An extremely safe skin-pricker device in the form of an open-ended tubular shell which carries an open-coil actuator spring which when released by a latchable trigger pushes an actuator shaft to move and cause the pricker needle to travel not only to an intermediate position of relieved stress but also...http://www.google.es/patents/US5147375?utm_source=gb-gplus-sharePatente US5147375 - Safety finger prick instrument
