Mannheim Institute for Intelligent Systems in Medicine, Heidelberg University, Mannheim, Germany.
Int J Comput Assist Radiol Surg. 2023 Sep;18(9):1571-1575. doi: 10.1007/s11548-023-02882-6. Epub 2023 Apr 14.
A robotic assistive device is developed for needle-based percutaneous interventions. The aim is a hybrid system using both manual and actuated robotic operation in order to obtain a device that has a large workspace but can still fit in the gantry opening of a CT scanner. This will enable physicians to perform precise and time-efficient CT-guided percutaneous interventions. The concept of the mechanics and software of the device is presented in this work.
The approach is a semi-automated robotic assistive device, which combines manual and robotic positioning to reduce the number and size of necessary motors. The system consists of a manual rough positioning unit, a robotic fine positioning unit and an optical needle tracking unit. The resulting system has eight degrees of freedom, of which four are manual, which comprise encoders to monitor the position of each axis. The remaining four axes are actuated axes for fine positioning of the needle. Cameras are attached to the mechanical structure for 3D tracking of the needle pose. The software is based on open-source software, mainly ROS2 as robotic middleware, Moveit2 for trajectory calculation and 3D Slicer for needle path planning.
The communication between the components was successfully tested with a clinical CT scanner. In a first experiment, four needle insertions were planned and the deviation of the actual needle path from the planned path was measured. The mean deviation from the needle path to the target point was 21.9 mm, which is mainly caused both by translational deviation (15.4 mm) and angular deviation (6.8°) of the needle holder. The optical tracking system was able to detect the needle position with a mean deviation of 3.9 mm.
The first validation of the system was successful which proves that the proposed concept for both the hardware and software is feasible. In a next step, an automatic position correction based on the optical tracking system will be integrated, which is expected to significantly improve the system accuracy.
开发一种用于基于针的经皮介入的机器人辅助设备。目的是开发一种混合系统，结合手动和驱动机器人操作，以获得具有大工作空间但仍可适应 CT 扫描仪龙门开口的设备。这将使医生能够进行精确和高效的 CT 引导经皮介入。本文介绍了该设备的机械和软件概念。
该方法是一种半自动机器人辅助设备，它结合了手动和机器人定位，以减少所需电机的数量和尺寸。该系统由手动粗定位单元、机器人精定位单元和光学针跟踪单元组成。由此产生的系统具有八个自由度，其中四个是手动的，包括编码器以监控每个轴的位置。其余四个轴是用于针精确定位的驱动轴。相机安装在机械结构上，用于跟踪针的三维姿态。软件基于开源软件，主要是 ROS2 作为机器人中间件、Moveit2 用于轨迹计算和 3D Slicer 用于针路径规划。
成功地使用临床 CT 扫描仪对组件之间的通信进行了测试。在第一个实验中，计划了四次针插入，并测量了实际针路径与计划路径的偏差。实际针路径与目标点的平均偏差为 21.9 毫米，主要由针架的平移偏差（15.4 毫米）和角度偏差（6.8°）引起。光学跟踪系统能够以平均 3.9 毫米的偏差检测针的位置。
系统的首次验证取得了成功，这证明了硬件和软件的提出概念是可行的。下一步将集成基于光学跟踪系统的自动位置校正，预计这将显著提高系统的精度。
