EP1916941A2

EP1916941A2 - Intolerance testing device and system

Info

Publication number: EP1916941A2
Application number: EP06765052A
Authority: EP
Inventors: Johathon Mark Griffiths; Huw John Griffiths; Paul Anderson; Guy Tritton
Original assignee: CWM Dulas Corp Ltd
Current assignee: CWM Dulas Corp Ltd
Priority date: 2005-07-22
Filing date: 2006-07-21
Publication date: 2008-05-07
Also published as: WO2007010269A2; WO2007010269A3

Abstract

An intolerance testing device and an intolerance testing system for determining a person's intolerance of specific substances, primarily specific foodstuffs. The device includes a memory for storing data which represents a signature frequency that is characteristic of a number of substances. The device includes a stimulation electrode for applying an alternating stimulation voltage signal, derived from the memory, at a selected frequency, to a user's skin. An amplifying and filtering circuit is coupled to a sensing electrode to detect a change in sensed body voltage.

Description

INTOLERANCE TESTING DEVICE AND SYSTEM

This invention relates to an intolerance testing device and an intolerance testing system for determining a person's intolerance of specific substances, primarily specific foodstuffs.

Research has established that the human body responds to electrical signals which are emitted by substances, chemicals and foodstuffs.

It is also known in the prior art that every substance has a characteristic frequency which arises from the inherent vibrational nature of atoms. That frequency can be measured by measuring the nano-voltage of the Hertzian wave as it passes through an object.

It has also been established, through research seeking to explain the properties of acupuncture and related techniques, that those substances to which the human body has intolerance and which stress the body, affect electrical signals generated within the body, and it has been found that such signals may be picked up at acupuncture locations.

The latter property is sometimes referred to as the electrodermal response of the body, and is measured by monitoring changes in electrical parameters of the body, e.g. its electrical resistance in particular regions, when the person is subjected to different compounds. There are on the market a number of so-called bio-resonance systems making use of the electrodermal response to test for food allergies as well as various other ailments and disorders. AU of these systems involve the patient being connected to a number of electrodes and tested by a therapist. Typically, the electrodes are applied to the ankles, wrists, and the head. In some cases, the patient holds an electrode to complete the circuit.

In general, intolerance to a particular compound is tested by placing a sample of the compound or a homeopathic trace of the compound in a small vial which is located on a metal plate or in a metal honeycomb forming part of an electrical transmission circuit for applying a stimulation signal via the electrodes. A resultant change in resistance of the body is used to determine "rejection" or intolerance of the compound.

There are a number of disadvantages with these prior systems. Firstly, the prior systems are bulky and not easily transportable. They thus tend to reside in one place like a health centre. Secondly, they are very expensive, often in the order of thousands of pounds sterling. This means that they are not suitable for purchase by the average consumer. Thirdly, they require a skilled operator to use. The skilled operator will often have to calibrate the machine for each patient and spend some time selecting the acupuncture points. Fourthly, the prior systems tend to use a machine to measure electrical resistance of the body and then intelligently use the machine to determine whether there is a substantial reaction. This gives rise to a number of problems, in particular the fact that the body's resistance is considerably affected by surface perspiration (this is well-known in lie detector tests). Fifthly, since the reactivity of the human body changes continually, any such intolerance test is a snapshot in time and, as a result, may not consistently and reliably indicate the overall pattern of intolerances of a patient unless the test is repeated over a period of time, which is expensive and time-consuming. When one of these tests has been completed, typically the therapist recommends remedial steps, but such advice, although informative and helpful, may raise more questions for the patient than it answers. The cost of a visit to the therapist often has an inhibitory effect on a return visit. Thus, the patient is often left with a snapshot of reactivities but this is not followed up by either the therapist or the patient which is unsatisfactory for medium to long term patient care.

