ABSTRACT. Additive Manufacturing or 3D printing presents unique capabilities in producing intricate shapes and mechanisms, particularly advantageous in the domain of miniature, high-precision instruments, such as those utilized in eye surgery. Despite the benefits of Additive Manufacturing, challenges persist in miniaturized applications, stemming from size constraints and the accuracy limitations of current 3D printers. This paper introduces a novel approach to develop an ultraslender steerable light pipe, named Acci, for eye surgery using conventional 3D print technology. Acci’s design addresses challenges in manufacturing miniature negative features using Stereolithography, by employing a helical structure. The optical fiber, essential for illumination, also serves as the actuation cable, eliminating additional parts and assembly steps. The non-assembly 360-degree precision-grip handle, designed for single-step printing, enhances maneuverability. Acci was tested successfully in an artificial eye, demonstrating its illumination capabilities and the potential for further customization. This design illustrates the capacity of non-assembly Additive Manufacturing to create tailored medical instruments for specific applications at the intersection of the capabilities of Additive Manufacturing and medical device design boundaries.

ABSTRACT. Magnetically responsive soft materials hold great potential for the future development of surgical tools, soft orthoses, and intelligent medical textiles. To date, however, the fabrication of highly integrated magnetic fibers with extreme aspect ratios, that can be used as steerable catheters, endoscopes, or within functional textiles remains challenging. Here, we propose multi-material thermal drawing as a material and processing platform to realize 10s of meters long soft, ultra-stretchable, yet highly resilient magnetic fibers. We demonstrate fibers with a diameter as low as 300 µm and an aspect ratio of 100000, integrating nanocomposite domains with ferromagnetic micro-particles embedded in a soft elastomeric matrix [1]. By carefully selecting the filler content to balance magnetization density and mechanical stiffness, we present fibers capable of withstanding strains exceeding 1000%. These fibers can be magnetically actuated and can twist, turn, and steer through complex pathways, delivering drugs in a minimally invasive environment. Moreover, the fibers can be magnetized in different orientations and woven into functional textiles capable of exerting a force of 22 N. The resulting magnetic textile is programmable for shape morphing, enduring extreme mechanical deformation and multiple machine-wash cycles. Additionally, we introduce carbon nanotube (CNT) nanocomposite piezoresistive layers alongside magnetic fibers to create highly integrated smart catheters and medical textile systems. These systems can extract shape-morphing information, delivering optimal rehabilitation doses to damaged joints. This research presents a promising avenue for the next generation of magnetic-based soft prosthetics, surgical tools, wearable robotics, and human-machine interactions.

[1] Banerjee, Hritwick, et al. "Soft Multi‐Material Magnetic Fibers and Textiles." Advanced Materials (2023): 2212202.

ABSTRACT. Neural networks offer a promising approach for modeling the nonlinearities and hysteretic behavior of continuum robot kinematics that are often neglected in existing models. This study explores the forward kinematics of tendon-actuated continuum robots, focusing on the modeling their hysteretic characteristics using three different neural network architectures. The architectures investigated include Feed-forward Neural Networks (FNNs), a modified version of FNNs equipped with a history input buffer (FNN-HIB), and Long Short-Term Memory networks (LSTM). The modeling comparison reveals that standard FNNs lack the capability to reproduce hysteresis while temporal dependencies can be well modeled by both FNN-HIBs and LSTMs. In addition, the examination of training factors in LSTM models highlights the importance of two aspects for developing accurate kinematic models: selection of the appropriate input trajectories and the choice of loss function.

ABSTRACT. Tumour removal surgery aims to preserve healthy tissue while ensuring the complete excision of tumours, thereby reducing the risk of recurrence. The lack of precision of surgical instruments may lead to the over-excision of healthy tissue or residual diseased tissue, which results in more serious sequelae. Our study introduces the advancement with an electrothermally actuated robotic fibre designed for tumour resection. This robotic fibre enables precise manipulation of surgical laser fibres with sub-50µm accuracy. The fibre's slender profile, with an outer diameter of less than 2 mm, makes it suitable for minimally invasive surgery (MIS) applications. However, the robotic fibre's limited motion range (sub-centimetre) presents challenges, prompting us to integrate it with surgical instruments like laparoscopic and flexible endoscopic tools to extend its range of motion. This integration involves threading the robotic fibre through the working channel of an endoscope, necessitating a passive fibre length. In this work, we developed a partial actuation approach to only actuate the fibre’s 12cm distal end, out of a total length of 1.2 m, thereby reducing the actuation power usage and enhancing patient safety. This paper details the design and fabrication of the robotic fibre, along with the development of a telemanipulation algorithm for controlling its movement. We demonstrate the fibre's efficacy and potential for clinical application through integration with a customised da Vinci surgical instrument and testing within an abdominal phantom, serving as a proof-of-concept for future MIS advancements.

