Note: Descriptions are shown in the official language in which they were submitted.
38
; ~ACKGROUND OF THE INVE~TION
The present invention relates to therapeutic and pro-
phylactic devices, and more particularly to devices for applying
compressive pressures ayainst a patient's limb.
It is known that the velocity of blood flow in a
patient's extremities, particularly the legs, markedly decreases
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 confined to bed for
extended periods of time. It is also known that stasis of blood
is a si~nificant cause leading to the formation of thrombi in
the patient's extremities, which may have a severe deleterious
effect on the patient, including death. Additionally, in cer-
tain patients it is desirable to move fluid out of interstitial
spaces in extremity tissues, in order to reduce swelling asso-
ciated with edema in the extremities.
Devices have been disclosed in U.S. patents ~,013,0~9
and 4,030,488 which develop and apply the desired compressive
pressures against the patient's limbs. Such devices comprise
a pair of sleeves which envelop the patientis limbs, and a con-
troller for supplying fluid pressure to the sleeves. When the
devices are used on legs during certain surgical procedures,
such as total hip replacement, it is necessary to utilize ster-
ile sleeves since the entire leg is considered part of the
sterile operative field. In case the sleeves ventilate the
patient's legs with air or in the unlikely event that the
sleeves may become punctured or ruptured, the air passing
through the nonsterile inside of the controller may pass through
the outside of the sleeves, and may contaminate the operative
; 30 field which should remain sterile. Hence, it is desirable
3~
to prevent such contamination by the device in the event of a
deective sleeve or for embodiments of the sleeve in which the
patient's limb is ventilated with air.
SUMMARY OF THE INVENTION
The principal feature of the present invention is the
provision of an improved device for applying compressive pres-
sures from a source of pressurized fluid against a patient's
limb.
The device comprises an elongated sterile pressure
sleeve for enclosing a length of the patient's limb, with the
sleeve having a plurality of laterally extending separate fluid
pressure chambers progressively arranged longitudinally along
the sleeve from a lower portion of the limb to an upper portion
of the limb proximal the patient's heart relative to the lower
portion. The device has conduit means for establishing communi-
cation between the fluid source and the sleeve chambers.
A feature of the present invention is the provision of
filtering means to filter bacteria from the fluid passing through
the conduit means.
Thus, another feature of the invention is that the
fluid passing into the chambers is rendered sterile by the fil-
tering means.
Yet another feature of the invention is that the ster-
ile air in the chambers will not contaminate the operative ster-
ile field in the region of the sleeve in the event that the
sleeve should become ruptured or punctured.
A further feature of the invention is that if the
sleeve has a ventilation channel for ventilating the patient's
limb with air, the air passing to the ventilation channel is
`
flltered to prevent contamination of the operative field.
Further features will become more fully apparent in
the following description of the embodiments of this invention
and from the appended claims.
DESCRIPTION OF THE DRAWINGS
In the drawings:
Fig. 1 is a fragrnentary perspective view of a compres-
sive pressure device of the present invention;
Fig. 2 is a front plan view, partly broken away, of a
compression sleeve for the device of Fig. l;
Fig. 3 is a back plan view, partly broken away, of the
sleeve of Fig. 2;
Fig. 4 is a front plan view on page 2 of the drawings
of fluid impervious sheets defining chambers in the sleeve of
Fig. 2;
Fig. 5 is a back plan view of the fluid impervious
sheets of Fig. 4;
Fig. 6 is a fragmentary sectional view taken substan-
tially as indicated along the line 6-6 of Fig. 4;
Fig. 7 is a fragmentary sectional view taken substan-
; tially as indicated along the line 7-7 of Fig. 4;
Fig. 8 is a fragmentary sectional view on page 1 of
the drawings taken substantially as indicated along the line
8-8 of Fig. 4;
; Fig. 9 is a perspec-tive view on page 3 of the drawings
illustrating the sleeve during placement on a patient's leg;
Fig. 10 is an exploded perspective view of connecting
devices for attaching conduits to chambers of the sleeve;
Fig. 11 is a sectional view of the assembled connect-
ing devices of Fig. 10;
Fig. 12 is a sectional view taken substantially as
indicated along the line 12-12 of Fig. 11;
-3
3~
Fig. 13 is a fragmentary sectional view taken substan-
tially as indicated along the line 13-13 of Fig. 11; and
Fig. 14 is a graph illustrating a typical pressure pro-
file developed in the sleeve chambers during use of the device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to Fig. 1, there is shown an intermittent
compression device generally designated 20 having a controller
22, and a pair of elongated compression sleeves 26 for enclosing
a length of the patient's extremities, such as the legs as shown.
