Note: Descriptions are shown in the official language in which they were submitted.
1~7'~3'7~;
BACKGROVND OF THE INVENTION
The present invention relates to therapeutic and
prophylactic devices, and more particularly to devices for
applying compressive pressures against a patient's limb.
It is known that the ve:Locity of blood flo~ in a
patient's extremities, particular:Ly the legs, markedly de-
creases during confinement of the patient. Such pooling or
stasis of blood is particularly pronounced during surgery,
immediately after surgery, and when-the patient has been con-
~ined to bed for extended periods of time. It is also known
that stasis of blood is a significant cause leading to the
formation of thrombi in the patient's extremities, which
~` may have a severe deleterious effect on the patient, includ-
ing death. Additionally, in certain patients it is desirable
to move fluid out of interstitial spaces in extremity tissues,
in order to reduce swelling associated with edema in the
extremities.
SUMMARY OF THE INVENTION
A principal feature of the present invention is
the provision of a device of simplified construction for
applying compressive pressures against a patient's limb in
an improved manner.
The device of the present invention comprises, an
elongated pressure sleeve for enclosing a length of the
patient's limb, with the sleeve having a plurality of separate
fluid pressure chambers progressively arranged longitudinally
along the sleev~e from a lower portion of a limb to an upper
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portion of the limb proximal the patient's heart relative
the lower portion. The device has means for intermittently
forming a plurality of fluid pressure pulses from a source
of pressurized fluid in a timed sequence during periodic com-
pression cycles. The device has means for connecting thedifferent pressure pulses of the sequence to separate cham-
bers in the sleeve in an arrangement with later pulses in
the sequence being connected to more upwardly located cham-
bers in the sleeve. The device has means for intermittently
connecting the chambers to an exhaust means during periodic
` decompression cycles between the compression cycles.
A feature of the present invention is that the de-
vice applies a compressive pressure gradient against the pa-
tient's limb by the sleeve which decreases from the lower to
upper limb portions.
Another feature of the present invention is that
the device may be adjusted to control the duration of the com-
pression cycles.
Yet another feature of the invention is that the
device may be adjusted to control the duration of the decom-
pression cycles between the intermittent compression cycles.
Still another feature of the invention is that the
duration of the timed intervals between the fluid pressure
pulses may be separately adjusted to control initiation of
compression by selected chambers.
Thus, a feature of the present invention is that
the timing of the applied pressure gradient, as well as the
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compression and decompression cycles, may be suitably mod-
ified to conform with the physiology of the patient.
The connecting means of the device preferably
connects each of the pressure pulses to sets of adjoining
chambers in the sleeve, such that different pulses are con-
nected to contiguous sets of adjoining chambers. The device
also has means for progressively decreasing the rate of pres-
sure increases in progressively located upper chambers of
each adjoining chamber se'c.
Thus, a feature of the invention is that different
pulses are sequentially applied to separate sets of adjoining
chambers.
- Another feature of the invention is that the pres-
sure rise times in the adjoining chambers of each set are con-
trolled to produce a progressively aecreasing compressive pres-
- sure profile in the chambers of each set.
Yet another feature of the invention is that the
pressure rise times in the chambers of progressively located
chamber sets are controlled to produce a desired compressive
pressure profile from a lower to upper portion of the sleeve.
` Still another feature of the invention is that the
forming means preferably forms later pulses in the sequence
` from a preceding pulse in the sequence to prevent a possible
inversion of the compressive pressure gradient,
A feature of the present invention is that the de-
vice applies continued pressure against a lower portion of the
leg while an upper portion of the leg is being compressed,
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.
Yet another feature of the invention is that the
slee~e preferably defines chambers having progressively
increasing volumes progressively upwardly along the sleeve
to facilitate formation of a compressive pressure profile
against the limb which decreases from a lower to upper por-
tion of the sleeve. -
Still another feature of the invention is that thedevice empties the sleeve during the decompression cycles while
maintaining a pressure profile which decreases from a lower to
upper portion of the sleeve.
Further features will become more fully apparent
in the following description of the embodiments of this inven-
tion and from the appended claims.
- DESCRIPTION OF THE DRAWINGS
In the drawings:
Fig. 1 is a perspective view of a pair of compres-
sion sleeves used- in the sequential intermittent compression ¦~
~evice of the present invention;
Fig. 2 is a front plan view of a compression sleeve
. . .
of Fig. l;
Fig. 3 is a back plan view of the sleeve of Fig. 2;
Fig. 4 is a sectional view taken substantially as
indica~ed along the line 4-4 of Fig. 3;
Fig. 5 is a schematic view of a manifold for use l;
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in connection with the device of Fig. l;
Fig. 6 is a perspective view of the manifold ~or
use with the device of Fig. l;
Fig. 7 is a sectional view taken substantially as
indicated along the line 7-7 ~ Fig. 6;
Fig. 8 is a graph illustrating pressure-time
curves during operation of the compression device;
Fig. 9 is a schematic diagram of one embodiment
of a pneumatic control circuit for the compression device7
Fig. 10 is a schematic diagram of another embod-
iment of a pneumatic control circuit for the compression de-
vice; and
Fig. 11 is a schematic diagram of another embod-
iment of a pneumatic control circuit for the compression de-
vice.
.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to Figs. 1, 6, and 9-11, there is
sho~n a sequential intermittent compression device generally
designated 20 for applying compressive pressures against a
patient's extremities, such as the legs. The device 20
has a controller 22, as illustrated in Figs. 9-11, a manifold
24, as shown in Fig. 6, and a pair of compression sleeves 26
for enclosing lengths of the patient's legs, as shown in Fig.
