Surgical Training Using Augmented Reality-Based Optical Head-Mounted Displays: A Pilot Study.

While the educational benefits of the modern techniques such as virtual reality (VR) or augmented reality (AR) have been suggested, there is still a lack of reports on actual surgeons' experiences. In this study, we evaluated the effectiveness of a holographic AR-based surgical training in tonsillectomy. Two otolaryngologists, 1 trainee and 1 instructor, performed 5 tonsillectomies using an AR headset (HoloLens 2, Microsoft, USA). The trainee wore the AR headset to share the surgical view through front camera while the instructor remotely accessed the device using the Microsoft Teams program and provided real-time guidance. The AR-based surgical training offered several advantages, including direct real-time guidance for the trainee and clear instructions without disturbing the surgical process. However, there were also drawbacks, such as the front camera not always matching the trainee's view and some difficulty with focusing, depending on the depth of the oral cavity. Our study suggests that AR devices are a feasible and alternative method for surgical training. With the ability to provide clear guidance, even from a distance, this technology has the potential to revolutionize surgical training in the future.

Robot-Assisted Transarterial Chemoembolization of Hepatocellular Carcinoma Using a Coaxial Microcatheter Driving Controller-Responder Robot System: Clinical Pilot Study.

PURPOSE: To evaluate the feasibility and safety of robot-assisted transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) using a new coaxial microcatheter driving controller-responder robot (CRR) system. MATERIALS AND METHODS: A single-center prospective pilot study approved by the institutional review board was conducted using this CRR developed after analyzing 20 cases of conventional TACE procedures from May to October 2021. The study included 10 patients with HCCs: 5 (median age, 72 years; range, 64-73 years) underwent robot-assisted TACE, and 5 (median age, 57 years; range, 44-76 years) underwent conventional TACE for comparison. The feasibility and safety of robot-assisted TACE were evaluated by assessing the technical success, procedure time, adverse event rate, radiation dose, and early tumor response. RESULTS: The entire TACE procedure was divided into 30 steps, of which 8 could be robotized. In robot-assisted TACE, technical success was achieved in 4 (80%) of 5 patients. No procedure-related adverse event was observed. The median procedure time was 56 minutes. At the 1-month follow-up, 3 of the 4 patients showed a complete or partial response after robot-assisted TACE. The median radiation doses for the operator and patients were 0.4 and 2,167.5 µSv in robot-assisted TACE and 53.2 and 2,989.7 µSv in conventional TACE, respectively. CONCLUSIONS: Robot-assisted TACE using a new CRR system was feasible and safe for the treatment of HCC and could remarkably decrease radiation exposure for the operators.

An Electromagnetically Controllable Microrobotic Interventional System for Targeted, Real-Time Cardiovascular Intervention.

Robotic magnetic manipulation systems offer a wide range of potential benefits in medical fields, such as precise and selective manipulation of magnetically responsive instruments in difficult-to-reach vessels and tissues. However, more preclinical/clinical studies are necessary before robotic magnetic interventional systems can be widely adopted. In this study, a clinically translatable, electromagnetically controllable microrobotic interventional system (ECMIS) that assists a physician in remotely manipulating and controlling microdiameter guidewires in real time, is reported. The ECMIS comprises a microrobotic guidewire capable of active magnetic steering under low-strength magnetic fields, a human-scale electromagnetic actuation (EMA) system, a biplane X-ray imaging system, and a remote guidewire/catheter advancer unit. The proposed ECMIS demonstrates targeted real-time cardiovascular interventions in vascular phantoms through precise and rapid control of the microrobotic guidewire under EMA. Further, the potential clinical effectiveness of the ECMIS for real-time cardiovascular interventions is investigated through preclinical studies in coronary, iliac, and renal arteries of swine models in vivo, where the magnetic steering of the microrobotic guidewire and control of other ECMIS modules are teleoperated by operators in a separate control booth with X-ray shielding. The proposed ECMIS can help medical physicians optimally manipulate interventional devices such as guidewires under minimal radiation exposure.

DNA-Helix Inspired Wire Routing in Cylindrical Structures and Its Application to Flexible Surgical Devices.

In general wire-driven continuum robot mechanisms, the wires are used to control the motion of the devices attached at the distal end. The slack and taut wire is one of the challenging issues to solve in flexible mechanism. This phenomenon becomes worse when the continuum robot is inserted into the natural orifices of the human body, which inherently have uncertain curvilinear geometries consisting of multiple curvatures. Inspired by the unique characteristic of DNA-helix structure that the length of the helix remains almost constant regardless of the deflection of the DNA structure, this article proposes a new idea to design useful flexible mechanism to resolve slack of wires. Using modern Lie-group screw theory, the analytic model for length of helix wire wrapped around a single flexible backbone is proposed and then extended to a general model with multiple flexible backbones and different curvatures. Taking advantage of this helix type wire mechanism, we designed and implemented a flexible surgical device suitable for laryngopharyngeal surgery. The effectiveness of the proposed flexible mechanism is demonstrated through both simulation and phantom experiment.