There is a need for a less expensive, more convenient and more reliable means for testing for intolerances. In particular, there is a need for a device which can be used by an individual without the need for a therapist and which permits ongoing testing and analysis of the reactivity of that individual to particular substances. According to a first aspect of this invention an intolerance testing device for determining a person's intolerance of specific substances comprises: storage means for storing a plurality of data each of which is representative of a signature frequency that is characteristic of a respective substance; a signal generator and at least one stimulation electrode, the signal generator being configured to apply to the stimulation electrode an alternating stimulation voltage signal, derived from the storage means, at a selected signature frequency; and a reaction sensing arrangement including at least one sensing electrode and an amplifying and filtering circuit coupled to the sensing electrode to detect a change in a sensed body voltage.

Preferably, the reaction sensing arrangement is arranged to sense only body voltage signals that meet a predetermined condition, typically where change to the body's natural resting voltage (normally about 4OmV) exceeds 25% of that resting voltage, i.e., normally 1OmV.

The stimulation and sensing electrodes are preferably skin contact electrodes, at least one sensing electrode being coupled to a voltage measuring circuit for measuring a DC body response voltage signal.

A particularly preferred device in accordance with the invention has a pair of stimulation electrodes and a pair of sensing electrodes which form part of a unitary stimulation and sensing module. For example, the electrodes may be integral with the module or one or more may be on flying leads, for example, for attachment to an arm or a leg. The module contains a signal generator coupled to the stimulation electrodes to generate an alternating stimulation voltage there between with a peak-to-peak value in the range of from 1OmV and 10V. The amplifying and filtering circuit is also within the unitary module and is coupled to the sensing electrodes and configured to measure a DC body response voltage of less than 10OmV between the sensing electrodes.

The module may be in the form of a bracelet, preferably for fitting to an arm or leg, having stimulation and sensing electrodes formed as spaced-apart skin contacts on the inwardly facing surfaces of the bracelet so that when the bracelet is tensioned around the wrist, the electrodes bear against the skin of the patient on both the back (upper or outer) and the front, (lower or inner) side of the wrist.

The unitary module preferably further includes the storage means for storing signature frequencies.

Prior systems require the user to locate accurately a suitable acupuncture point for measuring body resistance. Once the acupuncture point is located, the user must press, typically, a detection probe onto the skin at the acupuncture point and maintain a constant pressure while the resistance is monitored. This requires a skilled operator. Over a relatively short time, the sensitivity of the acupuncture point changes, typically becoming less sensitive. It will be understood that the interpretation of results requires a skilled person to evaluate the body response signals. Measurement of resistance is inherently unreliable and will normally require a skilled operator. For instance, surface perspiration can substantially affect the electroconductivity of the skin and variations in the resistance caused by perspiration can mask any minor variations caused by the adverse reaction of an individual to substances. Furthermore, generally, the measurement of resistance requires a substantial distance between the sensing electrodes to ensure that there is not mere measurement of resistance due to conduction of surface perspiration but rather measurement of the conduction of the body. (Generally, where the electrodes are placed close to each other, measurement of current between them is often confined to the surface of the skin and does not pass through the body.) Moreover, resistance measurements can be affected by the variation in pressure applied to electrodes, their location and accuracy of probe location.

The device disclosed in this application is user-operable in the sense that the user may select a particular substance and apply a stimulation voltage at the corresponding stored signature frequency. No sample or homeopathic trace of the substance is required. Measurement of a response voltage rather than resistance substantially reduces variations in response due to, for instance, variations in electrode location on the body, surface perspiration and applied pressure. As a result, patients can use the device themselves on a day-to-day basis away from a treatment centre or clinic. They may test themselves for intolerance of whichever substances they choose, and where and when they want to use the device. There is no need for a trained therapist, for instance, to locate acupuncture points and to ensure suitable and stable testing conditions are maintained.

It is desirable to avoid stressing the user's body by, for instance, applying over too great a period of time a stimulation signal at a frequency characteristic of a substance of which the body is intolerant because, firstly, the body's sensitivity to the stimulation signal falls quite markedly after a short time (typically a few seconds) and, secondly, delivery of such a signal can produce the same effect in the body as the substance itself to the extent of causing an unpleasant physiological effect . hi particular, persistent stimulation can cause the patient to experience actual symptoms associated with their intolerance, such as physical discomfort, mental stress, nausea or tiredness.

