A haptic guidance system for simulated catheter navigation with different kinaesthetic feedback profiles.

BACKGROUND: This paper proposes a haptic guidance system to improve catheter navigation within a simulated environment. METHODS: Three force profiles were constructed to evaluate the system: collision prevention; centreline navigation; and a novel force profile of reinforcement learning (RL). All force profiles were evaluated from the left common iliac to the right atrium. RESULTS: Our findings show that providing haptic feedback improved surgical safety compared to visual-only feedback. If staying inside the vasculature is the priority, RL provides the safest option. It is also shown that the performance of each force profile varies in different anatomical regions. CONCLUSION: The implications of these findings are significant, as they hold the potential to improve how and when haptic feedback is applied for cardiovascular intervention.

Visual servoing of continuum robots: Methods, challenges, and prospects.

BACKGROUND: Recent advancements in continuum robotics have accentuated developing efficient and stable controllers to handle shape deformation and compliance. The control of continuum robots (CRs) using physical sensors attached to the robot, particularly in confined spaces, is difficult due to their limited accuracy in three-dimensional deflections and challenging localisation. Therefore, using non-contact imaging sensors finds noticeable importance, particularly in medical scenarios. Accordingly, given the need for direct control of the robot tip and notable uncertainties in the kinematics and dynamics of CRs, many papers have focussed on the visual servoing (VS) of CRs in recent years. METHODS: The significance of this research towards safe human-robot interaction has fuelled our survey on the previous methods, current challenges, and future opportunities. RESULTS: Beginning with actuation modalities and modelling approaches, the paper investigates VS methods in medical and non-medical scenarios. CONCLUSIONS: Finally, challenges and prospects of VS for CRs are discussed, followed by concluding remarks.

Roboethics principles and policies in Europe and North America.

Robotics and artificial intelligence (AI) are revolutionizing all spheres of human life. From industrial processes to graphic design, the implementation of automated intelligent systems is changing how industries work. The spread of robots and AI systems has triggered academic institutions to closely examine how these technologies may affect the humanity-this is how the fields of roboethics and AI ethics have been born. The identification of ethical issues for robotics and AI and creation of ethical frameworks were the first steps to creating a regulatory environment for these technologies. In this paper, we focus on regulatory efforts in Europe and North America to create enforceable regulation for AI and robotics. We describe and compare ethical principles, policies, and regulations that have been proposed by government organizations for the design and use of robots and AI. We also discuss proposed international regulation for robotics and AI. This paper tries to highlight the need for a comprehensive, enforceable, and agile policy to ethically regulate technology today and in the future. Through reviewing existing policies, we conclude that the European Unition currently leads the way in defining roboethics and AI ethical principles and implementing them into policy. Our findings suggest that governments in Europe and North America are aware of the ethical risks that robotics and AI pose, and are engaged in policymaking to create regulatory policies for these new technologies.

RoboEthics in COVID-19: A Case Study in Dentistry.

The COVID-19 pandemic has caused dramatic effects on the healthcare system, businesses, and education. In many countries, businesses were shut down, universities and schools had to cancel in-person classes, and many workers had to work remotely and socially distance in order to prevent the spread of the virus. These measures opened the door for technologies such as robotics and artificial intelligence to play an important role in minimizing the negative effects of such closures. There have been many efforts in the design and development of robotic systems for applications such as disinfection and eldercare. Healthcare education has seen a lot of potential in simulation robots, which offer valuable opportunities for remote learning during the pandemic. However, there are ethical considerations that need to be deliberated in the design and development of such systems. In this paper, we discuss the principles of roboethics and how these can be applied in the new era of COVID-19. We focus on identifying the most relevant ethical principles and apply them to a case study in dentistry education. DenTeach was developed as a portable device that uses sensors and computer simulation to make dental education more efficient. DenTeach makes remote instruction possible by allowing students to learn and practice dental procedures from home. We evaluate DenTeach on the principles of data, common good, and safety, and highlight the importance of roboethics in Canada. The principles identified in this paper can inform researchers and educational institutions considering implementing robots in their curriculum.

