CA1312513C

CA1312513C - Cyclically inflatable bag for attachment to foot

Info

Publication number: CA1312513C
Application number: CA000515462A
Authority: CA
Inventors: Arthur Michael Newsam Gardner; Roger Harrington Fox
Original assignee: Novamedix Ltd
Current assignee: Novamedix Ltd
Priority date: 1985-08-08
Filing date: 1986-08-07
Publication date: 1993-01-12
Anticipated expiration: 2010-01-12
Also published as: US4696289B1; DK161426C; US4696289C1; ES2001189A6; IE59493B1; DK379786D0; DK379786A; JP2582277Y2; PT83176B; IE862107L; PT83176A; JP2545982Y2; US4696289A; DE3677565D1; EP0221636A1; JPH09398U; GR862079B; EP0221636B1; NO863194D0; DK161426B

Abstract

F. 6066 MEDICAL APPLIANCE

ABSTRACT OF THE DISCLOSURE

The invention contemplates a non-invasive technique and apparatus for artificially stimulating the venous-return flow of blood from the foot by inducing fast-rising pulsed squeezing or necking-down of the vessels of the venous-pump mechanism within the foot. The stimulation results from transient flattening of the plantar arch, in that an induced transient spread of the heel with respect to the ball of the foot stretches, and therefore necks-down involved blood vessels; stimulation also results from such a squeeze of the plantar-arch region as to concurrently squeeze the involved blood vessels. Cyclically inflatable devices, local to the foot-pump region, are disclosed for inducing either or both of the indicated actions; and enhanced arterial throughput is achieved when the stimulating pulse is sustained for a brief period prior to a relaxation dwell between pulses.

Description

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~1- 73275-1 Cyclically Infl~table Bag for Attachm~nt to F~ot The invention relates to a medical appliance, and particularly to a medical appliance for applylng pressure to a part of a human body for the purpose of stimulating blood circulation.
In our specification EP-A-0150553, there is described such a medical appliance comprising an inflatable bag shaped for engagement in the plantar arch of a human foot; means adapted to engage ov~r the instep of a human foot thereby to secure the bag to the foot in the plantar arch thereof;
in~lation means connected to the bag and capabls of cyclically inflating the bag within two seconds such that the bag applies a pumping pressure to the plantar arch of the foot thereby to extend the foot, as would occur during walking on the foot, by urging the ball and the hecl of the foot away rom each other, the pumping pressure serving to drive blood from the veins of the foot; and means cyclically to deflate the bag between inflations thereof for a time necessary for return of blood to the veins of the foot.
The device of said specification is operative upon a venous pump mechanism in the sole of the human foot, which, under normal walking conditions ~or the foot, serves to return blood from the leg and into the a~domen with no assistance from muscular action. And we have discovered that when this is modified to stimulate the venous pump mechanism in a particul~r manner which is not analogous to normal walking conditions for the foot, an overall improvement in blood ~low specifically includes enhanced arterial flow, of specific therapeutic value.

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According to -the present invention, a medical appliance of the character indicated includes means to maintain the lnElatable bag in its inflated state Eor a period of time which substantially exceeds the inflation time, the bag being then deflated over an even greater period of time, to allow veins of the plantar complex to refill with blood, prior initiation of the inflation pulse of the next cycle. More specifically, the device of the present invention incorporates means to more rapidly inElate the bag, in one second or less (preferably about a half second), and to retain the inflation pressure Eor a period up to five seconds ~preferably about three seconds), before releasing inflation pressure in a prolonged relation phase which is in the range 10 to 60 seconds (preferably about 20 seconds).
The invention herein comprises a medical appliance comprising an inflatable bag shaped for engagement in the plantar arch of human foot, means adap-ted to engage over ~he instep of a human foot thereby to secure the bag to the foot in the plantar arch thereof; inflation means connected to the bag and capable of cyclically inflating the bag within two seconds such that when being inflated the bag applies a pumping pressure to the plantar arch of the foot whereby to extend the foot, as would occur during ; walking on the foot, by urging the ball and the heel of the foot away from each other, the pumping pressure serving to drive blood from the veins of the foot; and means cyclically to deflate the bag between inflations thereof in a time necessary for return of blood to the veins of the foot, including means to maintain the bag in its inflated state for a period after each inflation thereof, before deflation of the bag is effected.