It has been found that pulsing reduces the rate at which the sensitivity of the body to the stimulation signals reduces during testing. Therefore, according to one embodiment of the invention, the stimulation voltage is pulsed, the pulse repetition rate being in the range of from 0.1Hz to 100Hz, preferably 0.2Hz to 2Hz, and the pulse duty cycle being in the range of from 0.1% to 50%, preferably from 1% to 30%. It has been found that these parameters represent a good compromise between loss of sensitivity and provoking a response.

The body exhibits a natural DC voltage of approximately 4OmV across any two points of the body. In prior systems, calibration and testing of prior intolerance testing systems is done by the therapist using considerable experience and intuition. With a home use intolerance testing system, that is not possible and represents a considerable deterrent to manufacturing and marketing a home use intolerance testing system. Furthermore, it has been found that different patients require different stimulation levels for optimum sensitivity and that each patient has a "base stimulation level" below which it is difficult to detect any sensitivity in the patient but above which small increases in the stimulation level of the voltage will show substantial changes in the body's voltage of an individual for frequencies for which that individual is intolerant.

Thus, the preferred device is configured such that the amplitude of the stimulation voltage is initially set at a predetermined minimum level and is subsequently incremented at least once by a predetermined amount. The signal generator may be configured to apply the alternating stimulating voltage signal to the stimulation electrode successively at different selected signature frequencies.

Changes in the body response voltage signal are measured at the sensing electrode or electrodes and may be stored in a memory of the device which relates them to corresponding portions of the applied signal.

Furthermore, by pulsing the stimulation signal, the difference between the stimulated and unstimulated body response voltage may be measured a number of times in succession. This is especially useful because, as the amplitude of the stimulation voltage is increased, pulsing allows tracking of the sensitivity level of a person. A further advantage of pulsing the stimulation signal is that the change in body response voltage due to stimulation is measured rather than the absolute body voltage, which latter voltage may change over time.

In the preferred embodiment, for each signature frequency of the applied signal, a change in the body response voltage is compared against predetermined sensitivity criteria and an output is provided via an audio-visual display to indicate the likelihood of sensitivity to the substance characterised by the signature frequency.

In a preferred embodiment of the invention, the intolerance testing device is arranged to carry out the following steps when determining the intolerance of an individual: (i) the frequency of the stimulation voltage signal is selected to be a signature frequency represented by the said stored data;

(ii) the amplitude of the stimulation voltage signal is set at a predetermined minimum level; (iii) the stimulation voltage signal is administered as pulses of a predetermined duration to the individual via the stimulation electrode or electrodes; (iv) corresponding changes in the body voltage of the individual are measured via the reaction sensing arrangement and are stored in a memory; (v) the amplitude of the pulsed stimulation voltage is increased by at least one predetermined increment;

(vi) steps (iii) to (v) are repeated until either a predetermined maximum amplitude of the stimulation voltage signal has been reached, or the reaction sensing arrangement has reached a saturation level;

(vii) the changes in the body voltage are compared against predetermined sensitivity criteria; and

(viii) an output is provided via an audio-visual display means which is indicative of the individual's sensitivity to the substance characterised by the signature frequency.

Preferably, the device is also arranged to repeat steps (ii) to (viii) at least once for other signature frequencies.

The predetermined minimum amplitude level of the stimulation voltage is preferably in the region of 0.25V, the duration of the pulses being about 0.1s, repeating about every second. The predetermined maximum amplitude is preferably in the region of 10V.

Generally, the predetermined criteria will be based on the change in voltage of the subject once the stimulation voltage has passed an individual's base stimulation voltage level. People who are not reactive to a particular signature frequency do not experience only minor changes in their voltage once their base stimulation level has been reached.

According to another aspect of the invention, there is provided an intolerance testing device for determining a person's intolerance to specific substances comprising a stimulation circuit arranged to apply an alternating stimulation voltage to at least one stimulation electrode at a signature frequency in a range of from 4kHz to 15MHz, and a response measuring circuit for measuring the change in a body voltage developed across a pair of sensing electrodes in response to application of the stimulation voltage, the response circuit excluding signals at frequencies above 100Hz. The stimulation frequency range has been determined by experimentation. Excluding body voltage changes at frequencies above 100Hz largely prevents interference from other parts of the device and stimulation signal components.