ABSTRACT. Epilepsy affects more than 50 million people worldwide, afflicting patients with debilitating seizures. While antiepileptic drugs are available, 20-40% of patients remain medically refractory, leaving surgical intervention as the remaining option. Hippocampal resection is the gold standard surgical therapy while laser interstitial thermal therapy (LITT) offers a minimally invasive alternative. Current LITT interventions use a straight laser probe to deliver thermal energy through a burr hole in the back of the skull guided by magnetic resonance imaging (MRI). LITT has been associated with lower seizure freedom rates which we hypothesize is related to the use of straight-line trajectories in a naturally curved structure. Our previous work proposed a percutaneous approach whereby a helically pre-curved needle is deployed through the foramen ovale to ablate along the hippocampal midline maximizing tissue coverage. This minimally invasive approach demands a safe, compact, and accurate actuation system capable of operating within the MRI scanner. Concentric tube actuation units typically leverage transmission tube or lead screw-based designs which effectively double their overall length. A direct drive architecture can eliminate these components offering a more compact design. This paper presents a direct drive actuation system that minimizes overall device length using a novel pneumatic actuator for MR-guided, transforamenal epilepsy interventions.

ABSTRACT. Tremor, a widespread neurological disorder impacting individuals of various ages, can greatly hinder their quality of life and occupational functioning. Wearable medical devices for suppressing tremors, typically low-frequency vibrations ranging between 3 and 12 Hz, are gaining popularity since active vibration absorbers integrated into such devices have demonstrated immediate efficacy and noninvasive nature. However, there are challenges in miniaturizing active absorbers for wearable applications with traditional actuators. To address this problem, here we present a light wearable active finger tremor-suppressing orthosis that consists of a stacked polyvinyl chloride (PVC) gel actuator-based absorber, an inertial measurement unit (IMU), and a force sensor. This allows the system to simultaneously detect tremors and trigger the absorber to suppress vibrations, regardless of whether the fingertip is vibrating in the air or applying tremor force while in contact with an object. This innovative wearable finger tremor absorption system has the potential to stabilize fingers in various applications of daily life.

ABSTRACT. Patients experiencing certain forms of heart failure may require cardiac resynchronization therapy, which can be accomplished through biventricular pacing. To achieve this type of pacing, clinicians must cannulate the coronary sinus (CS) with a pacemaker’s electrical lead, using off-the-shelf catheters to articulate within the right atrium’s challenging anatomy. However, many commercially available catheters have limited degrees of freedom, making it difficult to maneuver inside a beating heart. Here, we demonstrate a soft robotic system that can self-stabilize proximal to the interventional site and reduce the time required to cannulate the CS. The soft robotic manipulator’s task space spans the right atrium, making it suitable for a variety of cardiac interventions. Additionally, CS cannulation trials on an explanted porcine heart showed that the robot could successfully enable cannulation in just over a minute on average. The radiopaque nature of the robot's components also allowed for localization and CS cannulation under X-ray fluoroscopy. Future works will further validate the device’s utility in an in-vivo environment with a porcine model. We anticipate our device to ease the interventionalist’s workload in a variety of procedures requiring a balance of robotic dexterity and stability, including but not limited to CS cannulation for biventricular pacing, conduction system pacing, and structural repair.

ABSTRACT. Vine robots are a form of soft continuum robot formed of a thin-wall cylinder which has been partially inverted. When pressure is applied internally, the inverted material is propelled outwards causing the body to extend. This unique form of navigation facilitates shear-free locomotion and high tip force, leading to their proposed use in endoluminal interventions. These properties have the potential to minimize potential traumatic tissue interactions and, due to their inherent minaturizability, facilitate navigation deep within the anatomy.

This study examines the use of magnetic actuation in steering miniaturized Magnetic Vine Robots (MVRs) formed of a magnetically active skin. Contrary to other steering methodologies, our vine robot retains an entirely soft body whilst boasting high bending angles and miniaturized form. In this work we fabricate MVRs with a diameter of 8 mm that are manipulated via EPMs mounted to two robot manipulators. The MVR’s deformation under external magnetic field is tested and empirically assesed in relation to its internal pressure. We then show the growth and steering of the MVR steering around obstacles and its navigation through three bifurcating bronchial tree phantom pathways, indicating the possible clinical use of MVRs.