1. The controllers 22 of Figs. 9-11 intermittently form a
plurality of fluid pressure pulses from a source S of pressur-
ize~ gas in a timed sequence during periodic compression or
inflation cycles, and the pulses are separately applied to
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the manifold 24 of Fig. 6 through conduits 28a, 28b, and 28c
at inlet ports of the manifold ~. The manifold 24 of Fig. 6
separates the pulses for passage to the separate sleeves 26
through two sets of conduits 34a and 34b which are separately
connected to the sleeves, as shown in Fig. 1.
As shown in Figs. 2-4, the sleeves 26 have a pair
of flexible sheets 36 and 38 which are made from a fluid im-
pervious material, such as polyvinyl chloride. The sheets 36
and 38 have a pair of side edges 4Oa and 4Ob, and a pair of end
10 edges 42a and 42b connecting the side edges 40a and b. As shown
in Figs. 3 and 4, the sheets have a plurality of laterally ex-
tending lines 44, such as lines of sealing, connecting the sheets
36 and 38 togetherj and a pair of longitudinally extending lines
46, such as lines of sealing, connecting the sheets 36 and 38
together and connecting ends of the lateral lLnes 44, as shown.
The connecting lines 44 and 46 define a plurality of contiguous -
chambers 48a, 48b, 48c, 48d, 48e, and 48f which extend lateral-
ly in the sheet, and which are disposed longitudinally in the
; sleeve between the end edges 42a and 42b. When the sleeve is
placed on the patient's leg, the lowermost chamber 48a is lo-
cated on a lower part of the leg adjacent the patient's ankle,
while the uppermost chamber is located on an upper part of the
leg adjacent the mid-thigh.
In a preferred embodiment, the side edges 40a and
4Ob and the connecting lines 46 are tapered from the end edge
42a toward the end edge 42b. Thus, the sleeve 26 has a re-
duced configuration adjacent its lower end to facilitate place-
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ment of the sleeve on the more narrow regions of the legadjacent the patient's ankles. Moreover, it will be seen
that the connecting lines 44 and 46 define chambers having
volumes which progressively increase in size from the lower-
most chamber 48a to the uppermost chamber 48f. The relativesize of the chambers facilitates the device in conjunction
- with orifices to develop a compressive pressure gradient
during the compression or inflation cycles which decreases
from a lower part of the sleeve adjacent the end edge 42b
toward an upper part of the sleeve adjacent the end edge 42a.
.
~- As illustrated in Figs. 3 and 4, the adjoining cham-
bers 48c and 48d may have their adjacent portions defined by
spaced connecting lines 44' and 44" which extend laterally in
the s'eeve between the connecting lines 46. The sheets 36 and
38 may be severed, such as by slitting, along a line 50 between
the lines 44` and 44" to separate the adjoining chambers 48c
and 48d. As shown, the severence line 50 may extend the width
of the chambers between the connecting lines 46. The line 50
- permits free relative movement between the adjoining chambers
when ~he sleeve is inflated to prevent hyperextension of the
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leg during operation of the device, and also facilitates siz-
ing o~ the sleeve to the leg of a paxticular patient.
The sleeve 26 may have one or more sheets 52 of a
soft flexible material for covering the outside of the fluid
impervious sheets 36 and 38 relative the patient's leg. The
sheets 52 may be made of any suitable material, such as Tvvek,
a trademark of E.I. du Pont de Nemours, and provide an aes-
thetically pleasing and comfortable outer surface for the sleeve
26. The sheets 52 may be attached to the sheets 36 and 38 by
any suitable means, such as by lines 54 of stitching along the
side edges 4Oa and b and end edges 42a and b which pass through
the sheets 52 and sheets 36 and 38 to secure the sheets together.
As shown in Fig. 2, the sheets 52 may have a plurality of open-
ings 56 to receive a plurality of connectors 58 which are se-
cured to the sheet 36 and which communicate with the separate
ohambers in the sleeve 26. As illustrated in Fig. 1, the con-
nectors 58 are secured to the conduits 3~a and b, such that the
conduits separately communicate with chambers in the sleeve
` through the connectors 58.
As best shown in Fi~s. 2 and 3, the sleeves 26 may
have a plurality of hook and loop strips 60 and 62, respectively,
to releasably secure the sleeves about the patient's legs. The
hook strips 60 extend past one of the side edges 4Ob of the
sleeve, while the loop strips 62 are secured to the outside of
the outer sheet 52. During placement, the sleeves 26 are wrapped
; around the patient's legs, and the hook strips 60 are releasably
attached to the associated loop strips 62 on the outside of the
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sleeves in order to secure the sleeves on the legs and confine
movement of the sleeves away from the patient's legs when in-
flated during operation of the device.
As will be further discussed below, the controllers
22 of Figs. 9-11 intermittently form a plurality of fluid pres-
sure pulses in a timed sequence during the periodic inflationor compression cycles, in order to sequentially initiate in-
flation of different chambers in the sleeves. In the particular
embodiments shown, the controllers 22 form three timed pressure
pulses during each inflation cycle which are utilized to inflate
; the six chambers in each of the sleeves, such that each pulse is
associated with two chambers in the sleeves. However, it will
be understood that a timed pulse may be formed for each of the
chambers in the sleeves, and that the number of timed pulses
may be varied in accordance with the particular type of sleeve
being used in the device.
