, while
maintaining the structural integrity of the adjacent restraint
cloth and bladder material during sequence pulsation operation on
all upper extremities of the human body.
Pressurizable boots are provided with means for removing all slack
from the restraint cloth of each boot assembly prior to the
application of pressure to assure that all restraint material of
said boots is fully prestretched prior to the application of
pressure loads. The pressurizable boots include positive means for
controlling the bladder volume and a means for providing a
rigidized integral support structure to the sole of the foot, while
maintaining a maximum of applied force (up to 10 p.s.i. or more)
from pulsating pressures applied to the arteries and veins of the
foot, concurrently, during operation on all lower extremities of
the human body. Rapid donning and doffing of the presurrizable
boots is attained by a proper structural integration of zippers,
Velcro, or similar type closures without affecting the pressure
integrity or mechanical efficiency of operation of each boot of
each lower extremity cuff assembly in maintaining the restraint
cloth in a pre-stretched condition and maintaining structural and
mechanical function during sequence pulsation operation on all the
lower extremities of the human body. High pressure (up to 10 p.s.i.
or more) is introduced into the boot bladder compartment,
concurrently and sequentially, while maintaining the structural
integrity of the adjacent restraint cloth and bladder material
during sequential pulsation operation on all lower extremities of
the human body.
Means, for example a slot or slit, are provided in the cuff
assemblies for the upper extremities, structurally re-enforced with
restraint tape and located at the proper level of the inner surface
of the elbow between pressure zones and within the circumferential
restraint structure, to enable the physician to insert cardiac
catheters or the like into the arteries or veins of the patient as
may be required in the clinical evaluation of the patient without
interfering with the structural integrity or the mechanical
efficiency and the effective transfer of force from the pulsating
pressures within adjacent bladder zones of each cuff assembly,
concurrently, during operation on all upper extremities of the
human body.
The complete structural integration of all materials in the
construction of this cardiovascular assist device will minimize
and/or eliminate the effect stretching of textile-type materials
has in reducing force transfer as each zone of each cuff assembly
is pressurized, and thereby increase the total effective mechanical
force applied inwardly to the arteries and veins in each zone,
assuring a more effective mechanical pumping pressure acting on the
blood in the arteries and veins.
BRIEF DESCRIPTION OF THE DRAWING
Further objects, features and advantages of the present invention
will become more clear from the following description of a
preferred embodiment shown in the drawing, wherein:
FIG. 1 is a full view of the total cardiovascular assist device
applied, concurrently, to all the extremities of the human
body;
FIG. 2 is a cross section of a cuff assembly taken on line II--II
of FIG. 1, shown in an expanded view to reveal the intimate
relationships for the integration of all component parts as
arranged around each extremity of the wearer;
FIG. 3 is an enlarged cross-sectional view of the high pressure
line connection shown in FIG. 2;
FIG. 4 is an enlarged cross-sectional view taken on line IV--IV of
FIG. 1 showing a catheter slot or slit;
FIG. 5 is a cross-sectional view taken on line V--V of FIG. 1
showing the anchoring of the restraint cloth, bladder material and
pressure pouch material;
FIG. 6 shows a modification of the FIG. 5 structure;
FIG. 7 shows the means for providing overlap of each pressure zone
compartment throughout the length of each cuff assembly in the
enlarged cross section taken essentially on the line VII--VII of
FIG. 1;
FIG. 8 shows the means for removing all slack material from each
cuff assembly before application of pressure in the lateral
pressure tube as shown in the enlarged cross section taken
essentially on the line VII--VII in FIG. 1, with the lacings
closed; FIG. 9 shows the lateral pressure tubes and the
interlapping tapes that provide the means of maximally stretching
the restraint cloth in cross section taken essentially on line
IX--IX as seen in FIG. 1;
FIG. 10 shows the essential details of a pressurized boot, which is
substantially identical to the pressurized mitten except for the
angular relationship between the wrist and ankle;
FIG. 11 is an enlarged cross section of the pressure boot, taken
essentially on line XI--XI as seen in FIG. 10; and
FIG. 12 is a partial cross section of a modification of the FIG. 11
structure.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the cardiovascular assist device of the present
invention includes one or more, with four being shown, cuff
assemblies 1, each of which is designed to encompass an extremity
of the body, for example, the arms and legs. Preferably, each cuff
assembly 1 is tubular in shape with its outer extremity end being
closed and its opposite end being open. The two cuff assemblies for
the two arms of the wearer may be identical or mirror images of
each other. Similarly, the two cuff assemblies for the two legs of
the wearer may be identical or mirror images of each other.
