GB2076577A

GB2076577A - Clinical Training Device

Info

Publication number: GB2076577A
Application number: GB8016760A
Authority: GB
Original assignee: University of Surrey
Current assignee: University of Surrey
Priority date: 1980-05-21
Filing date: 1980-05-21
Publication date: 1981-12-02

Abstract

A clinical training device, which simulates the pregnant abdomen ultrasonically for training operators in the use of ultrasonic diagnosis, comprises a container (2) filled with a liquid (16) and having a model foetus (26) movably mounted therein. The model foetus (26) is rotatable generally about its longitudinal axis by means of a turning member (40) arranged outside the container (2) and is movable in all other directions by means of sensing rods (18) which extend through the side walls of the container (2). <IMAGE>

Description

SPECIFICATION Clinical Training Device This invention relates to a clinical training device.

Approximately ninety per cent of ultrasonic diagnostic investigations carried out at the present time are concerned with assessment in the field of obstetrics. Of these, the majority are concerned with the estimation of foetal maturity.

The most commonly employed technique is the measurement of the biparietal (skull) diameter of the foetus.

Errors may arise in ultrasonic diagnoses of this type due to machine inaccuracies, biological variation and operator error. This latter is largely due to the fact that the operators have to be trained to use ultrasonic diagnostic apparatus on the patients themselves. The estimates obtained by trainee operators are not always very accurate and patients may be exposed to unnecessary ultrasound. In view of the rapid increase in the use of ultrasonic diagnosis at the present time, a large number of operators need to be trained and so the problem of inaccuracy from this source is also increasing.

The present invention provides a clinical training device which simulates the pregnant abdomen ultrasonically.

A device embodying the invention will now be particularly described, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a section through a clinical training device; Figure 2 is a view of portion A of Figure 1 to an enlarged scale; and Figure 3 is a plan view of the device of Figure 1.

The illustrated device comprises a box-like container 2 (Fig. 1) which is made of plastics material such as PERSPEX (Registered Trade Mark).

A circular lid comprising a flexible membrane 4 of a plastics material such as polyethylene is mounted in the top of the container 2.

The membrane 4 is secured to the container by a locking means 6 (Fig. 2) comprising an inner locking member 8 and an outer locking member 10 arranged to co-operate with each other to hold an edge portion of the membrane 4. The outer locking member 10 is secured to the container top by a plurality of screws 12. A rubber seal 14 is provided around the membrane in the region of the inner locking member 8 to prevent leakage of liquid.

The container 2 is completely filled with a liquid 1 6 having a speed of ultrasonic wave propagation close to that of soft human tissue, for example water. The membrane 4 is shaped such that it curves convexly outward from the top face of the container 2 under the influence of the pressure of the liquid 16.

Sensing rods 1 8 slidably extend through apertures 20 in opposed side walls of the container 2. The end portion of each rod 1 8 inside the container 2 is provided with an enlargement 22 which has a greater cross sectional area than the respective aperture 20 and so prevents the rod 1 8 from being completely retracted from the container 2. The apertures 20 are dimensioned such that the rods 1 8 have some degree of movement in the plane perpendicular to their longitudinal axes. Flexible fluid seals 24 are provided around the apertures 20 on the outer surface of the container 2 to prevent leakage of liquid 16.

Inside the container 2 is mounted a model foetus 26 which can comprise a vacuum-formed acetate moulding or shell of an appropriate shape and filled with a liquid such as water.

The model foetus 26 is mounted at one end portion of a rod 28, the other end of which is connected to the ball 30 of a ball and socket joint 32. The socket 34 of the joint is connected with a shaft 36 which extends outside the container 2 through a tunnel-shaped opening 38 and which can be rotated by means of a turning member 40.

An 'O' ring seal 42 is provided around the shaft 36 to prevent leakage of liquid through the opening 38. This arrangement allows the rod 28 and thereby the model foetus 26 to be rotated about its longitudinal axis by means of the turning member 40 and to be moved in any other direction by means of the sensing rods 1 8.