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-2a 73275-1 The invention also comprises a medical appliance, comprising circumferential-tie means adapted to peripherally envelop essent.ially only and to conform generally to the instep region of a foot and to the planter region of the foot wi.thin the span between the ball and heel of the foo~, a single inflatable bag adapted for retention within and by said circumfeLential-tie means, said bag having an active-surface portion longitudinally limited to said span and conformable to the sole of the foot within said span, and means to inflate, maintain pressure and deflate said bag in a recurrent cycle wherein a single pulse of inflation pressure has a rise time within one second, the bag is maintained in its inflated state for a period of time before deflation is begun and deflation ls prolonged for such period of time as is necessary for return of blood to the veins of the foot.
Several medical appliances embodying the invention will be described by way of example, with reference to the drawings, in which: :
Figure 1 is a view of a first appliance according to the invention, partly broken away and in position on a human foot;
Figure 2 is a view similar to Figure 1, but showing a sectional view of a second ap~liance according to the invention;
Figure 3 is a sectional view on the line 3-3 in Figure 2;
Figure ~ is a partly broken-away plan view o~ a third appliance according to the invention, with a phanto~ superposed plan view of a right ~oot, positioned for wrapped application o~
the appliance thereto;

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`- 1312513 -2b- 73275-1 Figures 5 and 6 are views similar to Figure 4, to show modifications;
Fig\lre 7 is a side view in elevation of a slipper applied over a foot that has been fitted wi~h an inflatable device, thereby becoming a further appliance according to the invention;
Figure 8 is a plan view of the sl.ippex of Figure 7, in a flattened condition, prior to use; and '"~ .

