Prospective single-arm trial on feasibility and safety of endoscopic robotic system for colonic endoscopic submucosal dissection.

Introduction The development of EndoMaster EASE system aims to enhance safety and efficacy of colonic ESD through two flexible robotic arms for tissue retraction and dissection. This is the first clinical trial to evaluate the performance of colorectal ESD using EndoMaster. Method Patients with early mucosal colorectal neoplasia not feasible for en-bloc resection with snare-based techniques were recruited. The EndoMaster EASE robotic system consisted of an independently designed flexible robotic platform with 2 robotic arms. The primary outcome was complete resection rate using EndoMaster. Secondary outcomes included operating time, hospital stay, procedure-related complications and oncological outcomes. Results From May 2020 to Jan 2022, 43 patients received robotic ESD with median age of 66 years (40-83). The mean robotic dissection time was 62.0 ± 45.1 minutes. All procedures except six were completed using EndoMaster with technical success rate of 86.1% (37/43). The en-bloc resection rate among cases with technical success was 94.6% (35/37) while the complete resection rate was 83.8% (31/37). The median size of specimen was 35mm (15-90mm). The mean hospital stay was 2.6 ± 1.2 days and there was one delayed bleeding 4 days after ESD which was controlled by endoscopy. One patient sustained perforation during procedure which was completely closed using clips without sequelae. 2 patients required salvage surgery due to deep margin involvement by adenocarcinoma in histopathology. Conclusion This first clinical trial confirmed the safety and efficacy of performing colorectal ESD using EndoMaster EASE robotic system (Clinicaltrial.gov: NCT04196062).

Colonic endoscopic submucosal dissection using a novel robotic system (with video).

BACKGROUND AND AIMS: One of the difficulties in performing endoscopic submucosal dissection (ESD) is the lack of retraction during submucosal dissection. The development of the EndoMaster EASE System (EndoMaster Pte Ltd, Singapore) aims to enhance the safety and efficacy of ESD through 2 flexible robotic arms for tissue retraction and dissection. This is a preclinical animal study to evaluate the performance of colorectal ESD using the latest version of the EndoMaster EASE System. METHODS: The latest version of the EndoMaster EASE System consists of an independently designed, flexible platform with a built-in endoscopic imaging system and 3 working channels, 2 for the passage of robotic arms and 1 for accessories. In this animal study, the outcome measures were operating time (from starting incision to finishing dissection), completeness of resection, procedure-related adverse events, and limitations of arm manipulation in a narrow working space as assessed by counting the frequency of blind cutting. RESULTS: Five ESD procedures were performed in a 66.7-kg porcine model with the animal under general anesthesia. The mean operative time was 73.8 minutes, and the mean size of the specimen resected was 1340 mm2. There was no perforation, although profuse bleeding was encountered during 1 robotic ESD procedure. CONCLUSIONS: The current preclinical study confirmed the feasibility of performing colorectal ESD using the latest version of the EndoMaster EASE System. The system was also tested for the ability to manage adverse events including bleeding and perforation. This study provided important preclinical experience for clinical trial.

A Low-Cost, Point-of-Care Test for Confirmation of Nasogastric Tube Placement via Magnetic Field Tracking.

In this work, we aim to achieve low-cost real-time tracking for nasogastric tube (NGT) insertion by using a tracking method based on two magnetic sensors. Currently, some electromagnetic (EM) tracking systems used to detect the misinsertion of the NGT are commercially available. While the EM tracking systems can be advantageous over the other conventional methods to confirm the NGT position, their high costs are a factor hindering such systems from wider acceptance in the clinical community. In our approach, a pair of magnetic sensors are used to estimate the location of a permanent magnet embedded at the tip of the NGT. As the cost of the magnet and magnetic sensors is low, the total cost of the system can be less than one-tenth of that of the EM tracking systems. The experimental results exhibited that tracking can be achieved with a root mean square error (RMSE) of 2-5 mm and indicated a great potential for use as a point-of-care test for NGT insertion, to avoid misplacement into the lung and ensure correct placement in the stomach.