Dynamic Reconfiguration of Redundant Haptic Interfaces for Rendering Soft and Hard Contacts.

There are conflicting objectives between required characteristics of haptic interfaces such as maximum force feedback capability versus back-drive friction, which can be optimally traded-off in a redundant haptic interface; a redundant haptic interface has more degrees of freedom than minimally required ones for a given task. In this article, a contact-aware null-space control approach for redundant haptic interfaces is proposed to address these trade-offs. First, we introduce a task-dependent null-space controller in which the internal motion of the redundant haptic interface is appropriately controlled to achieve a desired performance; i.e., low back-drive friction in case of free-space motion and soft contact or large force feedback capability in case of stiff contact. Next, a transition method is developed to facilitate the adaptation of the null-space controller's varying objectives according to the varying nature of the task. The transition method prevents discontinuities in the null-space control signal. This transition method is informed by a proposed actuator saturation observer that monitors the distance of joint torques from their saturation levels. The overall outcome is an ability to recreate the feelings of soft contacts and hard contacts with higher fidelity compared to what a conventional non-redundant haptic interface can achieve. Simulations are provided throughout the paper to illustrate the concepts. Moreover, experimental results are reported to verify the effectiveness of the proposed control strategies. It is shown that the proposed controller can perform well in the soft-contact, hard-contact, and transition phases.

Evaluation of haptic devices and end-users: Novel performance metrics in tele-robotic microsurgery.

BACKGROUND: Here, we present performance evaluation methodology that distinguishes the performance of a haptic device from end-user skill level in a tele-robotic system. METHODS: A pick-&-place experiment was designed and eight participants micromanipulated cotton strips, similar to maneuvers performed during microsurgery. Using three nonredundant haptic devices: neuroArmPLUS HD , a custom developed master manipulator, and two commercially available products, sigma.7 and HD2 , several features including the speed, effort, consistency, hand/gimbal agility, and force characteristics were measured and recorded for each participant and device. RESULTS: The participants showed variable skill level. For consistency, hand/gimbal agility and force characteristics, they performed significantly better when using neuroArmPLUS HD prototype. Based on the experimental data, performance metrics for both the device and the end-users were established. CONCLUSIONS: The integrated performance metrics allows independent evaluation of both the user and haptic device, thereby quantifying human-machine interactions.

Challenges in developing a magnetic resonance-compatible haptic hand-controller for neurosurgical training.

A haptic device is an actuated human-machine interface utilized by an operator to dynamically interact with a remote environment. This interaction could be virtual (virtual reality) or physical such as using a robotic arm. To date, different mechanisms have been considered to actuate the haptic device to reflect force feedback from the remote environment. In a low-force environment or limited working envelope, the control of some actuation mechanisms such as hydraulic and pneumatic may be problematic. In the development of a haptic device, challenges include limited space, high accuracy or resolution, limitations in kinematic and dynamic solutions, points of singularity, dexterity as well as control system development/design. Furthermore, the haptic interface designed to operate in a magnetic resonance imaging environment adds additional challenges related to electromagnetic interference, static/variable magnetic fields, and the use of magnetic resonance-compatible materials. Such a device would allow functional magnetic resonance imaging to obtain information on the subject's brain activity while performing a task. When used for surgical trainees, functional magnetic resonance imaging could provide an assessment of surgical skills. In this application, the trainee, located supine within the magnet bore while observing the task environment on a graphical user interface, uses a low-force magnetic resonance-compatible haptic device to perform virtual surgical tasks in a limited space. In the quest to develop such a device, this review reports the multiple challenges faced and their potential solutions. The review also investigates efforts toward prototyping such devices and classifies the main components of a magnetic resonance-compatible device including actuation and sensory systems and materials used.

Nonparametric bootstrap technique for calibrating surgical SmartForceps: theory and application.

