CN-122004917-A - Self-adaptive control method and device for ultrasonic probe

CN122004917ACN 122004917 ACN122004917 ACN 122004917ACN-122004917-A

Abstract

The invention discloses an adaptive control method and device for an ultrasonic probe, which belong to the field of ultrasonic probes, and are characterized in that a binocular camera is adopted to acquire a dynamic image sequence of a body surface in a three-dimensional visual mode, depth information of the body surface is calculated according to the dynamic image sequence to generate three-dimensional point cloud data, a rigid body transformation matrix obtained by calibrating the three-dimensional point cloud data through external parameters is converted to a mechanical arm base coordinate system, key frame characteristic points of video streams acquired by the binocular camera in real time are extracted, a sparse point cloud map is constructed according to the key frame characteristic points, pose of the camera relative to a global environment is acquired, the sparse point cloud map is aligned with an operation space of the mechanical arm according to the pose, path planning is carried out according to the three-dimensional point cloud data of the mechanical arm base coordinate system to generate an initial motion track, and through the steps, the body surface can be finely controlled and the tactile perception with high precision.

Inventors

GUO KAI
WU YUWEN
WU CUICUI
DING MENGMENG
WANG CAN
WANG JIE
Mustafa Orban
Mahmud Elsa Manti

Assignees

中国科学院苏州生物医学工程技术研究所
苏州市相城人民医院

Dates

Publication Date: 20260512
Application Date: 20251212

Claims (10)

1. An adaptive control method of an ultrasonic probe is characterized by comprising the following steps: Binocular vision modeling, namely acquiring a dynamic image sequence of a body surface in real time in a stereoscopic vision mode by adopting a binocular camera, calculating depth information of the body surface according to the dynamic image sequence, and generating three-dimensional point cloud data; Coordinate system calibration, namely converting the rigid transformation matrix obtained by external parameter calibration of the three-dimensional point cloud data into a mechanical arm base coordinate system; extracting key frame feature points of a video stream acquired by a binocular camera in real time, constructing a sparse point cloud map according to the key frame feature points, acquiring the pose of the camera relative to a global environment, and aligning the sparse point cloud map with the operation space of the mechanical arm according to the pose; Generating an initial motion track, namely performing path planning according to three-dimensional point cloud data of a mechanical arm base coordinate system to generate the initial motion track.
2. The method of claim 1, wherein the step of calibrating the coordinate system further comprises moving the end effector of the mechanical arm to a plurality of known spatial points and recording the actual position of the end effector of the mechanical arm And theoretical waypoint And calculating an error after comparison, and when the error is smaller than or equal to a preset value, the precision of the coordinate system calibration meets the requirement, and when the error is larger than the preset value, adjusting a rigid body transformation matrix obtained by external parameter calibration.
3. The method for adaptively controlling the ultrasonic probe according to claim 1, further comprising a step of adjusting the pose of the tail end of the mechanical arm, wherein the step of adjusting the pose of the tail end of the mechanical arm is characterized in that the contact pressure distribution of the probe and the body surface is monitored in real time through a three-dimensional force sensor array arranged on the probe, the distance information of the probe and the body surface is monitored in real time through a distance measuring unit arranged on the probe, and the pose of the tail end of the mechanical arm is adjusted according to the pressure distribution and the distance information.
4. The method of claim 3, wherein in the step of adjusting the pose of the distal end of the arm, when the distance between the probe and the body surface is 60mm or less, the arm is switched to a low-speed mode, and the speed of the arm is adjusted by the amount of the adjustment Wherein For the distance feedback gain factor, For the force feedback gain factor to be a function of, In order for the target distance to be desired, In order to actually measure the distance, Is the force deviation.
5. The method of claim 3, wherein the step of adjusting the pose of the distal end of the mechanical arm further comprises reconstructing a body surface curved surface model according to the three-dimensional point cloud data in the step of binocular vision modeling, extracting a normal vector of the body surface curved surface model, guiding the adjustment of the incident pose of the distal end of the mechanical arm, and ensuring the vertical incidence of ultrasonic waves.
6. The method for adaptively manipulating an ultrasonic probe according to claim 5, wherein said adjusting of an incident attitude of said arm tip probe is performed by adjusting an angle of a tip joint of said arm, and an increment vector of said angle of said tip joint of said arm Wherein The jacobian matrix is the jacobian matrix of the mechanical arm under the current gesture; Is a rigidity matrix; Is the desired contact force; Is the actual contact force.
7. An ultrasonic probe self-adaptive control device for implementing the ultrasonic probe self-adaptive control method according to any one of claims 1-6, the ultrasonic probe self-adaptive control device comprises a mechanical arm and an ultrasonic probe arranged at the tail end of the mechanical arm, and is characterized in that the ultrasonic probe self-adaptive control device also comprises The binocular camera is used for acquiring a dynamic image sequence of the body surface in real time; the three-dimensional force sensor array is arranged on the ultrasonic probe and monitors the contact pressure distribution of the ultrasonic probe and the body surface in real time; the distance measuring unit is arranged on the ultrasonic probe and monitors the distance information between the probe and the body surface in real time; and the processor generates an initial motion track according to the dynamic image sequence, and adjusts the tail end pose of the mechanical arm according to the pressure distribution and the distance information.
8. The ultrasonic probe adaptive control device of claim 7, wherein the three-dimensional force sensor comprises a surface layer, a piezoresistive layer and a substrate, the piezoresistive layer is positioned between the surface layer and the substrate, the surface layer is made of flexible materials, the piezoresistive layer comprises a plurality of cage-shaped structures, and two adjacent cage-shaped structures are connected through a piezoresistive unit.
9. The device of claim 8, wherein the piezoresistive unit is made of a carbon nanotube/PDMS composite.
10. The apparatus of claim 7, wherein the ranging unit is an infrared TOF ranging sensor.