A graph of the pressures P formed in the chambers of
each sleeve with respect to time T is shown in Fig. 8. The time
to designates the start of an inflation cycle when a first pres-
sure pulse is formed by the controller, and the first pulse is
appliea to the two lowermost chambers in each of the sleeves at
that time~ As will be discussed below, the manifold separates
the first pulse, and connects the separated pulses to the two
lowermost chambers 48a and 48b, as designated on the correspond-
ing curves of Fig. 8. As shown, the pulse applied to the lower-
most chamber 48a has a faster pressure rise time than the pulseapplied to the adjoining upper chamber 48b, such that the rate
of change of pressure in the lowermost chamber 48a is greater
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than the rate of change of pressure in the adjoining chamber
48b. Accordingly, the sleeve will exert a compressive pres-
sure gradient against the limb which decreases from the lower-
most chamber 48a to the adjoining upper chamber 48b in the
lower set of adjoining chambers until the maximum pressure
in the two chambers is reached and the chambers are ~illed.
The controllQr ~orms the second pressure ~ulse at
the time tl during the inflation cycle, and inflation of the
third and fourth chambers 48c and 48d in the sleeve is initi-
ated at this time. It will be seen that the device initiatesinflation of the third and fourth chambers while the first
and second chambers are still being filled from the first pres-
sure pulse. The second pressure pulse is also separated by the
-~ manifold for the set of the third and fourth adjoining chambers
which have different pressure rise times, as shown, with the
pressure rise time for the third chamber 48c being greater than
. . .
the pressure rise time for the fourth chamber 48d. Thus, as in
; the case of the set of lowermost adjoining chambers, the rate
of pressure change in the third chamber 48c is greater than the -
rate of pressure change in the fourth chamber 48d, such that
the set of intermediate adjoining chambers also exerts a com-
pressive pressure gradient against the limb which decreases from
the third to fourth chamber. Additionally, it will be seen that
the rates of pressure increases in the third and fourth chambers
~ 25 are less than those in the corresponding first and second chambers.
Accordingly, while the third and fourth chambers are being filled,
the pressures applied by the third and fourth chamber of the
sleeve are less than the pressures applied by the first and second
chambers, and the first, second, third, and fourth chambers thus
exert a compressive pressure gradient which d~creases from the
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lowermost chamber 48a through the fourth chamber 48d.
- At the time t2 the controller initiates formation of
the third pressure pulse for the fifth and sixth chambers 48e
and 48f. As before, the pressure rise time in the fifth chamber
48e is greater than that in the uppermost sixth chamber 48f, such
that the rate of change o~ pressure in the fifth chamber is
greater than the rate of change of pressure in the sixth chamber.
` Accordingly, the set of adjoining uppermost chambers applies a
compressive pressure gradient against the patient's limb which
decreases from the fifth to sixth chambers. As shown, the pres-
sure rise times in the fifth and sixth chambers are less than
those in the four lowermost chambers, and while the fifth and
- sixth chambers are being filled, the pressure in these uppermost
chambers is less than the pressures in the four lowermost cham-
bers. Thus, the sleeve applies a compressive pressure gradient
against the patient's limb which decreases from the lowermost
chamber 48a to the uppermost chamber 48f in the sleeve. Once
reached, the maximum pressures in the two lowermost chambers 48a
and 48b are generally maintained throughout the inflation cycle
while the remaining chambers are still being filled. Similarly,
when the maximum pressures are attained in the third and fourth
chambers 48c and 48d, these pressures are generally maintained
while the pressures are increased in the uppermost fifth and sixth
chambers 48e and 48f. Maintenance of pressures in a lower set of
chambers may be subject to slight diminution when inflation of an
upper set of chambers is initiated. Finally, when the maximum
pressures are obtained in the fifth and sixth chambers, all of
the chambers have achieved bheir maximum pressures durin~ the
inflation cycle. In a preferred form, as shown, the maximum
pressures attained in a lower set of chambers is greater than
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those in an upper set of chambers, although the maximum pressures
in the various sets may approach a comparable value, as desired.
In this manner, the device intermittently applies a compressive
pressure gradient by the sleeve during the inflation cycles which
decreases from a lower part of the sleeve to an upper part of the
sleeve.
The controller initiates a deflation cycle at the time
t3 when the air is released from the chambers, in order to
deflate the chambers-and release the pressures applied by the
sleeves against the limb.
The deflation cycle continues through a period of time
until the subsequent time to~ when the controller again initiates
formation of the first pressure pulse during a subsequent infla-
tion cycle. The controller thus intermittently forms a Plurality ~ -
o~ pressure pulses in a timed sequence for inflating the sleevesdu~ing periodic inflation cycles, and intermittently releases
pressure from the sleeves during periodic deflation cycles between
the inflation cycles.
As will be seen below, the time intervals between initia-
tion of the sequential pressure pulses, i.e., between times to andtl, and between times tI and t2, is adjustable to modify the timed
relationship of the pulse sequence. Additionally, the time inter-
val elapsed during the inflation cycle, i.e., the time interval
between times to and t3 is also adjustable to modify the duration
of the periodic inflation cycles. Moreover, the time interval
during the deflation cycles, i.e., the time interval bètween times
t3 and to~ is adjustable to modify the duration of the periodic
deflation cycles. Thus, the various time intervals associated
with applying an~ removing the pressure gradients by the sleeves
are suitabl~ adjustable according to the physiology of the patient.