An energy efficient MAC protocol for multi-hop swallowable body sensor networks.

Swallowable body sensor networks (BSNs) are composed of sensors which are swallowed by patients and send the collected data to the outside coordinator. These sensors are energy constraint and the batteries are difficult to be replaced. The medium access control (MAC) protocol plays an important role in energy management. This paper investigates an energy efficient MAC protocol design for swallowable BSNs. Multi-hop communication is analyzed and proved more energy efficient than single-hop communication within the human body when the circuitry power is low. Based on this result, a centrally controlled time slotting schedule is proposed. The major workload is shifted from the sensors to the coordinator. The coordinator collects the path-loss map and calculates the schedules, including routing, slot assignment and transmission power. Sensor nodes follow the schedules to send data in a multi-hop way. The proposed protocol is compared with the IEEE 802.15.6 protocol in terms of energy consumption. The results show that it is more energy efficient than IEEE 802.15.6 for swallowable BSN scenarios.

Feasibility of a low-cost magnet tracking device in confirming nasogastric tube placement at point of care, a clinical trial.

An affordable and reliable way of confirming the placement of nasogastric tube (NGT) at point-of-care is an unmet need. Using a novel algorithm and few sensors, we developed a low-cost magnet tracking device and showed its potential to localize the NGT preclinically. Here, we embark on a first-in-human trial. Six male and 4 female patients with NGT from the general ward of an urban hospital were recruited. We used the device to localize the NGT and compared that against chest X-ray (CXR). In 5 patients, with the sensors placed on the sternal angle, the trajectory of the NGT was reproduced by the tracking device. The tracked location of the NGT deviated from CXR by 0.55 to 1.63 cm, and a downward tracking range of 17 to 22 cm from the sternal angle was achieved. Placing the sensors on the xiphisternum, however, resulted in overt discordance between the device's localization and that on CXR. Short distance between the sternal angle and the xiphisternum, and lower body weight were observed in patients in whom tracking was feasible. Tracking was quick and well tolerated. No adverse event occurred. This device feasibly localized the NGT in 50% of patients when appropriately placed. Further refinement is anticipated.ClinicalTrials.gov identifier: NCT05204901.

Robot-assisted endoscopic submucosal dissection is effective in treating patients with early-stage gastric neoplasia.

BACKGROUND & AIMS: Endoscopic submucosal dissection (ESD) is a new technique for endoscopic resection of early-stage gastrointestinal cancers. Though ESD achieves high rate of en bloc resection, it is technically difficult to master. The development of a novel robotic endoscopic system that has 2 arms attached to an ordinary endoscope-Master and Slave Transluminal Endoscopic Robot (MASTER)-has improved the performance of complex endoluminal procedures. We evaluated the efficacy of MASTER-assisted ESD in treatment of patients with early-stage gastric neoplasia. METHODS: We performed a multicenter prospective study of 5 patients with early-stage gastric neoplasia, limited to the mucosa. After markings and circumferential mucosal incision, all submucosal dissections were performed using the MASTER system. We measured baseline demographics, tumor characteristics, and perioperative and clinical outcomes. RESULTS: All patients underwent successful MASTER-assisted ESD. The mean submucosal dissection time was 18.6 minutes (median, 16 minutes; range, 3-50 minutes). No perioperative complications were encountered. Three patients were discharged from the hospital within 12 hours and 2 on the third day after the procedures. Two patients were found to have intramucosal adenocarcinoma, 1 had high-grade dysplasia, 1 had low-grade dysplasia, and 1 had a hyperplastic polyp. The resection margins were clear of tumors in all 5 patients. No complications were observed at the 30-day follow-up examination. Follow-up endoscopic examinations revealed that none of the patients had residual or recurrent tumors. CONCLUSIONS: A flexible endoscopy robotic system can be used to perform ESD and effectively treat patients with early gastric neoplasia.

Can the Shape of a Planar Pathway Be Estimated Using Proximal Forces of Inserting a Flexible Shaft?