Description

Self-adaptive control method and device for ultrasonic probe Technical Field The invention relates to the field of ultrasonic probes, in particular to an adaptive control method and device for an ultrasonic probe. Background The existing ultrasonic diagnostic equipment generally adopts a handheld probe, and a doctor manually controls the contact pressure, angle and movement track of the probe and the body surface of a patient, so that the mode has the obvious defects that firstly, manual operation is easy to cause inconsistent scanning paths and influence image data comparability due to the experience difference of the doctor, secondly, muscle fatigue of an operator is easy to be caused after long-time operation, contact pressure fluctuation is caused, image quality stability is reduced, thirdly, a real-time self-adaptive adjusting mechanism is lacked, the optimal fit state of the probe and the body surface is difficult to accurately maintain, and the problems of sound beam incidence angle deviation, couplant uneven distribution and the like are caused. Disclosure of Invention In order to overcome the defects of the prior art, one of the purposes of the invention is to provide an adaptive control method of an ultrasonic probe, which can finely control the body surface of a patient and sense the touch with high precision. In order to overcome the defects of the prior art, the second aim of the invention is to provide an ultrasonic probe self-adaptive control device capable of finely controlling the body surface of a patient and realizing high-precision tactile sensation. One of the purposes of the invention is realized by adopting the following technical scheme: an adaptive control method of an ultrasonic probe comprises the following steps: Binocular vision modeling, namely acquiring a dynamic image sequence of a body surface in real time in a stereoscopic vision mode by adopting a binocular camera, calculating depth information of the body surface according to the dynamic image sequence, and generating three-dimensional point cloud data; Coordinate system calibration, namely converting the rigid transformation matrix obtained by external parameter calibration of the three-dimensional point cloud data into a mechanical arm base coordinate system; extracting key frame feature points of a video stream acquired by a binocular camera in real time, constructing a sparse point cloud map according to the key frame feature points, acquiring the pose of the camera relative to a global environment, and aligning the sparse point cloud map with the operation space of the mechanical arm according to the pose; Generating an initial motion track, namely performing path planning according to three-dimensional point cloud data of a mechanical arm base coordinate system to generate the initial motion track. Further, the coordinate system calibration step further comprises the steps of moving the end effector of the mechanical arm to a plurality of known space points and recording the actual positions of the end effector of the mechanical armAnd theoretical waypointAnd calculating an error after comparison, and when the error is smaller than or equal to a preset value, the precision of the coordinate system calibration meets the requirement, and when the error is larger than the preset value, adjusting a rigid body transformation matrix obtained by external parameter calibration. The method for adaptively controlling the ultrasonic probe further comprises a step of adjusting the pose of the tail end of the mechanical arm, wherein the step of adjusting the pose of the tail end of the mechanical arm is characterized in that the contact pressure distribution of the probe and the body surface is monitored in real time through a three-dimensional force sensor array arranged on the probe, the distance information of the probe and the body surface is monitored in real time through a distance measuring unit arranged on the probe, and the pose of the tail end of the mechanical arm is adjusted according to the pressure distribution and the distance information. Further, in the step of adjusting the pose of the tail end of the mechanical arm, when the distance between the probe and the body surface is less than or equal to 60mm, the mechanical arm is switched to a low-speed mode, and the speed adjustment amount of the mechanical arm is as followsWhereinFor the distance feedback gain factor,For the force feedback gain factor to be a function of,In order for the target distance to be desired,In order to actually measure the distance,Is the force deviation. Further, the mechanical arm tail end pose adjustment step further comprises the steps of reconstructing a body surface curved surface model according to the three-dimensional point cloud data in the binocular vision modeling step, extracting a normal vector of the body surface curved surface model, guiding the incident pose adjustment of the mechanical arm tail end probe, and guaranteei