Knowledge of forces, exerted on the brain tissue during the performance of neurosurgical tasks, is critical for quality assurance, case rehearsal, and training purposes. Quantifying the interaction forces has been made possible by developing SmartForceps, a bipolar forceps retrofitted by a set of strain gauges. The forces are estimated using voltages read from strain gauges. We therefore need to quantify the force-voltage relationship to estimate the interaction forces during microsurgery. This problem has been addressed in the literature by following the physical and deterministic properties of the force-sensing strain gauges without obtaining the precision associated with each estimate. In this paper, we employ a probabilistic methodology by using a nonparametric Bootstrap approach to obtain both point and interval estimates of the applied forces at the tool tips, while the precision associated with each estimate is provided. To show proof-of-concept, the Bootstrap technique is employed to estimate unknown forces, and construct necessary confidence intervals using observed voltages in data sets that are measured from the performance of surgical tasks on a cadaveric brain. Results indicate that the Bootstrap technique is capable of estimating tool-tissue interaction forces with acceptable level of accuracy compared to the linear regression technique under the normality assumption.

Tool-Tissue Interaction Forces in Brain Arteriovenous Malformation Surgery.

OBJECTIVE: Surgical resection of a brain arteriovenous malformation (AVM) poses a technical challenge because of the fragility and number of small feeding and draining vessels around the nidus. Acquiring knowledge of the optimal force applied to such tissue is important in surgical performance and education. METHODS: A force-sensing bipolar forceps was developed through installation of strain gauge sensors, and force profiles were obtained from 2 AVM surgeries. The force data associated with vessel injury, unsuccessful trial, was compared with that from successful trials. Receiver operating curve analysis was used for determining optimal force threshold and evaluating the discriminative accuracy of measurement. RESULTS: Force data from 519 trials was collected, of which 16 (3.1%) were unsuccessful. The mean and maximum forces in successful trials were 0.23 ± 0.06 N and 0.35 ± 0.11 N compared with unsuccessful trials of 0.33 ± 0.05 N and 0.53 ± 0.11 N, respectively (P < 0.001). There was a strong association of mean and maximum force peaks with unsuccessful trials as reflected by the area under the curve of 0.91 and 0.87, respectively. Threshold analysis showed that the rate of unsuccessful trials and error forces tended to increase with surgical time. CONCLUSIONS: Excessive force at the tool tip may result in injury to fragile vessels during AVM surgery. A quantifiable metric through force sensing instruments can detect and predict the occurrence of such injury. Such an instrument may be ideal for resident training and evaluation.

Effects of Transcranial Direct-Current Stimulation on Neurosurgical Skill Acquisition: A Randomized Controlled Trial.

BACKGROUND: Recent changes in surgical training environments may have limited opportunities for trainees to gain proficiency in skill. Complex skills such as neurosurgery require extended periods of training. Methods to enhance surgical training are required to overcome duty-hour restrictions, to ensure the acquisition of skill proficiency. Transcranial direct-current stimulation (tDCS) can enhance motor skill learning, but is untested in surgical procedural training. We aimed to determine the effects of tDCS on simulation-based neurosurgical skill acquisition. METHODS: Medical students were trained to acquire tumor resection skills using a virtual reality neurosurgical simulator. The primary outcome of change in tumor resection was scored at baseline, over 8 repetitions, post-training, and again at 6 weeks. Participants received anodal tDCS or sham over the primary motor cortex. Secondary outcomes included changes in brain resected, resection effectiveness, duration of excessive forces (EF) applied, and resection efficiency. Additional outcomes included tDCS tolerability. RESULTS: Twenty-two students consented to participate, with no dropouts over the course of the trial. Participants receiving tDCS intervention increased the amount of tumor resected, increased the effectiveness of resection, reduced the duration of EF applied, and improved resection efficiency. Little or no decay was observed at 6 weeks in both groups. No adverse events were documented, and sensation severity did not differ between stimulation groups. CONCLUSIONS: The addition of tDCS to neurosurgical training may enhance skill acquisition in a simulation-based environment. Trials of additional skills in high-skill residents, and translation to nonsimulated performance are needed to determine the potential utility of tDCS in surgical training.