The shape information of flexible endoscopes or other continuum structures, e.g., intro-vascular catheters, is needed for accurate navigation, motion compensation, and haptic feedback in robotic surgical systems. Existing methods rely on optical fiber sensors, electromagnetic sensors, or expensive medical imaging modalities such as X-ray fluoroscopy, magnetic resonance imaging, and ultrasound to obtain the shape information of these flexible medical devices. Here, we propose to estimate the shape/curvature of a continuum structure by measuring the force required to insert a flexible shaft into the internal channel/pathway of the continuum. We found that there is a consistent correlation between the measured insertion force and curvature of the planar continuum pathway. A testbed was built to insert a flexible shaft into a planar continuum pathway with adjustable shapes. The insertion forces, insertion displacement, and the shapes of the pathway were recorded. A neural network model was developed to model this correlation based on the training data collected on the testbed. The trained model, tested on the testing data, can accurately estimate the curvature magnitudes and the accumulated bending angles of the pathway simply based on the measured insertion force at the proximal end of the shaft. The approach may be used to estimate the curvature magnitudes and accumulated bending angles of flexible endoscopic surgical robots or catheters for accurate motion compensation, haptic force feedback, localization, or navigation. The advantage of this approach is that the employed proximal force can be easily obtained outside the pathway or continuum structure without any embedded sensor in the continuum structure. Future work is needed to further investigate the correlation between insertion forces and the pathway and enhance the capability of the model in estimating more complex shapes, e.g., spatial shapes with multiple bends.

A Three-Limb Teleoperated Robotic System with Foot Control for Flexible Endoscopic Surgery.

Flexible endoscopy requires a lot of skill to manipulate both the endoscope and the associated instruments. In most robotic flexible endoscopic systems, the endoscope and instruments are controlled separately by two operators, which may result in communication errors and inefficient operation. Our solution is to enable the surgeon to control both the endoscope and the instruments. Here, we present a novel tele-operation robotic endoscopic system commanded by one operator using the continuous and simultaneous movements of their two hands and one foot. This 13-degree-of-freedom (DoF) system integrates a foot-controlled robotic flexible endoscope and two hand-controlled robotic endoscopic instruments, a robotic grasper and a robotic cauterizing hook. A dedicated foot-interface transfers the natural foot movements to the 4-DoF movements of the endoscope while two other commercial hand interfaces map the movements of the two hands to the two instruments individually. An ex-vivo experiment was carried out by six subjects without surgical experience, where the simultaneous control with foot and hands was compared with a sequential clutch-based hand control. The participants could successfully teleoperate the endoscope and the two instruments to cut the tissues at scattered target areas in a porcine stomach. Foot control yielded 43.7% faster task completion and required less mental effort as compared to the clutch-based hand control scheme, which proves the concept of three-limb tele-operation surgery and the developed flexible endoscopic system.

Two Magnetic Sensor Based Real-Time Tracking of Magnetically Inflated Swallowable Intragastric Balloon.

This paper presents a two magnetic sensor based tracking method for a magnetically inflated intragastric balloon capsule (MIBC) which is used for obesity treatment. After the MIBC is swallowed, it is designed to be inflated inside the stomach by approaching a permanent magnet (PM) externally near the abdomen. However, if the balloon inflation is accidentally triggered while the MIBC is still in the esophagus, the esophagus will be damaged. Therefore, to safely inflate the MIBC, we aim to track the MIBC's position along the esophagus and confirm the MIBC passes through. Typically, magnetic sensor based tracking systems tend to be bulky and costly since they involve computationally intensive optimization with many magnetic sensors. To solve those problems, we develop an algorithm that estimates the position of the PM inside the MIBC by using the grid search combined with the dynamically confined search range and search threshold modulation. Our tracking method achieved an average 1D position error of 3.48 mm which is comparable to the up to 4 mm average error for the other magnetic sensor based tracking systems that require more sensors and computational power compared to our system.

EndoPil: A Magnetically Actuated Swallowable Capsule for Weight Management: Development and Trials.

