CN-122006147-A - Off-line navigation system of flexible afterloading source applicator in rectum cavity

CN122006147ACN 122006147 ACN122006147 ACN 122006147ACN-122006147-A

Abstract

The invention discloses an off-line navigation system of a flexible post-load applicator in a rectal cavity, which comprises data processing equipment and the flexible post-load applicator for off-line navigation in the rectal cavity, wherein the applicator comprises a flexible applicator main body, a space positioning mark and a deformation sensing module, an axial graduated scale and a circumferential reference mark are arranged on the surface of a flexible shell of the applicator, and four groups of U-shaped foldback resistance wire type strain sensors are embedded in the surface of the flexible shell of the applicator in an orthogonal manner in the circumferential direction. The physiological bending and unexpected torsional distortion of the applicator are accurately decoupled and monitored through the change of the pull-voltage differential signal and the neutral plane resistance value, and the accurate positioning of the applicator is realized from a physical bottom layer through the physical criterion of a 3% steady state early warning threshold. The patient only needs to carry out single CT scanning gear establishment during the first treatment, and the subsequent treatment can be accurately registered by means of internal and external feature cross verification of physical dimension. The waiting time of single treatment is greatly shortened, the accumulated radiation toxic and side effects of patients are obviously reduced, and the operation load of large-scale image equipment in hospitals is greatly released.

Inventors

XIE PENGCHENG
LI JING
WANG HAO
MA YITAO
DING YUMEI
YANG WEIMIN

Assignees

北京化工大学

Dates

Publication Date: 20260512
Application Date: 20260320

Claims (6)

1. The utility model provides a flexible post-load source ware off-line navigation in rectum intracavity, its characterized in that includes data processing equipment and flexible post-load source ware of the flexible post-load of rectum intracavity off-line navigation, and data processing equipment specifically includes: The image coordinate system construction module is used for acquiring the target area anatomical structure based on the single medical image scanning data and establishing an image reference coordinate system; The physical coordinate system construction module is used for constructing a physical coordinate system by taking objective anatomical marks of the target body surface as reference points; The system comprises an applicator coordinate system construction module, a control module and a control module, wherein the applicator coordinate system construction module is used for constructing an applicator local coordinate system based on the axial scale structure of the applicator and the space reading of the circumferential reference mark; the spatial registration and verification module is used for realizing three-dimensional spatial mapping association of the image coordinate system, the physical coordinate system and the applicator coordinate system through a rigid body registration algorithm, and realizing high-precision spatial positioning confirmation of the applicator under the condition of avoiding continuous image scanning assistance by aligning the physical coordinate system with the external identifier of the applicator coordinate system and synchronously analyzing the deformation electric signal output by the deformation sensing module in the subsequent off-line image guiding treatment stage; the flexible post-loading applicator in the rectal cavity comprises a flexible applicator main body, a deformation sensing module and a space positioning mark; The flexible applicator body comprises an integrally formed flexible housing, a plurality of radiation source channels extending along the axial direction of the flexible housing and a plurality of sensor channels extending along the axial direction of the flexible housing are arranged in the flexible housing in a penetrating manner, and the radiation source channels are used for accommodating radiation source guide tubes; The deformation sensing module comprises a plurality of resistance wire type strain sensors which are respectively and independently arranged in the sensor channel, and is configured to output deformation electric signals representing that the flexible shell is axially bent or circumferentially twisted under the stress state; The space positioning mark is arranged on the outer surface of the flexible shell and comprises an axial scale structure for indicating the implantation depth of the applicator and a circumferential reference mark which is arranged at the tail end of the flexible shell and used for indicating the rotation deflection angle of the applicator; The deformation electric signal output by the deformation sensing module, the axial scale structure and the circumferential reference mark are configured to be matched with each other so as to establish the three-dimensional space deformation and pose state of the applicator in the target cavity.
2. The off-line navigation system of the flexible post-load applicator in the rectal cavity of claim 1, wherein the number of radiation source channels of the flexible post-load applicator in the rectal cavity is eight, the radiation source channels are uniformly distributed along the circumferential direction of the cross section of the flexible shell, the number of sensor channels is four, the radiation source channels are uniformly distributed at ninety-degree intervals along the circumferential direction of the cross section of the flexible shell, and each sensor channel is internally and fixedly provided with one resistance wire type strain sensor.
3. The system for offline navigation of a flexible post-load applicator in a rectal cavity of claim 1, wherein the four resistance wire type strain sensors of the flexible post-load applicator in the rectal cavity are divided into a first sensor and a second sensor which are positioned on a bending plane of the applicator expected to be stressed and a third sensor and a fourth sensor which are positioned on a non-bending plane by taking the phase of the circumferential reference mark as a reference, wherein the first sensor and the second sensor are arranged in a radial opposite manner, and the third sensor and the fourth sensor are arranged in a radial opposite manner; When the flexible shell is subjected to unidirectional bending deformation according to the physiological radian of a target cavity, differential resistance change signals with opposite directions are generated respectively due to tensile stress and compressive stress; The third sensor and the fourth sensor are configured to maintain the resistance change within a preset steady-state reference tolerance range when the flexible housing is subjected to the expected unidirectional bending deformation.
4. The flexible post-load applicator offline navigation system of claim 1, wherein the third sensor and the fourth sensor of the flexible post-load applicator are further configured to monitor an unintended torsional distortion of the flexible housing, and when a rate of change of relative resistance output by the third sensor and/or the fourth sensor exceeds a preset threshold, to determine that the applicator is axially torsionally offset from an intended plane and trigger an early warning electrical signal indicative of an abnormality in position.
5. The flexible post-load applicator off-line navigation system in a rectal cavity of claim 1, wherein a front end fixing block and a tail end fixing block are respectively and fixedly arranged at the front end and the tail end of each sensor channel of the flexible post-load applicator in the rectal cavity, the resistance wire type strain sensor comprises a continuous resistance wire, the resistance wire is folded in a U shape at the front end fixing block, two ends of the resistance wire are tensioned in parallel and extend to the tail end fixing block, and a resistance measurement interface for externally connecting detection equipment is led out from the outer side of the tail end fixing block.
6. The post-flexible rectal applicator of claim 5, wherein said predetermined threshold for determining the occurrence of an unintended torsional excursion is 3% of an initial baseline resistance of the sensor.