Surgical Skill Assessment Using Motion Quality and Smoothness.

OBJECTIVES: This article presents a quantitative technique to assess motion quality and smoothness during the performance of micromanipulation tasks common to surgical maneuvers. The objective is to investigate the effectiveness of the jerk index, a derivative of acceleration with respect to time, as a kinetostatic measure for assessment of surgical performance. DESIGN: A surgical forceps was instrumented with a position tracker and accelerometer that allowed measurement of position and acceleration relative to tool motion. Participants were asked to perform peg-in-hole tasks on a modified O'Connor Dexterity board and a Tweezer Dexterity pegboard (placed inside a skull). Normalized jerk index was calculated for each individual task to compare smoothness of each group. SETTING: This study was conducted at Project neuroArm, Cumming School of Medicine, the University of Calgary. PARTICIPANTS: Four groups of participants (surgeons, surgery residents, engineers, and gamers) participated in the tests. RESULTS: Results showed that the surgeons exhibited better jerk index performance in all tasks. Moreover, the residents experienced motions closer to the surgeons compared to the engineers and gamers. One-way analysis of variance test indicated a significant difference between the mean values of normalized jerk indices among 4 groups during the performance of all tasks. Moreover, the mean value of the normalized jerk index significantly varied for each group from one task to another. CONCLUSIONS: Normalized jerk index as an independent parameter with respect to time and amplitude is an indicator of motion smoothness and can be used to assess hand motion dexterity of surgeons. Furthermore, the method provides a quantifiable metrics for trainee assessment and proficiency, particularly relevant as surgical training shifts toward a competency-based paradigm.

Improved transoral surgical tool design by CT measurements of the oral cavity and pharynx.

The majority of head and neck cancers arise from the oral cavity and oropharynx. Many of these lesions will be amenable to surgical resection using transoral approaches including transoral robotic surgery (TORS). To develop and control TORS tools, precise dimensions of the oral cavity and pharynx are desirable. CT angiograms of 76 patients were analyzed. For the oral cavity, only the maximum length and width were measured, while for the pharynx, the width, length, and areas of the airway were all measured and the volume calculated. A prototype TORS tool was developed and tested based on the findings and dimensions. The design modification of the tool is in progress. The mean male oral cavity width and length were 93.3 ± 4.3 and 77.0 ± 7.2 mm, respectively, and the mean male pharyngeal width, length, area, and volume were 26.5 ± 7.2 mm, 16.2 ± 8.8 mm, 325 ± 149 mm2, and 28,440 ± 14,100 mm3, respectively, while the mean female oral cavity width and length were 84.5 ± 12.9 and 71.0 ± 6.3 mm, respectively, and the mean female pharyngeal width, length, area, and volume were 24.8 ± 5.6 mm, 13.7 ± 3.2 mm, 258 ± 98 mm2, and 17,660 ± 7700 mm3, respectively. The developed TORS tool was tested inside the oral cavity of an intubation mannequin. These data will also be used to develop an electronic no-go cone-shape tunnel to improve the safety of the surgical field. Reporting the oral cavity and pharyngeal dimensions is important for design of TORS tools and creating control zones for the workspace of the tool inside the oral cavity.

Vibrational Profiling of Brain Tumors and Cells.

This study reports vibration profiles of neuronal cells and tissues as well as brain tumor and neocortical specimens. A contact-free method and analysis protocol was designed to convert an atomic force microscope into an ultra-sensitive microphone with capacity to record and listen to live biological samples. A frequency of 3.4 Hz was observed for both cultured rat hippocampal neurons and tissues and vibration could be modulated pharmacologically. Malignant astrocytoma tissue samples obtained from operating room, transported in artificial cerebrospinal fluid, and tested within an hour, vibrated with a much different frequency profile and amplitude, compared to meningioma or lateral temporal cortex providing a quantifiable measurement to accurately distinguish the three tissues in real-time. Vibration signals were converted to audible sound waves by frequency modulation, thus demonstrating, acoustic patterns unique to meningioma, malignant astrocytoma and neocortex.

