Imaging skins: stretchable and conformable on-organ beta particle detectors for radioguided surgery

While radioguided surgery (RGS) traditionally relied on detecting gamma rays, direct detection of beta particles could facilitate the detection of tumour margins intraoperatively by reducing radiation noise emanating from distant organs, thereby improving the signal-to-noise ratio of the imaging technique. In addition, most existing beta detectors do not offer surface sensing or imaging capabilities. Therefore, we explore the concept of a stretchable scintillator to detect beta-particles emitting radiotracers that would be directly deployed on the targeted organ. Such detectors, which we refer to as imaging skins, would work as indirect radiation detectors made of light-emitting agents and biocompatible stretchable material. Our vision is to detect scintillation using standard endoscopes routinely employed in minimally invasive surgery. Moreover, surgical robotic systems would ideally be used to apply the imaging skins, allowing for precise control of each component, thereby improving positioning and task repeatability. While still in the exploratory stages, this innovative approach has the potential to improve the detection of tumour margins during RGS by enabling real-time imaging, ultimately improving surgical outcomes

A Fluidic Soft Robot for Needle Guidance and Motion Compensation in Intratympanic Steroid Injections

Intratympanic steroid injections are commonly employed in treating ear diseases, such as sudden sensorineural hearing loss or Meniere's disease through drug delivery via the middle ear. Whilst being an effective treatment, the procedure has to be performed by a trained surgeon to avoid delicate regions in the patient's anatomy and is considered painful despite the use of topical anaesthesia. In this letter we introduce a fluid-driven soft robotic system which aims at increasing patient-comfort during the injection by counteracting unwanted needle motion, reducing the cognitive load of the clinician by autonomously identifying sensitive regions in the ear and de-risking the procedure by steering the needle towards the desired injection site. A design comprising of six embedded fluidic actuators is presented, which allow for translation and rotation of the needle as well as adaptive stiffening in the coupling between needle and ear canal. The system's steering-capabilities are investigated and the differential kinematics derived to demonstrate trajectory tracking in Cartesian space. A vision system is developed which enables tracking of anatomical landmarks on the tympanic membrane and thus locating the desired needle insertion site. The integrated system shows the ability to provide a safe guide for the inserted needle towards a desired target direction while significantly reducing needle motion. The proposed tracking algorithm is able to identify the desired needle insertion site and could be employed to avoid delicate anatomical regions

Toward a Common Framework and Database of Materials for Soft Robotics

To advance the field of soft robotics, a unified database of material constitutive models and experimental characterizations is of paramount importance. This will facilitate the use of finite element analysis to simulate their behavior and optimize the design of soft-bodied robots. Samples from seventeen elastomers, namely Body Double™ SILK, Dragon Skin™ 10 MEDIUM, Dragon Skin 20, Dragon Skin 30, Dragon Skin FX-Pro, Dragon Skin FX-Pro + Slacker, Ecoflex™ 00–10, Ecoflex 00–30, Ecoflex 00–50, Rebound™ 25, Mold Star™ 16 FAST, Mold Star 20T, SORTA-Clear™ 40, RTV615, PlatSil® Gel-10, Psycho Paint®, and SOLOPLAST 150318, were subjected to uniaxial tensile tests according to the ASTM D412 standard. Sample preparation and tensile test parameters are described in detail. The tensile test data are used to derive parameters for hyperelastic material models using nonlinear least-squares methods, which are provided to the reader. This article presents the mechanical characterization and the resulting material properties for a wide set of commercially available hyperelastic materials, many of which are recognized and commonly applied in the field of soft robotics, together with some that have never been characterized. The experimental raw data and the algorithms used to determine material parameters are shared on the Soft Robotics Materials Database GitHub repository to enable accessibility, as well as future contributions from the soft robotics community. The presented database is aimed at aiding soft roboticists in designing and modeling soft robots while providing a starting point for future material characterizations related to soft robotics research

