Sphincter tone examination, as part of digital rectal examination (DRE), can provide essential information to support the early detection of colorectal cancer. Mastering DRE skills for junior doctors is always challenging due to the lack of real training cases. In this article, we developed a soft pneumatic active actuator,made of a compound of silicone rubber materials, to mimic human sphincter muscles and simulate various anal sphincter tones for the purpose of training. Different pumping actuation (syringe and bellows) and driving mechanisms (linear, stepper, and servo motor) were implemented and compared for their effect on the rendered tones. A further comparison was made with a previous prototype based on a cable-driven mechanism. Both quantitative and qualitative assessments were conducted to evaluate the performance of each mechanism. A differential pressure sensor was used to measure applied pressure on a catheter balloon placed inside the sphincter, comparing the readings with anorectal manometry data obtained from real patients. Qualitative feedback was gathered through a user study with ten colorectal expert practitioners. Four questions were asked targeting reaction/response time, pressure level, pressure quality, and similarity to a real case. The results show the capacity and limitation of each mechanism, with the one based on a servo motor and a bellows being the most favourably rated.

中文翻译：

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用于呈现肛门括约肌音调的软气动执行器

括约肌张力检查作为直肠指检 (DRE) 的一部分，可以提供重要信息以支持结直肠癌的早期检测。由于缺乏真正的培训案例，初级医生掌握 DRE 技能总是具有挑战性。在本文中，我们开发了一种由硅橡胶复合材料制成的软气动主动执行器，以模拟人体括约肌肌肉并模拟各种肛门括约肌音调，以进行训练。实施了不同的泵驱动（注射器和波纹管）和驱动机制（线性、步进和伺服电机），并比较了它们对渲染音调的影响。与之前基于电缆驱动机构的原型进行了进一步比较。进行了定量和定性评估以评估每种机制的性能。使用压差传感器测量放置在括约肌内的导管球囊上施加的压力，将读数与从真实患者获得的肛门直肠测压数据进行比较。通过与十名结直肠专家从业人员进行的用户研究收集了定性反馈。针对反应/响应时间、压力水平、压力质量以及与真实案例的相似性提出了四个问题。结果显示了每种机构的容量和局限性，其中基于伺服电机和波纹管的机构的评价最高。通过与十名结直肠专家从业人员进行的用户研究收集了定性反馈。针对反应/响应时间、压力水平、压力质量以及与真实案例的相似性提出了四个问题。结果显示了每种机构的容量和局限性，其中基于伺服电机和波纹管的机构的评价最高。通过与十名结直肠专家从业人员进行的用户研究收集了定性反馈。针对反应/响应时间、压力水平、压力质量以及与真实案例的相似性提出了四个问题。结果显示了每种机构的容量和局限性，其中基于伺服电机和波纹管的机构的评价最高。