According to a further aspect of the invention, an intolerance testing system for determining a person's intolerance to specific substances comprises a self- contained wearer unit configured to be worn by the person being tested and comprising means for connecting to a power supply, stimulation contacts and response sensing contacts, a storage device storing a plurality of data, each of which is representative of a signature frequency that is characteristic of a respective substance, wearer operable control means for initiating a testing procedure, and a display for displaying the result of the testing procedure. The wearer unit may comprise means for connecting to a power supply or advantageously comprise a battery.

According to yet a further aspect of the invention, an intolerance testing system comprises a source of electrical signature data external to a wearer unit and an interface which allows for the transfer of the electrical signature data from the source to the wearer unit in response to a wearer request. The interface may also allow for the transfer of data from the wearer unit to a remote server. Thus, the device unit may be arranged to interface to a communication unit such as a personal computer with an Internet connection so that information gathered by the unit can be analysed by the user and/or additional testing signature frequencies can be downloaded from a remote database. The personal computer may embody a proprietary software package for providing more detailed results than can be displayed on the device itself. The Internet connection allows exchange of data with a specially built database at a remote server. Individuals may then store results from their device in their own confidential health-check files to allow them to monitor not only the test results, but also, for instance, other remedial steps and associated data, in particular information on the substance which the individual has been identified as having an intolerance. The invention will now be described by way of example with reference to the drawings in which:-

Figures IA and IB are perspective views of a wristlet device shown, respectively, fastened and laid out flat; and

Figure 2 is a functional block diagram of the wristlet unit.

There are a number of devices in the prior art which permit one to measure the frequencies that are emitted by a substance, for example, the BT3 monitor supplied by Infinity Resources of Cheney, Washington, USA. These emissions are at the nano-volt level. The signature frequency of a particular substance is identified in the following manner. Each variant of a particular substance is put into a test vial (e.g., if testing milk, one would take skimmed, semi-skimmed and full fat milk). An ambient reading would be taken of the sensor of the device to create the base reading. Then a large number of readings are taken using a particular setting (e.g. 1 second setting) for the substance in the vial. For each substance, an average of all the readings would be calculated. Furthermore, for each class of substance, e.g., milk, the range of relevant frequencies would be determined by taking the highest and lowest average of particular variants. Thus, for milk, the range would be the average frequency for semi-skimmed milk to the average for full fat milk (these being found to have the lowest and highest average frequencies of the milk class of products). The mid-point of that range can be used to give a signature frequency which can be used for testing purposes. However, it will be apparent other methodologies can be used to determine a particular signature frequency.

Referring to Figures IA and IB, an intolerance testing device in accordance with the invention comprises a wristlet 10 having an enclosure 1OA and a strap 1OB with a buckle 1OC. The wristlet 10 has four spaced-apart electrical skin contacts on its inwardly facing surfaces. These four contacts comprise a first pair of stimulation electrodes 12A₅ 12B, or skin contacts, on the enclosure 1OA, positioned to bear against one surface of the wrist, here the back surface i.e. the surface of the wrist adjacent the back of the hand, and a second pair of sensing electrodes 14A, 14B, or acupuncture point contacts, on the strap 1OB, positioned so as to be located on the oppositely facing surface of the wrist, here called the front side. In practice, the sensing electrodes are located so as to bear against acupuncture points on the underside of the wrist. The location of the stimulation electrodes 12 A, 12B is not critical, but they are preferably mounted well spaced apart, e.g., 15mm apart or more. Generally, it is preferable that the stimulation electrodes are on or close to the subject's acupuncture points on the wrist as this causes greater sensitivity. The enclosure 1OA contains electronic circuitry, and has a display 15, user-operated keys (not shown) and a battery power supply. In fact, this preferred device contains all the necessary circuitry for autonomous operation, i.e., without connection to external power supplies, signal sources or the like. The display 15 indicates, amongst other information, the substance being tested and the level of sensitivity to that substance.

