Method for improving leaf position detection accuracy of multi-leaf collimator

Abstract

The invention provides a method for improving the leaf position detection accuracy of a multi-leaf collimator. The method sequentially comprises the following steps that (a), the phase A of an incremental encoder is connected with an external interrupt interface of a single-chip microcomputer, and the phase B of the incremental encoder is connected with an I / O interface of the single-chip microcomputer; (b), when an interrupt happens, the single-chip microcomputer judges that the phase A is located on the rising edge or the falling edge when in the interrupt position and detects that a signal of the phase B is in high level or in low level at the moment; (c), if the phase A is located on the rising edge and the phase B is in low level, the single-chip microcomputer judges the forward rotation and one is added to the number of a counter; if the phase A is located on the rising edge and the phase B is in high level, the micro-chip microcomputer judges backward rotation and one is subtracted from the number of the counter; if the phase A is located on the falling edge and the phase B is in high level, the micro-chip microcomputer judges forward rotation and one is added to the number of the counter; if the phase A is located on the falling edge and the phase B is in low level, the micro-chip microcomputer judges backward rotation and one is subtracted from the number of the counter. Accumulated errors of the incremental encoder are effectively avoided in the frequent forward rotation and backward rotation process of a motor, and the leaf position detection accuracy of the multi-leaf collimator is improved.

Description

technical field [0001] The invention relates to the technical field of medical device control, in particular to a method for detecting the blade position of a multi-leaf collimator. Background technique [0002] The multi-leaf collimator is an advanced stereotactic radiosurgery medical device, which can cooperate with a linear accelerator or a cobalt-60 machine to perform conformal intensity-modulated treatment of tumors, so as to improve the gain ratio of radiotherapy (that is, to maximize the intensity of the radiation The purpose is to concentrate the dose into the lesion, kill tumor cells, and make the surrounding normal tissues and organs receive less or avoid unnecessary irradiation). It is one of the main devices for tumor treatment today. It replaces the traditional lead baffles with several pairs of high-density tungsten alloy blades arranged in opposite directions in A and B groups to shield the rays, drives the blades and blade groups with corresponding logarithm...

AI Technical Summary

Problems solved by technology

However, in the process of conformal intensity-modulated treatment, the blades frequently move forward and backward, that is, the motors driving the blades frequently rotate forward and reverse.

This method has serious cumulative errors, which affect the accurate counting of encoder output pulses

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