Liquid 16 can be fed into the container 2 by means of a liquid inlet valve 44 provided in a side wall of the container 2. Since any air present in the container would cause problems in ultrasonic diagnosis, an air bleed valve 46 is also provided in the upper region of a side wall of the container 2.

The above described device simulates a pregnant abdomen and enables a trainee operator to practice ultrasonic diagnosis by ultrasonically scanning the container 2 and attempting to measure the size of the "skull" of the model foetus 26. The accuracy of the results obtained can be checked by measuring the actual size of the "skull" before or after the model foetus 26 is inserted into the container 2 for a particular trial or series of trials.

The orientation of the model foetus 26 can be altered by pushing the rod 28 or model foetus 26 itself with the enlargements 22 of the sensing rods 18, or by rotating the rod 28 about its longitudinal axis by means of the turning member 40.

In order to gain access to the model, for example to change the model foetus 26 for a model of a different size, the membrane 4 is removed from the container 2 by removing the screws 1 2 thereby releasing the locking means 6.

The above described device is advantageous in that it allows trainees to practice ultrasonic diagnosis on a model foetus of any size and in any orientation likely to be found in the womb of a patient. The improved training resulting from the use of this device will mean that the results of ultrasonic diagnosis will be less liable to operator error and so more reliable.

Claims

1. A clinical training device comprising a hermetically-closable container for liquid and means arranged to adjust the location and/or orientation of a model immersed in liquid in the container from externally of the container.

2. A device according to claim 1, wherein the said means comprises rods extending through sealed apertures in walls of the container, each rod being movable in the direction of its longitudinal axis and angulady with respect of the wall of the container through which it extends.

3. A device according to claim 1, wherein each rod is provided with an enlargement at an end portion thereof, the enlargement being of a size sufficient to prevent retraction of the rod through the respective apertures in the container.

4. A device according to any one of the preceding claims further comprising means upstanding from the base of the container for displaceably mounting a model in the container.

5. A device according to claim 4 wherein the model mounting means comprises a rod pivotally mounted on a base of the container, and rotatable about its longitudinal axis from externally of the container.

6. A device according to any one of the preceding claims, further comprising a model which comprises a vacuumformed acetate shell filled with a liquid and shaped to simulate a foetus.

7. A device according to any one of the preceding claims, wherein the container is closable by means of a flexible membrane which is securable over an opening in the container.

8. A device according to claim 7 wherein the flexible membrane is securable to the container by means of an inner annular locking member and outer annular locking member, which members cooperate to hold an edge portion of the membrane therebetween with the said edge portion in sealing contact with the inner locking member, the outer locking member being securable to the wall of the container surrounding the opening.

9. A device according to any one of the preceding claims wherein the container is provided with an air bleed valve.

1 0. A clinical training device comprising a hermetically-closable container for liquid, a mounting rod upstanding from a base of the container, the mounting rod having means for supporting a model at the end remote from the said base and being connected to a ball of a ball and socket joint at the other end thereof, means connected to the socket of the ball and socket joint for rotating the said mounting rod about its longitudinal axis from externally of the container, rods extending through sealed apertures in walls of the container, said rods being movable from externally of the container to adjust the orientation and/or location of model supported on the mounting rod, a flexible membrane arranged to close the upper part of the container by being secured over an opening therein, an inner annular locking member and an outer annular locking member for securing the said membrane, the said members cooperating to hold an edge portion of the flexible membrane in sealing engagement with walls of the container surrounding the said opening, and an air bleed valve provided in the container to allow the container to be completely filled with liquid.

11. A device according to any one of the preceding claims, wherein the model has ultrasonic-response characteristics at least approximately matched to the ultrasonic characteristics of the modelled article.

12. A clinical training device substantially as hereinbefore described with reference to the accompanying diagrammatic drawings.