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The controller 22 ard manifold 24 are illustrated in
schematic form in Fig. 5. The controller 22 forms and applies
the first pressure pulse to a first manifold section 6~a throu~h
the conduit 28a. The manifold section 64a separates the first
pulse through a pair of orifices 66a and 66b, and simultaneously
supplies the separated first pulses to separate manifold sections
68a and 68b. In turn, the manifold section 68a further separates
the pulse through orifices or ports 70a and 70b, which permit
free passage of gas therethrough or are of~equal size, an~ simul-
taneously supplies the separated pulses to the two lowermost cham-
~bers 48a in the pair of sleeves respectively through the associated
conduits 34a and 34b. Similarly, the manifold section 68b sepa-
rates the pulse through similar orifices or ports 70c and 70d, and
simultaneously supplies the separated pulses to the two second
chambers 48b in the pair of sleeves through the associated conduits
34a and 34b. As shown, the effective size of the orifice 6~a is
substantially greater than the effective size of the orifice 66b
in the manifold section 64a, such that the rate of flow o~ gas
to the manifold section 68a is greater than the rate of flow of
gas to ~the manifold section 68b. However, the effective sizes of
the orifices 70a, b, c, and d in the sections 68a and b are such
; that the rate of gas flow through the section 68a to the two
- lowermost chambers 48a in the sleeves will be the same, while the
rate of gas flow through the section 68b to the two second chambers
48b-in the sleeves will also be the same although less than that
to the two lowermost chambers. Accordingly, the rate of gas flow
- through the section 64a ~o the two lowermost chambers 48a will be
greater than the rate of gas flow through the section 64a to the
two second chambers 48b, although the rate of flow to the two
~0 lowermost~chambers 48a will be the same and the rate of flow to
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the second chambers 48b will be the same. In this manner, the
lowermost chambers are filled at a greater rate than the second
chambers and have faster pressure rise times, such that a com-
pressive pressure gradient is produced in the first and second
chambers of the separate sleeves which decreases from the first
- chamber 48a to the second chamber 48b. The relative rate of gas
flow through the manifold section 64a may be controlled by suit-
able selection of the internal diameters of the orifices 66a and
66b.
The controller 2~ forms and supplies the second pulse
in the sequence to the manifold section 64b. The section 64b
separates the second pulse through a pair of orifices 66c and 66d,
with the orifice 66c having an effective greater size than the
orifice 66d, such that the resulting pulse supplied to the mani-
fo~ section 68c will have a greater flow rate than the pulse sup-
plied to the section 68d. As shown, the section 68c separates the
pulse through orifices 70e and 70f, and simultaneously supplies the
separated pulses to the two third chambers 4~c in the pair of
sleeves through the associated conduits 34a and 34b. The effec-
2Q tive sizes-of the orifices 70e and f are such that the rate of
gas-flow into the third chambers 48c of the two sleeves will be
approximately the same. Similarly, the section 68d separates the
pulse supplied to this section through orifices 70g and 70h, and
simultaneously supplies the resulting separated pulses to the two
25 - fourth chambers 48d of both sleeves through the associated con-
duits 34a and 34b. Again, the effective sizes of the orifices
70g and 70h are such that the rate of gas flow into the fourth
chambers through conduit 34a and 34b will be approximately the
same. However, since the effective size of orifice 66c is greater
10'7'~3~
than that of orifice 66d, the flow rate through section 68c to
the third chambers 48c is greater than that through the section
68d to the fourth chambers 48d. Thus, the pressure rise times in
the third chambers of the sleeves is greater than those in the
fourth chambers of the sleeves, and the third and fourth chambers
apply a compressive pressure gradient against the p~tient's limb
which decreases from the third to fourth chambers. As previously
discussed in connection with Fig. 8, the second pressure pulse is
formed by the controller 22 after formation of the first pulse,
and the pressure rise times in the chambers decrease upwardly
along the sleeve. Accordingly, the timed pulses supplied to the
lower four chambers in the sleeves result in application of a com-
pressive pressure against the patient's limb which decreases from
the lowermost chamber 48a to the fourth chamber 48d.
As will be discussed below, the controller 22 forms the
second pressure pulse, which is supplied to the manifold through
.
the conduit 28b, from the first pressure pulse which is supplied
to the manifold through the conduit 28a. The controller forms
the second pulse in this manner to produce the progressively
decreasing pressure rise times in the chamber sets and to prevent
a possible inversion of the pressure gradients applied by the
sleeves, since the second pressure pulse will not~be formed unless
the first pulse has been properly formed.
However, since both manifold sections 64a and b are
supplied from the first pulse after the second pulse has been
formed, a lesser filling pressure is available to the section 64b
than was initially available to the section 64a b~fore formation
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of the second pulse. Thus, the effective size of the orifice 66c
: of section 64b is made greater than that of the corresponding
orifice 66a in the section 64a to obtain the desired comparable,
although decreasing, pressure rise times in the.correspond-
S ing first and third chambers. Similarly, the orifice 66d of sec-
tion 64b, although smaller than the orifice 66c in the same sec-
tion, has an effective greater size than the corresponding orifice
.~ 66b in the section 64a to obtain the aesired comparable and
decreasing pressure rise times in the corresponding second and
fourth chambers. Thus, although the controller supplies gas for
the second pressure pulse to the section 64b from the first pres-
. sure pulse, the effectively increased orifice sizes in the section
64b provide separate filling rates for the third and fourth cham-
bers which are comparable to, but preferably less than, the sepa-
rate filling rates for the first and second chambers of the sleeves
respectively, such that the pressure rise times in the third and
~ fourth chambers are comparable to, but preferably less than, the
: corresponaing pressure rise times in the first and second chambers,
.. as previously discussed in connection with Fi~ 8. `
20 . ~he controller then forms the third pulse, and sup-
plies this pulse to the manifold section 64c through the conduit
. 28c. The section 64c separates the third pulse through flow con-
trol orifices 66e and 66f having effective different sizes, and
simultaneously supplies the separated pulses to the manifold sec-
~5 tions 68e and 68f. In turn, the sections 68e and f separate the
pulses through orifices 70i, 70j, 70k, and 701, and simultane-
ously supplies separated pulses to the fifth ana sixth chambers
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48e and 48f, respectively, of both sleeves through the associated
conduits 34a and 34b. Accordingl~, the rate of gas flow from
the section 64c through orifice 66e to the fifth chambers 48e is
greater than that through the orifice 66f to the uppermost sixth
chambers 48f, such that the pressure rise times in the two fifth
chambers of the sleeves is greater than that in the uppermost
sixth chambers of the sleeves. Thus, the fifth and sixth cham-
bers apply a compressive pressure gradient against the patient's
limb which decreases from the fifth to sixth chambers. Addi-
tionally, since the third pressu~e pulse is delayed relative the
first two pressure pulses and since the pressure rise times in
the fifth and sixth chambers is less than the corresponding
lower chambers, the pressures applied by the fifth and sixth cham-
bers against the patient's limb while being filled are less than
those applied by the lower four chambers, as discussed in con-
nection with Fig. 8, and the six chambers of the two sleeves
thus combine to apply a compressive pressure gradient against
the limbs which decreases from the lowermost chambers 48a to the
uppermost chambers 48f of the sleeves.
