Method and apparatus for determining parameters of linear motion in a surgical instrument

摘要

A surgical instrument and method of controlling the surgical instrument are disclosed. The surgical instrument includes a housing and an elongated shaft that extends distally from the housing and defines a first longitudinal axis. The surgical instrument also includes a firing rod disposed in the elongated shaft and a drive mechanism disposed at least partially within the housing. The drive mechanism mechanically cooperates with the firing rod to move the firing rod. A motion sensor senses a change in the electric field (e.g., capacitance, impedance, or admittance) between the firing rod and the elongated shaft. The measurement unit determines a parameter of the motion of the firing rod, such as the position, speed, and direction of the firing rod, based on the sensed change in the electric field. A controller uses the measured parameter of the motion of the firing rod to control the drive mechanism.

主权项

1. A surgical instrument, comprising:
a housing; an elongated shaft extending distally from the housing and defining a first longitudinal axis; a firing rod disposed at least partially within the elongated shaft; a drive mechanism disposed at least partially within the elongated shaft, the drive mechanism being in mechanical cooperation with the firing rod; a sensor that senses a change in an electric field between the firing rod and the elongated shaft; a signal generator that generates a pulse signal that varies with the change in the electric field between the firing rod and the elongated shaft; and a measurement unit that includes a counter that counts pulses of the pulse signal, and a data processor that computes a pulse signal frequency based on the counted pulses and measures a parameter of a motion of the firing rod based on the pulse signal frequency.