ABSTRACT. Global demographic aging poses a major challenge to healthcare systems, intensified by the significant increase in medical needs specific to the elderly population. To address these increasing demands and minimize risks associated with medical vascular interventions, such as aortic valve stenosis pathology, prioritizing less invasive approaches has become imperative. In this context, Transcatheter Aortic Valve Implantation (TAVI) has emerged as a significant advancement, offering a less invasive alternative to traditional cardiac surgery. To optimize the precision and efficiency of this procedure, the use of a growing robot stands out as an innovative approach. Its ability to deploy from the inside ensures flexibility tailored to the unique morphology of each patient, thus reducing the risks of tissue perforation. Inspired by the work of Li et al., a cadaveric clinical test was undertaken, implementing an 8 mm diameter growing robot made from silicone-coated Ripstop Nylon and pressurized with an iodine solution. The results of these trials revealed difficulties in navigating through narrow anatomical areas such as stenosis. Consequently, a study on the compliance of growing robots was undertaken, exploring the use of various materials with different properties.

ABSTRACT. Haptic feedback enhances the awareness of the surgeons in robot-assisted surgeries, reducing applied forces,shortening completion time, and improving success rates. Conventional force sensors for tip force measurement in compact, tendon-driven surgical manipulators face challenges in miniaturization, sterilization,and cost-effectiveness. Sensor-less tip force estimation from surgical images and intrinsic joint-level information is feasible but faces difficulties in generalization due to transmission loss in actuation lines. This is especially true for flexible manipulators for endoscopic surgeries, where unpredictable shape-dependent friction losses occur due to the unknown sheath shape through the torturous natural orifices. This work presents a tip force estimation method for a novel hybrid manipulator designed for lower gastrointestinal (GI) interventions. The hybrid manipulator comprises three active segments in series. Two soft robotic segments (∅12-mm) actuated pneumatically are at the proximal end, and one tendon-driven segment (∅3.8 mm) is stacked at the distal end. The soft segments act as a carrier for the distal instrument. Thus the systems provides fine surgical manipulation with improved triangulation and reduced occlusion to the surgical view. When the tip of the distal segment interacts with the environment, external forces perturb the soft segments, leading to an error in the commanded bending angle at the soft segments. To this end, a nonlinear observer and a model-based controller have been employed to regulate the bending angles of the soft segment while estimating the disturbance caused by external forces at the tip. The proposed method is validated through experiment. The results demonstrate the ability to provide haptic feedback in the range of 0.07 to 0.15 N corresponding to low-force dissection, with good resolution without requiring additional sensors mounted on the manipulator.

ABSTRACT. Our society is aging, not just in Europe, but worldwide. This poses numerous challenges to healthcare systems. With regard to surgical interventions, society demands shorter treatment times, rapid recovery, and minimally invasive procedures. Consequently, hospitals are expected to perform faster, more cost-effective, and more complex treatments. One way to meet these requirements is to use robotic-assistance systems. The use of surgical robots is intended to further develop and accelerate procedures and enable more complex interventions. The advantages of robotics should also be used to counteract the shortage of skilled labor and increase the "productivity" of clinics through simple and easy-to-learn operations. Our goal is to develop endoscopes into low-cost, flexible medical robots (endoscopic robots). In addition to diagnostic tasks, they should be able to perform a variety of challenging therapeutic tasks. For hygienic reasons, disposable systems are preferable to complicated reusable systems. This paper presents a demonstrator of an endoscopic robot. The Twisted Sting Actuation drive system and the additively manufactured endoscopic tip are presented. The force required to bend the tip up to 180° is shown. This was done by simulating the endoscope tip using FEM and validated experimentally.

ABSTRACT. Tethered endoscopic procedures have traditionally been used to study and perform minimally invasive surgeries in the gastro-intestinal (GI) tract but have drawbacks relating to patient discomfort and their inability to explore much of the small intestine. The advent of ingestible capsule endoscopes (CE) has allowed many of these drawbacks to be addressed. However, CE are still unable to reliably perform actions such as tissue/microbiota sample collection or microsurgery within the gut. Such applications will require CE to be equipped with small, safe, and wirelessly controllable actuation mechanisms. Miniature electronic motors have previously been used to achieve actuation within CE. While the high torque and repeatable motion of electronic actuators are advantageous, complex logic and communication circuitry is often required to control them. Furthermore, the internal batteries which power the motors raise concerns relating to their size, safety, and lifetime. This work presents a near-field wireless power transfer (WPT) system and circuit for controlling electronic motors in CE without the need for batteries or complex circuitry. The WPT system works on the principle of magnetic inductive coupling under resonant conditions between a transmitter (Tx) coil external to the patient’s body and a receiver (Rx) coil internal to the capsule. A simple circuit was built to rectify the AC power induced in the Rx coil to the DC power required for a motor. A means of reversing the motor was then developed using an H-bridge of reed switches which can be actuated by the application of a DC magnetic field. The maximum operating distance between Rx and Tx coils which allowed successful actuation of a motor was then characterised. An example of how the system could be employed in a multi-capsule assembly for collecting and storing a site-specific sample of microbiota to aid in the diagnosis of disease is also highlighted.