As will be discussed below, the third pressure pulse
supplied by the controller 22 through the conduit 28c is formed
from the second pulse supplied through the conduit 28b in order
to prevent an inversion of the desired pressure gradient and to
provide the decreasing pressure rise times. Accordingly, the
effective size of the orifice 66e in the section 64c is made
greater than the effective size of the orifice 66c in the section
64b, while the effective size of the orifice 66f in the section
64c is greater than the effective size of the orifice 66d in the
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section 64b, which also permits the device to maintain the
desired pressures in the lower chambers while filling the upper-
most chambers. Thus, although the lower four sleeve chambers
are driven from the first and second pulses and the third pulse
is driven from the second pulse, the effective increased size
of the orifices in the section 64c relative the sections 64b
and 64a provides comparable, but decreased, pressure rise times
in the uppermost fifth and sixth chambers, in a manner as previ-
ously described.
Referring now to Figs. 5-7, the first, second, and
third pressure pulses are supplied to a manifold housing 72
through the conduits 28a, b, and c, respectively. The manner
in which the first pressure pulse is separated by the manifold
24 for filling the first and second chambers 48a and 48b will
be described in conjunction with Fig. 7. The first pulse is
supplied through the conduit 28a and inlet port 73 to a chan-
nel 74 in the housing 72, and the first pressure pulse is then
separated through the orifices 66a and 66b in the housing 72.
As shown, the internal diameter of the orifice 66a is greater
than the internal diameter of the orifice 66b, such that the
rate of flow of gas from the channel 74 into the housing chan-
nel 76 is greater than the rate of flow from the channel 74 into
the housing channel 78. The pulse formed in the channel 76 is
separated through orifices or outlet ports 7Oa and 7Ob having an
internal diameter of approximately the same size, or of suffi-
ciently large size to prevent obstruction to passage therethrough,
and the separated-pulses from orifices 70a and b are then sepa-
rately supplied to the two lowermost chambers 48a of the pair of
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sleeves through the associated conduits 34a and 3~b. Similarly,
the pulse formed in the channel 78 is separated by the orifices
or outlet ports 70c and 7Od havin~ an internal diameter of
approximately the same size as the orifices 70a and 70b or of non-
obstructive size. The separated pulses pass from the orifices 70cand d through the associated conduits 34a and b to the two second
chambers 48b in the pair of sleeves.
In this manner, the first pulse passing through the
inlet port 73 is separated into separate pulses in the channels
76 and 78, with the pulse in the channel 76 having a faster
pressure rise time than the pulse in the channel 78. In turn,
the pulse in the channel 76 is separated and supplied to the
two lowermost chambers in the pair of sleeves, while the pulse
in the channel 78 is separated and supplied to the two second
ch~nnels in the pair of sleeves. Referring to Figs. 6 and 7j
the second pressure pulse supplied to the manifold 24 through
the conduit 28b is separated in a similar manner through a ser-
ies of channels and orifices for filling the third and fourth
chambers. Similarly, the third pulse, supplied to the manifold
24 through the conduit 28c, is separated by interconnected chan-
nels and orifices, ~ith the resulting pulses being supplied to
the uppermost fifth and sixth chambers. As shown, the manifold
may have a pressure relief valve or pressure indicatlng device
81 secured to the housing 72 and communicating with the channel
74 or with any other channel or port, as desired
In a preferred form, the controller 22 is composed
of pneumatic components, since it is a preferred procedure to
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minimize electrical components in the potentially explosive
environment of an operating room. Referring to Fig. 9, the
controller 22 has a regulator 100 connected to the source S
of pressurized gas in order to lower the supply pressure and
drive the controller circuitry. 'rhe regulator 100 is connect-
ed to a two-position switch 102 through a filter 104. When
ihe switch 102 is placed in an off condition, the gas supply
is removed from the circuitry components, while the switch
connects the supply to the components when placed in its on
condition.
When the switch 102 is turned on, the air supply
passing through the switch 102 is connected to port 105 of a
two-position or shift valve 106. In a first configuration of
the valve, the supply is connected by the valve through the
15 valve port 108 to port 110 of shift valve 112, to port 114 of
shift valve 116, and to port 118 of a positive output timer
120. Actuation of the shift valve 112 at port 110 causes the
valve 112 to connect its port 122 to valve port 124 and exhaust
line 126. Similarly, actuation of the shift valve 116 at port
20 114 causes the valve 116 to connect its port 128 to port 130
and exhaust line 132. Also, the valve 106 connects the line
134 through its ports I36 and 138 to the exhaust line 140.
