Swall-E: A robotic in-vitro simulation of human swallowing

Swallowing is a complex physiological function that can be studied through medical imagery techniques such as videofluoroscopy (VFS), dynamic magnetic resonance imagery (MRI) and fiberoptic endoscopic evaluation of swallowing (FEES). VFS is the gold standard although it exposes the subjects to radiations. In-vitro modeling of human swallowing has been conducted with limited results so far. Some experiments were reported on robotic reproduction of oral and esophageal phases of swallowing, but high fidelity reproduction of pharyngeal phase of swallowing has not been reported yet. To that end, we designed and developed a robotic simulator of the pharyngeal phase of human swallowing named Swall-E. 17 actuators integrated in the robot enable the mimicking of important physiological mechanisms occurring during the pharyngeal swallowing, such as the vocal fold closure, laryngeal elevation or epiglottis tilt. Moreover, the associated computer interface allows a control of the actuation of these mechanisms at a spatio-temporal accuracy of 0.025 mm and 20 ms. In this study preliminary experiments of normal pharyngeal swallowing simulated on Swall-E are presented. These experiments show that a 10 ml thick bolus can be swallowed by the robot in less than 1 s without any aspiration of bolus material into the synthetic anatomical laryngo-tracheal conduit.

吞咽是一项复杂的生理功能，可通过荧光透视吞咽检查（videofluoroscopy, VFS）、动态磁共振成像（dynamic magnetic resonance imagery, MRI）以及纤维内镜吞咽评估（fiberoptic endoscopic evaluation of swallowing, FEES）等医学影像技术开展研究。尽管VFS会使受试者暴露于辐射环境中，但它仍是吞咽功能研究的金标准。目前，人类吞咽的体外建模研究成果相对有限：已有实验报道了吞咽口期与食管期的机器人复现方案，但尚未见吞咽咽期高保真复现的相关研究。为此，我们设计并开发了一款用于复现人类吞咽咽期的机器人模拟器Swall-E。该机器人集成了17个驱动单元，能够模拟吞咽咽期发生的多项关键生理机制，包括声带闭合、喉上抬与会厌倾斜。此外，配套的计算机交互界面可实现对各驱动机构的精准控制，其时空精度可达0.025毫米与20毫秒。本研究展示了在Swall-E上开展的正常吞咽咽期模拟初步实验。实验结果显示，该机器人可在1秒内完成10毫升稠厚食团的吞咽操作，且未出现食团误吸入合成解剖学喉气管导管的情况。