Technical Field

The present invention relates to heat therapy garments, and in particular, although not exclusively, to powered heat therapy garments for the treatment of injuries, post operative or emergency care and other applications of "P.R.I. C.E." guidelines in humans and/or animals.

Background

When sports injuries or other soft tissue damage occurs it is known to apply an ice compress onto the injured area. However, this requires not only a supply of ice on-hand, but also requires that the injured player manually holds the compress in position. This is generally an unsatisfactory solution

Summary

According to a first aspect of the invention there is provided a heat therapy garment capable of providing a cooling effect to a body part, the garment comprising a solid-state heat pump, the solid-state heat pump provided in a layer of the garment, a heat distributor arranged to absorb heat on one side thereof and distribute the heat internally of the heat distributor and then dissipate heat from the opposite side of the heat distributor, said heat distributor forming another layer of the garment, a heat exchanger arranged to carry a fluid which carries heat from the solid state pump away from the solid state heat pump, and the heat exchanger forming a further layer, and an inflatable bladder provided outwardly of the garment and forming a further layer of the garment, wherein, a plurality of solid state heat pump units are provided each associated with a respective parallel branch of a heat exchanger circuit.

The heat distributor may be in the form of sheet material. The garment may comprise two heat distributors, each in the form of a heat distribution sheet, and the heat pump units and the heat exchanger are located intermediate of the heat distribution sheets. A surface of the heat exchanger may be in thermal communication with one of the heat distribution sheets, and a surface of a heat pump unit may be in thermal communication with the other heat distribution sheet.

The solid state heat pump units may comprise Peltier devices. One side of one of the heat distributor may be arranged to absorb heat from the solid-state heat pump means, and the other side is arranged to transfer heat to the wall of the heat exchanger.

The heat exchanger may comprise a chamber, an inlet and an outlet, wherein the inlet is misaligned from the outlet.

In one embodiment one side of one of the heat distributor is arranged to absorb heat from the solid-state heat pump units, and the other side is arranged to transfer heat to the wall of the heat exchanger, which is arranged to receive a flow of heat sink fluid therethrough.

The pneumatic bladder may be provided outwardly of the heat exchanger layer. The pneumatic bladder is such that, in use, when sufficiently filled with air, localised swelling to a respective part of a human or animal patient's limb is restricted by application of pressure thereto.

The garment may comprise magnetised material.

The heat distributor may be in the form of sheet material. One embodiment of the invention comprises a group of semiconductor devices, mounted in an inflatable cuff placed on an injury area, the cuff is inflatable to reduce swelling at the injury area, and wherein the injury area is cooled. Excess heat is pumped away from the cuff and dissipated. Timers control the duration of cuff inflation, whereas deflation is automatic after a pre-set time, and a display on a control unit advises when the cuff is to be re-inflated. Sequencing of the cooling, 'soft-start' circuits, pump cutout and temperature control advantageously extend battery life and improve patient comfort. Advantageously, the control unit and the cuff are self- contained and self-powered, and capable of being carried onto a sports arena/field for use. The cuff may be capable of cooling an injury area to the levels as published P.R.I.C.E. guidelines.

Separate (respective) battery packs may be provided for the control logic and the Peltier device/ solid-state heat pumps.

The garment may comprise a range of transducers/sensors to monitor and control temperature and or pressure at the injury area or of part of the garment.

The garment may be of flexible construction, capable of being attached around a limb or other body part/area.

According to a second aspect of the invention there is provided a heat therapy garment apparatus comprising the heat therapy garment of the first aspect of and a control unit arranged to control the garment.

The control unit may comprise a fluid pump arranged to pump fluid through the heat exchanger. The control unit may be arranged to send electrical signals to the heat pump.

The control unit may comprise rechargeable batteries.

The control unit may be a manually portable device.

Can take the form of a garment with flexible solid state heat pumps embedded in a thermal gel like substance incorporating a heat transfer device and a circumferential pneumatic or hydraulic pressure vessel.

Dependant upon the size and power requirements of a particular form of the garment and engine, they may be combined into a single unit, without the need for two separate parts and an umbilical.

The unit may be controlled and/or operated by wireless connection(s). Brief description of the drawings

Various embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a perspective exploded view of various layers of a heat therapy garment, Figure 2 is a perspective view of a heat exchanger,

Figure 2a is a plan view of the heat exchanger of Figure 2,

Figure 3 is a schematic representation of a heat exchanger fluid circuit, and Figure 4 is a block diagram of a heat therapy garment and a control unit to operatively control the garment.

Detailed Description

With reference to Figure 1 there is shown a powered injury treatment garment 1 which is arranged to apply heat therapy to an injured limb of a human or animal. The garment comprises a plurality of solid-state heat pump units 2 in the form of Peltier devices. Each Peltier device 2 comprises an upper ceramic plate and a lower ceramic plate which sandwich therebetween an array of Bismuth Telluride cubes (or similar). The Peltier devices may have a degree of flexibility. The Peltier devices are capable of providing either heating or cooling. The Peltier devices are flanked by pads (not illustrated) which are positioned such that devices are protected from damaging impacts, and are strategically positioned to allow for flexible confirmation around limbs and the like. The pads may contain magnetised material of a therapeutic nature. The layer 9, located adj acent to the heat exchanger 7, comprises a pneumatic bladder which in use is adapted to be filled with air and so apply a pressure to the limb part to which the garment is attached and thereby restrict the localised swelling of that limb part. The bladder 9 could be inflated/deflated manually or automatically by way of a pump/valve arrangement (not shown).