Further, the basic structural features for the leg cuff assemblies
and the arm cuff assemblies are correspondingly identical, except
that there is an angular relationship at the ankle portion of each
leg cuff assembly, because of the correspondingly different angular
relationship between the ankle and wrist of the intended wearer.
For this reason, only one cuff assembly will be described in detail
with the understanding that there is a correspondance between the
cuff assemblies.
Each cuff assembly 1 includes a main body portion 2 and a lateral
body portion 3, which are cooperatively held with respect to each
other by means of interlooping or crossing interconnecting tape
connecting members 4. The main body portion 2 is provided with a
releasable closure, 5 preferably interengaging, for example Velcro,
a zipper, or snaps, which extends from the open end down to the
wrist or ankle area, respectively, so that the main body portion
may be laid open for easy insertion of the wearer's extremity. The
insertion of the extremity is further facilitated by means of
reclosable fasteners, for example Velcro, zippers or snaps, 6 (not
shown in FIG. 1) on their respective hand or foot mittens 7. The
easy donning or doffing of the cuff assemblies by the wearer is
particularly enhanced by the above features and important in view
of the anticipated convalescent condition of the wearer, for
example if the wearer is in a coma resulting from a heart attack.
Each mitten 7 is peripherally secured to the adjacent tubular
structure of the main body portion and their respective fasteners
may or may not be aligned.
Due to the different size extremities to be encountered with
different wearers, the slack in the main body portion 2 existing
after the fasteners 5 and 6 have been closed in taken up as much as
possible manually by means of a lacing 8 extending parallel to and
for the full length of each fastener 5, 6. It is important to take
up this slack because the interior of each main body portion,
including mitten 7, contains an inflatable structure for receiving
pulsed air for cardiovascular assist, which pulsing is known per
se. More efficient transfer of pulsing pressure and a quicker
response time is obtained correspondingly with a tighter fit for
each main body portion 2.
Before the pulsing begins, but after the donned cuff assembly has
been manually tightened by means of the lacings 8, further slack is
mechanically taken out of the main body portions by means of
inflating the lateral body portions to apply a force through the
connecting tape members 4 to tightly constrict the main body
portions about the wearer's extremities. For this purpose, high
pressure air inlet nipples 9 are provided for access to the
inflatable interior of each lateral body portion 3.
Thereafter, known high pressure air pulsating equipment, which will
not be described in detail in this application, is fluid connected
by means of the fluid couplings 10 to the inflatable interior of
each main body portion 2.
The somewhat schematic representation in FIG. 2 shows the over-all
arrangement of the various components in cross section, which
components will be shown in more detail in subsequent figures with
more detailed explanation. The extremity 11 of the wearer is
directly contacted by a suitable pouch material 12 which may be
cotton, nylon, or the like. Surrounded by the pouch material 12,
there is an overlapping inflatable bag structure 13, which overlaps
as shown at its ends 14 beneath the fastener 5. The tape connecting
members 4, as seen in FIG. 2, extend from the lacing 8
counterclockwise approximately one-fourth of the way around the
main body portion 2, between the main body portion 2 and the
lateral body portion 3, clockwise substantially the entire way
around the lateral body portion 3, between the main body portion 2
and the lateral body portion 3, and counterclockwise for less than
one-fourth of the way around the main body portion 2 to its free
terminal end 15 where it is secured to the main body portion 2.