The keys allow the user to control the unit to select substances for which an intolerance is to be tested and to control the tests to be carried out, to store results in a memory within the device, and to switch the device on or off.

Referring to Figure 2, the electronic circuitry contained within the wristlet housing 1OA comprises logic control circuitry 20 (controller logic (functional logic)) which may be a micro-controller or a field-programmable gate array (FPGA), a secure (encrypted) signature frequency memory 22, an analogue stimulation channel 24 and an analogue sensing channel 26. A user interface 28 couples the logic control circuitry 20 to the display and keys referred to above.

The stimulation channel 24 comprises a programmable signal generator 24A coupled to the signature frequency memory 22. The signature frequency memory 22 is connected to the logic control circuitry 20 via a data and control link 2OC. Generator 24A generates at its output 24AA a continuous wave (CW) alternating signal the frequency of which is dependent on one or both of a control signal received from the control logic 20 via a connection 24AB and frequency data received from the signature frequency memory 22. In particular, the frequency may be a predetermined single frequency selected from the frequencies stored in the memory 22 according to a control signal from the control circuitry or, alternatively, the frequency may be swept continuously or in steps according to the control signal.

The signal generator 24A may generate signals at frequencies within the range of a few kilohertz up to and beyond 15MHz. As explained above, individual substances tend to have specific associated signature frequencies. Typically these are located in the range of from 3OkHz to IMHz but it is thought that signature frequencies in a wider range above IMHz exist as well. Signature frequencies corresponding to particular substances are stored in the signature frequency memory 22.

A pulse modulator 24B receives the CW signal from the generator 24A and modulates it according to a modulation signal received from the control circuitry 20 over connection 24BA and the resulting pulsed signal is delivered to an output level controller 24C.

In the present embodiment, pulse modulation is applied at a pulse repetition rate of about IHz with a pulse width in the region of 10OmS. The repetition rate and pulse duration may be altered but it must exceed the minimum sample period which is determined by body response time and filter delay characteristics.

The level controller 24C feeds an output amplifier 24D having output terminals 24DA which are coupled to the stimulation electrodes 12A₅ 12B (outputs 1 and 2 respectively) referred to above. The level controller and output amplifier 24C and 24D act together to deliver the modulated stimulation signal to the stimulation electrodes at a level set by the control circuitry 20 via a connection 24CA (output level control) to the output level controller. Typically, the peak to peak stimulation voltage at the output terminals 24DA of the amplifier 24D lies in the range of from 1OmV to 10V

Testing is performed at specific stimulation frequencies and voltages which are controlled by the control circuitry and any significant body responses are recorded by the control circuitry for analysis. The system performs an automatic testing process as follows. (i) the voltage of the stimulating voltage is set at a level which is just below the minimum voltage which has been found to cause an effect in people, preferably 0.1V (ii) the lowest frequency of the database of stored signature frequencies in the signature frequency memory 22 is selected

(iii) a pulsed voltage of a fixed duration, preferably 1/10^th second every second at that frequency is administered to the subject via the stimulation electrode or electrodes (iv) the change in voltage of the subject (if any) at the sensing electrodes is measured (this is called "the delta voltage") and stored in memory (v) the stimulation voltage is increased by a predetermined criteria, preferably 0.1V, and steps (iii) and (iv) are repeated until either a predetermined criterion, preferably 10V, or the sensing circuitry has reached saturation level; (vi) the next frequency from the database of stored signature frequencies is selected and steps (iii) to (v) are repeated until all stored frequencies have been tested

(vii) the delta voltages for each stored signature frequency (which typically tend to vary between 0 and 5 mV but can go up much higher e.g. 4OmV) is compared against predetermined sensitivity criteria and the subject is informed by audiovisual display means of his or hers level of sensitivity to the substance which is the frequency is associated with e.g. using a numerical scale or words such as very strong, strong, moderate, minor sensitivity.