Localization of Interaction using Fibre-Optic Shape Sensing in Soft-Robotic Surgery Tools

Minimally invasive surgery requires real-time tool tracking to guide the surgeon where depth perception and visual occlusion present navigational challenges. Although vision-based and external sensor-based tracking methods exist, fibre-optic sensing can overcome their limitations as they can be integrated directly into the device, are biocompatible, small, robust and geometrically versatile. In this paper, we integrate a fibre Bragg grating-based shape sensor into a soft robotic device. The soft robot is the pneumatically attachable flexible (PAF) rail designed to act as a soft interface between manipulation tools and intra-operative imaging devices. We demonstrate that the shape sensing fibre can detect the location of the tools paired with the PAF rail, by exploiting the change in curvature sensed by the fibre when a strain is applied to it. We then validate this with a series of grasping tasks and continuous US swipes, using the system to detect in real-time the location of the tools interacting with the PAF rail. The overall location-sensing accuracy of the system is 64.6%, with a margin of error between predicted location and actual location of 3.75 mm

A spherical joint robotic end-effector for the Expanded Endoscopic Endonasal Approach

The endonasal transsphenoidal approach allows surgeons to access the pituitary gland through the natural orifice of the nose. Recently, surgeons have also described an Expanded Endoscopic Endonasal Approach (EEEA) for the treatment of other tumours around the base of the brain. However, operating in this way with nonarticulated tools is technically very difficult and not widely adopted. The goal of this study is to develop an articulated end-effector for a novel handheld robotic tool for the EEEA. We present a design and implementation of a 3.6mm diameter, three degrees-of-freedom, tendon-driven robotic end-effector that, contrary to rigid instruments which operate under fulcrum, will give the surgeon the ability to reach areas on the surface of the brain that were previously inaccessible. We model the end-effector kinematics in simulation to study the theoretical workspace it can achieve prior to implementing a test-bench device to validate the efficacy of the end-effector. We find promising repeatability of the proposed robotic end-effector of 0.42mm with an effective workspace with limits of ±30∘, which is greater than conventional neurosurgical tools. Additionally, although the tool’s end-effector has a small enough diameter to operate through the narrow nasal access path and the constrained workspace of EEEA, it showcased promising structural integrity and was able to support approximately a 6N load, despite a large deflection angle the limiting of which is scope of future work. These preliminary results indicate the end-effector is a promising first step towards developing appropriate handheld robotic instrumentation to drive EEEA adoption

An intuitive surgical handle design for robotic neurosurgery.

PURPOSE: The expanded endoscopic endonasal approach, a representative example of keyhole brain surgery, allows access to the pituitary gland and surrounding areas through the nasal and sphenoid cavities. Manipulating rigid instruments through these constrained spaces makes this approach technically challenging, and thus, a handheld robotic instrument could expand the surgeon's capabilities. In this study, we present an intuitive handle prototype for such a robotic instrument. METHODS: We have designed and fabricated a surgical instrument handle prototype that maps the surgeon's wrist directly to the robot joints. To alleviate the surgeon's wrist of any excessive strain and fatigue, the tool is mounted on the surgeon's forearm, making it parallel with the instrument's shaft. To evaluate the handle's performance and limitations, we constructed a surgical task simulator and compared our novel handle with a standard neurosurgical tool, with the tasks being performed by a consultant neurosurgeon. RESULTS: While using the proposed handle, the surgeon's average success rate was [Formula: see text], compared to [Formula: see text] when using a conventional tool. Additionally, the surgeon's body posture while using the suggested prototype was deemed acceptable by the Rapid Upper Limb Assessment ergonomic survey, while early results indicate the absence of a learning curve. CONCLUSIONS: Based on these preliminary results, the proposed handle prototype could offer an improvement over current neurosurgical tools and procedural ergonomics. By redirecting forces applied during the procedure to the forearm of the surgeon, and allowing for intuitive surgeon wrist to robot-joints movement mapping without compromising the robotic end effector's expanded workspace, we believe that this handle could prove a substantial step toward improved neurosurgical instrumentation

