Yoon W Jong, Park Sangtae, Reinhall Per G, Seibel Eric J
Department of Mechanical Engineering, University of Washington, Seattle, WA 98195,
J Med Device. 2009 Mar 1;3(1):11004. doi: 10.1115/1.3054381.
Given the advantages of cystoscopic exams compared with other procedures available for bladder surveillance, it would be beneficial to develop an improved automated cystoscope. We develop and propose an active programmable remote steering mechanism and an efficient motion sequence for bladder cancer detection and postoperative surveillance. The continuous and optimal path of the imaging probe can enable a medical practitioner to readily ensure that images are produced for the entire surface of the bladder in a controlled and uniform manner. Shape memory alloy (SMA) based segmented actuators disposed adjacent to the distal end of the imaging probe are selectively activated to bend the shaft to assist in positioning and orienting the imaging probe at a plurality of points selected to image all the interior of the distended bladder volume. The bending arc, insertion depth, and rotational position of the imaging probe are automatically controlled based on patient-specific data. The initial prototype is tested on a 3D plastic phantom bladder, which is used as a proof-of-concept in vitro model and an electromagnetic motion tracker. The 3D tracked tip trajectory results ensure that the motion sequencing program and the steering mechanism efficiently move the image probe to scan the entire inner tissue layer of the bladder. The compared experimental results shows 5.1% tip positioning error to the designed trajectory given by the simulation tool. The authors believe that further development of this concept will help guarantee that a tumor or other characteristic of the bladder surface is not overlooked during the automated cystoscopic procedure due to a failure to image it.
鉴于膀胱镜检查与其他用于膀胱监测的方法相比具有优势，开发一种改进的自动膀胱镜将是有益的。我们开发并提出了一种主动可编程远程转向机制和一种用于膀胱癌检测及术后监测的高效运动序列。成像探头的连续且最优路径能够使医生轻松确保以可控且均匀的方式为膀胱的整个表面生成图像。设置在成像探头远端附近的基于形状记忆合金（SMA）的分段致动器被选择性激活，以使探头轴弯曲，从而协助在多个选定的点对成像探头进行定位和定向，以便对扩张膀胱容积的所有内部区域进行成像。成像探头的弯曲弧度、插入深度和旋转位置基于患者特定数据自动控制。最初的原型在一个3D塑料模拟膀胱上进行测试，该模拟膀胱用作概念验证的体外模型和电磁运动跟踪器。3D跟踪的尖端轨迹结果确保运动排序程序和转向机制能有效地移动图像探头以扫描膀胱的整个内部组织层。比较实验结果显示，与模拟工具给出的设计轨迹相比，尖端定位误差为5.1%。作者认为，这一概念的进一步发展将有助于确保在自动膀胱镜检查过程中，不会因未能对膀胱表面的肿瘤或其他特征进行成像而导致其被忽略。
