Mapping acupuncture points using multi channel device.

The practice of acupuncture involves the stimulation of specific points on the skin called 'acupuncture points' which are small regions of local or referred pain that are more sensitive than surrounding tissue. The fact that acupuncture points can be identified subjectively as tender points and are found to have characteristic electrical properties suggest that they are functional entities rather than structural ones. These functional properties are used diagnostically in a clinical setting as pathology in a particular body location has been shown to correlate with increased tenderness and electrical conductivity of the 'corresponding' acupuncture point using electronic 'point locators', which measure the DC resistance of points compared to surrounding skin. Commercially available point locators generally utilize a metal locator probe and an indifferent electrode and are designed to produce an auditory output (usually a high pitched tone) when a point is located. These devices however, are open to criticism. They are unable to control for local variations in skin thickness, surface secretions, or pressure placed on the electrode, and are only able to measure a single point at a time. These make them time consuming to use and subjective to user bias in point selection. Furthermore these devices do not store data and are therefore unsuitable for producing a map of skin resistance, which can be accessed over time. To overcome some of the limitations of currently available single probe devices, we have designed a multi-channel probe capable of measuring and then mapping the skin resistance of multiple points.