Thus, it is seen that the tapes 4 extend between the main body
portion 2 and the lateral body portion 3 in the manner of a fugure
8 so that inflation of the lateral body portion 3 from its full
line position to the dotted line position 16 will exert a
considerable force upon the tape connecting members 4, which will
be applied around the entire periphery of the main body portion 2
for constricting the main body portion 2 tightly around the
extremity 11 of the wearer. To assist in the transfer of these
forces and to enclose the bag structure 13, substantially the
entire outer surface of the main body portion 2 is provided by an
outer layer of restraint material 17, which may be cotton, nylon or
the like. Preferably, the restraint material 17 is a woven material
with the warp and woof oriented at approximately an angle of
108.degree..
One of the couplings 10 is shown in detail in FIG. 3, and is
substantially identical to the structure of the nipples 9. As
shown, the coupling provides fluid access from the exterior through
the restraint material 17, and an outer air impermeable wall 18 of
the bag structure to the interior of the bag structure for
inflating and deflating the bag structure 13, or the inflatable
lateral body portion in the case of nipples 9. A threaded stem 19
is provided with an inner flange 20, which one-piece construction
may be of metal or like rigid materials. A plurality of angular
gaskets 21 are cemented respectively between the flange 20 and the
bag material 18, between the bag material 18 and the restraint
material 17, and between the restraint material 17 and a nut 22
threaded onto the stem 19. In this manner, the stem 19 is sealingly
secured to the assembly and provided with an outer portion for the
reception of a complementarily formed pressure nozzle. The nut will
clamp the gaskets and assist the cement in this sealing.
As seen in FIG. 1 and in more detail in FIG. 4, an aperture or slot
23 is provided in at least one of the arm cuff assemblies 1 in the
region opposite the elbow, which provides access to the wearer's
arteries and veins for the insertion or maintenance of cardiac
catheters or the like. A physician or technician may insert these
catheters while the cuff is on the patient or prior to the cuff
assembly being donned for required clinical evaluation of the
patient, without interfering with the structural integrity or the
mechanical efficiency and effective transfer of force from the
pulsating pressures within the adjacent bladder zones of each cuff
assembly. If the catheter is inserted into the patient prior to
donning of the cuff assembly, the various tubes may be threaded
through the aperture 23 without removal of the catheter during
donning of the cuff assembly.
As shown most clearly in FIG. 4, the aperture 23 extends through
the outer restraint material 17, both layers of the bag material
18, and the inner pouch material 12. Preferably, cement is provided
between each of these layers so that there is a tight sealing
arrangement, particularly with respect to the two layers of the bag
material 18, which must have an airtight seal. For reinforcement of
the aperture, a restraint tape 24 of suitable strong and thick
woven material or the like is provided on all sides of the aperture
23, which restraint tape may be approximately three-fourths inches
wide and 11/4 inches long To provide a smooth lining for the
aperture 23 between the layers, a binding material 25 extends over
the restraint tape 25, lines the aperture 23 and extends under the
pouch material 12 as shown on all sides of the aperture 23. The
restraint tape 24 and binding material 25 may be cemented and/or
stitched to the adjacent layers. A suitable method of assembly
would include the cementing and perhaps stitching of he layers 12,
18, 17 and 24, the forming of the aperture 23 with a sharp blade or
electric burning tool to approximately a length of 1 inch through
all of the layers, and the later cementing and/or stitching of the
binding tape 25 around the thus formed aperture to prevent fraying
and abrasion.
From a comparison of FIGS. 1 and 5, it is seen that each of the
cuff assemblies 1 includes a plurality, particularly 4 excluding
the mittens, of independently inflatable bags or bladders 26, which
extend circumferentially around the wearer's extremity and are
axially spaced with respect to each other. Each of these inflatable
bags 26 may be formed by pairs of bag material 18 or by only two
sheets of bag material 18 for each cuff assembly by providing a
cemented seam 27 between adjacent bags 26. The bags 26 are anchored
adjacent their seams 27 to the adjacent layers of restraint
material 17 and pouch material 12 by means of a plurality of anchor
tabs 28 that are cemented to their respective restraint material 17
or pouch material 12 at one end and cemented at their other end to
the adjacent layer of bag material 18. The restraint tape 24 is
provided immediately overlying the seams 27 and the anchor tabs 28
to provide additional reinforcement in this important area.