The controller 22 is connected through a tube 28 to a source S
of pressurized gas, and to an exhaust tube 30. Also, the con-
troller 22 is connected to the separate sleeves 26 through sepa-
rate sets of conduits 34 and 35. The controller may be of any
suitable type, such as the controllers described in U.S. patents
4,013,069 and 4,030,488.
With reference to Figs. 2 and 3, the sleeve 26 has an
outer cover sheet 36 covering the entire outer surface of an
outer fluid impervious barrier sheet 38. Also, the sleeve 26 has
an inner cover sheet 40 covering an inner surface of an inner
fluid impervious barrier sheet 42. The outer cover sheet 36 may
comprise a relatively inelastic fabric with a brushed matte or
napped finish of nylon or polyester, such as a fabric sold under
the trademark Flannel/Flannel II, No. 11630, by Guilford Mills,
Greensboro, North Carolina, which provides an attractive outer
surface for the sleeve, and also defines brushed or napped fibers
across the entire outer surface of the sleeve for a purpose which
will be described below. In suitable form, the fabric of the
~ sheet 36 may be warp knit from polyester yarns on a tricot
; machine, after which the fabric is dyed to a suitable color, and
the fabric is brushed or napped on a suitable machine to raise
loops from the fabric. The inner cover sheet 40 may comprise a
suitable nonwoven material which provides a comfortable inner
surface of the sleeve for the patient. The barrier sheets may
be formed from a suitable flexible plastic material, such as poly-
- vinylchloride. If desired, a segment of the brushed nylon fabric
may be formed into a tube 44 to cover the conduits which extend
from the sleeve to the controller. As shown, the conduits and
covering tube 44 may extend through an opening 46 in the inner
cover sheet 40.
The sleeve 26 may have a pair of side edges 48a and
48b, and a pair of end edges 50a and 50b connecting the side
edges 48a and b, with the side edges 48a and b being tapered
toward a lower end of the sleeve. The sleeve 26 may also have
an elongated opening 52 extending through a knee region 53 of
the sleeve, and defined by peripheral edges 54 extending around
the opening 52. In addition, the sleeve 26 has an elongated
opening or cut-out 56 in the knee region 53 extending from the
side edge 48a toward a lateral central portion of the sleeve,
with the opening 56 being defined by peripheral edges 58 extend-
; ing from the side edge 48a around the opening 56. As shown, the
inner end of the opening 56 is spaced from the opening 54, and
the opening 56 defines an upper flap 60 and a lower flap 62 of
the sleeve which are separated by the opening 56. Further, the
~5 sleeve 26-may have a pair of lower fastening strips 61, such as
a hook material sold under the trademark Velcro, secured to the
inner cover sheet 40 along the side edge 48b.
With reference to Figs. 4-8, the inner and outer fluid
impervious barrier sheets 38 and 42 have a plurality of later-
ally extending lines 64, such as lines of sealing, connecting
the barrier sheets 38 and 42 together, and longitudinally extend-
ing lines 66, such as lines of sealing, connecting the sheets 38
and 42 together and connecting ends of the lateral lines 64, as
shown. The connecting lines 64 and 66 define a plurali.ty of
longitudinally disposed chambers 68a, 68b, 68c, 68d, 68e, and
68f, which Eox convenience will be termed contiguous. ~s shown,
the chambers 68 extend laterally in the sheets 38 and 42, and
are disposed in the longitudinal arrangement between the end
edges 50a and 50b. When the sleeve is placed on the patient's
leg, the lowermost chamber 68a is located on a lower part of the
leg adjacent the patient's ankle, while the uppermost chamber
68f is located on an upper part of the leg adjacent the midthigh.
