Institute of Medical Device Technology, University of Stuttgart, Stuttgart, Germany.
Department of Urology and Pediatric Urology, University of Ulm, Ulm, Germany.
Proc Inst Mech Eng H. 2022 Mar;236(3):406-415. doi: 10.1177/09544119211058918. Epub 2021 Dec 1.
Detection of metastasis spread at an early stage of disease in lymph nodes can be achieved by imaging techniques, such as PET and fluoride-marked tumor cells. Intraoperative detection of small metastasis can be problematic especially in minimally invasive surgical settings. A γ-radiation sensor can be inserted in the situs to facilitate intraoperative localization of the lymph nodes. In the minimally invasive setting, the sensor must fit through the trocar and for robot-aided interventions, a small, capsule-like device is favorable. Size reduction could be achieved by using only a few simple electronic parts packed in a single-use sensor-head also leading to a low-cost device. This paper first describes the selection of an appropriate low-cost diode, which is placed in a sensor head (Ø 12 mm) and characterized in a validation experiment. Finally, the sensor and its performance during a detection experiment with nine subjects is evaluated. The subjects had to locate a Cs source (138 kBq activity, 612 keV) below a wooden plate seven times. Time to accomplish this task and error rate were recorded and evaluated. The time needed by the subjects to complete each run was 95 ± 68.1 s for the first trial down to 40 ± 23.9 s for the last. All subjects managed to locate the Cs source precisely. Further reduction in size and a sterilizable housing are prerequisites for in vitro tests on explanted human lymph nodes and finally in vivo testing.
通过成像技术，如正电子发射断层扫描和氟标记肿瘤细胞，可以在疾病早期检测到淋巴结中的转移扩散。术中检测小的转移可能会有问题，特别是在微创手术环境中。γ辐射传感器可以插入到肿瘤部位，以方便术中定位淋巴结。在微创手术中，传感器必须通过套管插入，对于机器人辅助手术，一个小的胶囊状装置是有利的。通过使用仅包含少数几个简单电子部件的传感器头，将其封装在一次性传感器头中，可以实现尺寸缩小，从而制造出低成本设备。本文首先描述了选择合适的低成本二极管的过程，该二极管被放置在传感器头中（Ø 12mm），并在验证实验中进行了表征。最后，评估了传感器及其在九名受试者的检测实验中的性能。受试者必须七次定位在一块木板下的 Cs 源（138kBq 活度，612keV）。记录并评估完成此任务所需的时间和错误率。受试者完成每次运行所需的时间从第一次试验的 95±68.1s 减少到最后一次试验的 40±23.9s。所有受试者都能够精确地定位 Cs 源。进一步缩小尺寸和可消毒外壳是在离体人淋巴结和体内试验之前进行体外试验的先决条件。