Accordingly, when the shift valve 106 connects the
gas supply through its ports 105 and 108, the controller in
itiates a deflation cycle during which gas passes from the
sleeve chambers to the various exhaust lines, as will be seen
below. At this time, the supply also initiates the timer 120
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which controls the duration of the deflation cycle. The timer
120 is adjustable to modify the duration of the d,eflation cycle,
and when the timer 120 tumes out, the timer actuates the shift
valve 106 at port 142 to initlate an inflation cycle.
The actuated valve 106 connects the gas supply through
ports 105 and 136 to port 14~ of a positive output timer 146, to
port 148 of a positive output timer 150, to port 152 of a posi-
tive,output timer 159, and through the flow control valve 156 to
port 158 of shift'valve 116. The actuated valve!106 also dis-
connects its port 1~5 from port 108. The flow control valve 156
serves to reduce the relatively high pressure utilized to act-
uate the pneumatic components of the circuitry to a lower pres-
sure for inflating the chambers 1n the sleeves.
The gas supply passing through line 134 and valve 156
also passes through the conduit 28a to the manifold. Accor~ingly,
' the first pressure pulse is formed throuyh the conduit 28a for
filling the first and second chambers 48a and b of the sleeves
at this time. When the timer 15~ times out, the gas supply is
' connected by the timer to port 160 of shift valve 116', which
causes the valve 116 to connect its port 158 to port 128. Thus,
the gas supply passing through flow control valve 156 is connectea
`, ` through the shift valve 116 to the conduit 28b, and the second
pressure pulse is formed and supplied to the manifold for inflat-
ing the'thira and fourth chambers of the sleeves. It will be
seen that the controller forms the second pressure pulse from the
first pressure pulse which is continuously supplied to the mani-
fold through the conduit 28a. The time interval between inltiation
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of the first and second pressure pulses, respectively supplied
through the conduits 28a and 28b, is controlled by the adjust-
able timer 154. Accordingly, the Iduration between formation
. of the first and second pressure pulses may be modified by sim-
ple adjustment of the timer 154.
When the timer 150 times out, the timer 150 connects
the gas supply through the timer t~ port 162 of shift valve 112,
causing the valve to connect its port 164 to port 122. The gas
supply then passes through the ports 164 and 122 of shift valve
112 to the conduit 28c and manifold in order to inflate the fifth
and sixth chambers of the sleeves. Accordingly, the third pres-
sure pulse supplied to the manifold is formed at this time by
the control circuitry. It will be seen that the controller forms
the third pressure pulse from the second pressure pulse supplied
to conduit 28b, which in turn is formed from the first pressure
pulse, as previously described, and the first and second pressure
pulses are continuously supplied to the manifold after the third
pressure pulse is passed through conduit 28c. The time interval
between initation of the second and third pulses is determined by
the adjustable timer 150, and the timer 150 may be adjusted to
suitably modify the duration between the third pulse and the ear-
lier pulses. Accordingly, the controller 22 forms a timed se-
quence of pressure pulses, with the time intervals between the
sequential pressure pulses being adjustable, as desired.
When the timer 146 times out, the timer 146 connects
the gas supply through the timer to port 166 of`shift valve 1~6.
At this time, the shift valve 106 again connects its port 105 to
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port 108, and disconnects the port 105 from port 136 of the
valve, while the timer 120 is again actuated to begin a de-
flation cycle. It will be seen that the timer 146 controls
the duration of the inflation cycles, since the deflation
cycles are initiated when the timer 146 times out. The timer
146 also may be suitably adjusted to modify the duration of
the inflation cycles.
As previously discussed, when the deflation cycles
are initiated, the port 122 of shift valve 112 is connected to
10valve port 124 and the exhaust line 126. Thus, the two upper-
most chambers 48e and 48f in the sleeves are deflated through
the conduit 28c and the exhaust line 126 at this time. Similar-
ly, when the valve 116 is actuated at port 114, the port 128 of
shift valve 116 is connected to valve port 130 and exhaust line
1532, such that the third and fourth chambers 4~c and 48d are
-~flated through conduit 28b and the exhaust line 132. Finally,
the shift valve 106 also connects its port 136 to port~l38, such
that the two lowermost chambers 48a and 48b are deflated through
conduit 28a, valve ports 136 and 138, and exhaust line 140. In
this manner, the various chambers in the sleeves are deflated
during the deflation cycle. Referring to Fig. 5, it will be
apparent that the pressure gradien " which decreases from a lower
- part of the sleeve to an upper part of the sleeve, is maintained
during the deflation cycle, since the orifices in the section
64c are effectively larger than the corresponding orifices in
the section 64b, while the orifices in the section 64b are effect-
ively larger than the corresponding orifices in the section 64a.
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Thus, the two uppermost chambers ~8e and f deflate throu~h the
orifices 66e and 66f and conduit 28c at a greater rate than
the third and f~urth chambers 48c and d through the orifices
66c and 66d in section 64b and conduit 28b. Similarly, the
third and fourth sleeve chambers deflate at a greater rate than
the two lowermost chambers 48a and b through orifices 66a and
66b in section 64a and conduit 28a. Accordingly, the compressive
pressure gradient is maintained during inflation and deflation
of the sleeves.
Referring again to Fig. 9, it will be seen that the
controller 22 intermittently forms the first, second, and third
pressure pulses in a timed sequence during periodic inflation
or compression cycles of the device. Also, the controller inter-
mittently deflates the chambers in the sleeve during periodic
deflation or decompression cycles between the periodic inflation
cycles.
; Another embodiment of the controller 22 of the present
~- invention is illustrated in Fig. 10. In this embodiment, the
source of pressurized gas S is connected to a regulator 200, a
20 filter 202, and an on-off switch 204, as described above. When
the switch 204 is placed in its off configuration, the gas supply
S is removed from the pneumatic components of the controller,
while the supply S is connected to the components when the switch
is placed in its on configuration.