Evaluation of A Novel Organ Perfusion Research Platform

This paper presents a novel, low cost, organ perfusion machine designed for use in research. The modular and versatile nature of the system allows for additional sensing equipment to be added or adapted for specific use. Here we introduce the system and present its preliminary evaluation by assessing its ability to maintain a predetermined input pressure. A proportional-integral-derivative (PID) controller was implemented and tested on a porcine liver to maintain input pressure to the hepatic artery and compared to bench tests. The results confirmed the effectiveness of the controller for maintaining input through the hepatic artery (HA) in a timely manner. Clinical Relevance-Machine Perfusion (MP) is proving to be an invaluable adjunct in clinical practice. With its ongoing success in the transplant arena, we propose MP for use in research. A cost-effective, versatile system that can be modified for specific research use to test new pharmacological therapies, imaging techniques or develop simulation training would be beneficial

An adaptable research platform for ex vivo normothermic machine perfusion of the liver

PURPOSE: This paper presents an assessment of a low-cost organ perfusion machine designed for use in research settings. The machine is modular and versatile in nature, built on a robotic operating system (ROS2) pipeline allowing for the addition of specific sensors for different research applications. Here we present the system and the development stages to achieve viability of the perfused organ. METHODS: The machine's perfusion efficacy was assessed by monitoring the distribution of perfusate in livers using methylene blue dye. Functionality was evaluated by measuring bile production after 90 min of normothermic perfusion, while viability was examined using aspartate transaminase assays to monitor cell damage throughout the perfusion. Additionally, the output of the pressure, flow, temperature, and oxygen sensors was monitored and recorded to track the health of the organ during perfusion and assess the system's capability of maintaining the quality of data over time. RESULTS: The results show the system is capable of successfully perfusing porcine livers for up to three hours. Functionality and viability assessments show no deterioration of liver cells once normothermic perfusion had occurred and bile production was within normal limits of approximately 26 ml in 90 min showing viability. CONCLUSION: The developed low-cost perfusion system presented here has been shown to keep porcine livers viable and functional ex vivo. Additionally, the system is capable of easily incorporating several sensors into its framework and simultaneously monitor and record them during perfusion. The work promotes further exploration of the system in different research domains

Toward a common framework and database of materials for soft robotics

To advance the field of soft robotics, a unified database of material constitutive models and experimental characterizations is of paramount importance. This will facilitate the use of finite element analysis to simulate their behavior and optimize the design of soft-bodied robots. Samples from seventeen elastomers, namely Body Double™ SILK, Dragon Skin™ 10 MEDIUM, Dragon Skin 20, Dragon Skin 30, Dragon Skin FX-Pro, Dragon Skin FX-Pro + Slacker, Ecoflex™ 00–10, Ecoflex 00–30, Ecoflex 00–50, Rebound™ 25, Mold Star™ 16 FAST, Mold Star 20T, SORTA-Clear™ 40, RTV615, PlatSil® Gel-10, Psycho Paint®, and SOLOPLAST 150318, were subjected to uniaxial tensile tests according to the ASTM D412 standard. Sample preparation and tensile test parameters are described in detail. The tensile test data are used to derive parameters for hyperelastic material models using nonlinear least-squares methods, which are provided to the reader. This article presents the mechanical characterization and the resulting material properties for a wide set of commercially available hyperelastic materials, many of which are recognized and commonly applied in the field of soft robotics, together with some that have never been characterized. The experimental raw data and the algorithms used to determine material parameters are shared on the Soft Robotics Materials Database GitHub repository to enable accessibility, as well as future contributions from the soft robotics community. The presented database is aimed at aiding soft roboticists in designing and modeling soft robots while providing a starting point for future material characterizations related to soft robotics research