Abstract: A compression sleeve (1) comprises two sheets of laminated materials welded to form a number of airtight chambers (P1, P2 and P3) between the two layers. Restrictors (5 and 6) interconnect the chambers (P1, P2 and P3). Chambers (P2 and P3) also have orifices (8 and 9) of a predetermined size for exhaust of air to atmosphere. Chamber (P1) is provided with a conduit (14) connecting chamber (P1) to the pump (2). Compressed air is supplied to chamber (P1) by conduit (14). The compressed air inflates the subsequent chambers (P2, P3) through restrictors (5 and 6), giving a sequential rise in pressure to each chamber (P2 and P3). The orifices (8 and 9) to atmosphere, control the leak rate out of each chamber (P2, P3) and are sized to give a predetermined pressure gradient between chambers (P1, P2, P3). The pressure is lower in the successive chambers (P1, P2 and P3), varying the pressure from ankle to calf to thigh.

Abstract: An exemplary embodiment of the invention is a dual speed air control valve including a first sheet having an aperture therein and a second sheet continuously secured to the first sheet along a periphery of the first and second sheets. Further, a third sheet in continuously secured to the second sheet along a periphery of the third and second sheets. The first sheet defines at least one aperture in fluid communication with the third sheet. The third sheet defines at least one aperture in fluid communication with the first sheet.

Abstract: A low air loss mattress continuously supports a person lying thereon, and includes an upper layer of inflatable cells, and a separate lower layer of inflatable cells. The lower layer of inflatable cells is always maintained at a constant pressure which is higher than the pressure in the upper layer of cells to prevent a person lying on the mattress from contacting the underlying support surface, in particular, when sitting or during transport. Cells forming the upper layer may be inflated at different pressures to provide optimum support to different parts of the body.

Abstract: A pressure control system controls pressure in a fluid system, and includes a compressor for producing pressurized fluid, with the compressor coupled to a rotor valve and pressure controller. A manifold supports at least the valve and pressure controller, and the manifold has integral passages within establishing a connection for fluids from the compressor to the valve and pressure controller for controlling the fluid pressure to the system.

Abstract: A garment includes a compression system useful for stimulating venous and/or arterial blood flow in a limb, such as the foot or leg, by applying cyclic compressive pressures thereto. The garment has at least one inflatable bladder which is gradually inflated to slowly compress the foot substantially in the sole, the upper dorsi-medial areas, and dorsi-lateral areas of the foot, and then deflated to rapidly release the pressure. The muscle mass of the foot is thus squeezed and, upon sudden release, reactive hyperaemia is produced which increases arterial inflow, thus increasing venous flow in the foot and/or the leg thereof. The compression system may be used alone or in conjunction with a garment of similar structure, applied to other portions of the limb, such as the calf or thigh, for simultaneous or sequential stimulation of venous blood flow in the limb.

Abstract: An adjustable pressure relief valve has a movable valve closure member with a spring applying a closing force. An adjuster can set the size of this closing force. Pressure responsive means applies an opening force corresponding to a fluid pressure. This pressure responsive means includes a plurality of pressure sensors which can be respectively connected to one or more sources of fluid pressure. Each of these sensors is adapted to apply an opening force to the closure member which has a respective different relationship to the pressure of the source connected thereto. The relief valve opens when the opening force matches the closing force applied by the spring. The different pressure sensors allow the valve to open in response to any one of a range of different pressures.

Abstract: An alternating pressure pad has two sets of alternately inflatable cells. The alternately inflatable cells overlie additional base cells in a lower layer of the mattress. These base cells are all simultaneously inflated whilst each of the sets of upper cells are repeatedly inflated and deflated in alternation over an inflation and deflation cycle. During a cycle each set of upper cells is deflated at least once while the patient is primarily supported by the other inflated set of cells. During each inflation and deflation cycle, the additional base cells are reduced in pressure at least once. In this way, even if a part of the patient is temporarily supported only on the lower base cells, the support pressure is temporarily reduced each cycle to minimize pressure effects on the patient.

Abstract: An inflatable garment applies compression to a limb for the treatment of vascular disorders. The garment is made with an inflatable chamber formed from a blank of superimposed layers of sheet material. Side portions of the blank are joined together in the garment to encompass the foot. An inflatable tongue is located to lie under the foot. The side portions of the blank and the tongue form intercommunicating inflatable sacs. The tongue itself is not laterally joined to the side portions of the blank. The resulting inflatable garment is more comfortable to wear and more effective therapeutically.

Abstract: A pressure controlled inflatable pad for supporting the body of a patient including a source of inflating fluid which provides a flow of fluid to inflate the pad through a fluid supply line. As the fluid flows through the fluid supply line, it passes through a sensor located beneath the pad to reduce fluid flow to an exhaust if the pad is insufficiently inflated to support the patient's body.

Abstract: A pressure controller for controlling fluid pressure in an alternating pressure pad which comprises a member sensitive to the fluid pressure and adapted to open a valve when the pressure exceeds a predetermined value, a sensor pad connected at one end of the valve and at the other end being adapted for connection to a pump for inflating the pad. The sensor pad is arranged, in use, to receive pressure exerted by a patient on the pad and to be compressible in dependence upon the pressure exerted by the patient to reduce the escape of fluid from the valve when the valve is open. Thereby, causing a proportion of fluid to continue to inflate the pad.

Abstract: An alternating pressure pad having at least two sets of alternately inflatable cells, with each cell having a height greater than its width. Each cell having at least one internal membrane arranged to restrict the shape of the cell and divide the cell into two communicating regions wherein the width of the lower of the two regions is greater than the width of the upper of the two regions.

Abstract: Disclosed is a ventilated support for living bodies comprising an inflatable alternating pressure pad which is either enclosed by or forms a part of an air permeable plenum chamber through which air is pumped at low pressure to provide a source of ventilating air to a body resting on the support. The alternating pressure pad which is inflated by a high pressure pump has two sets of interdigitated cells which are alternately inflatable and deflatable and carry the weight of a body, alternately, on each of the two sets of cells. The plenum chamber is provided with a separate low pressure air pump which passes through the air permeable upper element of the plenum chamber to reduce moisture build-up and otherwise cool the body resting on the support. In the embodiment in which the alternating pressure pad forms the upper element of the plenum chamber, it is provided with a plurality of apertures which are sealed from the alternating pressure cells to prevent the loss of pressure therein.