WO2012076199A1

WO2012076199A1 - Cushion for immobilizing a part of a body

Info

Publication number: WO2012076199A1
Application number: PCT/EP2011/062869
Authority: WO
Inventors: Christoph Schröter; Patrizia Fischer; Kurt Karrer; Thomas Müller
Original assignee: Pearltec Ag
Priority date: 2010-12-07
Filing date: 2011-07-27
Publication date: 2012-06-14
Also published as: CH705859B1; DE212011100179U1

Abstract

A cushion (1) for immobilizing a part of a body comprises two chambers (2, 3) : an air chamber (3) for receiving (9) pressured air in order to produce a force and being expanded; a chamber (2) is filled with a granular material. A membrane (6) separates the two chambers (2, 3) and the force affects the chamber (2) filled with granular material. The cushion (1) is built by an upper foil (10) and lower foil (11) being melded (8, 12) by a seam (8) on the membrane (6), where the upper foil (10) limits the chamber (2) filled with granular material and the lower foil (11) limits the air chamber (3). For stabilizing the cushion (1) cavities (4) are provided. The cavities are built by melding (12) upper foil (10), membrane (6) and lower foil (11). The cushion (1) according to the invention has the combined advantages such as: - almost no absorption of x-rays; - perfect fit for every kind of a part of a body; - comfortable for a patient; - reusable; - simple construction, low costs for the production; - easy application with an external hand pump.

Description

Cushion for immobilizing a part of a body

[ 0001 ] This invention relates to a cushion for immobilizing a part of a body according to the preamble of claim 1.

[ 0002 ] Immobilizing devices are frequently used for

stabilizing and positioning a part of a body during a medical analysis such as computed tomography CT or magnetic resonance imaging MRI . In vivo CT scanning involves the use of X-rays being passed through a body or through a part of a body to produce cross sectional images of body tissue. MRI involves the use of electromagnets and short bursts of powerful magnetic fields and radio waves. For the afore mentioned analysis it is a key issue, to have absolutely no motion in the area of the body being imaged. Patient motion is an ever- present-problem. During a measurement with one of the above mentioned devices the patient must remain absolutely still. If this requirement is not fulfilled, the resulting images are not interpretable and have to be repeated. This is known as «motion artefact». Especially in MRI a measurement may last up to one hour, where CT has shorter durations but higher requirements for the immobilization of a part of the body to be examined.

[ 0003 ] In order to immobilize a body or a part of a body the following cited documents revealed appropriate devices:

[ 0004 ] The document US 5,009,318 [1] discloses an apparatus for cushioning and maintaining an object by a device having a quantity of granular material. The apparatus comprises a retaining element defining a plurality of closed chambers, each chamber enclosing a portion of the granular material.

Furthermore a sealed housing made of material impermeable to gas encloses the retaining element. By depressurization of the inner volume of the sealed housing a part of a body is being immobilized.

[ 0005 ] The paper EP 1 582 187 Bl [2] describes a hybrid immobilisation device comprising two parts, each of them made of thermoplastic material with different melting temperatures. The first part is shaped by heating in order to soften it so it becomes mouldable on the patients' body. The second part has the function of fixing the position of the first part with respect to the patents' body. The higher melting point of the material of the second part avoids deforming the second part while melting and moulding the first part with the lower melting point.

[0006] In US 4,657,003 [5] an immobilizer device with the principle of a vacuum mattress is disclosed.

[0007] The immobilization device for a lower leg according to WO 2006/110028 Al [4] has a pumping chamber and a flexible chamber with a fluid connection between the said chambers. During walking when the foot is lifted a fluid flows partly from the flexible chamber to the pumping chamber in order to apply a varying pressure to the lower leg. Obviously this device is only useable for legs.

[0008] The apparatus disclosed in US 6,882,878 B2 [3] comprises

[0009] - a castable sleeve including a proximal layer and a distal layer, the proximal layer contacting a portion of a patients' limb and

[0010] - an expandable sleeve surrounding the distal layer of the castable sleeve, wherein the two layers form an inner space. The inner space receives a quick cast material to be optimally dispersed throughout the castable sleeve. The resulting force on the proximal layer immobilizes the portion of a patients' limb. This apparatus has the drawback that for each individual patient a part of the device has to be fabricated. Apart from being cost intensive, it requires time and chances that a patient even needs more than one device (pre- and postoperative examinations) is present. [0011] The immobilizing device for immobilizing a part of a body according to WO 2008/086943 Al [6] surrounds / encases the hole part of said body. This device is not applicable for e.g. an immobilizing a head of a human being inside a MRI- System.