Reduction of radiation exposure to operating physician and assistant using a real-time auditory feedback dosimeter during femoral artery puncturing: a study on swine model.

BACKGROUND: Real-time dosimeters may create a relatively safer environment not only for the patient but also for the physician and the assistant as well. We propose the use of a real-time radiation measurement dosimeter having auditory feedback to reduce radiation exposure. METHODS: Radiation dose rates were measured for 30 fluoroscopy-guided puncturing procedures of femoral arteries in swine. Fifteen puncturing procedures were performed with real-time radiation measurement dosimeter having auditory feedback and other 15 were performed without auditory feedback dosimeter by an interventional cardiologist with 10 years of experience. RESULTS: The left body side of the operating physician (38%, p < 0.001) and assistant (25%, p < 0.001) was more exposed as compared to the right body side. Radiation dose rate to the left hand, left arm and left leg were reduced from 0.96 ± 0.10 to 0.79 ± 0.12 mSv/h (17% reduction, p < 0.001), from 0.11 ± 0.02 to 0.07 ± 0.01 mSv/h (36% reduction, p < 0.001) and from 0.22 ± 0.06 to 0.15 ± 0.02 mSv/h (31% reduction, p < 0.001) with the use of auditory feedback dosimeter, respectively. The mean fluoroscopic time was reduced from 4.8 ± 0.43 min to 4.2 ± 0.53 min (p < 0.001). The success rate of performing arterial puncturing was 100%. CONCLUSIONS: The use of auditory feedback dosimeter resulted in reduction in effective dose. The sound beep alerted the physician from the danger of exposure, and this approach induced awareness and protective mindset to the operating physician and assistant.

Reduction of operator radiation exposure using a passive robotic device during fluoroscopy-guided arterial puncture: an experimental study in a swine model.

BACKGROUND: Vascular interventions imply radiation exposure to the operating physician (OP). To reduce radiation exposure, we propose a novel passive robotic device for fluoroscopy-guided arterial puncturing. METHODS: X-ray dose rates were measured for a total of 30 fluoroscopy-guided puncture femoral arteries in 15 pigs. Fifteen punctures were performed with the device while the other 15 were performed without the device by an interventional cardiologist with 10 years of experience. Parametric t test was used. RESULTS: The success rate with the device was 100%. Overall, the OP received more radiation (0.41 mSv/h) as compared to the assistant (0.06 mSv/h) (p <  0.001) and, amongst OP's body parts, hands received more radiation than other body parts (p <  0.001). The radiation dose rate to the OP's hands during arterial puncturing performed manually without the device was 0.95 ± 0.25 mSv/h whereas it was 0.14 ± 0.006 mSv/h using the device, resulting in an 85% reduction (p <  0.001). For the head, the dose was reduced from 0.16 mSv/h to 0.08 mSv/h (50% reduction, p <  0.001), and for the dominant arm, from 0.12 mSv/h to 0.07 mSv/h (42% reduction, p <  0.001). The fluoroscopy time was reduced from 4.5 ± 0.15 min to 4.3 ± 0.11 min device (p = 0.002). CONCLUSIONS: In a swine model, fluoroscopy time and radiation exposure for the OP puncturing femoral artery were significantly reduced by using the passive robotic device.

A Magnetically Controlled Soft Microrobot Steering a Guidewire in a Three-Dimensional Phantom Vascular Network.

Magnetically actuated soft robots may improve the treatment of disseminated intravascular coagulation. Significant progress has been made in the development of soft robotic systems that steer catheters. A more challenging task, however, is the development of systems that steer sub-millimeter-diameter guidewires during intravascular treatments; a novel microrobotic approach is required for steering. In this article, we develop a novel, magnetically actuated, soft microrobotic system, increasing the steerability of a conventional guidewire. The soft microrobot is attached to the tip of the guidewire, and it is magnetically steered by changing the direction and intensity of an external magnetic field. The microrobot is fabricated via replica molding and features a soft body made of polydimethylsiloxane, two permanent magnets, and a microspring. We developed a mathematical model mapping deformation of the soft microrobot using a feed-forward approach toward steering. Then, we used the model to steer a guidewire. The angulation of the microrobot can be controlled from 21.1° to 132.7° by using a magnetic field of an intensity of 15 mT. Steerability was confirmed by two-dimensional in vitro tracking. Finally, a guidewire with the soft microrobot was tested by using a three-dimensional (3D) phantom of the coronary artery to verify steerability in 3D space.

