Patent ID: 7476216
Filing Date: 2009-01-13
Classification: A61M

Abstract:
1. An electric syringe for injecting a dental anesthetic by pressing a rubber plug of a cartridge filled with an anesthetic, thereby injecting the anesthetic from a needlepoint of a dental needle connected to the cartridge, the electric syringe comprising: a push member configured to press and move the rubber plug of the cartridge; a drive motor configured to generate a drive force; a transmission mechanism part configured to transmit the drive force to the push member; an operation switch having a window hole portion and a sensor of a light reflection type which detects whether or not the window hole portion is closed; and a control unit configured to control a moving of the push member by controlling the drive motor; wherein the control unit starts the injection of the anesthetic when the sensor of the operation switch detects that the window hole portion is closed and controls the drive motor to move the push member to linearly increase an injection speed of the anesthetic at a constant, predetermined rate at the beginning of the injection and until reaching a selected injection speed, and then to move the push member to inject the anesthetic at the selected injection speed without further increase.