GB2263405A - Ambulatory pneumatic compression device - Google Patents

Abstract

Orthopaedic shoes include two depressions, one in the heel region and the other in the region of the metatarsal heads, which accommodate respective donor air cells. The heel donor cell is coupled to a recipient air cell, which is intended to be worn around the ankle, and the other donor cell is coupled to a further recipient air cell, which is intended to be wrapped around the calf. In use the recipient cells are fitted to a patient and inflated. When the patient walks air is pumped from the donor air cells to the recipient cells, so sequentially increasing the pressure exerted on the patient's ankle and calf, before returning to the donor cell. Use of the device augments venous return and can promote peripheral circulation while retaining a patient's mobility and independence. The device can be used to treat leg ulcers. <IMAGE>

Description

AMBULATORY PNEUMATIC COMPRESSION DEVICE It is estimated that over a half million patients in the United Kindom currently recieve treatment for venous ulcer every year. It has been stated that ulcers which healed on inpatient treatment recurred within three months of leaving hospital. This imposes a considerable strain on health service resources.

External compression of the lower limb is an effective conservative treatment for lymphodema and venous insufficiency. A number of compression devices are currently available for this purpose but suffer from a variety of inherent disadvantages.

Intermittent pneumatic compression devices such as the "Flowtron" or the "Lymphapress" rely on a power supply for an air pump and require the patient to be confined to bed, often in hospital, preventing him from mobolising without disconnecting and removing the device Elastic stocking allow patients to mobolise but those that exert sufficiently high compression levels to be effective are often difficult to put on, uncomfortable and may impair skin capillary perfusion and hence impair ulcer healing, The recent alternative approach is the use of a new ambulatory pneumatic compression device which provides intermittent calf compression by utilising the patient's weight applied during the stance phase of walking to air cells mounted in the sole of a shoe The aim of this new treatment, with the ambulatory device, is to augment venous return, to treat leg ulcers, and to promote peripheral circulation while retaining the patients mobility and independence, DESCRIPTION A new intermittent pneumatic device to treat lymphoedema and venous insufficiency in the lower limb is described, It consists of two "donor" air cells mounted in the footwear, one underneath the heel and the other under the metatarsals heads. Eac "donor" air cell is connected independently by means of tubing to another "recipient" cell mounted on the leg.The lower "recipient" cell, wrapped around the ankle, is connected to the "donor" air cell placed under the heal and the upper "recipient" cell, wrapped around the calf, is connected to the "donor" air cell placed under the metatarsals heads (Figure 1). The air cells are made from poly-vynil-chloride (pvc) cut to shape and heat sealed.

A special orthopaedic shoe is designed with two depressions are cut into the insoles at heel and forefoot, and are needed to accommodate the two small air cells. Four wide Velcro straps, with "D" rings, are used to hold the "recipient" air cells around the leg, these could be loosened or tightened to accommodate changes in limb volume.

The mechanism of the new system is to inflate the leg (recipient) air cells until a suitable interface pressure is obtained. When the patient then walk initially at heel strike, air is forced from the heel Cdonor) cell into the distal leg cell increasing its interface pressure.. At heel lift the distal leg cell (recipient) returns all its additional air back to the heel cell and the forefoot cell forces all its air into the proximal leg cell,producing an increased interface pressure . Finally in swing phase the interface pressure falls back to the resting value.

Claims (1)

1. l- A new ambulatory pneumatic device, which provides a sequential compression on the oedematous leg during walking, is designed to treat patients with lumphodema and venous insufficiency. The technique of this treatment depends, however, on the donor air cells (foot pump) mounted in the sole of the shoes. This concept is new and has the advantages of allowing the patient's mobility and independence, and also maintaining compression levels despite changes in oedema..

   2- The special orthopaedic shoes, with the two depressions, is an important creature of the device. These depressions are necessary to recess the donor air cells into the insole of the shoes to allow sufficient inflation of the donor cells (and hence deflation of the recipient cells) whilst the foot is off the ground.