As shown, the longitudinal line 66 nearest the side
edge 48b is separated intermediate the chambers 68b and c, 68c
and d, and the chambers 68e and f. The lateral lines 64 define
ventilation channels 70a, 70b, and 70c extending laterally in
the sleeve from the longitudinal line 66 adjacent the side edge
48a toward the longitudinal lines 66 adjacent the side edge 48b,
with the ventilation channels 70 being positioned at spaced
locations longitudinally along the sleeve intermediate different
pairs of adjoining chambers. Thus, the ventilation channel 70a
is located intermediate the chambers 68b and 68c, the ventilation
channel 70b is located intermediate the chambers 68c and 68d,
and the ventilation channel 70c is located intermediate the cham-
bers 68e and 68f. Moreover, the ventilation channels 70 have a
,,
width substantially less than the width of the chambers 68 such
that the channels 70 do not detract from the size and volume
required for the compression chambers 68. The inner and outer
barrier sheets 38 and 42 also have a longitudinally extending
line 72 which defines a connecting channel 74 intermediate the
; line 72 and the adjacent longitudinal line 66. As shown, the
connecting channel 74 extends along the sides of the chambers 68c,
68d, and 68e, and communicates with the ventilation channels 70a,
b, and c, such that the channel 74 connects the spaced ventila-
tion channels 70. Further, the inner barrier sheet 42 has a
plurality of openings or apertures 76 which communicate with the
channels 70. Thus, when the sleeve 26 is placed on the patient's
leg, the openings 76 face toward the leg.
With reference to Figs. 4-7, the longitudinal lines 66
and 72 adjacent the side edge 48b define a pair of flaps 78a and
78b of the barrier sheets 38 and 42 which extend between the
respective lines and the side edge 48b. As shown, the sheets 38
and 42 have a longitudinally extending line 79 which defines a
directing channel 80 intermediate the lines 79 and 72, with the
opposed longitudinal ends of the channel 80 being open. The
sleeve 26 has a first connecting device 82a which is commonly
connected in fluid communication to the two lowermost chambers
68a and 58b, and which is connected to a conduit 34a 1n the
illustrated conduit set 34. As shown, the conduit 34a passes
through an opening 84a in the upper barrier sheet flap 78a which
retains the conduit 34a at the desired position in the sleeve 26.
The sleeve 26 also has a second connecting device 82b which is
commonly connected in fluid communication to the second pair of
adjoining chambers 68c and 68d, and which is connected to a sec-
ond conduit 34b in the conduit set 34O The conduit 34b passes
through an opening 84b in the upper ~lap 78a which retains the
conduit 34b at the desired position. The sleeve 26 has a third
connecting device 82c which is commonly connected in fluid com-
munication to the uppermost chambers 68e and 68f, and which is
connected to a third conduit 34c in the conduit set 34. As shown,
the conduit 34c passes through an opening 84c in the upper flap
78a, with the conduit 34c extending through the directing chan-
nel 80 in order to retain the third conduit 34c at the desired
position in the sleeve. The sleeve 26 also has a connector 83
which is connected in fluid communication to the connecting chan-
nel 74 in order to permit passage of air to the ventilation chan-
nels 70. As shown, the connector 83 is connected to a fourth
conduit 34d in the conduit set 34, with the conduit 34d passing
through an opening 84d in the upper barrier flap 78a. Thus, the
conduits 34a, 34b, and 34c are separately connected to pairs of
adjoining chambers, while the conduit 34d is connected to the
connecting channel 74. Of course, the other sleeve associated
with the conduits 35 may he constructed in a similar manner. It
will be apparent that the barrier flaps 78a and 78b, the direct-
ing channel 80, and the openings 84 cooperate to retain the con-
duits at th~ desired position within the sleeve. Further, the
sleeve 26 has suitable securing means 86, such as regions of
heat sealing or adhesive, bonding the flaps 78a and 78b to
opposed sides of the conduits 34 adjacent the opening 46. Thus,
in the event that forces are applied to the conduits 34 exterior
the sleeve 26, the forces are transmitted to the flaps 78a and b
:~`
-~ rather than the connectors 82a, b, and c, in order to relieve
possible strain from the connectors and prevent severance of the
connectors from the sleeve.