Alternately, or in addition, the restraint tapes 24 and anchor tabs
28 may be stitched to their respective adjacent materials.
In FIG. 6, there is shown a construction that could be used instead
of a construction shown in FIG. 5 to form the plurality of separate
bags 26'. With this modification, the restraint tape 24', the
restraint material 17', the bag material 18', the pouch material
12', and an over-tape for reinforcement 29 are stitched and/or
cemented together. The construction shown in FIGS. 5 & 6 are
necessary to form the separate pressure zones or bags, for
circumferential alignment, and to assure proper bladder or bag
positioning and structural support. Thus, positive volume control
for each pressure zone is obtained by the complete integration of
all components as described above. This is accomplished by securely
anchoring all layers of materials one into the other and is
essential in preventing lateral or longitudinal displacement of the
pressure zones or bags of all cuff assemblies on the extremities of
the wearer as well as to assure the maximum inward direction of
mechanical forces during sequence pulsation operation.
FIG. 7 shows in greater detail some of the structural features that
were somewhat schematically shown in FIG. 2 and on a larger scale.
The fastener 5, which is shown as a zipper, has its connecting
tapes 29 stitched or otherwise secured to the adjacent restraint
material 17 and pouch material 12. Furthermore, the stitching will
secure the ends of the circumferentially extending restraint tapes
24 and extend along the outermost longitudinally extending
restraint tapes 24 for additional reinforcement. It is seen that
the pouch material 12 extends from where it is stitched as
mentioned above to the left of the fastener 5, as seen in FIG. 7,
downwardly and to the right to end 30 where it is folded back
around the sealed edges of the bag material 18 to overlie and
protect these edges, where it is stitched or otherwise secured. The
same sheet of material 12 may extend back towards the left or an
additional sheet of pouch material 12 may be used as shown, which
would also be secured at end 30. Similarly, the other terminal edge
of the pouch material 12 extends from where it is stitched to the
right-hand tape 29 of the fastener 5 downwardly and to the right to
point 31 where it is stitched or secured to an additional sheet of
pouch material 12 that extends back towards the left and over its
bag material 18. To assure the proper positioning of the
last-mentioned two sheets of pouch material 12, an anchor tab 28 is
secured between the pouch material 12 at point 31 and the adjacent
sheet of bag material 18. At securement point 32, the structure is
substantially a mirror image of the structure recited at end 30,
with a single sheet of pouch material 12 extending
circumferentially around the extremity of the wearer from edge 32
to end 30.
Also, the lacings 8 are shown in more detail in FIG. 7, wherein the
two parallel lacing tapes 33 are secured by stitching or the like
on the right to the restraint material 17, with the interposition
of the terminal ends of the circumferentially extending restraint
tapes 24, and on the left to the restraint material 17 with the
interposition of the terminal ends of the tape connecting members
4. Each of the lacing tapes 33 is provided on its edge facing the
other lacing tape with a plurality of loops 34, through which
extend the laces 35, in a known manner so that by adjustment of the
laces 35, the lacing tapes 34 may be drawn together for
constricting the restraint material 17 about the wearer's
extremity. Since the restraint material 17 extends as one piece
beneath the lacings 8, there will be formed slack restraint
material at 36 when the lacing tapes 34 are drawn together, so that
the cuff assemblies are sealed at the lacings.