ABSTRACT. This paper introduces an innovative advancement in capsule endoscopy, aimed at overcoming the limitations of passive navigation by incorporating robotic magnetic manipulation coupled with a novel robot mounted Wireless Power Transfer system. Traditional capsule endoscopy, while minimally invasive and patient-friendly, is hampered by its inability to focus examinations on specific GI tract regions, leading to variable diagnostic outcomes and potential risks of capsule retention. Our research addresses these challenges by developing a system that enables precise, active control of the capsule's movement through magnetic manipulation, thereby significantly enhancing diagnostic accuracy and procedure reliability. The core of our system features a transmitter coil mounted on a robotic arm and an advanced 3D receiver coil within the capsule, facilitating uninterrupted power supply through an autonomous power maintenance algorithm. Extensive testing within a colon phantom demonstrated the system's effectiveness in maintaining optimal power levels and control, showcasing its potential to reshape the landscape of GI diagnostics. Our findings highlight the promise of combining robotic magnetic manipulation with wireless power in setting new standards for capsule endoscopy technology, offering improved patient care and diagnostic capabilities.

ABSTRACT. This study introduces a novel endoscopic robotic system, integrating through-the-scope dexterous instruments with a handwriting-inspired control interface. Aimed at enhancing surgical precision and dexterity, this system is designed for complex therapeutic endoscopic procedures. By closely mimicking the act of handwriting, the control interface offers intuitive and precise manipulation of the continuum robotic system, potentially revolutionizing endoscopic surgery with improved operational intuitiveness and adaptability in real-world scenarios.

ABSTRACT. The repair and replacement of heart valves is an evolving field that can benefit from moving away from traditional open-heart surgeries and toward transcatheter procedures as safer alternatives. However, one of the challenges in transcatheter procedures is the limited visualization of valve tissue compared to open surgery. The conventional catheter imaging methods of fluoroscopy and ultrasound have their limitations in providing detailed and clear images. Cardioscopy (endoscopy inside the blood-filled heart), which allows for detailed visualization of the contact region between the catheter tip and the valve tissue, is a method that has been developed to address this imaging gap. We focus on developing a collapsible and steerable balloon cardioscope in order to overcome short comings in prior work on cardioscopes, which feature solid optical windows that are too large to introduce through the vasculature. Whereas the optical window of our collapsible balloon cardiscope can be introduced into the vasculature and subsequently expanded once positioned inside the heart. The balloon cardioscope design incorporates a flexural degree of freedom, allowing for finer positioning of a working channel inside the heart beyond what is possible with conventional telescoping steerable sheaths. The design of the balloon decouples the optical window diameter and deflection angle degrees of freedom with a singular pressure input, allowing for a controllable orientational degree of freedom without requiring an additional steerable sheath. These advancements on balloon cardioscopes for transcatheter procedures can enable robotic catheter designs combining tendon-actuated sheaths for tip positioning with cardioscopic balloons controlling tip orientation.

ABSTRACT. Medical errors are the third leading cause of death, right after cancer and heart diseases, causing around 250,000 deaths every year. Approximately 40% of these errors happen in the operating room (OR) and 50% of the resulting complications are avoidable. Most errors are related to communication. Effective communication among team members during cardiac surgery operations is paramount for ensuring patient safety and successful outcomes. Yet, evidence suggests that communication between team members can break when conveying critical patient information, coordinating instrument exchanges, or addressing emergent concerns. Behavioral data analytics leverage multimodal data and artificial intelligence (AI) methods and can offer valuable insights into communication cues during cardiac surgery. By integrating various data sources such as audio recordings, video feeds, physiological parameters, and electronic health records, AI algorithms can capture quantify cues such as tone of voice, language patterns, and body language, ultimately distinguishing between positive and negative interprofessional communication behaviors. This paper investigates acoustic measures of speech extracted from speech during two types of cardiac surgery operations representing good and bad interprofessional communication behaviors and examines potential differences in acoustic measures between the two types of sessions.

ABSTRACT. Cleft palate repair is a delicate and technically demanding procedure. Previous work by our group has demonstrated that robotic tools may be appropriate for this operation but currently available instruments are still too large. We present the experimental validation of a novel 3 mm diameter robotic wrist prototype for cleft palate repair. This prototype is used to suture within the confines of a simulated infant cleft palate phantom. Its performance is evaluated against existing 8 mm da Vinci EndoWrist instruments. Comparisons between both sets of tools demonstrate that our 3 mm wrist performs better in this application by reducing the number of observed collisions and increasing surgeon visibility through the endoscope camera. Future improvements to the design are discussed relating to tool performance and longevity of the prototype.