In use, the sleeve 26 may be placed below the patient's
leg preparatory to securement about the limb, as illustrated in
Fig. 9. Next, the upper flap 60 and lower flap 62 may be inde-
pendently passed around the patient's leg at locations above and
below the knee, respectively~ Thus, the opening 56 separates
the flap portions of the sleeve in the region of the knee to per-
mit independent wrapping of the upper and lower portions of the
sleeve about the leg and simpliEy placement of the sleeve, as
well as provide an improved fit. Af-ter both the upper and lower
flaps 60 and 62 have been suitable wrapped about the patient's
limb, the remaining part of the sleeve adjacent the side edge 48b
may be wrapped over the flaps 60 and 62, and the fastening strips
61 may ba pressed against the outer cover sheet 36. Thus, the
hook fastening strips 61 engage with the brushed fibers of the
outer cover sheet 36, such that the strips 61 and sheet 36 inter-
engage and retain the sleeve in the wrapped configuration.Since the sheet 36 extends entirely across the outer surface of
the sleeve 26, the sleeve may be readily adjusted as necessary
for the desired fit according to the size of the patient's leg.
Thus, the sleeve 26 may be placed in a simplified manner while
accomplishing an improved fit on patients having varying leg
sizes. In addition, the openings 52 and 56 greatly reduce the
amount of material and bulk for the sleeve in the region of the
patient's knee. Accordingly, the sleeve provides flexibility in
the knee region in order to prevent binding and permit flexation
of the knee during the extended periods of time while the sleeve
is secured about the leg.
After placement of the sleeves on the patient's limbs,
the controller 22 may be initiated in order to supply air to the
sleeves 26. The controller 22 intermittently inflates the cham-
bers 68 during periodic compression cycles, and intermittentlydeflates the chambers 68 through the exhaust tube 30 during peri-
odic decompression cycles intermediate the compression cycles.
The inelastic cover sheet 36 of the placed sleeve restricts the
size of the inflated chambers, and greatly enhances the compres-
sive action of the chambers to permit lower fluid volumes during
3~
the compression cycles. Further, the controller 22 supplies air
through the conduits to the connecting channels 74 in the two
sleeves. The air then passes from the common connectiny channels
74 to the spaced ventilation channels 70 and through the openings
76 onto the patient's legs. In this manner, the device 20 venti-
lates a substantial portion of the patient's legs to prevent
heat buildup and provide comfort for the patient during extended
periods of time while the sleeves are retained in a wrapped con-
dition about the patient's limbs. In a preferred form, the con-
troller 22 supplies air to the ventilation channels 70 during
the periodic decompression cycles. Also, the controller 22 may
have suitable means, such as a switch, to selectively permit
passage of air to the ventilation channels 70 or prevent passage
of air to the ventilation channels 70, as desired. In addition,
` 15 the switch may be utiliæed to control the quantity of air which
- ventilates the patient's limbs for maximum patient comfort.
- The connecting devices 82 are illustrated in Figs. 10-13, and comprise a connecting member 90, a pair of adapters 92a
. :
and 92b associated with the connecting member 90, and a restric-
tion member 94. The connecting member 90 has an elongated tubu-
lar member 96 defining a lumen 98, and an annular end section
~` 100 of smaller outside diameter for placement in the downstream
lumen end of the associated conduit. The connecting member 90
; also has a pair of spaced lower and upper connecting portions
102a and 102b, respectively, extending outwardly from the tubu-
lar member 96, with the connecting portions 102a and b defining
associated ports 104a and 104b of uniform diameter communicating
with the lumen 98 of the tubular member 96 through associated
apertures 106a and 106b. The connecting portions 102a and b
have annular end sections 108a and 108b of reduced external
--10--
diameter for a purpose which will be described below.