Generally, the predetermined criteria are based on the change in voltage of the subject once the stimulation voltage has passed an individual's base stimulation voltage level. People who are not reactive to a particular signature frequency experience only minor changes in their voltage once their base stimulation level has been reached.

In summary, the control logic circuitry controls the determination of optimum sensitivity, the modulation characteristics and the stimulation level and the stimulation frequency. The output amplifier includes isolation circuitry (not shown) for isolating the output terminals 24DA at DC from other parts of the electronic circuitry shown in Figure 2. The amplifier output is preferably a balanced output.

Stimulation of the patient with stimulation signals as described above results in a changing body response signal when the frequency of the stimulation signal corresponds to that of a substance of which the body is intolerant. The body response signal is picked up by the sensing electrodes 14 A, 14B (inputs 1 and 2 respectively) as a DC or very low frequency voltage arising from the modulated stimulation signal. Typically, the upper frequency limit is 100Hz. One of the sensing electrodes, here electrode 14A, is designated as a variable signal input electrode and is coupled to the input of a first signal amplifier first preamplifier 26A. The other sensing electrode is designated as a reference electrode and is coupled to a second preamplifier 26B, hereafter referred to as the reference preamplifier. Both preamplifiers 26A, 26B are voltage amplifiers which amplify the respective input body voltages with respect to each other and the outputs of the amplifiers are fed to the differential input of a difference amplifier 26C. In this way, the voltage at the second sensing electrode 14B is used as a reference input with the result that use of the difference between the outputs of the two preamplifiers substantially reduces DC voltage offsets and common-mode noise.

In practice, the differential voltage between the two inputs ranges from 0 to 5mV but will go up to 4OmV. The majority of the filtering of the sensing channel 26 in this preferred embodiment is performed by a filtering and amplifying stage 26D downstream of the difference amplifier 26C.

Filtering here is performed in such a way as to ensure that low level signals below 100Hz (i.e. the maximum modulated frequency) are treated as a wanted body response signal whereas signals with frequencies above that are rejected. In particular, the bandwidth and attenuation characteristics of the filter 26D is chosen to allow the modulation of the stimulation signal to be followed so not to allow any residual leakage signal from the stimulating signal to be measured directly. The bandwidth is also limited to avoid aliasing issues in the analogue to digital (AfD) conversion process downstream in the sensing signal at the end of the sensing channel 26.

Sufficient gain is provided by the filtering and amplifying stage 26D to raise the filtered and amplified body response signal to a level sufficient to allow conversion to digital signals in an A/D converter 2OA forming part of the control circuitry 20.

In this embodiment, the filter circuitry in the filtering and amplifying circuitry 26D includes a high -order low-pass filter with a roll-off set at 100Hz. The total gain of the amplifier chain from the input electrodes 14A, 14B to the A/D converter 2OA is approximately 1000. Gain is divided approximately equally between the pre-amplifiers 26A, 26B, the differential amplifier 26C, and the filtering an amplifying stage 26D in conjunction with an isolation amplifier 26E between the filtering an amplifying stage and the A/D converter 20A. Isolation amplifier 26E uses an opto-isolator to isolate the input amplifiers 26A, 26B, 26C,

26D from other parts of the electronic circuitry shown in Figure 2 by way of current leakage, thereby to reduce leakage of the stimulation signals into the sensing channel. Transformer or capacitive isolation may be used instead of or in addition to optical isolation.

The filtered and amplified sensing signals are converted into the digital domain by the A/D converter 2OA for measurement, analysis and processing by the control circuitry 20. The control circuitry 20 is arranged to respond to sensing signals which meet predetermined conditions, and not to respond to sensing signals which do not.

The control circuitry 20 may take various forms. Data security is achieved by using secure components, for example, a one-time programmable gate array together with an encryption facility for data stored externally of the device. Such security measures also apply to the download of signature frequencies. Included as part of the control circuitry 20 is a communication interface 2OB for connection to, for instance, external processing circuitry such as a personal computer, or a plug-in device such as a flash or memory card or similar. The interface 2OB may also be used for direct connection to the Internet, depending on the constitution of the control circuitry 20. The control circuitry may embody means for encrypting and decrypting data transmitted over the communication interface 2OB, e.g., for downloading signature frequencies from a remote source.