A cadaver study of mastoidectomy using an image-guided human-robot collaborative control system.

Objective: Surgical precision would be better achieved with the development of an anatomical monitoring and controlling robot system than by traditional surgery techniques alone. We evaluated the feasibility of robot-assisted mastoidectomy in terms of duration, precision, and safety. Study Design: Human cadaveric study. Materials and Methods: We developed a multi-degree-of-freedom robot system for a surgical drill with a balancing arm. The drill system is manipulated by the surgeon, the motion of the drill burr is monitored by the image-guided system, and the brake is controlled by the robotic system. The system also includes an alarm as well as the brake to help avoid unexpected damage to vital structures. Experimental mastoidectomy was performed in 11 temporal bones of six cadavers. Parameters including duration and safety were assessed, as well as intraoperative damage, which was judged via pre- and post-operative computed tomography. Results: The duration of mastoidectomy in our study was comparable with that required for chronic otitis media patients. Although minor damage, such as dura exposure without tearing, was noted, no critical damage to the facial nerve or other important structures was observed. When the brake system was set to 1 mm from the facial nerve, the postoperative average bone thicknesses of the facial nerve was 1.39, 1.41, 1.22, 1.41, and 1.55 mm in the lateral, posterior pyramidal and anterior, lateral, and posterior mastoid portions, respectively. Conclusion: Mastoidectomy can be successfully performed using our robot-assisted system while maintaining a pre-set limit of 1 mm in most cases. This system may thus be useful for more inexperienced surgeons. Level of Evidence: NA.

An assembly-type master-slave catheter and guidewire driving system for vascular intervention.

Current vascular intervention inevitably exposes a large amount of X-ray to both an operator and a patient during the procedure. The purpose of this study is to propose a new catheter driving system which assists the operator in aspects of less X-ray exposure and convenient user interface. For this, an assembly-type 4-degree-of-freedom master-slave system was designed and tested to verify the efficiency. First, current vascular intervention procedures are analyzed to develop a new robotic procedure that enables us to use conventional vascular intervention devices such as catheter and guidewire which are commercially available in the market. Some parts of the slave robot which contact the devices were designed to be easily assembled and dissembled from the main body of the slave robot for sterilization. A master robot is compactly designed to conduct insertion and rotational motion and is able to switch from the guidewire driving mode to the catheter driving mode or vice versa. A phantom resembling the human arteries was developed, and the master-slave robotic system is tested using the phantom. The contact force of the guidewire tip according to the shape of the arteries is measured and reflected to the user through the master robot during the phantom experiment. This system can drastically reduce radiation exposure by replacing human effort by a robotic system for high radiation exposure procedures. Also, benefits of the proposed robot system are low cost by employing currently available devices and easy human interface.

Development of a Robotic Colonoscopic Manipulation System, Using Haptic Feedback Algorithm.

PURPOSE: Colonoscopy is one of the most effective diagnostic and therapeutic tools for colorectal diseases. We aim to propose a master-slave robotic colonoscopy that is controllable in remote site using conventional colonoscopy. MATERIALS AND METHODS: The master and slave robot were developed to use conventional flexible colonoscopy. The robotic colonoscopic procedure was performed using a colonoscope training model by one expert endoscopist and two unexperienced engineers. To provide the haptic sensation, the insertion force and the rotating torque were measured and sent to the master robot. RESULTS: A slave robot was developed to hold the colonoscopy and its knob, and perform insertion, rotation, and two tilting motions of colonoscope. A master robot was designed to teach motions of the slave robot. These measured force and torque were scaled down by one tenth to provide the operator with some reflection force and torque at the haptic device. The haptic sensation and feedback system was successful and helpful to feel the constrained force or torque in colon. The insertion time using robotic system decreased with repeated procedures. CONCLUSION: This work proposed a robotic approach for colonoscopy using haptic feedback algorithm, and this robotic device would effectively perform colonoscopy with reduced burden and comparable safety for patients in remote site.

Semi-manual mastoidectomy assisted by human-robot collaborative control - A temporal bone replica study.

OBJECTIVE: To develop an otological robot that can protect important organs from being injured. METHODS: We developed a five degree-of-freedom robot for otological surgery. Unlike the other robots that were reported previously, our robot does not replace surgeon's procedures, but instead utilizes human-robot collaborative control. The robot basically releases all of the actuators so that the surgeon can manipulate the drill within the robot's working area with minimal restriction. When the drill reaches a forbidden area, the surgeon feels as if the drill hits a wall. RESULTS: When an engineer performed mastoidectomy using the robot for assistance, the facial nerve in the segmented region was always protected with a more than 2.5mm margin, which was almost the same as the pre-set safety margin of 3mm. CONCLUSION: Semi-manual drilling using human-robot collaborative control was feasible, and may hold a realistic prospect of clinical use in the near future.