The adapters 92a and b have generally planar lower
flanges llOa and llOb, respectively, for securement to the
sleeve with respective apertures 112a and 112b of the adapters
92a and b in communication with adjoining chambers of the sleeve.
The adapters 92a and b also have housings 114a and 114b, respec-
tively, defining outer openings 116a and 116b having an inner
diameter approximately equal to the outside diameter of the con-
necting member end sections 108a and b, such that the connecting
member end sections 108a and b may be received in the associated
openings 116a and b of the adapters 92a and b. Thus, each of
the connecting devices 82 establishes communication between a
conduit and adjoining sleeve chambers through the associated con-
necting member 90 and spaced adapters 92a and b communicating ~;
lS with the adjoining chambers.
The restriction member 94 has a cylindrical section
118 having an outside diameter approximately equal to the inside
diameter of the connecting portion ports 104a and b, with the
cylindrical section 118 defining a relatively short lumen 120.
The restriction member 94 also has an end wall 122 defining an
orifice 124 extending through the wall 122 and having a diameter
substantially less than the diameter o~ the ports 104a and b in
the connecting portions 102a and b and the sizes of the aper-
tures 106a and b of the connecting member 90. The restriction
members 94 may be inserted into the ports 104a and/or 104b of
the connecting portions 102a and b with the end walls 122 pref-
erably facing the connecting member apertures 106a and b, and
the orifice size of the restriction members 94 may be selected
to limit passage of fluid from the connecting member lumen 98 to
the adapters 92a and/or 92b and the associated adjoining cham-
bers. Accordingly, control of fluid passage may be accomplished
in the simplified manner of selecting and inserting a restric-
tion member 94 with desired orif:ice size into the desired con-
necting portions 102a and 102b. In this manner, the rate of
pressure increases may be readily controlled to produce the
desired pressure rise times in the sleeve chambers during infla-
tion thereof.
In a suitable form, the restriction members 94 may be
inserted only in the upper connecting portion 102b of each of
the connecting devices 82a, 82b, and 82c, while leaving the
ports 104a of the lower connecting portions 102a in the connect-
ing devices 82a, 82b, and 82c free of obstruction, although it
will be understood that suitable restriction members may be
inserted into the lower connecting portions 102a, if desired.
.
~ A suitable configuration for the sizes of the connecting member
.
ports and restriction member ori:Eices will be set forth as fol-
lows. The ports 104a and b of the connecting portions 102a and
b in each of the connecting members 90 may have an inside diame-
ter of approximately .141 inches. The restriction member 94
- 20 inserted into the upper connecting portion 102b of the connect-
ing device 82a may have a diameter of approximately .046 inches,
the restriction member 94 inserted into the upper connecting
portion 102b of the connectlng device 82b may have an inside
diameter of approximately .037 inches, and the restriction mem-
ber 94 inserted into the connecting portion 102b of the connect-
ing device 82c may have an inside diameter of approximately .04
inches.
