In this paper, we present a fully soft miniaturized continuum robot that integrates 3D optical shape sensing through functionalized tubing used as soft optical waveguides. The sensor is fabricated by laser patterning an off-the-shelf medical tubing, allowing for bidirectional responses to large curvatures in two bending directions, enabling 3D shape sensing and tip tracking of the continuum robot. The robot is able to bend and sense its own shape up to a curvature of 44.7 m-1, corresponding to a bending angle of 102°, having high-accuracy tracking capabilities, resulting in an average tracking error of 3.08 mm, that is 7.7 % of the robot length. The robot’s functionality was shown in validation experiments, including a real-time shape prediction through a graphical user interface.

In neurosurgery, soft robots have the potential to introduce significant benefits over traditional metal tools for their ability to safely interact with delicate tissues. In this paper, we introduce a proof-of-concept soft, capacitive origami sensing module (OSM) that can measure forces during neurosurgical retraction. Using origami-inspired design and fabrication principles, the OSM is easily folded and integrated within a soft robotic retractor that interacts with brain tissue to generate a surgical workspace upon actuation. We demonstrate the individual OSM signal response to forces and folding. We further characterize the OSM response within a fully-assembled soft robotic retractor to both folding and the application of forces over 0-5 N showing a 0.38 N average prediction error and resolution of 0.25 N. The sensing capability of the retractor is validated on an in-vitro model to demonstrate prediction errors of 0.06 N and the proposed operation during neurosurgery.

Soft optical sensing strategies are rapidly developing for soft robotic systems as a means to increase the controllability of soft compliant robots. In this paper, we present a roughness tuning strategy for the fabrication of soft optical sensors to achieve the dual functionality of shape sensing combined with contact recognition within a single multi-modal sensor. The molds used to fabricate the soft sensors are roughened via laser micromachining to achieve asymmetrical sensor responses when bent in opposite directions. We demonstrate the integration of these sensors into a fully soft robotic platform consisting of a multi-directional bending module with integrated 3D shape sensing and a gripper with tip position monitoring along with contact force recognition. We show the accuracy of our sensing strategy in validation experiments and a pick-and-place task is performed to demonstrate the robot's functionality.

Robotic palpation shows significant potential to improve the accuracy and speed of tumor identification. How-ever, robotic palpation mechanisms often lack haptic feedback, making it difficult for the surgeon to identify variations in tissue stiffness. This paper presents a soft optical sensor integrated with a wearable haptic glove for tumor detection during robotic palpation. The sensor contains an array of optical waveguides that can detect the presence of tumors embedded within a tissue phantom. Detection of a tumor results in an optical loss from the waveguide signal, triggering proportional inflation of the soft microfluidic actuators in the glove. The glove consists of four modular actuators placed at the fingertips, each corresponding to a sensing location on the waveguide array. The inflation of each actuator is proportional to the incident loss on the palpation sensor array, which is dependent on tumor depth. Thus, the glove is capable of alerting the user to the location of tumors during remote palpation.

This paper presents a proof-of-concept soft robotic glove that provides haptic feedback to the surgeon's hand during interventional endoscopy procedures, specifically colonoscopy. The glove is connected to a force sensing soft robotic sleeve that is mounted onto a colonoscope. The glove consists of pneumatic actuators that inflate in proportion to the incident forces on the soft robotic sleeve. Thus, the glove is capable of alerting the surgeon of potentially dangerous forces exerted on the colon wall by the colonoscope during the navigation. The proposed glove is adaptable to a variety of hand sizes. It features modular actuators that facilitate convenient and rapid assembly and attachment before the procedure and removal afterward. The glove is calibrated to respond to incident forces on the soft robotic sleeve ranging from 0–3 N. The glove's actuators are able to reach an internal pressure of 53 kPa and exert forces up to 20 N, thereby relaying and amplifying the force exerted by the colonoscope on the colon to the surgeon's hand.

Flexible endoscopes are still the gold standard in most natural orifice translumenal endoscopic surgery (NOTES) procedures; however their flexibility (necessary for navigating through the GI tract) limits their capabilities in terms of distal manipulation and stability. We propose a deployable endoscopic add-on aimed at locally counteracting forces applied at the tip of an endoscope. We analyze different designs: a fully soft version and two hybrid soft-folded versions. The hybrid designs exploit either an inextensible structure pressurized by a soft actuator or the stiffness provided by the unfolded “magic cube” origami structure. We focus on the fabrication and experimental characterization of the proposed structures and present some preliminary designs and integration strategies to mount them on top of current flexible endoscopes.

Numerous therapeutic transendoscopic procedures exist to treat lesions in the GI tract. However, these procedures are limited by their difficulty and the amount of training required to successfully perform them. The surgeon is tasked with simultaneously steering the distal tip of the endoscope, applying tension to tissue to retract it, and manipulating electro-cautery tools with limited dexterity. We propose a device designed to assist with anchoring and tissue retraction during endoscopic surgical procedures. The designed solution decouples the tissue-grasping function from the movement of the endoscope tip, leaving the surgeon free to use the endoscope tip solely for positioning of electro-cautery or biopsy tools deployed through the endoscope working channel. The anchoring and retraction device uses pop-up book MEMS techniques, allowing for a “flat” structure to expand into a 3-D structure. The proposed device has three main integrated components: a rigid expandable geometric structure, inflatable pneumatic actuators, and a vacuum gripper. These inflatable actuators include internal rigid discs, allowing for resistance to buckling while maintaining the benefits of the established lightweight, low profile actuator design scheme. Proof-of-concept ex vivo testing demonstrates that the integrated device can be used to retract tissue to a height of 13.5 mm, providing access for endoscopy tools to contact a sample of porcine stomach tissue.

Burgeoning transendoscopic procedures, such as endoscopic submucosal dissection (ESD), provide a promising means of treating early-stage gastric neoplasia in a minimally-invasive 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.

This paper introduces a manufacturing technique which enables the integration of soft materials and soft fluidic micro-actuators in the Pop-up book MEMS paradigm. Such a technique represents a promising approach to the design and fabrication of low cost and scalable articulated mechanisms provided with sensing capabilities and on-board actuation with potential applications in the field of minimally invasive surgery. Design and integration of soft components in the rigid-flex laminates is described along with the resulting soft pop-up mechanisms realized at different scales. Prototype characterization is presented, demonstrating forces and dexterity in a range suitable for surgical applications, as well as the possibility to integrate sensing capabilities. Based on these results, a multi-articulated robotic arm is fabricated and mounted on top of an endoscope model to provide a proof of concept of simple robotic mechanisms that could be useful in a surgical scenario.