Immediately above an upper surface of each Peltier device, there is provided a heat exchanger 7 which carries a heat sink fluid which is pumped therethrough. A respective heat exchanger 7, as best seen in Figures 2 and 2a, is provided for each heat pump 2. The heat exchanger 7 comprises a heat exchange chamber 7a and an inlet conduit 7b and an outlet conduit 7c. A lower surface of the chamber 7a is in thermal communication with (a lower surface of) a respective Peltier device 2. An opposite surface of the Peltier device 2 is in thermal communication with a heat distribution sheet 8.

As best seen in Figure 2a, the inlet conduit 7b and the outlet conduit 7c are offset from each other, when the heat exchanger is viewed in plan, with respect to the central longitudinal axis of the chamber 7a. This advantageously intentionally causes turbulent flow of the heat exchange fluid within the chamber. This turbulent flow enhances the heat dissipation in the heat exchanger.

The heat distribution sheet 8 is arranged to substantially evenly distribute over its area heat received by conduction from the respective Operative' side of the Peltier devices 2, and so provide a required temperature evenly and efficiently over the area requiring treatment. The sheet 8 is typically formed of a so-called phase change material and may comprise hydrated salt. The outer layer 12 is formed of a suitable flexible plastics material and serves to protect the layers below.

Finally, a skin facing layer 3 is provided which is arranged to contact a patient's skin. The layer 3 is an elastomer or polymer and provides structural integrity and fastening mechanisms. The skin layer may be disposable and in that instance is advantageously provided with an adhesive backing so that, for reasons of hygiene, if the garment 1 is to be used on another patient a replacement skin layer can be used.

As shown in Figure 3, the heat exchangers 7 form part of a heat exchanger fluid circuit, which includes an incoming conduit 20 and a return conduit 21. The inlet conduits 7b are in fluid communication with the incoming conduit 20, and the outlet conduits 7a are connected to the return conduit 21. Each of the heat exchangers is arranged in parallel fashion such that a heat exchanger 7 is provided on a respective branch of the heat exchange fluid circuit. A control unit, described below, houses a fluid pump which is connected to the incoming conduit 20 and the return conduit 21 , and is arranged to pump fluid through the heat exchanger fluid circuit. This parallel heat exchange system advantageously ensures that all heat pumps in the garment have an equal heat exchange mechanism. Consequently, this means that the electrical loading in respect of each of the Peltier devices is equalised and helps to eliminate uneven temperature areas on the garment.

As best seen in Figure 4 the garment 1 is connected to a control unit 30 by way of umbilicals/flexible tubing 40 and electric wiring 50 and 60. The control unit 30 is preferably readily portable and comprises a DC battery power source which is operative to power the Peltier devices 2 (through the electric wiring 50); the programmable controls 33 (embodied as firmware) and a heat sink fluid pump 3 1. The unit 30 may also include a pneumatic pump for the pressurising of the pressure bladder/chamber. The power source housed in the control unit 30 including suitable rechargeable and/or user interchangeable battery packs.

The programmable controls 33 are advantageously arranged to control power supplied to the Peltier devices in a gradual manner during start-up. The start-up procedure may be termed a soft-start which includes the gradual increase of voltage supplied to the Peltier devices, until a required operational voltage is achieved. This soft-start procedure not only prolongs the life of the Peltier devices, it also assists to prolong the battery life. A temperature measuring device (not shown) is embedded into the garment 1 and linked to the programmable control unit (see below), and controls power to the Peltier devices according to a required temperature setting using temperature feedback signals. One or more further temperature sensors may be provided to measure temperature differences within the system. A similar arrangement may also be present relating to the measurement and control of pressure in the system.

In use the system operates as follows. The garment 1 is attached to an injured limb by wrapping the garment therearound. The garment 1 is held in the attached condition by way of suitable fixtures, such as Velcro®, attached to the outer layer 12. The bladder 9 is then caused to be inflated with air so as to restrict the swelling in the injured region. The user interface 34 is then operated and the required treatment is selected, for example to cool the injured part. In turn the programmable controls 33 then instruct the power source 32 to provide an appropriate polarity of DC voltage to the Peltier devices 2 so as to cool the operative surfaces of the Peltier devices 2. The cooling effect is then conducted to the heat distribution sheet 8 and is distributed thereby towards the skin facing layer 3, and onwards to the patient's skin. On initiating the treatment the programmable controls 33 are further operative to cause the pump 3 1 to circulate water (or any suitable liquid) around the heat exchange fluid circuit. The increase in temperature of the Opposite' surfaces of the Peltier devices 2 is then conducted to the respective heat exchanger 7 and onwards to the heat sink fluid via the walls of the chambers 7a. Although not illustrated, the pump 3 1 has associated with it suitable heat exchange means (for example further solid-state heat pumps) to act on the fluid before being re-circulated to the garment 1. Should the patient require a heating effect to be applied, the patient manipulates the user interface 3 1 and the controls 33 to cause the power source to apply a DC voltage of reversed polarity to the Peltier device 2. This then causes the lower layers 20b of the Peltier devices to be heated and the upper layers to be cooled.