Pruritometer 2: portable recording system for the quantification of scratching as objective criterion for the pruritus.

Studies to evaluate therapies for itching (pruritus) related diseases often require the quantification of the itch sensation. Like all subjective symptoms the evaluation of itching is difficult and can only be done indirectly. With the Pruritometer 2 a measuring system is introduced that evaluates itching by detecting scratching movements. Based on the Pruritometer 1, that processes the signals of a piezoelectric vibration sensor, fixed on the midfinger of the patients dominant hand, and triggers a simple counter, the Pruritometer 2 allows to store the scratch activity during a 24 hours period. For each adjustable time slice of this time period, the amount of scratches and the scratch intensity are recorded. All data can be transferred to a PC via infrared link for further processing with a standard software package. An additional PC-software allows to set various parameters for optimal scratch detection and to test the patient attached system, also via the infrared link. All electronic components are shockproof encapsulated in a milled housing and are attached to a textile watchstrap that is worn by the patient like a wristwatch.