[0012] The above mentioned devices suffer from the drawback either of a relatively complicate handling like

- a vacuum has to be provided or

- the parts have to be heated or

- the immobilization device is not applicable e.g. for a head.

[0013] The object of the present invention is to overcome the problems presented by the above cited devices. There is a need for a device, which fulfils the following quoted

requirements:

[0014] - fixation, so that the patient respectively a

particular part (e.g. head) of his body is incapable of moving, therefore improved image quality by decreased motion artefacts; [0015] - influence on the quality of the image as low as

possible ;

[0016] - very easy to handle;

[0017] - simple construction;

[0018] - fits everyone; [0019] - no pain and comfortable for the patient;

[0020] - reusability for both cast and filling material.

[0021] This object of the present invention is solved by a cushion specified in claim 1. [0022] The cushion according to claim 1 has the positive properties :

[0023] - almost no absorption of X-rays;

[0024] - perfect fit for every kind of a part of a body; [0025] - comfortable for a patient;

[0026] - reusable;

[0027] - simple construction, low costs for the production;

[0028] - neutral smell;

[0029] - very light. [0030] Further advantageous embodiments are given in

dependant claims.

[0031] The invention will be now described in a preferred embodiment with reference to the accompanying drawings wherein : [0032] Figure 1 cross sectional views of the cushion;

[0033] Figure 2 perspective view of a cushion from the branch side;

[0034] Figure 3 perspective view of a cushion from the rear side. [0035] The principle of a cushion 1 according to the present invention is depicted in FIG 1. The cushion 1 is sometimes also denoted by pad, a multipad or a universally applicable patient support and fixation system. The cushion 1 comprises functionally two chambers:

- An air chamber 2,

- a chamber 3 filled with granular material

- the two chambers being separated by a membrane 6. [0036] The cushion 1 is produced with an upper foil 10, the membrane 6 and a lower foil 11 by welding. The three main components upper foil 10, membrane 6 and lower foil 11 are welded by a seam 8 along the border of the cushion 1, see FIG 2.

[0037] For improving the mechanical internal stability the cushion 1 comprises preferably in its center part at least one cavity 4 made by welding one foil 10 or 12 with the membrane 6 within an area 12. These cavities 4 or holes 4 have advantageously a cylindrical form. The walls of said hole have a function of a ligament for the cushion 1.

Preferably pairs of the cavities 4 are arranged opposite the membrane 6. In this embodiment the upper foil 10, the

membrane 6 and the lower foil are melded together on said area 12.

[0038] At one side, the cushion may have a recess 5. At this side with the recess 5 - but a recess 5 is not required - there is a notch 9 or branch 9 for connecting a tube. This notch is connected with the air chamber 3. With an external hand pump (not shown in the figure) connected via a tube the air chamber 2 receives pressured air in order to be expanded by a pressure P. This pressure P affects also on the chamber 2 filled with granular material. The hand pump allows an appropriate pressure of the cushion. Appropriate in the sense, pressure is still comfortable for the patient and the pressure allows an effective immobilization of a part of a body, e.g. within a MRI-tube.

[0039] The application of the cushion 1 is as follows:

The chamber 2 filled with granular material is put on the side of the patient or a part of the body of the patient whereas the air chamber 3 is put on the side of the medical device as e.g. a MRI coil or a CT (e.g. head) holder. The chamber 2 with the granular material fits by the pressure of the air chamber 3 is perfectly to the topology of the part of a body. Further by the pressure of the air chamber 3 to the part of a body via the chamber 2 the pearls become rigid.

[0040] When the air chamber 3 is filled with pressured air or being removed from pressured air, the chamber 2 filled with granular material moves accordingly. For allowing this moving, the chamber 2 has a plurality of ventilation holes 7 for the flux of air. It must be pointed out; there is no connection of air flux between the two chambers 2 and 3, since they are separated by the membrane 6. Preferably these ventilation holes 7are arranged along the border of the chamber 2, see FIG 2 and FIG 3.

