GB2346215A

GB2346215A - Visualisation system for bio-electric measurements

Info

Publication number: GB2346215A
Application number: GB9917271A
Authority: GB
Inventors: Gino Francesco
Original assignee: GRAF INTERNATIONAL Ltd
Current assignee: GRAF INTERNATIONAL Ltd
Priority date: 1999-01-27
Filing date: 1999-07-22
Publication date: 2000-08-02
Also published as: GB9917271D0; GB9901824D0

Abstract

The present invention relates to a system for the visualisation of waveforms especially waveforms derived from an activity of a human or other living body. In its broadest sense, the present invention takes a waveform, however that may have been generated, and processes the waveform into a pleasing graphic form which may be printed or otherwise displayed. In particular, there is described a visualisation system comprising acquisition means for acquiring an electrical signal corresponding to a function of a subject human or other body; data processing means and graphic processing means, the data processing means processing the electrical signal into a form from which the graphic processing means can produce a graphic representation of the function of the subject. There is also described a method of generating a graphic representation of a function of a human or other body, the method comprising the steps of obtaining an electrical signal corresponding to the function; processing the signal to obtain a dataset; and processing the dataset to produce a graphic image. Preferably the function relates to a physiological process, typically a brainwave function acquired using an electroencephalograph.

Description

VISUALISATION SYSTEM The present invention relates to a system for the visualisation of waveforms especially waveforms derived from an activity of the human or animal body.

In its broadest sense, the present invention takes a waveform, however that may have been generated, and processes the waveform into a pleasing graphic form which may be printed or otherwise displayed.

According to the present invention there is provided, in one aspect, a visualisation system comprising acquisition means for acquiring an electrical signal corresponding to a function of a subject human or other body; data processing means and graphic processing means, the data processing means processing the electrical signal into a form from which the graphic processing means can produce a graphic representation of the function of the subject.

In another aspect, the present invention provides a method of generating a graphic representation of a function of a human or other body, the method comprising the steps of obtaining an electrical signal corresponding to the function; processing the signal to obtain a dataset; and processing the dataset to produce a graphic image.

Preferably the function relates to a physiological process. Typically it is a brainwave function and the acquisition means comprises an electroencephalograph.

Alternatively, the function may be an audible output from the body, such as speech or singing. Typically, in this case, the acquisition means comprises a microphone coupled to a computer or other means for digitising the sound output.

Preferably, the data processing means and/or the graphic processing means includes data selection and manipulation means adapted to enable a user to select and manipulate portions of the data from which the graphic representation is produced.

Preferably, the system also includes means for combining datasets corresponding to a plurality of electrical signals.

The above and other aspects of the present invention will now be described in further detail with reference, by way of example only, to the accompanying drawings in which: Figure 1 is an electroencephalogram of a subject; Figure 2 shows the data encompassed in the T3 channel of the encephalogram of Figure 1, extracted into a spreadsheet format ; Figure 3 is a power spectrum of the data of Figure 2; Figure 4 is an enlarged section of the spectrum of Figure 3; Figure 5 is an expanded version of the spectrum of Figure 3; Figure 6 shows the spectrum of Figure 4 displayed in the format of a radar scan; Figure 7 is a collection of superimposed radar contour charts derived in the same manner as Figures 2 to 6 from the data of Figure 1; Figure 8 is a filled radar chart version of the chart of Figure 7; Figure 9 is a spectrum of a sampled section of a voice sound name; Figure 10 shows a radar contour chart derived from the spectrum of Figure 9; Figure 11 shows a filled radar chart derived from the spectrum of Figure 9; and Figure 12 shows a bubble chart version of the charts of Figures 7 and 8.

In a first embodiment, the system of the present invention obtains data corresponding to brain electrical activity by means of an electroencephalograph (EEG) apparatus which includes a plurality of electrodes placed upon the subject's head. EEG is typically used to monitor beta, alpha, theta and delta brainwave channels. The raw electroencephalogram data obtained is illustrated in Figure 1 and comprises a plurality of electrical signals or waveforms 10 corresponding to channels of data relating to the different types of brainwave (ex, ss, 0, y) and also to data retrieved from different locations on the skull, for example, forehead, temples and so on. In the following illustrative example, a single channel, known as T3, is used to generate the data to be processed, but any one or more channels could be used at the option of the user. A channel waveform with a wide variance in peak height could be chosen as being expected to produce an interesting graphic form. The waveform of a channel which is associated with a particular brain function might be selected.

The waveform data is converted into a spreadsheet format as shown in Figure 2. This conversion can be affected by suitable software such as the commercially available LabView (TM) and MATLAB (TM) software which can be used to respectively extract and analyse the EEG data. The spreadsheet data can then be processed using other software to generate preliminary waveforms such as that shown in Figure 3. Microsoft ExcelX 97 includes suitable routines. In Figure 3, the data from twenty three separate scans of the T3 channel have been processed as waveforms and superposed. It will be observed that there is a sharp peak at the 50Hz position. This, in fact, arises through interference from the mains electricity supply and can be filtered out. As shown in Figure 4, all or only a section of the full scan can be selected for further processing. Indeed, for the present purposes the range from 8Hz to 20Hz is preferred. In Figure 5, the scale of the abscissa of the spectra of Figure 3 has been expanded and then, using a routine in Microsoft Excel, converted into a"radar"chart (Figure 6). Preferably, for visual effect, each of the twenty three scans would be represented in Figures 3 to 6 in a different colour.

Figure 7 illustrates the same data processed into a radar chart using slightly different parameters. Figure 8 shows the same chart but with shading added to each set of scan data. It is important to realise that as each scan is superposed it may overlie the colouration of the spectrum below such that, in the shaded graphic, fewer than the full twenty three spectra may be visible.

