GB2192079A

GB2192079A - Automatic reading of data from the Farnsworth-Munsell 100- hue colour vision test

Info

Publication number: GB2192079A
Application number: GB08615530A
Authority: GB
Inventors: Peter Lancaster
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-06-25
Filing date: 1986-06-25
Publication date: 1987-12-31
Also published as: GB8615530D0

Abstract

The colour caps 4 used in the above test carry coded markings 7 which are read into a computer using a sliding detector 10 which thus reads the order of the caps. The caps are arranged in a slot in a rack 1 and so retain the freedom of movement during sorting that is an essential feature of the test. <IMAGE>

Description

SPECIFICATION Automatic reading of data from the Farnsworth-Munsell 100-hue colour vision test This invention relates to the automatic acquisition of results from the Farnsworth-Munsell100 Hue colour vision test prior to computer analysis of the data.

The Farnsworth-Munsell 100-Hue test was designed for the assessment of both hue discrimination in people for vocational reasons and chromatic discrimination loss in congenital and acquired colour vision defects. Shortly after its introduction the test was reduced to 85 hues.

The test consists of arranging caps containing a coloured disc into order of hue. The subject is presented with a long box containing a single line of freely located caps arranged randomly and is asked to arrange these into order of hue between the two reference caps fixed at each end of the box. The test is divided into four boxes of twenty one or twenty two caps and the order of the hues runs sequentially from one box to the next.

The sequence of hues is in the form of a circle, that is the last hue in the last box is adjacent in order to the first hue in the first box. Each box has two reference caps fixed at each end, these being the last hue of the previous box and the first hue of the following box. The results are calculated for each cap position and are plotted on a circular graph.

The recording and processing of the resuts, although simple, is time consuming and prone to arithmetic errors. Use of a computer alleviates many of these problems but it still involves tedious keyboard entering of the data.

This time factor reduces the opportunities for clinicians to use this test either routinely or for screening purposes.

According to the present invention there is provided a method of automatically reading the order of the colour caps into a computer.

This is achieved by encoding the caps and using a sliding detector to read the order of the codes. The caps are arranged in a slot in a rack and so retain the freedom of movement during sorting that is an important feature of the original test.

A specific embodiment of the invention will now be described by way of example and with reference to the accompanying drawings in which: Figure 3 shows a cross section through the reading head with the light emitters and detectors and the slide arrangement with the bearings Figure 2 shows a cross section through a cap with colour disc mounted on a bottle with the optical code Figure 1 shows an empty rack.

Figure 4 shows the reading head on its slide and the locating pins for the rack.

Figure 5 shows an end view cross section of the reading head on its track with a rack and bottle in position.

Figure 6 shows a side view of the reading head and a section of track with a rack with bottles in position for reading.

As illustrated in Fig. 1 each of the four racks (1) used for the test has a long slot (2) machined along it running between two holes (3) which are used to position the reference caps.

The original caps (4) containing the coloured discs (5) are coded by, for example, mounting them on a small plastic bottle cap (13) and bottle (6) to which the code can be affixed as shown in Fig. 2. The code used in this example is in the form of black or clear plastic film arranged in horizontal bands (7) inside the bottles. As the caps are split into four groups of about twenty one, the coding can be either unique for the caps in a particular rack or unique for the whole series of eighty five caps: the reference caps are coded to differentiate the particular racks and their orientation. A five part code would provide 32 variations, a seven part code would provide 128 variations.

The reading head (10) contains pairs of light emitters (8) and detectors (9), for example, light emitting diodes and light activated switches, these being arranged to produce horizontal beams of light vertically above each other as illustrated in Fig. 3. These beams will be interrupted by the codes in the bottles beneath the caps. The reading head can be made from a solid block of material, for example Tufnel, and the track (11) along which it is scanned could be a Hepco linier slide system or a linier bearing of some form.

Location pins (12) at the ends of the guide ensure correct positioning of the racks on the reader track as shown in Fig. 4.

Figs. 5 and 6 show a sectional view and side view respectively of the complete system-bottles with colour caps, reading head and track.

The outputs of the light sensors are connected to the computer where software can determine and store the order of the caps and process the results.

Claims

1. A method has been devised for automatically reading the order of colour caps into a computer by encoding the caps and using a sliding detector to read the order of the codes.

2. A method as claimed in Claim 1, wherein the caps are arranged in a slot in a rack and so retain the freedom of movement during any sorting procedure.

3. A method as claimed in Claim 1 wherein the reading head consisting of pairs of light emitters and detectors is attached onto and scans along a fixed track,

4. A method as claimed in Claim 1 wherein location pins in the track as claimed in Claim 3 locate in the rack claimed in Claim 2 ensuring correct positioning of the caps for reading.