Description

Off-line navigation system of flexible afterloading source applicator in rectum cavity Technical Field The invention relates to the field of medical instrument space positioning, in particular to an off-line navigation system of a flexible post-loading applicator in a rectal cavity. Background Brachytherapy is a central tool for local tumor control, and the postloading technique is used as a main implementation, and the accuracy of dose distribution is highly dependent on the accurate placement of the applicators in the target area. However, due to the unique anatomical features of the rectum, existing flexible endoluminal post-applicators are extremely difficult to accurately and reproducibly secure to the same ideal three-dimensional spatial location in a practical number of fractional treatments. Traditional clinical treatments are highly dependent on the subjective experience of the physician. To verify the exact pose of the applicators, a high frequency repeated CT scan is typically performed prior to each fraction of treatment. This not only greatly increases the patient's cumulative exposure to ionizing radiation and single treatment waiting time, but also greatly exacerbates the operating load of medical resources and patient pain during instrument retention. How to confirm the three-dimensional pose of the intracavity device on the premise of eliminating repeated image scanning is a technical bottleneck to be overcome in the field. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide an off-line navigation system of a flexible post-loading applicator in a rectal cavity, which aims to realize the physical accurate confirmation of the three-dimensional space pose of the applicator in the cavity channel under the condition of avoiding external high-frequency image positioning by fusing a physical strain sensing array and a multidimensional coordinate space mapping matrix and improve the safety and clinical efficiency of radiotherapy dose distribution. To achieve the above object, the present invention provides an offline navigation system for a flexible post-load applicator in a rectal cavity, comprising a data processing device and the flexible post-load applicator for the flexible post-load applicator in the rectal cavity, wherein the system is configured to execute an offline positioning method based on multi-source coordinate mapping, and the data processing device specifically comprises: The image coordinate system construction module is used for acquiring the target area anatomical structure based on the single medical image scanning data and establishing an image reference coordinate system; The physical coordinate system construction module is used for constructing a physical coordinate system by taking objective anatomical marks of the target body surface as reference points; The system comprises an applicator coordinate system construction module, a control module and a control module, wherein the applicator coordinate system construction module is used for constructing an applicator local coordinate system based on the axial scale structure of the applicator and the space reading of the circumferential reference mark; And in the subsequent off-line image guiding treatment stage, the consistency of the internal form of the applicator is verified by aligning the physical coordinate system with the external identifier of the applicator coordinate system and synchronously analyzing the deformation electric signal output by the deformation sensing module, so that the high-precision spatial positioning confirmation of the applicator is realized under the condition of avoiding continuous image scanning assistance. The flexible post-load applicator in the rectal cavity comprises: The flexible applicator body comprises an integrally formed flexible polyurethane shell, wherein the flexible shell is a cylinder with a ball head, and a plurality of radioactive source channels extending along the axial direction of the flexible shell are arranged in the flexible shell and used for accommodating a radioactive source guide tube, and a plurality of sensor channels extending along the axial direction of the flexible shell; the space positioning mark is arranged on the outer surface of the flexible shell and comprises an axial scale structure for indicating the implantation depth of the applicator and a circumferential reference mark which is arranged on the end face of the tail end of the flexible shell and used for indicating the space rotation deflection angle of the applicator; The deformation sensing module comprises a plurality of groups of resistance wire type strain sensors which are respectively, independently and precisely embedded and fixed in the sensor channel, and the deformation electric signal, the axial scale structure and the circumferential reference mark which are output by the deformation sensing module are configured to be matched with each other