The structure shown in FIG. 7 provides an overlapping of the
pressure bags beneath the fastener 5, which will not only
facilitate donning and doffing of the cuff assemblies 1, but will
also assure a continuous overlap of all pressure zones throughout
the entire length of each cuff assembly for all extremities and
provides for a uniform application of pressure to the surfaces of
all extremities during sequence pulsation operation. Structural
integrity is further maintained by means of circumferentially
extending restraint tapes 24 and the longitudinally extending
restraint tapes 24. Direct action and quick response of the
pressure pulsations within the pressure zones is assured by the
manual tensioning of the restraint cloth 17 through adjusting the
laces 35 to draw the lacing tapes 33 toward each other, which will
also maintain a continuous tension on the restraint cloth
circumferentially and longitudinally to thereby establish a
pre-stretched condition for the entire length of the cuff
assemblies. FIG. 8 illustrates the manner in which the restraint
material slacked at 36 will fold tightly under the pressure exerted
by the tensioned cuff assembly against the wearer's extremity
during tightening the laces 35.
After the laces 35 have been tightened as mentioned above to the
construction of FIG. 8, the lateral body portions 3 will be
inflated to react through the tape connecting members 4 for further
constricting the main body portion 2 about the wearer's extremity.
This relationship is shown particularly in FIG. 9. The lateral body
portion 3 has a longitudinally extending restraint tape 24, which
is stitched to the outer tubular restraint material 37 to securely
hold the tape connecting members 4 in their proper spacing
longitudinally of each other and to provide structural integrity
for the lateral body portion. Within each lateral body portion 3,
there is a single inflatable tube 38, which extends the entire
longitudinal length of the lateral body portion within the tube of
restraint material 37. It is thus seen by inflating the tube 38,
the restraint material 37 will expand to tension all of the tape
connecting members 4 and pull additional lengths of tape connecting
members 4 from the main body portion 2 to further constrict the
main body portion 2 about the wearer's extremity. The size of the
inflatable tube 38 is chosen such that its circumference is
approximately one-fifth the circumference of the main body portion
2. The functional length of the tape connecting members 4 is
selected such that maximum expansion of the lateral pressure
inflatable tube 38 will apply maximum stretching force,
circumferentially, through the diametrically opposed integrated
anchor of points for the terminal ends of the tape connecting
members 4 on the main body portion 2. Structural reinforcement of
the anchoring points is provided by the restraint tapes 24
extending for the entire longitudinal length of the lateral body
portion 3 along the middles of the tape connecting members 4 and
the main body portion 2 along the terminal ends of the tape
connecting members 4. As previously mentioned, each inflatable tube
38 has access to its inflatable interior by means of a nipple 9
shown in FIG. 1. In this manner, structural integration and support
of all component parts of each cuff assembly is provided, by
interconnection of all restraint material 17, restraint tapes 24,
bladder or bag material 18, pouch material 12, fastener 5, tape
connecting members 4, lacings 8, and the inflatable tube 38.
A mitten, particularly a foot mitten, is shown in FIG. 10, with
like numerals applied to structural elements that are identical to
previously described structural elements. It is understood that the
hand and foot mittens are substantially identical, except for the
correspondingly angular difference between the ankle and wrist
portions thereof. However, it is seen from FIG. 10 that two lacings
8 are provided, one on each side of the fastener 5, instead of only
one lacing as previously described with respect to the main body
portions 2. Each mitten is secured to the terminal end of its
respective main body portion 2, to close the same.
Specific details of the mittens are shown in FIG. 11, with like
numerals being used as mentioned above. The upper portion of FIG.
11 is substantially identical to the structure shown in FIG. 7 with
respect to the details of the fastener 5, lacings 8, and the
overlapping of pouch material 12 and bag material 18 beneath the
fastener 5, except that in FIG. 11, two lacings are provided.
Therefore, for details of the various structural components,
reference is made to the description with respect to FIG. 7, which
is equally applicable with respect to identical structural
components as shown by like numerals.
Each mitten is provided with a hard sole or palm portion 39, as the
case may be respectively for the foot or hand. This hard sole 39 is
covered on each face by means of pouch material 12. The hard sole
39 is constructed of metal, or similar rigid material, and of a
sufficient strength to resist bending during sequence pulsation and
thereby increase the effectiveness of the sequence pulsating
bladder 26. Fluid access to the bag 26 is provided by means of a
fluid coupling (not shown in FIG. 11) which is identical to the
fluid coupling shown in FIG. 3. It is seen that all of the terminal
ends of the sheet material, except for the restraint tapes 24, are
assemblied at the edges of the sole 39 where they are sealed by
cement and otherwise tightly secured together, with the outer layer
of restraint material 17 being folded around the edge portions to
prevent fraying and abrasion.