~` 1312513 _3_ Fig. 9 is a simple graph of pressure as a function of time, in aid of discussion of the invent;on.
Referring to Fig. l, the appliance here shown comprises an inflatable bag 1 formed of plastics material and shaped for engagement with the sole lO of a human foot 11 in the plantar arch thereof. ~he bag l is connected by way of a flexible pipe 2 to a pump apparatus 3 by which the bag l can be inflated.
The bag l may be secured to the foot ll by a suitable slipper or by adhesive means, but in the form shown a cloth sling 4 embraces ~he bag l and is secured over the instep 12 of the foot ll. Padding material can be located between the sling 4 and the instep 12 if necessary or desirable, and it is generally recommended that a porous knitted or other lS fabric such as stockinette be first applied to the foot so as to be interposed between the bag l and the foo-t, thus allowing for ventilation and preventing chafing of the skin.
The sling 4 and bag l are covered by a cloth slipper 6 which covers the majority of the foot ll.
In use of the appliance when secured to a foot as shown in Fig. l, the pump apparatus 3 operates rapidly to inflate the bag l which then applies a pumping pressure to the sole lO of the foot ll, and also urges the ball and heel of the foot away from each other, thus flattening the plantar arch as would occur if the foot 11 were placed on the ground during normal ambulation, thereby stimulating blood-flow.
Preferably, an accumulator tank is part of the pump apparatus 3, the same being continuously charged by the pump, and having the capacity for rapid inflation of bag 1. Inflation o the bag l is effected rapidly, preferably in 0.5 second, to provide a satisfactory pumping action. A valve arrangement (not shown) in the pump apparatus 3 maintains the bag l in the inflated state or approximately three seconds and then allows the bag 1 to deflate, whereafter the bag l is _4_ 1 31 2~1 3 again inflated, this inflation/deflation cycle being repeated as long as treatment with the appliance is required;
deflation of the bag 1 can take as long as is necessary for the return of blood to the foot 11.
The treatment thus provided improves blood circulation in a person being treated who would normally be unable to walk or possibly even stand on the foot.
A particular advantage of the appliance of this invention is that it can be used when a foot is to be encased in a plaster cast, or when the leg carrying the foot 11 has been subjected to surgery.
Figs. 2 and 3 of the drawings show an appliance according to the invention in position for use on a human foot 11 unaer a plaster cast 100, the same reference numerals as used in Fig. 1 being used for corresponding parts.
The appliance shown in Fig. 2 and 3 is similar to that shown in Fig. 1, but is larger and extends not only under the sole 10 of the foot 11, but also around the inside of the foot 11 and over the instep 12 of the foot 11.
For use, the appliance is positioned on the foot 11 and the plaster cast 100 is then formed over the bag 1 as required, with the pipe 2 from the pump apparatus 3 passing either through a hole in the cast 100 or out of one end of the cast 100.
The bag 1 can be maintained in a partially inflated condition while the plaster cast 100 is formed, whereby allo~ance for subsequent possible swelling of the foot 11 is made.
Referring now to Fig. 4, the appliance here shown comprises an inflatable bag 1 having two like panels 20-21 of flexible material, such as PVC or polyurethane film, peripherally sealed to each other as indicated at an edge seam 22. Each of the panels 20-21 comprises a plantar-aspect sole area A configured to longitudinally lap essentially only the region of the foot between adjacent plantar limits of 131~513 the ball and heel of the foot and to extend into substantial register with lateral limits of the sole of the foot. The panels 20-21 also include, within the same peripheral seam 22, an integrally formed dorsi-medial area B which extends transversely from one edge of the sole area A to a transverse extent which is substantially as great as the longitudinal extent of the area A. Typically, as shown, for a foot requiring a shoe in the size range 9 to 12, the longitudinal extent X of the bag is about 7 inches (18cm), and the maximum transverse extent Y of the bag is about 8 inches (20cm). The average width Wx of the sole area A is about 2.75 inches (7cm3, and the reduced width Wy of the area B is about 2 inches (5cm). Along its anterior edge C, the area B is substantially straight and transverse to the longitudinal direction of area A, and along its posterior edge D, the area B tapers in a concave sweep from the heel end of area A to the narrow transverse end at width Wy~ the inlet pipe 2 having sealed entry approximately midway along the edge D.
The bag 1 thus far described with reference to Fig. 4 will in and of itself serve well as an article of manufacture, in that gauze, muslin, bandage material and~or adhesive tape may be relied upon to retain a circumfer-entially wrapped application of the bag to the foot.
However, to facilitate such application without initial resort to such other instrumentalities, Fig. 4 additionally illustrates present preference for a flexible anchor tab 23 (as of vinyl sheet) which is integrally formed with bag 1, extending laterally beyond seam 22 at the longitudinal edge E
of area A, and for a tie-down tab 24, also integrally formed with bag 1 beyond seam 22 at the transverse tip F of area B.
A peel-off strip 25 oE suitable release material is shown protecting a coating of pressure-sensitive adhesive on tab 24, so that upon adhesive exposure, tab 24 may be "tacked" to tab 23 in adjustably secured retention of the wrapped application of bag 1 to a foot. And it will be noted for the preferred relatively non-stretch nature of the material of tabs 23-24, a "tacked" circumferential completion of the wrap, involving a fastening of tab 2~ in outer-end lap with tab 23, will enable circumferential hoop-tension force to be relatively uniformly distributed along substantially the entire longitudinal extent of area A, i~e., along edge E, thus assisting in the plantar-arch flatt:ening action described above. Plural apertures 26 in the larger tab 23 allow ventilation of adjacent skin but do not impair the indicated distribution of hoop-tension force.
Although Fig. 4 happens to show bag 1 for the situation in which the right foot is accommodated, it will be understood that the same accommodation to the left foot may also be made by the same article of manufacture. In application to the left foot, the plan view of Fig. 4 is reversed, from left to right, by placing the panel 20 on the bottom, beneath panel 21, and the pressure-sensitive adhesive is just as "tackable" to tab 23 as before, except for being engaged beneath tab 23.
As has already been noted, the release of pressure fluid after each pulsed delivery of inflation pressure is suitably via pores or apertures in one or both of panels 20-21. It may be found convenient to manufacture the bag 1 without such pores or apertures, using puncturable material. And the surgeon who makes the fitted application to a patient's foot need only first blow the bag via his mouth, then hold inlet 2 closed with a finger, while he uses a needle or other sharply pointed instrument to make plural punctures of the panel (20 or 21) which is to be adjacent the sole of the patient's foot; such puncturing may proceed while the surgeon squeezes the bag to satisf~ himself that the desired degree of fluid leakage will be achieved in use. On the other hand, we prefer that bags 1 be marketed with existing perforations in each of two configurations, one specifically committed to right-foot application and the other specifically committed to left-foot application.

