WO2003053194A1

WO2003053194A1 - System for determination and measure of optimal embossing for bedridden patients

Info

Publication number: WO2003053194A1
Application number: PCT/IT2002/000783
Authority: WO
Inventors: Guido A. Danieli; Marco S. Ghionna
Original assignee: Danieli Guido A; Ghionna Marco S
Priority date: 2001-12-12
Filing date: 2002-12-12
Publication date: 2003-07-03
Also published as: EP1505894A1; AU2002366760A1

Abstract

The invention is relative to a system of determination and measure of an optimal embossing for bedridden patients made as an adjustable structure composed by a certain number of independent modules, able to vary independently the internal pressure in order to balance these exerted on the embossing by a person forced on bed or on a wheelchair, and then to measure, through an interferometric laser, the exact internal configuration of each module, in order to allow, knowing also the exact position in space of each module, the determination of the correct configuration of the embossing so obtained, hence being able to produce through numerical control milling machines, also determining the local rigidity of the different parts of the patient body, in order to determine the optimal degree of elasticity that point per point better satisfies the patient needs.

Description

Description System for determination and measure of optimal embossing for bedridden patients General description of the field of application of the invention

The fact that decubitus sores are one of the more common complications facing bedridden patients is a well known fact. These are mainly caused by to high pressures between patient and supporting mattress, that induce local microcirculatory crises with related tissue ischaemia or ulcers. In order to reduce such problems, the attempt is made to introduce mattresses specially shaped to reduce the pressures on the patient skin through an ad hoc configuration. Till today, to determine the shape of an embossing apt to host a bedridden patient materials characterised by the ability to be embossed by the laying patient are utilised, the embossing being then scanned with an interferometric laser for distance measurement. The patient is thus transported on these mattresses to measure the shape that suits him best. This system, however, even using different supporting elements, guarantees only adaptability in horizontal position. Moreover, since the measure is accomplished on the embossing made by the patient, the resulting mattress may turn to be wrong due to the material elasticity.

With the equipment object of the present patent application the measure will be obtained not only in horizontal position, but also in sitting or in any intermediate position, fully determining the shape of the optimal embossing, accomplishing the measure in presence of the patient's load and while varying the internal pressure in order to register in the same time the patient's local tissue elasticity.

A particular embossing has been studied, able to control and measure the pressure exerted by the patient on the structure delegate to host the invalid, characterised by a series of inde- pendent modules, as it will be shown in the following. Once obtained the optimal

configuration for the given patient, the geometry of the single element is measured from

the inside, while the patient is laying on it, using an interferometric laser system. Knowing

the spatial position of each module, the embossing shape is determined.

Preferred embodiment (not the only possible one^").

The instrument looks like a "normal" mechanised bed, able to turn into a chair with back

and leg support fully perpendicular to the seat, passing through innumberables intermediate

positions, as illustrated in Tables 1 and 2.

The system presents a supporting surface, made up by a certain number of independent

elements. They are like independent cushions free to vary their internal pressure and

surface orientation, thanks to small displacements with respect to a base frame, that may

itself be oriented in different directions. It will also be possible to measure the internal

shape of the upper surface of each cushion, loaded by the patient's weight, using

interferometric lasers, which can be reduced to a single one. Since the controlling system,

through ad hoc angular encoders or other measuring devices, knows the position in space

of each element, it is possible to determine the geometry of the entire embossing. This will

hence be composed by the sequential "assembly" of a certain number of independent

modules, in order to generate a laying surface as continuous as possible and in the mean

time fully customisable (by supporting strips), being able to vary the cushion's internal

pressure and orientation.

The entire embossing will be composed by at least three different sub-frames individually

swivelling. A seat, fixed or also swivelling with respect to ground through variable geome¬

try supports specially designed, a back support, composed by a certain number of modules, and a leg support. Both leg and back support may be moved independently from the seat. The back support may in fact be variably inclined independently from the seat, its vertical (in order to host patients of any size) and horizontal position may also be changed (see Table l and 2).

These degrees of motion are made possible, for instance but not uniquely, thanks to an endless screw and matching nut, couplet to pendulums or directly fixed to the elements that one wants to move. The rotation of the leg support with respect to the seat is also guaranteed, as it is also possible to adjust the height of the assembly of the three modules. The degrees of motion just described may also be activated in the mean time, continuing to maintain its characteristics. All endless screws are actuated by independent motors, so guarantying the ability to adapt to the human body however positioned. The system may in fact adapt to the most usual or critical position thanks to the ability to vary the orientation of the various modules, and to regulate differently the pressures in ever}' strip, thus varying the support rigidity, using also, whenever necessary the possibility to vary the inclination and position of the frame's elements.

Passing to the module's description, they are the element fundamental of the system and collect all the informations necessary to the patient's optimal position. Inside the structure of each module, hollow and closed on the upper part by a membrane, air is present, whose pressure is monitored by barometers and regulated by compressors. The module will also host the laser detecting system. Each module is supported by three threaded bars, couplet to the module through spherical hinges hosted in cavities obtained in the module's lower portion, having axes coincident to that of the holes which can be observed in Table 3. The three cavities so disposed give the possibility to orient in space each module. The en- largement on the right shows the spherical slot; two rectangular cavities impeding the rotation of the sphere about the screw axis leaving free all other movements. The hinges are simply spheres presenting internally a threaded hole and small cylindrical protuberances on the external surface. The hinge's mechanism is completed by cavities corresponding to the previously described obtained on a plate of dimensions equal to the module's base .

Every module is supported by another plate on which it is fixed with cylindrical hinges, blocking the unthreaded portion of the screw, made by the union of two semi-cylinders; The lower one presents a threaded hole to connect the motor support and a circular cavity that coupled to that present un the upper portion of the hinge contains the head of the worm screw. The slots of these hinges are partly obtained on the supporting plate (part of the frame) and partly on some hinge covers that complete the hinge's lodging. Each worm screw is actuated by a motor, fixed on the lower part of the hinge by a supporting element. The cylindrical part of this supporting element, threaded in the final portion, sticks out from an ovoid hole having axis perpendicular to the hinge's axis. This hole allows the motor's supporting elements to move jointly to the hinge.

The hinge's position of the module system allows to obtain an isostatic system (zero degrees of freedom) for any length of the threaded bars between the lower and upper portion od each module, fundamental characteristic for the system stability.

Claims

Claims.

1) System for the determination and measure of an optimal embossing for bedridden patients characterized by independent modules that can be regulated in position and internal pressure, formed by a supporting and measure surface for the back, a similar surface for the seat and still another for the leg support, all of them being movable independently, and in which the geometry of each module is measured from the inside by using an interferometric laser system.

2) System for the determination and measure of an optimal embossing for bedridden patients as per claim 1, in which the actuating system is able to produce the translation and rotation of the back support and the rotation of the leg support with respect to the seat and the translation of back and leg support on special guides, along the direction of their frames, while also the seat may be variably inclined.

3) System for the determination and measure of an optimal embossing for bedridden patients as per claims 1 " and 2, in which the actuation systems are made by slippers and by endless screw and nut systems connected to pivots and pendulums able to produce the rotation and translation of back and leg supports.

4) System for the determination and measure of an optimal embossing for bedridden patients as per claim 1, in which every supporting module is independent and moved by an adjusting system characterized by the presence of three connecting bars resulting in an iso-static system allowing to vary its spatial configuration changing independently the length of the same bars, while permitting to measure from the inside of the shape impressed by the patient as a function of the pressure variation.