Chitosan-Polypyrrole Fiber for Strain Sensor.

A chitosan/polypyrrole composited fiber as bio-compatible materials for artificial muscles is investigated. The chitosan/polypyrrole fiber (CPF) is fabricated by in-situ chemical polymerization of pyrrole monomer solution using FeCl3 as an oxidant. The electrical resistivity of the fiber is changed according to the strain variation applied to the both ends of the specimen. The sensor built by using the CPF has a higher gauge factor (4) compared to conventional metal strain gauges (~2) indicating a suitable material for delicate force control in sensing work.

Suspension laryngoscopy using a curved-frame trans-oral robotic system.

PURPOSE: Suspension laryngoscopy has been employed for laryngeal diseases such as treatment for a polyp, cystoma, or granuloma. After securing a straight path with a laryngoscope, the surgeon inserts rigid instruments and examines the target lesion by using a microscope. However, many patients suffer from secondary complications due to the use of a rigid laryngoscope. In addition, about 11-12 % of patients cannot be operated on using laryngoscope because of anatomical restrictions. A surgical method to treat patients using a curved-frame trans-oral robotics system was developed. METHODS: A new surgical procedure is investigated using a new surgical robot system that employs a curved frame as a guide to insert flexible instruments into the target lesion. For this, a master-slave robotic system was developed, and the performance of the proposed procedure was tested by using a phantom laryngeal model. RESULTS: A routine laryngeal polypectomy procedure was simulated and performed using flexible instruments guided by a master-slave surgical robot in suspension laryngoscopy. CONCLUSION: A surgical robotic system was able to perform routine procedures to remove a polyp in the vocal cord under clinically realistic conditions on an adult phantom.

An assistive image-guided surgical robot system using O-arm fluoroscopy for pedicle screw insertion: preliminary and cadaveric study.

BACKGROUND: The biplane fluoroscopy guided robot system (BFRS) was developed for surgical robotic systems, minimally invasive surgeries, and cooperative robotic systems, as well as enhanced surgical planning and navigation with preoperative and intraoperative image data. OBJECTIVE: To propose a novel surgical robot system for percutaneous pedicle screw insertion. METHODS: The BFRS consists of an O-shaped biplane fluoroscope (O-arm), a surgical planning and operating system, and an assistive robot. Each part of the BFRS has a role in conducting percutaneous pedicle screw placements. To evaluate BFRS accuracy, each part was analyzed, and to assess the safety and feasibility of percutaneous pedicle screw insertions with the BFRS, cadaveric studies involving 14 levels in the thoracic and lumbar spine regions were conducted on 2 cadavers. RESULTS: Errors in each part of the system and within the entire system were evaluated. The accuracy of generating coordinates using O-arm images was 0.30±0.15 mm. The robot demonstrated a duplication value of 4.97 µm RMS and an accuracy of 0.358 mm RMS. Total system error was 1.38±0.21 mm. The results of the cadaveric studies show that inserted pedicular screws were adequately located within the spine with no unexpected malpositioning of the screws. The axial angle difference between planned and postoperative data was 2.45±2.56°, and the sagittal angle difference was 0.71±1.21°. CONCLUSION: The BFRS might be helpful in improving the accuracy of percutaneous pedicular screw insertion procedures. In the future, we will attempt to improve the accuracy and reliability of the BFRS and to determine new clinical applications for the BFRS.

Hysteresis in a carbon nanotube based electroactive polymer microfiber actuator: numerical modeling.

Hysteretic behavior is an important consideration for smart electroactive polymer actuators in a wide variety of nano/micro-scale applications. We prepared an electroactive polymer actuator in the form of a microfiber, based on single-wall carbon nanotubes and polyaniline, and investigated the hysteretic characteristics of the actuator under electrical potential switching in a basic electrolyte solution. For actuation experiments, we measured the variation of the length of the carbon-nanotube-based electroactive polymer actuator, using an Aurora Scientific Inc. 300B Series muscle lever arm system, while electrical potentials ranging from 0.2 V to 0.65 V were applied. Based on the classical Preisach hysteresis model, we presented and validated a numerical model that described the hysteretic behavior of the carbon-nanotube-based electroactive polymer actuator. Inverse hysteretic behavior was also simulated using the model to demonstrate its capability to predict an input from a desired output. This numerical model of hysteresis could be an effective approach to micro-scale control of carbon-nanotube-based electroactive polymer actuators in potential applications.