Quantifying force and positional frequency bands in neurosurgical tasks.

To establish the design requirements for an MR-compatible haptic hand-controller, this paper measures magnitudes and frequency bands of three mechanical motion and interaction components during the performance of neurosurgical tasks on a cadaveric brain. The hand-controller would allow the performance of virtual neurosurgical tasks within the bore of a high field magnet during image acquisition, i.e., functional MRI. The components are the position and the orientation of a surgical tool, and the force interaction between the tool and the brain tissue. A bipolar forceps was retrofitted with a tracking system and a set of force sensing components to measure displacements and forces, respectively. Results showed working positional, rotational, and force frequency bands of 3, 3 and 5 Hz, respectively. Peak forces of 1.4, 2.9 and 3.0 N were measured in the Cartesian coordinate system. A workspace of 50.1 × 39.8 × 58.2 mm(3) and orientation ranges of 40.4°, 60.1° and 63.1° for azimuth, elevation, and roll angles were observed. The results contribute in providing information specific to neurosurgery that can be used to effectively design a compact and customized haptic hand-controller reflecting characteristics of neurosurgical tasks.

Treatment of Glioma Using neuroArm Surgical System.

The use of robotic technology in the surgical treatment of brain tumour promises increased precision and accuracy in the performance of surgery. Robotic manipulators may allow superior access to narrow surgical corridors compared to freehand or conventional neurosurgery. This paper reports values and ranges of tool-tissue interaction forces during the performance of glioma surgery using an MR compatible, image-guided neurosurgical robot called neuroArm. The system, capable of microsurgery and stereotaxy, was used in the surgical resection of glioma in seven cases. neuroArm is equipped with force sensors at the end-effector allowing quantification of tool-tissue interaction forces and transmits force of dissection to the surgeon sited at a remote workstation that includes a haptic interface. Interaction forces between the tool tips and the brain tissue were measured for each procedure, and the peak forces were quantified. Results showed maximum and minimum peak force values of 2.89 N (anaplastic astrocytoma, WHO grade III) and 0.50 N (anaplastic oligodendroglioma, WHO grade III), respectively, with the mean of peak forces varying from case to case, depending on type of the glioma. Mean values of the peak forces varied in range of 1.27 N (anaplastic astrocytoma, WHO grade III) to 1.89 N (glioblastoma with oligodendroglial component, WHO grade IV). In some cases, ANOVA test failed to reject the null hypothesis of equality in means of the peak forces measured. However, we could not find a relationship between forces exerted to the pathological tissue and its size, type, or location.

Quantifying workspace and forces of surgical dissection during robot-assisted neurosurgery.

BACKGROUND: A prerequisite for successful robot-assisted neurosurgery is to use a hand-controller matched with characteristics of real robotic microsurgery. This study reports quantified data pertaining to the required workspace and exerted forces of surgical tools during robot-assisted microsurgery. METHODS: A surgeon conducted four operations in which the neuroArm surgical system, an image-guided computer-assisted manipulator specifically designed to perform robot-assisted neurosurgery, was employed to surgically remove brain tumors. The position, orientation, and exerted force of surgical tools were measured during operations. RESULTS: Workspace of the neuroArm manipulators, for the cases studied, was 60×60×60 mm(3) while it offered orientation ranges of 103°, 62° and 112°. The surgical tools exerted a maximum force of 1.86 N with frequency band of less than 20 Hz. CONCLUSIONS: This data provides important information specific to neurosurgery that can be used to select among commercially available, or further design a customized, haptic hand-controller for robot-assisted neurosurgical systems. Copyright © 2015 John Wiley & Sons, Ltd.

Evaluation of haptic interfaces for simulation of drill vibration in virtual temporal bone surgery.