When the switch 204 is turned on, the air supply S is
connected to port 206 of not gate 208. When pressure is absent
from port 210 of gate 208, the supply passes through port 206 of
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gate 208 to inlet ports 212 and 214 of a negative output timer
216. The supply actuates timer 216 at its port 212, and the
supply passes through port 214 of the timer to its outlet port
218. In turn, the supply is connected to port 220 of shift
valve 222, to port 224 of not gate 226, to ports 228 and 230
of a positive output timer 232, and to ports 234 and 236 of a
positive output timer 238. The pressure supply at port 224 of
gate 226 prevents the gate 226 from connecting port 240 of the
sate 226 to ports 242 and 244 of a negative output timer 246.
The supply at valve port 220 actuates shift valve
222 which connects its port 248 to port 250, and thus the gas
supply from switch 204 passes through the flow control valve
252, and ports 248 and 250 of shift valve 222, to the conduit
28a and manifold. The flow control valve 252 reduces the rel-
atively high pressure of the gas supply, which is utilized to
actuate the pneumatic components of the controller 22, to a
lower pressure for inflation of the chambers in the sleeve.
The conduit 28a is connected through the manifold to the two
~ lowermost sleeve chambers 48a and b, as previously described.
- 20 Thus, the device forms the first pressure pulse for filling
the two lowermost chambers of the sleeves at the start of the
inflation cycle.
When the positive output timer 232 times out, the
timer 232 connects the gas supply from its port 230 to port
256 of shift valve 258, which then connects its port 260 to
port 262. Thus, the actuated valve 258 connects the gas sup-
ply ~rom the conduit 28a through its ports 260 and 262 to the
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conduit 28b and manifold for inflating the third and fourth
chambers 48c and d of the sleeves, and forms the second pres-
sure pulse from the first pressure pulse at this time, with
the time interval between formatioII o~ the first and second
pulses being controlled by the timer 232. As before, the
duration between the first and second pulses may be modified
by suitable adjustment of the timex 232.
When the positive output timer 238 times out, the
timer 238 connects the supply from its port 236 to port 264
10 of shift valve 266. The actuated valve 266 connects~ s-port
268 to port 270, and thus connects the gas supply from conduit
28b through the valve ports 268 and 270 to the conduit 28c and
manifold. Thus, the valve 266 forms the third pressure pulse
from the second pulse at this time for--inflating the uppermost
fifth and sixth chambers 48e ~nd f in the sleeves. As before,
the time interval between the third pulse and earlier pulses is
controlled by the timer 238, and the duration between the pulses
may be modified by suitable adjustment of the timer 238. It is
notea at this time that the pneumatic components of the controller
22 are actuated by a portion of the circuitry which is separate
rom the gas supply passing through valve 252 and the conduits
28a, 28b, and 28c to the manifold and sleeves.
When the negative output timer 216 times out, the timer
216 removes the supply from port 220 of shift valve 222, from port
25 224 ~f gate 226, from ports 228 and 230 o~ timer 232, and from
ports 234 and 236 of timer 238. The absence of pressure at port
224 of gate 226 causes the gate to pass the supply through gate
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port 240 to ports 242 and 244 of the negative output timer 246
which initiates the start of the deflation cycle. Conversely,
the timer 216 initiates and controls the duration of the infla~
tion cycle, and the duration of the inflation and deflation cy-
cles may be modified by suitable adjustment of the timers 216and 246, respectively.
When the timer 246 is actuated at its port 242, the
timer 246 passes the gas supply from its port 244 to port 210
of gate 208, to port 274 of shift valve 222, to port 276 of
shift valve 258, and to port 278 of shift valve 266. The pres-
sure at port 210 of gate 208 ~auses the gate 208 to remove the
supply from the ports 212 and 214 of the inflation timer 216.
At-the-same-time, the pressure at port 274 of shift valve 222
actuates the valve which connects its port 250 to port 280 and
the exhaust line 282. Accordingly, the lowermpst sleeve cham-
bers 48a and b are connected by valve 222 to the exhaust line
282 through conduit 28a, and valve ports 250 and 280 of shift
valve 222. Similarly, the pressure of port 276 of shift valve
258 actuates this valve which connects its port 262 to~port 284
and the exhaust line 286. Thus, the third and fourth chambers
48c and d of the sleeves are deflated through conduit 28b, ports
262 and 284, and the exhaust line 286. Finally, the pressure at
valve port 278 actuates shift valve 266 which connects its port
270 to port 288 and the exhaust line 290. Accordingly, the upper-
most fifth and sixth chambers 48e and f of the sleeves are defla-
ted through conduit 28c, valve ports 270 and 288 and the exhaust
line 290. It will be ~een that all the chambers in the sleeves
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are simultaneously deflated through the various exhaust lines
282, 286, and 290, and the compressive pressure gradient which
decreases from the lower to upper part of the sleeves is main-
tained during deflation of the sleeves by the variously sized
manifold orifices, in a manner as previously dPscribed.
When the deflation time:r 246 times out, the timer
246 removes the supply from port 210 of gate 208,.as well as
:. ports 274, 276, and.278 of valves 2~2, 258, and 266, respect-
-ively, and the gas supply is again connected from port 206 of
gate 208 to ports 212 and 214 of timer 216 to initiate another
inflation cycle. It will thus be seen that the controller 22
of Fig. 10 also operates to intermittently form a plurality of
pressure pulses in a timed se~uence for inflating the sleeves
during periodic inflation cycles, and intermittently deflate
the filled sleeve chambers during periodic def~ation cycles
between the inflation cycles.