Intragastric balloons (IGBs), by occupying the stomach space and prolonging satiety, is a promising method to treat obesity and consequently improves its associated comorbidities, e.g. coronary heart disease, diabetes, and cancer. However, existing IGBs are often tethered with tubes for gas or liquid delivery or require endoscopic assistance for device delivery or removal, which are usually uncomfortable, costly, and may cause complications. This paper presents a novel tetherless, magnetically actuated capsule (EndoPil) which can deploy an IGB inside the stomach after being swallowed and being activated by an external magnet. The external magnet attracts a small magnet inside the EndoPil to open a valve, triggering the chemical reaction of citric acid and potassium bicarbonate to produce carbon dioxide gas, which inflates a biocompatible balloon (around 120 mL). A prototype, 13 mm in diameter and 35 mm in length, was developed. Simulations and bench-top tests were conducted to test the force capability of the magnetic actuation mechanism, the required force to activate the valve, and the repeatability of balloon inflation. Experiments on animal and human were successfully conducted to demonstrate the safety and feasibility of inflating a balloon inside the stomach by an external magnet.

Endoscopic submucosal dissection of gastric lesions by using a Master and Slave Transluminal Endoscopic Robot (MASTER).

BACKGROUND: Performing endoscopic submucosal dissection (ESD) by using standard endoscopy platforms is technically challenging because of the equipment's lack of dexterity. OBJECTIVE: To explore the feasibility of using the Master and Slave Transluminal Endoscopic Robot (MASTER), a novel robotics-enhanced endosurgical system, to perform ESD. DESIGN: ESD was performed on simulated gastric lesions in 5 Erlangen porcine stomach models (ex vivo) and 5 live pigs (in vivo). Performance of ESD by using the MASTER was compared with that using the insulation-tipped (IT) diathermic knife. SETTING: SMART Laboratory, Advance Surgical Training Centre, National University Hospital, Singapore. SUBJECTS: Five Erlangen porcine stomach models and 5 pigs, 5 to 7 months old, each weighing about 35 kg. INTERVENTIONS: ESD. MAIN OUTCOME MEASUREMENTS: Lesion resection time, grasper and hook efficacy grade, completeness of resection, and presence of procedure-related perforation. RESULTS: In the Erlangen stomach models, 15 simulated lesions from the cardia, antrum, and body were removed en bloc (mean dimension, 37.4 x 26.5 mm) by electrocautery excision using the MASTER. The mean ESD time was 23.9 minutes (range 7-48 minutes). There was no difference in the dissection times of lesions at different locations (P = .449). In the live pigs, the MASTER took a mean of 16.2 minutes (range 3-29 minutes) to complete the ESD of 5 gastric lesions, whereas the IT diathermic knife took 18.6 minutes (range 9-34 minutes). There was no significant difference in the times taken (P = .708). All lesions were excised en bloc; the mean dimensions of lesions resected by the MASTER and the IT diathermic knife were 37.2 x 30.1 mm and 32.78 x 25.6 mm, respectively. The MASTER exhibited good grasping and cutting efficiency throughout. Surgical maneuvers were achieved with ease and precision. There was no incidence of excessive bleeding or stomach wall perforation. LIMITATIONS: Exploratory study with limited sample size. CONCLUSIONS: Performing ESD by using the MASTER is feasible.

A Temperature-Dependent, Variable-Stiffness Endoscopic Robotic Manipulator with Active Heating and Cooling.

In flexible endoscopy, the endoscope needs to be sufficiently flexible to go through the tortuous paths inside the human body and meanwhile be stiff enough to withstand external payloads without unwanted tip bending during operation. Thus, an endoscope whose stiffness can be adjusted on command is needed. This paper presents a novel variable-stiffness manipulator. The manipulator (Ø15 mm) has embedded thermoplastic tubes whose stiffness is tunable through temperature. Temperature is adjusted through joule heat generated by the electrical current supplied to the stainless steel coils and an active air-cooling mechanism. Tests and modeling were conducted to characterize the performance of the design. The manipulator has a high stiffness-changing ratio (22) between rigid and flexible states while that of its commercial Olympus counterpart is only 1.59. The active cooling time is 11.9 s while that of passive ambient cooling is 100.3 s. The thermal insulation layer (Aerogel) keeps the temperature of the outer surface within the safe range (below 41 °C). The models can describe the heating and cooling processes with root mean square errors ranging from 0.6 to 1.3 °C. The results confirm the feasibility of a variable-stiffness endoscopic manipulator with high stiffness-changing ratio, fast mode-switching, and safe thermal insulation.