1~12513 The bag shown in Fig. 4 can be used within a circumfer-ential bandage or sling 4 as shown in Fig. l, or within a cast lO0 as shown in Figs. 2 and 3, to provide a peripherally continuous confinement of the midtarsal and plantar regions of a foot, with the action of rapidly shrinking the confinement, maintainin~ the shrunken confinement, and then releasing the shrink action. More specifically, this confinement and cyclical action may be viewed as the means of providing (a) upward and spreading force at longitudinally spaced plantar regions of the sole of the foot, these regions being essentially limited by and hetween the ball and heel of the foot and (b) downward force at the region of the midtarsal joint. As a result, the arch is caused to flatten periodically and thus to stretch and neck down the internal sectional area of the veins of the lateral plantar complex, with resultlng venous-pump action. Viewed in a still further light, this confinement and cyclical action will be sesn as the means of providing vertically opposed squeezing forces between the plantar region of the sole of the foot and the region of the midtarsal joint, to thereby stimulate the venous-pump mechanism of the foot.
In all cases, it is important and deemed significant that neither the distal calf pump nor the proximal calf pump, nor any other of the significant pumps of the venous-return system of the involved leg is actuated in time-coincidence with foot-pump actuation. This fact illustratively enables the described invention to be operative within a cast, or to be operative in a region remote from orthopedic fixation of a damaged tibia, knee, or femur, or to be similarly remote from the region of a vein-transplant operation, and thus to relatively rapidly dissipate the pain and swelling which are the normally expected post-operative consequence of such an operation. In spite of the remoteness of foot--pump actuation from these other regions of trauma, the fact of no other pump involvements means that foot-pump driven venous return flow can be substantially unimpeded in its direct delivery to and through the region of trauma.
Figs. 5 and 6 show further appliances according to the invention.
In Fig. 5, an elongate inflatable bag 30 corresponds generally to the function and placement of area A of the bag 1 in Fig. 4. Bag 30 thus is designed for application to the plantar region of the sole of the foot, being cyclically inflatable Yia a flexible inlet pipe 31 sealed to bag 30 via locally sealed access through the peripheral seam 32 of the bag. A perforated flexible tab 33 corresponds to the tab 23 of Fig. 4, and a similar but ultimately more narrow and more extensive tab 34 is connected to the opposite longitudinal lS edge of hag 30, being adhesively coated and protected by peel-off material 35. A retaining hoop is circumferentially completed by pressure adhesion of tab 34 to tab 33. In a cyclical application of pressure fluid to the device of Fig.
5, it is the longitudinal flattening of the arch which is primarily responsible for foot-pump stimulation.
In the arrangement of Fiy. 6, an inflatable bag 40, served by an inlet pipe 41 and peripherally sealed at seam 42, is generally rectangular but elongate in the direction transverse to the longitudinal direction of the foot (phantom outline). End ta~s 43-44 correspond to those previously described, to enable pressure-adhered completion of a circumferential hoop or belt around the midtarsal/plantar regions of the foot. In a cyclical application of pressure fluid to the appliance of Fig. 6, it is the generally vertical squeezing action at the midtarsal/plantar region which is primarily responsible for foot-pump stimulation, i.e., virtually without any arch flattening action.
In certain post-operative situations wherein a part of the leg other than the foot is involved, it is therapeutically beneficial not only to operate the foot pump but also to allow the patient a degree of freedom to stand and walk on his installed foot-pump bag 1, or 30, or 40. In such a situation, a fitted slipper 50 is most useful, and may take any one of a variety of forms, so that Figs. 7 and 8 will be understood to be merely i].lustrative of one of these forms.