ABSTRACT. Open Spina Bifida is a neural tube defect where repair of the defect involves suturing of the wound. Research on the procedure for performing this repair is currently focused on a minimally invasive robotic approach. This study proposes 2mm tools with a continuum tendon-driven wrist for suturing, implements a numerical inverse kinematics solver for teleoperation control of the tools and shows feasibility of suturing through timed trials to support in-utero OSB repair. The tools were tested on a 3-Dmed practice suture pad using an interrupted suture technique. The tools produced 12 successful sutures out of a total of 15 tests. The theoretical minimum time for a single interrupted suture is less than 3 min. However, the large standard deviation in times to complete a suture implies that the current tool design requires further improvement to be consistent and reliable. These improvements are discussed to be increased wrist strength and reduction in control instability.

ABSTRACT. Colonoscopy is a powerful tool for the early detection of colorectal diseases. The length of the colon requires state-of-the-art colonoscopes to have a certain bending stiffness to resist buckling and looping during insertion, leading to substantial contact forces exerted on the colon wall. This contributes to patient discomfort and the risk of injuries or perforations of the colon. In addition, advancing the colonoscope up to the ileocecal valve demands a high level of expertise of the physician. Expanding robots, based on the eversion of a tubular vessel, present a promising solution, allowing for smooth locomotion in the colon without friction-related issues. Aim of this work is to enable systematic investigation of the parameters influencing the locomotion. A modular setup is described, that allows for fast and simple testing of different parameter configurations. A preliminary validation of the setup is described using a simplified colon model. The expanding robot comprises an actuation unit for the tubular vessel, an actuation unit for the working channel, and a storage section. Gas pressure induces expansion of the robot body, and the design enables controllable advancement and retraction without being dependent on the gas flow rate. Preliminary tests on a simplified colon model revealed insights into the expanding locomotion within the confined space of the colon. The robot successfully advanced up to the left colic flexure when triggered by a working channel with a steerable tip. Challenges were encountered with a passive working channel in traversing the sigmoid curve due to excessive bending, highlighting the need for further exploration. The modular design facilitates quick testing without the need for miniaturization or encapsulation of actuation components. The locomotion principle has the potential to be a cost-effective approach to colonoscopy or enhance existing colonoscopes by acting as a sheath to facilitate advancement into the colon.

ABSTRACT. Robot-Assisted Surgical Systems (RASS) are increasingly widespread and researchers aim to introduce automation during operations, supporting a progressive increase in the autonomy of RASS. Given the significant successes obtained in other robotic applications, many works adopt Reinforcement Learning (RL) to support the RASS execution of different tasks, such as the manipulation of deformable tissues, the removal of debris or liquids during operations. Generally, RL training requires numerous task repetitions, which are unsafe and impractical in real RASS. FF-SRL addresses this by creating a realistic and computationally efficient simulator that runs entirely on a single GPU, eliminating bottlenecks associated with data transfer. The goal is to accelerate learning rates, making experimentation with RL in robotic surgery more accessible. The results indicate a significant reduction in training time for complex tasks, down to a couple of minutes compared to conventional CPU/GPU simulators. Such advancements are important in facilitating the development of autonomous and efficient RASS through RL techniques.

ABSTRACT. In the realm of soft robotics, the integration of stimuli-responsive materials offers a pathway to enhanced control and manipulation. Among these materials, light-responsive hydrogels have emerged due to their ability to undergo volume changes upon light irradiation, allowing for non-invasive remotely controlled actuation. While these hydrogels have already been used to create microvalves for lab-on-chip technology, they have never been studied in the macroscale. This study introduces a novel method for embedding photoresponsive valves into soft channels, to enable light-controlled fluid regulation in soft robotic actuators. Experimental results demonstrate rapid valve response under white light illumination suggesting promising applications in medical devices and flexible robotic systems.

ABSTRACT. Cardiovascular diseases, including Abdominal Aortic Aneurysms (AAA), pose a significant global health threat, resulting in millions of annual deaths. The conventional treatment for AAA involves minimally invasive endovascular surgery, inserting catheters and guidewires through the femoral artery to the target lesion, guided by X-ray Fluoroscopy. Challenges in this procedure include difficulty in manipulating the catheter tip, increased risk of vessel dissection, and reliance on surgeon skills. This study addresses these limitations through a threefold contribution: (1) the development of a surgical scene simulator aesthetically replicating tissue-instrument interaction, (2) integration with Augmented Reality (AR) technology and the CathBot robotic platform to introduce a novel guidance system, and (3) experimentation with users that have no prior AR experience. The surgical scene simulator uses a particle-based approach to model deformable tissue-instrument interaction. The AR interface, presented through the Microsoft HoloLens 2 headset, enhances user visualisation during catheterization. Experimental evaluation across three visualisation modes reported that AR-guided navigation exhibits more predictability and stability. The results show lower forces, distances, and measurement variance with AR, highlighting the improvement in catheterisation safety, as parameters can be better controlled. Subjective assessments through NASA TLX questionnaires reported high user satisfaction. These results hold good premises for improving patient outcomes in endovascular surgery procedures.

