Therapeutic limb covering using hydrostatic pressure
The present invention provides a therapeutic limb covering and an associated method of treating chronic swelling of a limb. The limb covering is uses hydrostatic pressure provided by liquid contained within the covering to apply pressure to the limb. The limb covering comprises a substantially non-distensible flexible outer layer, a distensible flexible inner layer joined together and a liquid tight bladder therebetween. The covering may be adapted for releasable securement about a limb such as an arm or a lower leg and foot of a patient. After placement on the limb, when the bladder is filled with a liquid, such as water, it expands to contact and apply pressure to the limb.
1. A therapeutic limb covering for treatment of chronic swelling comprising:
a substantially non-distensible shell having an inner surface;
an elastic double-walled bladder joined to the inner surface of the shell, the bladder containing a liquid;
a structural support between the bladder and the shell to resist collapse of the covering under the weight of the liquid in the bladder;
wherein the double-walled bladder has an outer periphery along which the walls are bonded to each other and along which the bladder is bonded to the shell.
2. A therapeutic limb covering as defined in claim 1 wherein the bonds are formed by RF welding.
3. A therapeutic limb covering as defined in claim 1 wherein the bladder is configured to substantially surround a limb about which the limb covering is fitted.
4. A therapeutic limb covering as defined in claim 3 that is configured to be placed over a lower leg and foot of a patient with the shell and bladder extending from the bottom of the foot to approximately the top of the calf thereby surrounding substantially fully the lower leg.
5. A therapeutic limb covering as defined in claim 1 further comprising a filling port defined through the shell and communicating with the bladder.
6. A therapeutic limb covering as defined in claim 5 wherein the filling port comprises a valve with a quick connect fitting for receiving, in fluid communication, a line from a source of liquid.
7. A therapeutic limb covering as defined in claim 1 further comprising:
a securable opening extending longitudinally along the covering to facilitate placement of the covering around the limb.
8. A therapeutic limb covering as defined in claim 7 , further comprising at least one securement mechanism for altering the closeness of fit of the covering about the limb.
9. A therapeutic limb covering as defined in claim 1 wherein the structural support has a periphery that is substantially co-extensive with that of the shell.
10. A therapeutic limb covering as defined in claim 9 wherein the structural support comprises a sheet of flexible, semi-rigid material having sufficient compressive strength to prevent budding of the covering under weight of the liquid.
11. A therapeutic limb covering as defined in claim 10 wherein the structural support member comprises a sheet of polymeric closed cell foam.
12. A therapeutic limb covering as defined in claim 4 further comprising:
the shell having a sole portion adapted to underlie the sole region of a patient's foot;
the bladder having a sole portion thereof overlying the sole portion of the shell and located to be compressed under the influence of the weight of the patient when the patient's weight is applied to the sole portion of the bladder, the sole portion of the bladder being in communication with the other portions of the bladder thereby to transmit pressure from the sole portion of the bladder to the limb portion.