Another embodiment of the sequential intermittent
compression controller of the present invention is illustrated
in Fig. 11. As before, the source S of pressurized gas is con-
nected to a regulator 300, after which the source passes througha primary filter 302 and an oil filter 304 to a two-position
: switch 306. Again, when the switch is placed in its off condi-
tion, the source or supply is removed from the pneumatic compon-
ents of the circuitry, while the source is connected to the com-
ponents when the switch 306 is placed in its on condition.
When the switch is turned_on, the suppl;y is-connected
through the switch 306 to port 308 of shift valve 310. During
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the deflation cycles, the valve 310 connects its port 308 to
port 312, such that the gas supply is connected to port 314 of
a positive output timer 316, to port 318 o~ shift valve 320, to
port 322 of shift valve 324, and to port 326 of shift valve 328.
The actuated shift valvle 320 connects its port~ 330
to port 332 and exhaust line 334, such that the ~wo lowermost
chambers 48a and b of the sleeves are deflated through the man-
ifold, the conduit 28a, the valve ports 330 and 332, and the ex-
haust line 334. Also, the actuated shift valve 324 connects its
port 336 to port 338 and the exhaust line 340. Accordingly, the
valve 324 connects the third and fourth chambers 48c and d of the
sleeves through the manifold, the conduit 28b, the valve ports
336 and 338, and the exhaust-line 340 in order to deflate the
third and fourth chambers at this time. Finally, the actuated
valve 328 connects its port 342 to port 3~4 and the exhaust line
346. The actuated valve 328 connects the two uppermost chambers
48e and f in the sleeves through the maniEold, the conduit 28c,
the valve ports 342 and 344, and the exhaust line 346 in order to
deflate the fifth and sixth chambers of the sleeves. Accordingly,
at the start of the deflation cycles the chambers in the sleeves
are simultaneously deflated through the exhaust lines 334, 340,
and 346. ~ -
When the positive output timer 316 times out, the timer
316 connects the gas supply from port 312 of valve 310 through
the timer 316 to port 350 of the shift valve 310 to actuate the
valve at the start of an inflation cycle. The actuated valve 310
connects its port 308 to port 352 of the valve. In turn, the gas
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supply is connected to port 354 of a positive output timer 356,
to port 358 of a counter 360, to port 362 of shift valve 320,
to port 364 of a positive output timer 366, and to port 368 of
a positive output timer 370. The actuated valve 320 connects its
port 372 to port 330, and, accordingly, the gas supply is connect-
ed through the flow control valve 374, the valve ports 372 and
330, the conduit 28a, and the manifold to the two lowermost cham-
bers 48a~and b of the sleeves. The flow control valve 374 serves
to reduce the relatively high pressure of the gas supply utilized
to actuate the pneumatic components of the controller circuitry,
in order to limit the supply pressure for inflating the sleeves.
Accordingly, the first pressure pulse is formed by the controller
22 at this time to inflate the first and second chambers in the
sleeves.
When the positive output timer 366 times out, the ti-
mer 366 connects the gas supply at port 364 of the timer to port
376 of shift valve 324. The actuated shift valve 324 connects
~; its port 378 to port 336 and the conduit 28b. Thus, the control-
ler forms a second pressure pulse at this time from the first
pulse, with the second pulse being supplied through the conduit
28b and the manifold to the third and fourth chambers 48c and d
- in the sleeves. The interval of time between formation of the
first and second pressure pulses is determined by the adjustable
timer 366, and the duration between the pulses may be modified
by suitable adjustment of the timer 366.
When the positive ~utput timer 370 times out, the
; ~ timer 370 connects the supply through its port 368 to port 380
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of the shift valve 328. The actuated shift valve 328 connects
its port 382 to port 342 and the conduit 28c. Thus, the control-
ler 22 forms the third pressure pulse at this time which passes
through the conduit 28c and the manifold to the uppermost cham-
bers 48e and f in the sleeves. As before, the third pulse isformed from the second pulse which is supplied through the con-
duit 28b. The interval of time between formation o~ the third
pulse and the earlier pulses is controlled by the timer 370,
and the timer 370 may be suitably adjusted to modify the duration
- 10 between the pulses. Accordingly, the timed sequence of first,
second, and third pulses may be modified through adjustment of
the timers 366 and 370.
- The counter 360 is actuated at its inlet port 358 to
increment the counter 360 by one count corresponding to each in-
flation cycle of the controller. A user of the device may thus
determine the number of inflation cycles initiated by the device
during use on a patient.
When the positive output timer 356 times out, the
timer 356 connects the gas supply through its port 354 to port
20 38~ of shift valve 310 to again start a deflation cycle. As be-
fore, the deflation timer 316 is actuated at port 314 when the -~
shift valve 310 connects the supply through valve ports 308 and
312. Also, the actuated shift valves 320, 324, and 328 connect
respective conauits 28a, 28b, and 28c to the exhaust lines 334,
~5 340, and 346 to simultaneously deflate the chambers in the sleeves
while maintaining a graduated pressure gradient, as previously de-
scribed. It will be seen that the timer 356 controls the duration
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of the inflation cycles which may be suitably modified by ad-
justment of the timer 356. Accordingly, the controller 22 in-
termittently forms a plurality of pressure pulses in a timed
sequence during periodic inflation cycles, and the controller
intermittently deflates the pressurized chambers in the sleeves
during periodic deflation cycles w:hich take place between the
inflation cycles.
The foregoing detailed description is given for
clearness of understanding only, and no unnecessary limitations
should be understood therefrom, as modifications will be obvious
to those skilled in the art.
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