The slipper 50 comprises a sole member 51 of relatively rigid, porous, light-weight material, centrally adhered to a sheet 52 of light weight duck or canvas, leaving flexible lateral flaps M-N projecting laterally beyond the respective longitudinal side edges of sole member 51; flaps M-N are adapted for wrap-around fit to the particular foot, the lap of flap M over flap N being visible in Fig. 7. Woven-fabric straps 53-54-55-56 have centrally-sewn connection to the underside of sheet 52, at regions marked 53'-54'-55'-56' in Fig. 8, leaving free ends for completion of circumferential fastening of sole member 52 to the foot at each of three longitudinally spaced locations; it is convenient to have one end of each strap fitted with a wire bail, so that the other end of each strap can be threaded through the corresponding bail and be hook/loop fastened against itself, to hold each adjusted strap connection.
A tail portion 52' of fabric sheet 52 extends rearward of a small yieldable heel step 57 at the back end of sole member 51, and tail portion 56 is characterized by like, oppositely directed tabs 58-59, each of which has an exposed patch of loop material 58'-59'. These patches are selectively engageable with patches 60-61 of hook material sewn to the underside of panels M-N, as viewed in the sense of Fig. 8. A
thin panel 62 of anti-skid material is bonded to the underside of the described assembly, to complete the slipper.
In use, and after installation of an inflatable-bag (1, 30, 40~ with its inlet pipe illustratively projecting upward and rearward from the inner lateral side of the ankle, the flaps M-N are first folded into overlap over the midtarsal -lo- 1312513 region, and the straps 53-54-55 set to hold the overlap.
Then, tail 56 is folded upward and each of the tabs 58-59 is wrapped around the back of the heel, into completion of hook/loop engagements, at 58'-60 and at 59'-61, respectively. The slipper and foot-pump actuator are now in readiness to accept cyclical pressure-fluid stimulation via connection to inlet 2. It will be understood that the relatively rigid sole member 51 provides an excellent reference against which to react, upon bag inflation, for application of arch-flattening and/or midtarsal/plantar -~ squeezing action of the nature discussed above.
As a modification of the appliances thus far shown and described, it will be understood that inflatable foot-pump bag 1 can be incorporated in an article of footwear, such as a conventional boot, to be worn by a person needing to use the appliance.
An inflatable bag 1 of the nature described in connection with Fig. 4 never requires a large volume change in proceeding through its inflation/deflation cycle. The maximum inflated volume is in the order of 300 to 350 cc, and on deflation the inflated volume can be expected to reduce to 100 to 120 cc. Thus, the pressure-fluid supply equipment 3 may be relatively small and convenient for table-top or shelf ; mounting, with flexible-hose and disconnectable coupling to ; 25 the inlet pipe 2; this is true, whether the supply and control means 3 is merely timed valving to assure programmed delivery of pressure pulses of a fluid, such as oxygen from a ; locally available tank supply, or the means 3 incorporatesits own pumping and/or accumulator mechanism to provide the needed pressure fluid. Whatever the alternative, standard regulator, bleed orifices, time delay devices and their adjustability are all well known and therefore the supply means 3 may take on a variety of different physical embodiments. What is important, however, is that delivery of pressure fluid to inlet 2 and the bleed of fluid in the deflation phase shall meet certain criteria. Presently preferred criteria will be stated in the conte~t of Fig. 9, which shows pressure P to develop quickly in the inflation phase a and to dissipate somewhat exponentially, ti~ in the deflation phase k for primarily venous-return action and (ii) in the deflation phase b' for an illustrative arterial-flow enhancement as a consequence of having held the pumped pressure P for a predetermined period c prior to deflation.
Although it has been stated above that bag 1 should be inflated in one second or less t it is preferred that inflation be as quick as possible, preferably about 0.5 second, to imitate the normal impact of the sole of the foot on the ground when walking. Such fast inflation imparts a jerk or sharply pulsed action in return blood flow, and such action is likely to be helpful in preventing venous thrombosis. It is believed that ma~imum velocity, however transient upon pulsed excitation, is more important than total blood flow. The veins have check-valve formations, and the downstream side of each check valve is a site where stagnation and clotting may occur; it is believed that with bag inflation as rapid as possible, the opening phase for each check valve i5 correspondingly rapid, thus locally stirring stagnant return-flow blood and reducing the chances of a clotting constriction of return-flow passages.
