GB2194149A

GB2194149A - Diagnosis of joint dislocation

Info

Publication number: GB2194149A
Application number: GB08718749A
Authority: GB
Inventors: James Bruce Richardson; Martin Hope Stone
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-08-07
Filing date: 1987-08-07
Publication date: 1988-03-02
Anticipated expiration: 2007-08-07
Also published as: GB8619291D0; GB2194149B; GB8718749D0

Abstract

The apparatus is a diagnostic tool to recognise joint dislocations, particularly hip-joints, at an early, pre-walking stage in infants. The apparatus comprises signal generating means for location at one side of a joint to be tested, signal receiving means for location at the other side of said joint and means for measuring the received signal which is representative of joint congruity. It also includes means for controlling qualitatively the generated signal, e.g. by varying the intensity, frequency or duration of the signal or by causing generation of a continuous, intermittent or alternating signal. It can also include means for producing a reference measurement, either absolute or comparative, the latter being achieved by the pad of a second sound generator or a second signal generating means and/or a second sound receiving means being placed at the other side of a like joint, and the two identical parts being worked in alternating fashion.

Description

SPECIFICATION Apparatus for diagnosis of joint dislocation This invention relates to apparatus for diagnosis of joint dislocation, particularly the hip joints of infants.

There have been various attempts to produce a diagnostic tool to recognise hip dislocations at an early, pre-walking stage in infants, but at present a child is only found to have a dislocated hip after he or she has failed to walk readily at the expected age.

It is an object of the present invention to provide a method of recognising joint dislocation.

According to the present invention there is provided apparatus for diagnosis of joint dislocation, comprising signal generating means for location at one side of a joint to be tested, signal receiving means for location at the other side of said joint, means for controlling qualitatively the generated signal, and means for measuring the received signal which is representative of joint congruity.

The means for controlling qualitatively the generated signal may include means to vary the intensity or frequency or duration of the signal, or means to generate a continuous intermittent or alternating signal.

The signal may be produced by a tuning fork or an electrical sound-producing device with associated attachment pad and may be battery or mains operated, and may be computer operated and connected to a timer to control a series of signals.

Measurement of the received signal may be a measure of volume or duration of the transmitted signal.

The signal receiving means may be the human ear, a stethoscope or an electrical receiver provided with a microphone-containing attachment pad.

Preferably, there are included means for producing a reference measurement, either absolute or comparative, the latter being achieved by the pad of a second sound generator or a second signal generating means and/or a second sound receiving means being placed at the other side of a like joint to be tested, and being operated in alternating fashion.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawing, in which: Figure 1 is a schematic illustration of one embodiment of apparatus for diagnosis of joint dislocation in accordance with the present invention; and Figure 2 is a schematic illustration of a second embodiment of apparatus for diagnosis of joint dislocation in accordance with the present invention.

Referring to the drawing, there is shown apparatus for diagnosis of joint dislocation, being employed in the diagnosis of congenital hip dislocation in an infant 1. A transmitting attachment pad 2 of a signal generator 3 is affixed over the symphysis pubis 4 (the line of junction between the two bones of the pelvic girdle) of the infant 1 and receiving attachment pads 5 of a signal receiver 6 are placed one on each patella 7 of the infant 1. When switched to the operating mode, the signal travels across the hip joints, through the femurs to the patellae 7, joint incongruity registering as reduced transmission of sound.

The signal generator 3 includes means 3a for controlling qualitatively the signal generated. These means 3a can vary the intensity, frequency or duration of the sound signal, and also vary the signal from continuous to intermittent to alternating.

The signal generator 3 is connected to a timer 8 which controls the production of a regular series of signals, the receiving attachment pads 5, 5a operating in an alternating fashion such that there is a comparative as well as an absolute reference measurement.

Both types of measurement are required to allow for variation between individuals and since double dislocation would result in equally poor transmission through each hip joint. The microphones contained in each receiving attachment pad 5, 5a are connected to the signal receiver 6 which comprises of an amplifier 9 with a decibel-calibrated meter 10 also provided with a timer 11 to measure duration as well as level of signal transmission. The receiver 6 is connected to a digital recorder 13 and printer 13a to allow a subsequent thorough study of the results.

In an alternative embodiment, the position of signal generator 3 and signal receiver 6 and recorder 12 are transposed, the receiver 6 now only having a single receiving attachment pad 15 and the generator 3 having two transmitting attachment pads 12, 12a one attached to each patella 7. In this instance, a comparative measurement is obtained by alternating the generation of the signal rather than alternating the reception of the signal.

In another embodiment, both the receiver 6 and the generator 3 have only one attachment pad each located at either side of the joint to be tested and the conduction measurement is therefore only compared to an absolute reference measurement.

An absolute reference measurement may be adjusted to reflect the age of the infant under study. This is done automatically in yet other alternative embodiment which includes a suitably programmed, computer controlled system of signal generation, reception and measurement.

If a hip joint under analysis registers as abnormal or, in the case of two joints, a suspected double dislocation has occured, a further clinical test to verify the diagnosis is to asculate each leg in flexion and extension. For a normal hip joint, there is a reduction in volume in flexion.

The use of signal transmission applied to the surface of the skin is a safe inexpensive and convenient method of diagnosis that #thus could be used in a community screening programme.

Modifications and improvements may be incorporated without departing from the scope of the invention.

Claims

1. Apparatus for diagnosis of joint dislocation, comprising signal generating means for location at one side of a joint to be tested, signal receiving means for location at the other side of said joint, means for controlling qualitatively the generated signal, and means for measuring the received signal which is representative of joint congruity.

2. Apparatus according to Claim 1 wherein the means for controlling qualitatively the generated signal comprises means to vary at least one of the parameters of duration, frequency and intensity.

3. Apparatus according to Claim 1 or 2, wherein the means to quantively control the signal generation comprises means to generate at least one of the parameters of a continuous signal, an intermittent signal, and an al; ternating signal.

4. Apparatus according to any one of Claims 1 to 3, wherein the signal generating means comprises a tuning fork.

5. Apparatus according to any one of Claims 1 to 3, wherein the signal generating means comprises a sound-producing device with at least one associated attachment pad.

6. Apparatus according to any one of Claims 1 to 5, wherein the signal receiving means measures the parameters of the transmitted sound.

7. Apparatus accqrding to any one-of Claims 1 to 6, wherein the signal receiving means comprises a stethoscope.

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8. Apparatus according to any one -of Claims 1 to 7, wherein the signal receiving means comprises an electrical receiver provided with- at least one microphone-containing attachment pad.

9. Apparatus according to any one of the Claims 1 to 8, wherein there are included means for producing a reference measurement.

10. Apparatus for diagnosis of joint-di-slo- cation as herein described with reference to the accompanying drawing.