Patent ID: 6776773
Filing Date: 2004-08-17
Classification: A61M,Y10S

Abstract:
A liquid infusion apparatus comprising a pushing holder for pushing a plunger into a cylinder of a syringe, a pulse motor for moving the pushing holder, an incremental linear encoder having a plate with slits arranged along a moving direction of the plunger and a position detecting device moved together with the pushing holder, counting means for counting encoder pulses from the encoder, means for counting instruction pulses to the pulse motor, and a sensor, the mounting position of the sensor being recognized as a counting number of instruction pulses to the pulse motor, wherein the sensor is arranged along the plate with slits at a portion between a position where the pushing holder is connected to the plunger for the liquid infusion, and a start position where the pushing holder is separated from the plunger, wherein the counting means is reset when the sensor is detected by the position detecting device, and started to count the encoder pulses according to the movement of the pushing holder, and wherein a time to complete the liquid infusion is calculated by using a distance between the position where the plunger is connected to the holder and a liquid infusion finish position proper to the syringe, and a predetermined liquid infusion speed, and displayed.