In the application of the present invention, the data used may be extracted from an EEG used for medical purposes. However, this is not essential for the purposes for which the present invention is particularly intended. As such, accuracy in data acquisition is not of paramount importance. The present inventor has also devised a headset (not illustrated) which includes means for holding the headset on a wearer's head and incorporates the necessary electrodes to enable a brainwave activity scan to be obtained. Typically, the electrodes need only sense a single channel. The headset is connected to an electroencephalogram processing unit, typically in the form of a computer expansion card. The data is then software processed further as described above to produce the output graphic. Additional channels can be"generated" electronically based on the data derived from the channel data actually acquired.

The quantity of data required to be acquired will depend upon the level of detail required in the final image. Acquisition for ten seconds may provide sufficient data for a single channel.

To illustrate the wide application of the present invention, reference is made to Figures 9,10 and 11. Instead of an EEG, the waveform is the power spectrum derived from sampling (at 22.05 KHz) a 3 to 5 second recording of a person's speech (Figure 9). The recording was made using a conventional computer fitted with a sound card and microphone and was saved as a'Wave sound (. wav)'file. As before the data is processed into a Microsoft Excçl spreadsheet from which a radar contour plot (Figure 10) and radar filled plot (Figure 11) were obtained. Figure 10 and 11 show plots obtained at just one sampled frequency. Several frequencies can be sampled sequentially and the results overlayed to produce a multiple layer graphic as, for example, is shown in Figure 7 or 8.

Alternative graphic outputs are, of course, derivable from the same data. For example, the same data used to produce the radar plot of Figure 8 can produce a scatter chart of the"bubble"type as shown in Figure 12.

The graphic image (as, for example, shown in Figures 6 to 8 or 10 to 12) can be combined with other images before being output. For example, the image could be a photographic image of the person who provided the original data or simply an additional background graphic.

The graphic image can then be output in the form desired by the user. For example, it could be printed out simply to provide a picture for mounting or for forming greetings cards or badges etc. Alternatively, the graphic can be reverse printed using transfer inks to enable the graphic to be subsequently applied to clothing such as Tshirts.

The image can, of course, be saved in a digital format for further manipulation and subsequent use by the user. Particularly as regards the multiple layer or threedimensional graphics, these can be further processed into holographic images.

Additionally, a plurality of images, perhaps collected over an extended period of time, can be adapted into the form of a personalised screen saver for a computer.

The data could be adapted such as by rotation, translation and/or changing of colours, such that a moving and changing graph can be displayed on a computer screen, Additional features, such as zooming in and zooming out could be added.

All of these forms of data manipulation are well known for screen savers and would be readily apparent to a person skilled in the art. It will be apparent that any portion of the data (for example, the frequency portion) from any EEG scan or sound extract could be used to produce a screen saver, as can any of the EEG channels.

It is also envisaged that the screen saver could be formed from scans of a plurality of individuals, such as of all the people who would use a particular computer.

For the finished screen saver, the user will be able to see on the screen of their personal computer their personal brainwave which will be automatically manipulated to cause visually appealing effects. This data has never been used for such a purpose before and the user will have a sense not only of this unique data which they may not have appreciated before but will also provide an important psychological link with the computer itself.

The skilled reader will readily appreciate methods for improving the capture of data on the EEG, such as coupling the electrodes to the right parts of a person's head, providing or, selectively, withdrawing particular stimuli from the person during capture of brainwaves (for example ensuring the person closes his/her eyes during data capture, and so on).

It is not necessary for the brainwave or audible data to be human data, it could, for example, relate to a bird or animal of particular interest to the user, for example a pet.

Given the above discussion of the various aspects of the present invention, those skilled in the art will be readily able to devise and construct apparatus suitable for acquiring and processing the relevant data without further instruction.

Claims

CLAIMS 1. A visualisation system for visualising a function of the body of a living being; the system comprising acquisition means for acquiring an electrical signal corresponding to a function of a subject body; data processing means and graphic processing means, the data processing means processing the electrical signal into a form from which the graphic processing means can produce a graphic representation of the function of the subject.
2. A visualisation system as claimed in Claim 1 wherein the function relates to a physiological process.
3. A visualisation system as claimed in Claim 2 wherein the physiological process is a brainwave function and the acquisition means comprises an electroencephalograph.
4. A visualisation system as claimed in Claim 1 wherein the function is an audible output from the body.
5. A visualisation system as claimed in Claim 4 wherein the acquisition means comprises a microphone coupled to a computer or other means for digitising the sound output.
6. A visualisation system as claimed in any one of claims 1 to 5 wherein the data processing means and/or the graphic processing means includes data selection and manipulation means adapted to enable a user to select and manipulate portions of the data from which the graphic representation is produced.
7. A visualisation system as claimed in Claim 6 wherein the system also includes means for combining datasets corresponding to a plurality of electrical signals.
8. A visualisation system substantially as herein described with reference to the accompanying drawings for visualising a function of the body of a living being.
9. A method of generating a graphic representation of a function of a body of a living being, the method comprising the steps of obtaining an electrical signal corresponding to the function; processing the signal to obtain a dataset; and processing the dataset to produce a graphic image.
10. A method as claimed in Claim 9 wherein the function relates to a physiological process.
11. A method as claimed in Claim 10 wherein the physiological process is a brainwave function and is obtained by means of an electroencephalograph.
12. A method as claimed in Claim 9 wherein the function is an audible output from the body.
13. A method as claimed in any one of claims 9 to 12 wherein portions of the data may be selected and manipulated prior to production of the graphic representation.
14. A method as claimed in Claim 13 wherein datasets corresponding to a plurality of electrical signals are combined.
15. A method of generating a graphic representation of a function of a body of a living being substantially as herein described with reference to the accompanying drawings.