Patent ID: 6966895
Filing Date: 2005-11-22
Classification: A61M

Abstract:
1. A syringe pump adapted to receive a syringe having a plunger movable along a barrel, the pump comprising: a plunger head actuator; an electric motor; a drive mechanism between said motor and said plunger head actuator to move said plunger head actuator and hence said plunger along said barrel; a speed sensor arranged to measure the rotational speed of the motor; and an arrangement for detecting a fall in the rotational speed of the motor indicative of an obstruction to movement of said plunger and for stopping the motor in response to the detected fall in speed; wherein the speed sensor is arranged to produce pulses at a frequency dependent on the speed of said motor, and wherein the arrangement for detecting a fall in speed of the motor is arranged to time the intervals between said pulses and to compare the time intervals against a predetermined variable multiple of a preset minimum time.