An Integrated Sensor-Model Approach for Haptic Feedback of Flexible Endoscopic Robots.

Haptic feedback for flexible endoscopic surgical robots is challenging due to space constraints for sensors and shape-dependent force hysteresis of tendon-sheath mechanisms (TSMs). This paper proposes (1) a single-axis fiber Bragg grating (FBG)-based force sensor for a TSM of a robotic arm and (2) an integrated sensor-model approach to estimate forces on other TSMs of that arm. With a robust and simple structure, a temperature-compensated sensor can be mounted on the distal sheath to measure forces applied by the TSM. This proposed sensor was integrated with a Ø4.2 mm articulated robotic arm driven by six TSMs, with a measurement error of 0.37 N in this work. The measurement from the single sensor was used to identify parameters in the force-transmission models of all other TSMs in the robot, realizing a one-sensor-for-all-distal-forces measurement method. The sensor-model approach could accurately estimate the distal force with an RMSE of 0.65 N. An animal study was carried out to demonstrate the sensor's feasibility in real-life surgery. The sensor-model approach presented a robust, space-saving, and cost-effective solution for haptic feedback of endoscopic robots without any assumption on the shapes of the robot.

Global Evaluative Assessment of Robotic Skills in Endoscopy (GEARS-E): objective assessment tool for master and slave transluminal endoscopic robot.

BACKGROUND AND STUDY AIMS: The Master and Slave Transluminal Endoscopic Robot (MASTER) is a novel robotic endosurgical system with two operating arms that offer multiple degrees of freedom. We developed a new assessment tool, the Global Evaluative Assessment of Robotic Skills in Endoscopy (GEARS-E), derived from existing tools in laparoscopic and robotic surgery, and evaluated its utility in the performance of procedures using MASTER. METHODS: This was a pilot study conducted in vivo and ex vivo on animals. Three operators (Novice-1, Novice-2 and Expert) performed a total of five endoscopic submucosal dissections (ESD) using MASTER. Novice operators had no MASTER experience and the expert had previously performed eight MASTER ESDs. Operator performance was assessed by four independent evaluators using GEARS-E, which has a maximum score of 25 for five domains representing various skill-related variables (depth perception, bimanual dexterity, efficiency, tissue handling and autonomy). RESULTS: The mean global rating scores for Novice-1 first attempt, Novice-1 second attempt, Novice-2 first attempt, Novice-2 second attempt and Expert's cases were 13.0, 16.0, 13.3, 15.5, and 21.5, respectively. The mean scores of each of the five domains were statistically higher for the second attempts compared to the first attempts for both Novice-1 and Novice-2. The mean scores of each of the five domains for the Expert's case were consistently higher than those for the two novice operators in both their first and second attempts. CONCLUSION: Results using GEARS-E showed correlations between surgical experience and MASTER ESD. As an assessment tool for evaluation of surgical skills, GEARS-E has great potential for application in MASTER procedures.

Use of the EndoMaster robot-assisted surgical system in transoral robotic surgery: A cadaveric study.

BACKGROUND: The EndoMaster is a novel robot-assisted surgical system originally designed for endoscopic resection of gastrointestinal polyps and tumours. It incorporates two robotic arms (a grasper and a probe for monopolar diathermy) into the end of a flexible endoscope, creating improved manoeuvrability, with two arms allowing for 9 degrees of movement and triangulation; this enables fine manipulation and dissection of tissues. METHODS: The EndoMaster was used in two human cadavers to perform 4 radical tonsillectomies to evaluate its performance in transoral robotic surgery (TORS). RESULTS: The EndoMaster allowed for good visualization of the surgical field and its compact form factor allowed for quick docking and avoided the problem of clashing of the working arms. CONCLUSION: The EndoMaster system shows promising potential for use in TORS. Further refinements to movements of the effector arms are required.