Additional functions performed by the control circuitry 20 are:

1. To receive and convert the amplified body response signals and to determine which parts of those signals represent valid responses relevant to intolerance testing,

2. To sweep the frequency of the signal generator 2OA,

3. To supply a modulation signal for modulating the stimulation signal,

4 To control the output level controller 24C,

5. To interface with secure data, including signature frequency data stored in the memory 22 and other secure data received from and transmitted over the communication interface 2OB.

6. To send and receive control signals and data to and from the user interface 28 (for controlling and responding to the user keys and for generating display information),

7. To provide a USB type interface for connection to any computer, and

8. To control power-up and power-down, etc...

The control circuitry embodies software allowing secure transfer of data to and from a remote database server accessed using a personal computer connected to the interface 2OB (Figure 2) and to the Internet. This data could consist of, for instance, instruction data for the control circuitry or signature frequencies. Data passing between the server and the control circuitry is encrypted, the connected computer preferably taking no part in encryption or decryption. Data processing is performed at the server and information is passed back to the user by way of a dumb browser-type interface on the computer. Personal intolerance substance data can be uploaded from the control circuitry to a remote server which the subject can view and/or at the same time new signature frequencies downloaded to the control circuitry. A subject can also view his personal data file on the remote server (or download it to his computer) which may be associated with other data such as dietary or lifestyle suggestions for a person with an intolerance profile as indicated by that subject's intolerance substance data. It is envisaged that users would pay a periodic fee for such services.

Claims

1. An intolerance testing device for determining a person's intolerance to specific substances comprising:- storage means for storing a plurality of data each of which is representative of a signature frequency that is characteristic of a respective substance; a signal generator and at least one stimulation electrode, the signal generator being configured to apply to the stimulation electrode an alternating stimulation voltage signal, derived from the storage means, at a selected signature frequency; and a reaction sensing arrangement including at least one sensing electrode and an amplifying and filtering circuit coupled to the sensing electrode to detect a change in a sensed body voltage.

2. A device according to claim 1, wherein the reaction sensing arrangement is arranged to detect only changes in the sensed body voltage that meet a predetermined condition.

3. A device according to claim 1 or claim 2, wherein the sensing arrangement is configured to measure a DC voltage at the sensing electrode.

4. A device according to any preceding claim, wherein the stimulation and sensing electrodes are skin contact electrodes.

5. A device according to claim 1, having a pair of stimulation electrodes and a pair of sensing electrodes, wherein the signal generator is coupled to the stimulation electrodes to generate a peak-to-peak stimulation voltage therebetween in the range of from 10 mV to 10 V, and wherein the amplifying and filtering circuit is coupled to the sensing electrodes and configured to measure a DC response voltage signal of less than 100 mV therebetween.

6. A device according to any preceding claim, wherein the stimulation and sensing electrodes form part of a unitary stimulation and sensing module.

7. A device according to claim 6, wherein the module is in the form of a bracelet in which the stimulation and sensing electrodes comprise spaced apart skin contacts.

8. A device according to claim 7, wherein the skin contacts are arranged such that, when the bracelet is worn on the wrist, the stimulation electrode or electrodes are on the back side of the wrist and the sensing electrode or electrodes are on the front side.

9. A device according to any one of claims 6 to 8, wherein the unitary module includes the storage means, the signal generator and the amplifying and filtering circuitry.

10. A device according to any preceding claim, wherein the stimulation voltage is pulsed.

11. A device according to claim 10, wherein the pulse repetition rate is in the range of from 0.1 Hz to 100 Hz and the pulse duty cycle is in the range of from 0.1% to 50%.

12. A device according to any preceding claim, configured such that the amplitude of the stimulation voltage signal is initially set at a predetermined minimum level and is subsequently incremented at least once by a predetermined amount.

13. A device according to any preceding claim, wherein the signal generator is configured to apply the alternating stimulation voltage signal to the stimulation electrode successively at different selected signature frequencies.