The peak pressure P for any delivered inflation impulse should be that which is sufficient to produce the appropriate venous impulse, whilst not being too uncomfortable for the patient to tolerate. This will of course mean a different peak pressure P which will be various, depending upon the particular patient and his affliction. However, it can be said that, in our experience to date in cases in which the need for venous-return enhancement and/or action is primary, a peak pressure within bag 1 (20, 30, or 40) of 200 to 220-mm Hg has been satisfactory, although there may be times when it is advisable to use a peak pressure somewhat greater than 220-mm HgO Such peak pressure has produced comfortable actuation of the patient's foot pump, in the circumstance wherein the supply apparatus 3 has provided time-switched delivery of oxygen from a pressurized tank and wherein the inflation time a was 0.4 second.
The total period (a + k) of the inflation/deflation cycle will also be various, depending upon the confronting pathological condition and, in particular, on the severity of venous obstruction and on how quickly the physiological venous pump becomes filled. As a rough guide, it can be said that in severe venous obstruction, as in a limb with marked swelling, the cycle a + b might be as fre~uent as every 10 seconds. In moderate swelling, 30 seconds would probably be adequate, whereas for maintenance purposes a 60-second cycle should suffice. The optimum frequency of the cycle can be audibly determined by the clinician, listening to the flow in the posterior tibial veins with a Doppler monitor.
Although the interval between inflation pulses is very much greater than the indicated rapid inflation time a, we believe that when the need for venous-return action is primary, deflation should commence automatically at achievement of predetermined peak pressure, and initial deflation should be rapid and follow an exponential pattern.
Thus, in the indicated circumstance, we currently recommend leakage in bag 1 to the extent that, for example, for a peak pressure P of 210-mm Hg, deflation to 30-mm Hg should be in about one second, and to 20-mm ~g in about 1.9 seconds. A
timer, within apparatus 3, will be understood to reinitiate the cycle upon predetermined time-out of the interval b.
Operations in which the described foot-pump (venous-return) actuating means and pressure cycle a ~ k are likely to be particularly useful include leg fractures and operations around the knee joint, where the leg veins may become compressed either during or after an operation. It has been found very useful in arterial and vein-graft operations, where some of the leg veins have had to be ligated and where the collateral venous-return channel (the long saphenous vein) has had to be removed for use as an arterial graft.
The described foot-pump activation will be seen to involve, in the interval a, a vein-compression step in which the veins of the plantar complex are compressed, with resulting venous-pump action. ~t the same time, arterial capillaries draining into the plantar complex are also compressed, with resultant briefly pulsed local blockage or reduction of arterial flow. When the need for venous-return action is primary, as in the a + k cycle of Fig. 9, this pulsed local blockage or reduction is so brief as to be of minor significance. However, we have discovered that if this local compression is extended, for a period up to about five seconds, as suggested by the holding interval c in the cycle a ~ c ~ b' of Fig. 9, a therapeutically beneficial result is obtained in treatment of leg-artery afflictions which involve ischaemia from various causes, such as athero-sclerosis, and diabetes that has produced arterial obstruction in an ~ extremity. To date, we have ound that pressure release ; following a holding period c of approximately three seconds produces greatest arterial-flow enhancement, which we see fit to describe as improved "throughput". The enhanced-throughput effect is discernible for maximum pressures P as low as 50-mm Hg, and the effect appears to have no relation to the patient's systolic pressure; we speculate -that the effect is more likely related to local capillary pressure, which we have not thus far been able to assess. But we maximize the effect for any given patient by selecting the maximum pressure P which the particular patient can comfortably tolerate.