A chart of a typical pressure profile developed by the
device is illustrated in Fig. 14 where the pressure P is plotted
against the time t, with the sleeve chambers being intermittently
-12-
inflated during periodic inElatlon cycles between the times to
to t3, and being intermittently deflated during periodic decom-
pression cycles between the times t3 to to, i.e., between the
inflation cycles. In a preferred form, a plurality of timed
fluid pressure pulses are applied at time to to chambers 84a and
84b, at time tl to chambers 84c and 84d, and at time t2 to cham-
bers 84e and 84f. During inflation of the lower first set of
adjoining chambers 84a and b, the associated restriction member
94 limits passage of fluid into the upper chamber 84b of the set,
such that the rate of pressure increase of the lower chamber 84a
is greater than that in the upper chamber 84b. During subsequent
inflation of the second set of adjoining chambers 84c and 84d,
the associated restriction member 94 limits passage of fluid
into the upper chamber 84d of the set, such that the rate of
pressure increase of the lower chamber 84c is greater than that
of the upper chamber 84d. Similarly, during subsequent inflation
of the third set of adjoining chambers 84e and 84f, the asso-
ciated restriction member limits passage of fluid into the upper
chamber 84f of the set, resultlng in a rate of pressure increase
of the lower chamber 84e greater than the rate of pressure
increase of the upper chamber 84f. Accordingly, through use of
the timed pulses at times to, tl, and t2, in combination with
the restriction members 94 to control the rate of pressure
increases in the chamber sets, a compressive pressure gradient
is developed which decreases from the lowermost chamber 84a to
the uppermost chamber 84f of the sleeve.
Filtering means for the device is illustrated in Figs.
10-13. In a first embodiment, the device may have a single fil-
tering element 130 associated with each of the connecting members
82 and the connector 83. The filtering element 130 comprises a
-13~
3:~3
disc of bacteria Eiltering material having an outside diame-ter
approximately equal to the inside diameter of the conduits 34.
The device also has a tubular section 132 having a lumen 134 and
an outside diameter approximately equal to the inside diameter
of the conduits 34. With reference to Fig. 11, the filtering ele-
ment 130 is positioned in a lumen 135 in the downstream end por-
tion 136 of the conduit 34, with the filtering element 130 being
located against the end section 100 of the connecting devices 82.
The tubular section 132 is snugly received in the downstream end
portion 136 of the conduit 34, and is positioned to retain the
filtering element 130 against the connecting device end section
100. In this manner, the filtering elements 130 are securely
retained in the downstream end portion 136 of the conduit lumens
135. In the case of the connector 83, the filtering element 130
may be retained by a suitable tubular section 132 at the down-
stream end of the associated conduit 34~ Thus, the filtering
elements 130 filter bacteria from the alr passing from the con-
duits 34 into the sleeve chambers 68 and the ventilation chan-
nels 70.
An alternative form of the filtering means for the con-
necting devices 82 is also illustrated in Figs. 10-13. In this
embodiment, the device has a pair of filtering elements 140a and
140b which comprise a disc of bacteria filtering material having
an outside diameter approximately equal to the inside diameter
of the openings 116a and b of the adapters 92a and b, respec-
tively. As shown, the filtering elements 140a and b are received
in the openings 116a and b, and are located in the adapters 92a
and b against an outer end of the end section 108a and b of the
connecting device 82, such that the filtering elements 140a and
b communicate with the ports 104a and b. In this manner, the
-14
33~3
filtering elements 140a and b filter bacteria from air passing
into the aAjoining chambers of the sleeve. In both embodiments,
the Eiltering elements 130 and l~Oa and b may be made of a mate-
rial comprising a woven fiberglass fabric with a teflon coating,
which material freely permits the passage of air therethrough
while filtering out bacteria in the air passing through the fil-
tering elements~
Thus, in accordance with the present invention, the
filtering elements filter bacteria from the air which passes from
the controller 22 through the conduit sets 34 and 35 to the cham-
bers 68 and ventilation channels 70 in the sleeves 26. Accord-
ingly, when it is necessary to use a sterile sleeve during cer-
tain surgical procedures, such as total hip replacement when the
entire leg is part of the sterile field, the filtering elements
cause sterile air to pass into the sleeve chambers 68. In the
event that the sleeve should become ruptured or punctured,
resulting in a leak from the sleeve chambers 68, the filtering
elements assure that the air passing from the nonsterile inside
of the controller 22 will not contaminate the sterile operative
field. Also, the filtering element associated with the connec-
tor 83 assures that the air used for ventilation purposes will
not contaminate the sterile field on the patient's leg.
The foregoing detailed description is given for clear-
ness 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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