Snap-on robotic wrist module for enhanced dexterity in endoscopic surgery

Abstract

Burgeoning transendoscopic procedures, such as endoscopic submucosal dissection (ESD), provide a promising means of treating early-stage gastric neoplasia in a minimallyinvasive way. However, the remote locations of these lesions, coupled with their origination in the submucosal layers of the gastrointestinal tract, often lead to extreme technical, cognitive and ergonomic challenges which combat the widespread applicability and adoption of these techniques. Among these challenges is achieving the in vivo dexterity required to retract and dissect tissue. By leveraging workspace and force data obtained through clinical studies, we developed a modular, disposable, distally-mounted actuator (an 'active endcap') that can augment an endoscopist's distal dexterity in ways that are not achievable with the endoscope's built-in degrees-of-freedom. The device consists of a flexible articulating 'exoskeleton' manufactured via printed-circuit MEMS (PCMEMS) which engages and deflects electrosurgical tools that are passed through the endoscopic working channel. Embedded proprioceptive sensing is implemented on-board using distributed LED/phototransistor pairs and the principle of light intensity modulation (LIM). The distal degree-of-freedom is actuated using shape memory alloy (SMA) technology, and the actuation transmission system is fully contained within a 1-inch-long end cap that can be mounted on the distal end of the endoscope, thereby obviating the need for a mechanical connection to a proximal source. Proof-of-concept tests demonstrate that the actuator adds over 50 degrees of distal articulation to existing tools and can generate 450 mN of lateral force which has been clinically determined to be sufficient for performing circumferential incisions in ESD.

A Soft Inflatable Robot Driven by Hydraulic Folded Pouch Actuators for Minimally Invasive Surgery

“…8(c). As shown in Table II, the maximum forces in each axis are all greater than 0.4 N, which is reported as the nominal force required to perform endoscopic submucosal dissection (ESD) in the colon [24]. The maximum force magnitude was 1.50 N.…”

Integrated Sensors for Soft Medical Robotics

“…Minimally invasive continuum robots that enter the human body through natural orifices can be actuated by different mechanisms, such as robotic guidance (attachment of rigid manipulators that control the soft robot), [5] cable-driven propulsion, [14] pneumatic [15] and hydraulic actuators, [16][17][18][19] smart shape memory alloys (SMAs), [20] as well as magnetic actuation. In order to improve the end-effector payload while maintaining its compliance, a range of variable stiffness mechanisms have been explored.…”

Biologically inspired electrostatic artificial muscles for insect-sized robots

“…Nevertheless, their intrinsic backlash, low accuracy, and unpredictable failure are bottlenecks to efficient and safe surgical manipulation (Vitiello et al, 2013; Yeung and Gourlay, 2012). SMAs may be another possible solution, but their nonlinearity and hysteresis effects limit their applications (Gafford et al, 2016). In addition, the high temperature generated during actuation may damage the surrounding tissue (Gafford et al, 2017).…”

“…Nevertheless, their intrinsic (Lu et al, 2009) 7 45 174 14 c DEA (Duduta et al, 2016) 10 b 20 0.2 -DEA (Shian et al, 2015) 12 1.1 --DEA (Choi et al, 2002) 30 -9.7 1.6 c SMA (Lee and Kim, 2008) 35 0.57 29 13.8 SMA (Koh and Cho, 2009) 20 5 --Piezoelectric actuator (Wu et al, 2019) 4.2 b 200 0.024 60 d Pneumatic actuator (Lim et al, 2007) 16 backlash, low accuracy, and unpredictable failure are bottlenecks to efficient and safe surgical manipulation (Vitiello et al, 2013;Yeung and Gourlay, 2012). SMAs may be another possible solution, but their nonlinearity and hysteresis effects limit their applications (Gafford et al, 2016).…”