In any event, the rapid rise period a, in conjunction with holding period c, followed by a relaxation period b' which substantially exceeds period c (whether or not considered with the rapid-rise period a) is seen to produce venous-return action in interlacing coaction with and thus in aid of arterial-flow enhancement. In this connection, we state tha-t the relaxation period b' should be in the range of 10 to 60 seconds, and preferably about 20 seconds.

Claims

1. A medical appliance comprising an inflatable bag shaped for engagement in the plantar arch of human foot;
means adapted to engage over the instep of a human foot thereby to secure the bag to the foot in the plantar arch thereof; inflation means connected to the bag and capable of cyclically inflating the bag within two seconds such that when being inflated the bag applies a pumping pressure to the plantar arch of the foot whereby to extend the foot, as would occur during walking on the foot, by urging the ball and the heel of the foot away from each other, the pumping pressure serving to drive blood from the veins of the foot; and means cyclically to deflate the bag between inflations thereof in a time necessary for return of blood to the veins of the foot, including means to maintain the bag in its inflated state for a period after each inflation thereof, before deflation of the bag is effected.

2. An appliance as claimed in claim 1, in which said maintenance means maintains the bag in its inflated state for up to five seconds.

3. An appliance as claimed in claim 1, in which said pressure maintenance means maintains the bag in its inflated state for approximately three seconds.

4. An appliance as claimed in claims 1, 2, or 3, in which the inflation means inflates the bag within 0.5 second.

5. An appliance as claimed in claims 1, 2, or 3, in which the deflation means is operative to establish a deflation period of up to 60 seconds.

6. An appliance as claimed in claims 1, 2, or 3, in which the deflation means establishes a deflation period of about 20 seconds.

7. An appliance as claimed in claims 1, 2, or 3, in which the inflation means has the capacity to inflate the bag to substantially 220-mm Hg or less.

8. An appliance as claimed in claims 1, 2, or 3, in which the inflation means has the capacity for selective delivery of inflation pressure to the bag over the range 40-mm Hg to 220-mm Hg.

9. An appliance as claimed in claim 1, in which the inflatable bag is of flexible material having two like panels peripherally sealed to each other, at least one panel being of porous material or of a puncturable material, said panels each having a plantar-aspect sole area configurated to longitudinally lap essentially only the region of a foot between adjacent plantar limits of the heel and ball of the foot and to extend transversely into substantial register with lateral-edge limits of the sole of the foot, said panels integrally including within the same peripheral seal a dorsi-medial area extending transversely from one lateral edge to the sole area to a transverse extent substantially as great as the longitudinal extent of the sole area and being of width very substantially less than the longitudinal extent of the sole area, whereby with said sole area positioned in the plantar area of the foot, the dorsi-medial area may be applied over the medial inner side of the foot, and a supply-tube connection to said bag within said sole area.

10. An appliance as claimed in claim 9, in which a first tab extends transversely outward from the dorsi-medial area of said bag and a second tab extends transversely outward from the other lateral edge of said sole area, said tabs being engageable to each other for circumferential completion of a wrapped application of the appliance around the plantar and dorsum regions of a foot.