ABSTRACT. Endotracheal intubation (ETI) is a critical procedure used to maintain airway patency during anesthesia or respiratory distress. Existing tools like introducers or "bougies" assist in navigating the endotracheal tube (ETT) into the laryngeal opening, yet their passive nature and stiffness of the device may compromise success rates and pose a risk of injury. This study proposes a novel approach utilizing a soft pneumatic continuum actuator to enhance ETI efficiency, by replacing conventional introducers' distal tip structures with a two-chamber soft robot manipulator, providing the ability to actively control the device mid-insertion process. The investigation focuses on enhancing the stiffness of the soft robot manipulator through the integration of reinforcement structures and manipulation of pressurization in each chamber. Our study demonstrates consistent manufacturing quality of the actuators, evidenced by a satisfactory cross-section and a close alignment between simulation and experimental results for bending angle (RMS error of 8.2°). Preliminary results indicate a statistically significant effect from multi-chamber pressurization in improving the soft robot manipulator's stiffness within the same bending angle as single-chamber pressurization. However, future investigation is required to further improve the stiffness to get closer to the stiffness of elastic gum bougies while still retaining the soft and flexible characteristics of soft robots.

ABSTRACT. Telerobotic and Autonomous Robotic Ultrasound Systems (RUS) help alleviate the need for operator-dependability in free-hand ultrasound examinations. However, the state-of-the-art RUSs still rely on a human operator to apply the ultrasound gel. The lack of standardization in this process often leads to poor imaging of the scanned region. The reason for this is an inappropriate amount of gel, resulting in air-gaps between the probe and the human body. In this paper, we developed an end-of-arm tool for RUS, referred to as UltraGelBot. This robot can autonomously detect and dispense the gel. UltraGelBot uses a deep learning model to detect the gel from images acquired using an on-board camera. A motorized mechanism is also developed, which will use this feedback and dispense the gel. Experiments for ultrasound scanning of artery revealed that UltraGelBot increases the acquired image quality by 18.6% and reduces the procedure time by 37.2%.

ABSTRACT. A Chronic Total Occlusion is a type of heart disease which can be better treated with catheter based approaches that offer smaller incisions and exploit the vessels as access routes to remote anatomic regions. Making the catheters steerable and utilizing non-ionizing imaging techniques and robotic control approaches can further help enhance the safety. Further, remote actuation with magnetic fields could be useful to traverse tortuous vessels. In this work, a prototype of a medical robotic platform aimed at magnetic catheterization is shown. The system is designed to operate in two stages. Initially, a multi-lumen steerable guide catheter is advanced and positioned at pre-defined positions in the aorta. Then, a magnetic catheter is advanced through one of its lumen and guided to the left coronary artery under the influence of magnetic fields. An optimal position for the placement of the guide catheter for effective catheterization is evaluated.

ABSTRACT. This paper details the design and construction of a 3D printer based on a polar kinematics model which has been optimised for the high speed manufacturing of prosthetic sockets in low and middle income countries and conflict zones. The paper discusses the engineering challenges associated with the manufacture of prosthetic sockets at scale and describes the design of a 3D printer intended to meet these requirements. Simulated performance data is presented and compatred with two comparable consumer grade printers of similar specifications.

ABSTRACT. Advancements in MRI-guided diagnostic and therapeutic interventions for abdominal tumours, particularly in liver and kidney oncology, have been substantial, thanks to the exceptional soft-tissue contrast and versatile imaging capabilities offered by MRI machines. However, challenges persist, including the limited space within MRI scanning bores and the time-intensive process of repositioning patients during interventions. Surgeon-controlled robots offer a promising solution to overcome these obstacles. Yet, optimising the robotic workspace to align with the clinical requirements of interventional MRI remains a significant challenge. Moreover, ensuring compliance with MR safety standards through the use of non-metallic materials is paramount. This paper introduces an MR-safe needle insertion robot tailored for abdominal interventions. The proposed parallel robot comprises three main components: two double arches, multiple carriages moving along such arches, two double scissor-folding mechanisms carried by the carriages, and a needle holder interlinking the scissor-folding mechanisms. Five degrees-of-freedom (DoFs) at the end effector, i.e. the needle tip, are achieved through coordinated motion of arches, carriages, and scissor-folding mechanisms. Specifically, translational motion along the Y-axis is facilitated by sliding two double arches on their respective rails with the same velocity. Translation along the X and Z axes is achieved through differential motion of carriage groups and sets within each group. Needle rotation around the X-axis is achieved by combining translational movements along the Y and Z axes. Similarly, rotation along the Y-axis necessitates coordinated translational movements along the X and Z axes. A prototype of this robot was successfully assembled and evaluated within a 70-cm MRI scanning bore. The robot boasts a generous end-effector workspace of 25,800 cm³ while maintaining satisfactory volume occupancy relative to the scanning bore.