[0041] The cushion 1 has preferably a cuboid form with rounded edges.

[0042] The granular material in chamber 2 is of hundreds of tiny balls or pearls.

[0043] Depending on the examination method as e.g. CT or MRI the materials used for the cushion 1 may be chosen as follows :

[0044] The upper and lower foil as well as the membrane are preferably made by polyurethane . The granular material is of EPS. EPS as well as the PUR-foils have low X-Ray- coefficients . A cushion with the before mentioned components does not impact the quality of the MRI- or CT-images.

[0045] For Computer Tomography CT :

In principal every material can be scanned by a CT . Never^¬ theless metallic parts or high density materials in the beam path will cause artefacts. Therefore radiolucent (= low absorption) materials are of advantage for the application in CT. [0046] For Magnetic Resonance Imaging MRI:

Ferromagnetic bodies cannot be scanned at all as they would experience acceleration due to the enormous magnetic fields. List of reference numerals, glossary

I cushion, pad; universally applicable patient support and fixation system

2 chamber filled with granular material

3 air chamber

4 cavity, hole

5 recess

6 membrane

7 ventilation holes

8 seam, welded seam

9 notch for flexible tube attachment; branch connection

10 upper foil

II lower foil

12 welded area comprising a part of upper foil, membrane and lower foil

EPS Expanded Polystyrol

PU, PUR Polyurethane

References

[1] US 5,009,318

«Method, device and padded product for maintaining an ob ect»

Dominique Lepinoy, FR - Dijon

Publication date 23 April 1991.

[2] EP 1 582 187 Bl

«Hybrid immobilisation device»

Orfit Industries, BE - 2110 Wijnegen

Publication 5 October 2005. [3] US 6,882,878 B2

«Restraining Apparatus and method for use in procedures))

Berndt P. Schmit, et al . , US - Salt Lake City Publication date 1 July 2004.

[4] WO 2006/110028 Al

immobilization device for immobilizing a lower leg, pressure device apparently suitable for use in the immobilization device, and method for manufacturing the pressure device»

Somas Groep B.V.; NL - 3261 VB Oud Beijerland Publication date 19 October 2006.

[5] US 4,657,003

«Immobilizer device»

H. Robert Wirtz, Westlake Village, California Publication date 14 April 1987.

[6] WO 2008/086943 Al

immobilizing device for a part of a body»

ETH ZURICH, CH - 8092 Zurich

Publication date 24 July 2008

Claims

1. Cushion (1) for immobilizing a part of a body, the cushion (1) comprising two chambers (2, 3),

one chamber being an air chamber (3) for receiving (9) pressured air in order to produce a pressure and being expanded;

characterised in that

the other chamber (3) is filled with a granular material, a membrane (6) separates the two chambers (2, 3) and - the pressure affects the chamber (2) filled with granular material .

2. Cushion (1) according to claim 1 ;

characterised in that

a notch (9) is connected with the air chamber (3) for branching a tube, the tube delivering pressured air.

3. Cushion (1) according to claim 1 or 2 ;

characterised in that

the cushion (1) is built by an upper foil (10) and a lower foil (11) being melded (8) by a seam on the membrane (6), where the upper foil (10) limits the chamber (2) filled with granular material and the lower foil (11) limits the air chamber (3) .

4. Cushion (1) according to claim 3;

characterised in that

the cushion (1) comprises at least one cavity (4) built by melding a part of a foil (2, 3) with the membrane (6) on an area (12) for stabilizing the cushion (1) .

5. Cushion (1) according to claim 4 ;

characterised in that

pairs of the cavities (4) are arranged opposite the membrane (6) .

6. Cushion (1) according to one of the claim 3 to 5;

characterised in that

the foils (10, 11) are made of Polyurethane .

7. Cushion (1) according to anyone of the claims 1 to 6; characterised in that

the granular material comprises pearls made of expanded polystyrene .

8. Cushion (1) according to anyone of the claims 1 to 7 ; characterised in that

the chamber (2) filled with the granular material has a plurality of ventilation holes (7) allowing a free moving of said chamber (2) filled with the granular material.