11. An appliance as claimed in claim 10, in which the second tab is generally triangular, being connected continuously to and along substantially the entire length of said other lateral edge of said sole area, said second tab having front and back edges which converge toward each other in the transversely outward direction.

12. An appliance as claimed in claim 1, in which the inflatable bag is of flexible material having two like panels peripherally sealed to each other, at least one panel being of porous material or of a puncturable material, said panels each having an elongate plantar-aspect sole area configurated to longitudinally lap essentially only the region of a foot between adjacent plantar limits of the heel and ball of the foot and to extend transversely into substantial register with lateral-edge limits of the sole of the foot, a supply-tube connection to said bag near the sealed periphery thereof, and first and second tabs extending transversely outward from the respective lateral edges of said bag, said tabs being engageable to each other for circumferential completion of a wrapped application of the appliance around the plantar and dorsal regions of a foot.

13. An appliance as claimed in claim 12, in which said tabs are both generally triangular, one side of one triangle having continuous connection to and along substantially the entire length of one lateral edge of said sole area, the other side of the other triangle having continuous connection to and along substantially the entire length of the other lateral edge of said sole area, and each of said tabs having front and back edges which converge toward each other in the transversely outward direction.

14. An appliance as claimed in claim 1, in which the inflatable bag is of flexible material having two like panels peripherally sealed to each other, at least one panel being of porous material or of puncturable material, said panels being of generally rectangular configuration with a length dimension defined by generally opposed longer sides and with a width dimension defined by opposed shorter sides, the width dimension being in approach to but less than the span between the ball and heel of a foot, the length dimension being at least sufficient, when oriented transverse to the foot, to transversely and continuously lap the plantar and dorsi-medial regions of the foot, a supply-tube connection to said bag near the sealed periphery thereof, and first and second tabs extending outwardly from the respective shorter sides, said tabs being engageable to each other for circumferential completion of a wrapped application of the appliance around the plantar and dorsal regions of the foot.

15. An appliance as claimed in claim 1, further including a sandal appliance for removable application to a foot wherein said inflatable bag is positioned between said sandal appliance and the plantar region between the ball and heel of the foot, said sandal appliance comprising an elongate sole member of relatively rigid material and of length to overlap both the ball and heel of the foot, first and second side panels of flexible material secured to the bottom of said sole member and extending transversely thereof to an extent permitting an overlap of said side panels to complete a circumferential wrap of the plantar and dorsal regions of the foot, adjustable-strap means for retaining circumferential integrity of the envelopment of the foot, the bag and the sole member, and a tail panel of flexible material secured to the bottom of said sole member and extending behind the heel region thereof, said tail panel being foldable upward behind the heel of the foot and including lateral wing portions foldable forwardly into detachably retained overlap with portions of the respective side panels, whereby the circumferential retention of said envelopment is preserved against forward slippage in the course of cyclically pulsed inflation of said bag.

16. A medical appliance, comprising circumferential-tie means adapted to peripherally envelop essentially only and to conform generally to the instep region of a foot and to the plantar region of the foot within the span between the ball and heel of the foot, a single inflatable bag adapted for retention within and by said circumferential-tie means, said bag having an active-surface portion longitudinally limited to said span and conformable to the sole of the foot within said span, and means to inflate, maintain pressure and deflate said bag in a recurrent cycle wherein a single pulse of inflation pressure has a rise time within one second, the bag is maintained in its inflated state for a period of time before deflation is begun and deflation is prolonged for such period of time as is necessary for return of blood to the veins of the foot.

17. An appliance as claimed in claim 16, in which the single pulse is characterized by retention of inflation pressure for a period of up to five seconds prior to deflation.

18. An appliance as claimed in claim 16, in which the single pulse is characterized by a rise time of approximately one-half second and by retention of inflation pressure for approximately three seconds prior to deflation.

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