14. A device according to any preceding claim, wherein changes in the body response voltage signal are measured at the sensing electrode or electrodes and stored in a memory of the device which relates them to corresponding portions of the applied signal.

15. A device according to claim 14, wherein, for each signature frequency of the applied signal, a change in the body response voltage is compared against predetermined sensitivity criteria, and an output is provided via an audio-visual display to indicate the likelihood of sensitivity to the substance characterised by the signature frequency.

16. A device according to any preceding claim, arranged to carry out the following steps when determining the intolerance of an individual: (i) the frequency of the stimulation voltage signal is selected to be a signature frequency represented by the said stored data;

(ii) the amplitude of the stimulation voltage signal is set at a predetermined minimum level;

(iii) the stimulation voltage signal is administered as pulses of a predetermined duration to the individual via the stimulation electrode or electrodes;

(iv) corresponding changes in the body voltage of the individual are measured via the reaction sensing arrangement and are stored in a memory;

(v) the amplitude of the pulsed stimulation voltage is increased by at least one predetermined increment; (vi) steps (iii) to (v) are repeated until either a predetermined maximum amplitude of the stimulation voltage signal has been reached, or the reaction sensing arrangement has reached a saturation level;

(vii) the changes in the body voltage are compared against predetermined sensitivity criteria; and (viii) an output is provided via an audio-visual display means which is indicative of the individual's sensitivity to the substance characterised by the signature frequency.

17. A device according to claim 16, further arranged to repeat steps (ii) to (viii) at least once for other signature frequencies.

18. A device according to claim 16 or claim 17, arranged such that the predetermined minimum amplitude level of the stimulation voltage signal is in the region of 0.25 V, the duration of the pulses is about one-tenth of a second and repeats about every second and the predetermined maximum amplitude is in the region of 10 V.

19. An intolerance testing device for determining a person's intolerance to specific substances, comprising a stimulation circuit arranged to apply an alternating stimulation voltage to at least one stimulation electrode at a signature frequency in a range of from 4 kHz to 15 MHz, and a response measuring circuit for measuring the change in a body voltage developed across a pair of sensing electrodes in response to application of the stimulation voltage, the response circuit excluding signals at frequencies above 100 Hz.

20. An intolerance testing system for determining a person's intolerance to specific substances, wherein the system comprises a self-contained wearer unit which is configured to be worn by the person being tested and which includes: means for connecting to a power supply; stimulation contacts and response sensing contacts; a storage device storing a plurality of data, each of which is representative of a signature frequency that is characteristic of a respective substance; wearer operable control means for initiating a testing procedure; and a display for displaying the result of the testing procedure.

21. A system according to claim 20, wherein the system further comprises a source of electrical signature data external to the wearer unit, and an interface which allows for the transfer of the electrical signature data from the source to the wearer unit in response to a wearer request.

22. A system according to claim 15, wherein the interface allows for the transfer of data from the wearer unit to a remote server.

23. A system according to claim 21, arranged to allow the user to access on a remote server a personalised data file which is updated by the wearer unit when it is connected to the remote server and which contains substance intolerance data relating to the user, and which data file links to associated data such as dietary and lifestyle suggestions appropriate to persons who have such substance intolerance.

24. A method of testing a person's intolerance of specific substances comprising generating a stimulation signal as an alternating electrical voltage at at least one of a plurality of signature frequencies which are respectively characteristic of the substances and applying the stimulation signal to the person's body through at least one skin contact stimulation electrode, measuring a reaction voltage developed by the person's body in response to the stimulation signal by receiving the reaction voltage using at least one skin contact electrode located at position on the person's body spaced from the or each stimulation electrode, and amplifying, filtering and analysing the reaction voltage to produce a test result indicative of an intolerance of a substance when the reaction voltage associated with stimulation at the respective signature frequency meets a predetermined condition.

25. A method according to claim 24, wherein the substance tested comprises a foodstuff.

26. An intolerance testing device constructed and arranged substantially as herein described and shown in the drawings.

27. An intolerance testing system constructed and arranged substantially as herein described and shown in the drawings.