ABSTRACT. In this study, we further investigate the robustness and generalization ability of an neural network (NN) based force estimation method, using the da Vinci Research Kit Si (dVRK-Si). To evaluate our method's performance, we compare the force estimation accuracy with several baseline methods. We conduct comparative studies between the dVRK classic and dVRK-Si systems to benchmark the effectiveness of these approaches.

We conclude that the NN-based method provides comparable force estimation accuracy across the two systems, as the average root mean square error (RMSE) over the average range of force ratio is approximately 3.07% for the dVRK classic, and 5.27% for the dVRK-Si. On the dVRK-Si, the force estimation RMSEs for all the baseline methods are 2 to 4 times larger than the NN-based method in all directions. One possible reason is, we made assumptions in the baseline methods that static forces remain the same or dynamics is time-invariant. These assumptions may hold for the dVRK Classic, as it has pre-loaded weight and maintains horizontal self balance. Since the dVRK-Si configuration does not have this property, assumptions do not hold anymore, therefore the NN-based method significantly outperforms.

ABSTRACT. Soft robots have found application in a variety of clinical procedures, such as laparoscopic surgery, colonoscopy or endovascular catheterization. Unlike rigid robots, soft robots leverage deformation as a means to generate motion. Such deformation, however, leads to a large variation of their mechanical properties, and in particular the stiffness, across their movement range which hinders effective task performance and poses substantial control challenges when external contact is provided. Topology reconfiguration can be employed to account for stiffness variation of robotic systems, however, to date, this approach has only been applied in rigid robotic systems. Our work investigates the effect of reconfiguration on the workspace and stiffness of a parallel, soft fluidic robotics mechanism. The mechanism consists of two linear actuators attached to an outer mounting ring. Reconfiguration is achieved by manually adapting the angle between the two actuators. By reconfiguring the soft robot from 60° to 120°, the maximum axial extension is increased by 24.22%, while the transverse motion is decreased by 45.05%. In addition, the lateral stiffness increased from 1.9 N/mm to 4.3 N/mm, which is equivalent to 125.6%. The wide range of achieved stiffness variation for the investigated configuration angle shows that reconfiguration can potentially help in executing the task with constant stiffness through continuous reconfiguration during motion across the workspace.

ABSTRACT. The acquisition of multi-view datasets for depth reconstruction faces numerous challenges in surgical settings, including dynamic scenes, occlusions, and ethical considerations. These limitations have constrained the development and evaluation of new optical systems and algorithms for depth imaging, particularly in minimally invasive surgery (MIS). This study introduces a novel robotic arm system for capturing multi-view datasets, aimed at improving depth reconstruction in surgical settings. By employing a 7DOF robot arm integrated with ROS and MoveIt, the system is adaptable to various camera technologies and surgical environments. Utilizing calibration packages and the Fibonacci lattice for optimized pose distribution, the system efficiently overcomes the challenges associated with data collection in dynamic surgical scenes. Preliminary testing with a brain phantom validates the system's capability to efficiently capture data. In future this will facilitate the development and evaluation of new optical systems and algorithms for depth imaging in minimally invasive surgery (MIS).

ABSTRACT. The da Vinci surgical robot is the most widely-used surgical robotics platform in the world thus far. Its intrinsic cable-driven properties lead to an end-effector positioning error in the order of millimeters, which can hinder its deployment in a shared control setup. To address this problem, we propose a calibration framework, which we test on the first generation da Vinci Research Kit (dVRK). Our statistical analysis shows that, after calibration, positioning accuracy has been improved. In addition, our method demonstrates better performance than model-based calibration methods when the training data set available is small.

ABSTRACT. Force sensing allows surgeons to monitor interactions and locate inclusions during surgery. This paper presents a soft-tipped force sensor for use in minimally invasive surgery. A sensor was produced with an outer diameter of 11.6 mm, allowing it to fit through commonly available 12 mm trocars. This sensor uses a sinuscope to track the deformation of an elastomer membrane during interactions. The internal pressure of the sensor could be adjusted, allowing the membrane’s compliance to be controlled. The sensor’s performance measuring normal and angled forces was tested using a force/torque sensor mounted on a linear rail. Normal force sensing results showed that as the internal pressure of the sensor increased the force sensing range increased whilst the sensitivity decreased. Angled force sensing results showed that the sensor could use a neural network to measure the angle and magnitude of forces. This was done with RMSEs between 3.87% of range and 19.01% of range depending on how similar the testing parameters were to the training parameters.

