DE20310375U1 - Massaging device for lower leg, comprising pressure chambers acting successively on leg activated by mechanical pump, electrically driven, or working with membrane - Google Patents

Abstract

The device is designed in the shape of a hose segment accommodating the lower leg or a double walled sheet to be wrapped around the affected area and comprises several chambers which can pressurized successively in order to create a massaging effect. The device can either be operated mechanically with a piston (4) acting (5) against the forces of a spring (2), electrically using a battery, or with a hyper-elastic membrane.

Description

The present invention describes the design of the air supply for a portable device, which promotes blood circulation in the legs.

The device described here corresponds essentially to the application already established in medicine the "intermittent Compression ", which is already there, e.g. postoperatively, for thrombosis prophylaxis (DVT) is used. The air filling makes one or several blisters in a cuff that is fixed to the lower leg is, a temporally and locally controlled pressure exerted on the rear calf area.

The object of the invention is now in designing this device so that it is portable (independent of the network, handy) and continue to have the medically required properties, such as the quick filling of the chambers guaranteed. In addition to the cuff design, this is primarily the design the air supply over a reservoir of vital importance. There will be executions suggested to:

• 1. Portable device with filling from a reservoir
• 2. Design of the reservoir with variable volume

A device for intermittent Compression can be used for the following purposes:

• - Subjective more pleasant feeling through calf massage
• - improvement leg circulation by supporting the natural Muscle pump (reduction in the feeling of heavy legs after long standing activity, long-haul flights Etc.)
• - reduction of edema (Water in the legs due to reduced reflux of blood or lymphatic fluid)
• - Thrombosis prophylaxis (Prevention of blood clots in the leg veins)

The device essentially consists from a cuff attached to the calf and cyclically is pressurized with compressed air. The cuff around the lower leg would be conceivable to wrap and e.g. to close a Velcro fastener or to train as an elastic stocking that is pulled over the lower leg becomes. The cuff has one or more chambers which e.g. about one flexible hose is connected to an air supply unit. This air supply unit filled the air chambers in the cuff cyclically with pressure. Preferably should a local pressure gradient (in the chamber to the heel a higher one Pressure than in the chamber on the knee joint). Furthermore, should the chambers are filled at different times, so should in the lowest chamber on the heel, build up the pressure first and then wave to the knee joint. Through this pressure wave so impressed the blood is pumped out of the lower leg. The pressure should be approx. Work on the lower leg for 10 s. The amplitude of the pressure should be 40-120 mmHg. After the stress cycle is a long enough Provide a break during which the veins can fill with blood again. Consequently then follows to the pressurization followed by emptying of the chambers from a 40s long relaxation phase without pressure on the lower leg. After this period there is a new filling of the Chambers in the cuff. The total duration of the application should selected according to their condition become. usual Times are approximately ½ - 1 hour.

To be a portable device for this To use the application, the following are medically required Device requirements to deliver:

• - It must be one quick filling all or individual chambers possible his.
• - During the filling should be a local There is a pressure difference (see above) from chamber to chamber.

On the other hand, the following are for mobile use Adherence to boundary conditions:

• - battery operation (max.voltage 12V)
• - Small and handy device design

From the requirements for one mobile use, especially battery operation, that only Pumps with a low flow rate and a lower compression ratio (usually diaphragm pumps) can be used. However, these pumps are unable to meet the high requirements To promote volume flow for direct chamber filling. Because between the individual Cycles for medical reasons it is therefore necessary to provide sufficiently long breaks (approx. 40s) advisable that the Pump during this much longer Periodically filled a reservoir, subsequently the chambers from this reservoir are filled.

In order to keep the device small for mobile use, it is necessary to use the reservoir optimally. The reservoir has a variable volume. A rigid vessel would have to have a much larger total volume in order to provide a sufficiently large amount of air for filling the cuff after filling with a diaphragm pump up to a maximum counter pressure of usually 600 mmHg. During the filling process of the chambers in the cuff, the pressure difference between the cuff and the reservoir decreases and the flow or filling speed is therefore lower. With full pressure equalization, no further filling takes place. In this case, in order not to leave any dead volume in the reservoir that cannot be used to fill the cuff, it is sensible to design the reservoir in such a way that the volume is only at a certain minimum pressure is released. The following technical solutions are conceivable for such a reservoir:

• - At the reservoir is a vessel in which a wall (e.g. a piston in a cylinder) moves and releases the respective volume. The position of the wall results from the balance of forces between the pressure in the vessel and one Return force, preferably a spring. By the preload that the spring at Installation is stamped into the vessel, let yourself adjust the system so that the The piston only moves in the vessel at a defined minimum pressure and thus releases the volume. So it is possible that total reservoir volume for filling of the chambers in the cuff.
• - One Another variant of this reservoir design would be that the volume was not with a Pump to fill but to move the piston directly. This would be e.g. by a motor drive to realize. In this case it could the suction side of each valve control (piston sucks air from the environment) or the filling of the chambers in the cuff be released. This variant would also have compared to Filled with a pump a higher one Efficiency since the mechanical energy is directly converted into the volume change work would.
• - Another possibility of the reservoir design would be to design it with an elastic wall. Hyperelastic materials such as rubber, silicone or similar could be considered as walls. image 3 shows a way to run the membrane. In addition to the one in the picture 3 shown variants of filling via a pump, direct drive would also be conceivable in this case, for example, by a motor. A bulge in the basic state would allow a preload to be applied to the membrane, so that the membrane only releases the volume when the preload is exceeded. This would have the similar effect as a preloaded spring in the first version. In addition to the membrane design shown, further geometrical design options of the membrane are conceivable, such as in the form of a filling balloon with a hyperelastic wall.
• - Furthermore are other alternatives with the design of a reservoir variable volume conceivable, e.g. the use of so-called memory alloys that under the influence of external stimuli (e.g. heat flows) others conditions can enjoy and can do mechanical work.

The further medical requirement is a local Apply pressure difference between the chambers in the cuff.

The following alternatives are possible: 1. The chambers are directly over individual valves affected. Left here different valve opening times different pressures adjust in the chambers.

2. The chambers are with each other with pressure relief valves connected. It is conceivable to design the valves so that they are different pressures respond and thus set different pressures in the chambers.

3. The chambers are with flow resistances among themselves connected. Here could be through the choice of resistors different pressures while the filling phase adjust in the chambers.

The design of the chambers in the Cuff and its filling is independent of the requirement of a portable unit and is therefore not here the main aspect. For is all forms of filling however, with a view to rapid pressure build-up in or in some chambers a reservoir - preferably with variable volume - required.

The advantage of a mobile, network-independent unit would be that the device for each Location could be taken. It is e.g. conceivable to promote such a device in the workplace blood circulation to the leg when sitting. Likewise could such a device be taken on a plane. Here occur due to the limited range of motion for long-term flights very often Blood congestion in the legs, which could also lead to thrombosis.

There are already different manufacturers the devices offer for intermittent compression for clinical use. Such devices are not portable, need Mains power and have rigid vessels as a reservoir and need thus pumps with high compression capacities to ensure sufficient air volumes for filling of the chambers.

Another portable device, however with only one chamber in the cuff and no reservoir is through WO 00/00153 known.

1 shows a reservoir 1 with a feather 2 , an air supply from the pump to the cuff 3 , a piston 4 and a change in volume due to the piston movement 5 ,

2 shows a reservoir 6 with a feather 7 , a device for suctioning the piston and supplying air to the cuff 8th , a motor-driven piston 9 and a change in volume due to piston movement 10 ,

3 shows a reservoir 11 with an elastic membrane 12 , a bulge in the basic state 13 , an air supply from the pump to the cuff 14 and a change in volume due to membrane displacement 15 ,

Claims (7)

Intermittent compression device with a calf cuff that contains an inflatable bladder and having a interengageable with the bladder in fluid connection means for the intermittent supply of the bladder with fluid, in particular with air, the device comprising a reservoir for storing the fluid, characterized in that the reservoir comprises means for variable volume change. The device of claim 1, wherein the means is one in the reservoir have displaceably mounted pistons by its position the degree of filling the reservoir is fixed with fluid. Apparatus according to claim 2, wherein between a reservoir inner wall and a piston surface a spring is biased so that the piston against the spring tension is movable. Apparatus according to claim 2 or 3, wherein the lifting movement of the Piston is controlled by a motor drive. Device according to one of the preceding claims, wherein a hyperelastic wall is provided as a means, the curvature of which sets stored fluid volume Device according to one of the preceding claims, wherein the entire device is designed such that this network-independent and is portable to operate. Device according to one of the preceding claims, wherein the bladder has a plurality of fluid chambers that are inflatable in a cascade manner.