A Magnetic Soft Endoscopic Capsule-Inflated Intragastric Balloon for Weight Management.

Overweight and obesity have been identified as a cause of high risk diseases like diabetes and cancer. Although conventional Intragastric Balloons (IGBs) have become an efficient and less invasive method for overweight and obesity treatment, the use of conventional tools such as catheter or endoscope to insert and remove the IGBs from the patient's body causes nausea, vomiting, discomfort, and even gastric mucous damage. To eliminate these drawbacks, we develop a novel magnetic soft capsule device with gas-filled balloon inflation. The balloon is made from a thin and biocompatible material that can be inflated to a desired volume using biocompatible effervescent chemicals. In addition, both the outer balloon and inner capsule are designed to be soft and chemical resistance. The soft capsule shell is fabricated using scaffold-solvent approach while the outer balloon utilizes a novel fabrication approach for 3D spherical structure. A prototype of the proposed capsule and balloon is given. Experiments are successfully carried out in stimulated gastric environment and fresh porcine stomach to validate the effectiveness and reliability of the proposed approach.

Design and Control of a Mechatronic Tracheostomy Tube for Automated Tracheal Suctioning.

GOAL: Mechanical ventilation is required to aid patients with breathing difficulty to breathe more comfortably. A tracheostomy tube inserted through an opening in the patient neck into the trachea is connected to a ventilator for suctioning. Currently, nurses spend millions of person-hours yearly to perform this task. To save significant person-hours, an automated mechatronic tracheostomy system is needed. This system allows for relieving nurses and other carers from the millions of person-hours spent yearly on tracheal suctioning. In addition, it will result in huge healthcare cost savings. METHODS: We introduce a novel mechatronic tracheostomy system including the development of a long suction catheter, automatic suctioning mechanisms, and relevant control approaches to perform tracheal suctioning automatically. To stop the catheter at a desired position, two approaches are introduced: 1) Based on the known travel length of the catheter tip; 2) Based on a new sensing device integrated at the catheter tip. It is known that backlash nonlinearity between the suction catheter and its conduit as well as in the gear system of the actuator are unavoidable. They cause difficulties to control the exact position of the catheter tip. For the former case, we develop an approximate model of backlash and a direct inverse scheme to enhance the system performances. The scheme does not require any complex inversions of the backlash model and allows easy implementations. For the latter case, a new sensing device integrated into the suction catheter tip is developed and backlash compensation controls are avoided. RESULTS: Automated suctioning validations are successfully carried out on the proposed experimental system. Comparisons and discussions are also introduced. SIGNIFICANCE: The results demonstrate a significant contribution and potential benefits to the mechanical ventilation areas.

Development and Testing of a Magnetically Actuated Capsule Endoscopy for Obesity Treatment.

Intra-gastric balloons (IGB) have become an efficient and less invasive method for obesity treatment. The use of traditional IGBs require complex insertion tools and flexible endoscopes to place and remove the balloon inside the patient's stomach, which may cause discomfort and complications to the patient. This paper introduces a new ingestible weight-loss capsule with a magnetically remote-controlled inflatable and deflatable balloon. To inflate the balloon, biocompatible effervescent chemicals are used. As the source of the actuation is provided via external magnetic fields, the magnetic capsule size can be significantly reduced compared to current weight-loss capsules in the literature. In addition, there are no limitations on the power supply. To lose weight, the obese subject needs only to swallow the magnetic capsule with a glass of water. Once the magnetic capsule has reached the patient's stomach, the balloon will be wirelessly inflated to occupy gastric space and give the feeling of satiety. The balloon can be wirelessly deflated at any time to allow the magnetic capsule to travel down the intestine and exit the body via normal peristalsis. The optimal ratio between the acid and base to provide the desired gas volume is experimentally evaluated and presented. A prototype capsule (9.6mm x 27mm) is developed and experimentally validated in ex-vivo experiments. The unique ease of delivery and expulsion of the proposed magnetic capsule is slated to make this development a good treatment option for people seeking to lose excess weight.