A further modification of the sole structure is shown in FIG. 12.
In this modification, the bag material 18 extends completely across
the rigid sole 39 and is connected respectively by anchor tabs 28
to the inner pouch material 12 and the outer restraint material
17.
OPERATION
It is known physiologically that a pressure gradient exists,
inwardly whenever mechanical pressure is applied to the surface of
the human body. Therefore, it is an important feature of the
present invention to provide the means for introducing high
pressure (up to 10 p.s.i. or more) into all pressure zones or
individual pressure bags of the main body portions and inflatable
tubes of the lateral body portions to assure that adequate
mechanical forces are obtained during the operation of the
cardiovascular assist device. Each cuff assembly is so constructed
for each body extremity so that the pulsating forces tending to
increase the circumferential size and longitudinal length by
stretch of the fabric-type materials of each pressure zone
compartment will be optimally balanced, one against the other, when
pulsating pressures are applied. In this manner, the maximum
restraint characteristics inherent in the weave of the warp and
woof of the fabrics, due to the friction of interlocking threads
within the fabrics, are utilized to resist further stretching, when
pulsating pressure is applied, by first removing all slack within
the restraint cloth by manually tightening lacings to establish a
prestretched condition, and thereafter by mechanically
pre-stressing all of the fabrics with the introduction of high
pressure fluid within the lateral body portion inflatable tubes.
Maximum stretch, pre-setting the restraint cloth is then obtained
through the combined efforts of the manual lacing and the
pressurized lateral body portions that apply tension to the main
body portions through the tape connecting members.
In use of the cardiovascular assist device for encompassing all
extremities of the human body concurrently, the manipulative
procedures are as follows. The main body portions with their
pressure mittens are donned first with the fasteners 5 open and the
lacings 8 expanded. Each hand and foot is appropriately positioned
against the hard palm or sole support structure of the respective
mittens. Next, the pressure compartment flaps are carefully
overlapped beneath each fastener, which fastener is thereafter
joined and closed. Afterward, the laces are adjusted to manually
take up any slack within the restraint cloth and pre-tension the
restraint cloth for each main body portion, including mittens. The
wrist flaps and ankle flaps of adjacent inflatable bags are
configured such that the arm and leg cuff assemblies, respectively,
will overlap the flaps by approximately 3 or 4 inches. At
appropriate points within the preceding donning procedure, any
catheters that were previously inserted within the patient's
arteries or veins adjacent the elbow portion of his extremity, are
fed through the aperture or slot and the corresponding cuff
assembly, or after donning, the appropriate catheter is
inserted.
Thereafter, the inflatable tube of each lateral body portion is
connected by a suitable pressure coupling to a constant pressure
source of high pressure fluid to inflate the lateral body portions
and correspondingly constrict the main body portions.
Each separate pressure zone or bag of each cuff assembly is
independently connected by means of its fluid coupling to the
mechanical sequence pulsating unit (not shown, but conventional).
Suitable electrodes 40 are secured to the wearer in a known manner
as shown in FIG. 1 to obtain the electrocardiographic signals
required to control and phase the pulsating sequence with each
cardiac cycle of the patient. The total cardiovascular assist
device applied to all extremities of the human body is then ready
for sequence pulsation operation. The entire sequence pulsation,
simultaneously for all ends or extremities, takes place within the
pressure bladders of each zone concurrently in each cuff assembly
during the time of one heartbeat, at which time pressure is
released and the zonal sequence repeated with the next
heartbeat.
While several modifications of the preferred embodiment of the
present invention have been specifically illustrated and described,
it is understood according to the broader principles of the present
invention many modifications, embodiments and variations are
contemplated.
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