Patent ID: 7044933

Claim:
An injection apparatus, comprising: a control syringe including a manually movable plunger; a power syringe including a power-actuated plunger; a processor; a sensor operatively associated with the control syringe and transmitting a signal representative of control syringe plunger position to the processor, the processor generating a control signal based on the position signal and transmitting the control signal for movement of the power-actuated plunger; and a feedback device in communication with the power syringe and the control syringe, the feedback device affecting the force required to manually move the plunger of the control syringe, the feedback device including an electromagnet disposed adjacent a fluid line extending from the control syringe, the fluid line being filled with magnetic fluid, the electromagnet receiving the pressure signal and generating an magnetic field, the magnetic field constricting flow of the magnetic fluid within the fluid line based on the pressure signal to provide a user holding the control syringe with tactile feedback.