ABSTRACT. Current tools for moving brain tissue (i.e., tissue retraction to expose cancerous lesions) during neurosurgery are generally made out of stainless steel and create localized regions of pressure. These tool-tissue interactions can be harmful and lead to postoperative complications, especially when the forces are applied over longer periods of time. Soft robots show the potential for significant benefits over current tools due to their ability to safely interact within human tissue, a trait which can reshape tissue interactions in neurosurgery. This work presents capacitive, origami sensing modules (OSM) integrated into a soft robotic retractor for monitoring force during tissue retraction in neurosurgical procedures. Through layered fabrication techniques each OSM is easily foldable so that it may be pneumatically actuated through contraction, expansion, and stiffening of the robot. Each OSM is a Miura origami unit cell that changes in capacitance when force is applied to surrounding tissue. The retraction process can therefore be monitored by the surgeon to ensure that dangerous levels of forces are not exceeded. The relationship between force and capacitance changes are investigated through the calibration of the robot over the typical 0-5 N force range found in neurosurgery. Characterization of the force range, sensitivity, and accuracy are analyzed for making force predictions and to demonstrate feasibility in a surgical environment. In-vitro experiments further validate the accuracy of the OSM with errors of 0.06 N while displaying the proposed operation and capability to monitor distributed retraction forces.

ABSTRACT. Continuum robots are thin and flexible structures whose shape can be continuously deformed using remote actuators. Their form factor and inherent flexibility make them promising for many surgical applications. For safety reasons, it is important to be aware of the forces applied by the robot to surrounding tissue during deployment. Usual force sensors are cumbersome to be embedded into continuum robots. Alternatively, shape-based force estimation methods have been developed. Such methods estimate the contact location and corresponding force based on the comparison between a measured robot shape and the one predicted from robot modeling. Existing solutions have two limitations. First, they assume contact forces to be perpendicular to the robot curvilinear axis. It is unclear how this hypothesis affects the performance since most tool-organ contacts include friction. Second, they consist of iterative optimizations during which the whole robot model is computed at each iteration, using convex optimization routines. Such operations are time-consuming and do not necessarily yield a global optimum. In this paper, we propose a new compliance-based approach to estimate external forces applied on a continuum robot. The approach leverages an efficient computation of the compliance with respect to any force along the robot, which enables efficient computation of a global optimum without recomputing the robot model at each iteration. Simulations carried out on a Concentric Tubes Robot model with and without the assumption that forces has to be perpendicular to the robot are presented. Results show that the force magnitude and the loaded point estimations do not seem to be strongly affected by this assumption but the force direction estimation is strongly impacted. This variation proves the difficulty of estimating the tangential component of the applied force and the need to refined shape-based force sensing algorithms for future medical applications.

ABSTRACT. This paper presents a novel pneumatic pouch sensor designed to mount on a colonoscope that can effectively estimate the contact forces with the environment. The pneumatic pouch sensor was designed to maximize the sensing range, and it was fabricated using a 2D laser welding technique from our track record. The proposed system can reliably measure external forces up to 9.5 N with high repeatability. The system allows discriminating between different levels of force which are typically associated with increasing patient discomfort in colonoscopy: low (0-4 N), medium (4-6 N), and high (\(>\)6 N). This system achieves over 80\% accuracy in comparison to the ground truth and maintains over 60\% accuracy in dynamic scenarios.

ABSTRACT. Robotic microsurgical procedures, such as retinal surgery, could benefit from precise localization of the tool tip with respect to the tissue surface, both to improve patient safety and to provide closed-loop control. This paper describes the fabrication and evaluation of thin, high-resolution optical fiber sensors based on low coherence interferometry. The main length of the probe is formed of single mode fiber, spliced to a a section of 350 µm coreless fiber, acting as a beam expander, followed by a 70 µm section of multimode graded index fiber, which focuses the diverging beam to a point at an optimal working distance of 590 µm. The tip of the probe is sputtered with a thin layer of gold. The probe is connected to a common-path low coherence interferometer driven by an Axsun wavelength-swept source laser with a central wavelength of 1060 nm, a bandwidth of approximately 100 nm, and a 100 kHz sweep rate. Light back-scattered from the tissue is sent to a photodetector, and read-out of the photodetector is synchronized with the laser wavelength sweeping, resulting in the acquisition of optical spectra at a rate of 100 kHz. Light scattered from tissue layers interferes with light reflected from the gold layer on the tip of the probe, resulting in modulations of the spectrum with frequencies that depend on the distances to the reflective layers in the sample. A reflectivity-with-depth profile is then obtained via a Fourier transform, and to obtain the current distance to the tissue, the peak in the profile corresponding to the tissue surface is identified. The sensor can detect distances from tissue over a range of at least 2 mm and with a resolution of better than 20 µm.