Surgical training is evolving from an observership model towards a new paradigm that includes virtual-reality (VR) simulation. In otolaryngology, temporal bone dissection has become intimately linked with VR simulation as the complexity of anatomy demands a high level of surgeon aptitude and confidence. While an adequate 3D visualization of the surgical site is available in current simulators, the force feedback rendered during haptic interaction does not convey vibrations. This lack of vibration rendering limits the simulation fidelity of a surgical drill such as that used in temporal bone dissection. In order to develop an immersive simulation platform capable of haptic force and vibration feedback, the efficacy of hand controllers for rendering vibration in different drilling circumstances needs to be investigated. In this study, the vibration rendering ability of four different haptic hand controllers were analyzed and compared to find the best commercial haptic hand controller. A test-rig was developed to record vibrations encountered during temporal bone dissection and a software was written to render the recorded signals without adding hardware to the system. An accelerometer mounted on the end-effector of each device recorded the rendered vibration signals. The newly recorded vibration signal was compared with the input signal in both time and frequency domains by coherence and cross correlation analyses to quantitatively measure the fidelity of these devices in terms of rendering vibrotactile drilling feedback in different drilling conditions. This method can be used to assess the vibration rendering ability in VR simulation systems and selection of ideal haptic devices.

Performance evaluation of haptic hand-controllers in a robot-assisted surgical system.

BACKGROUND: This paper presents the experimental evaluation of three commercially available haptic hand-controllers to evaluate which was more suitable to the participants. METHODS: Two surgeons and seven engineers performed two peg-in-hole tasks with different levels of difficulty. Each operator guided the end-effector of a Kuka manipulator that held surgical forceps and was equipped with a surgical microscope. Sigma 7, HD(2) and PHANToM Premium 3.0 hand-controllers were compared. Ten measures were adopted to evaluate operators' performances with respect to effort, speed and accuracy in completing a task, operator improvement during the tests, and the force applied by each haptic device. RESULTS: The best performance was observed with the Premium 3.0; the hand-piece was able to be held in a similar way to that used by surgeons to hold conventional tools. CONCLUSIONS: Hand-controllers with a linkage structure similar to the human upper extremity take advantage of the inherent human brain connectome, resulting in improved surgeon performance during robotic-assisted surgery.

Robotics in the neurosurgical treatment of glioma.

BACKGROUND: The treatment of glioma remains a significant challenge with high recurrence rates, morbidity, and mortality. Merging image guided robotic technology with microsurgery adds a new dimension as they relate to surgical ergonomics, patient safety, precision, and accuracy. METHODS: An image-guided robot, called neuroArm, has been integrated into the neurosurgical operating room, and used to augment the surgical treatment of glioma in 18 patients. A case study illustrates the specialized technical features of a teleoperated robotic system that could well enhance the performance of surgery. Furthermore, unique positional and force information of the bipolar forceps during surgery were recorded and analyzed. RESULTS: The workspace of the bipolar forceps in this robot-assisted glioma resection was found to be 25 × 50 × 50 mm. Maximum values of the force components were 1.37, 1.84, and 2.01 N along x, y, and z axes, respectively. The maximum total force was 2.45 N. The results indicate that the majority of the applied forces were less than 0.6 N. CONCLUSION: Robotic surgical systems can potentially increase safety and performance of surgical operation via novel features such as virtual fixtures, augmented force feedback, and haptic high-force warning system. The case study using neuroArm robot to resect a glioma, for the first time, showed the positional information of surgeon's hand movement and tool-tissue interaction forces.

Quantification of Forces During a Neurosurgical Procedure: A Pilot Study.

OBJECTIVE: Knowledge of tool-tissue interaction is mostly taught and learned in a qualitative manner because a means to quantify the technical aspects of neurosurgery is currently lacking. Neurosurgeons typically require years of hands-on experience, together with multiple initial trial and error, to master the optimal force needed during the performance of neurosurgical tasks. The aim of this pilot study was to develop a novel force-sensing bipolar forceps for neurosurgery and obtain preliminary data on specific tasks performed on cadaveric brains. METHODS: A novel force-sensing bipolar forceps capable of measuring coagulation and dissection forces was designed and developed by installing strain gauges along the length of the bipolar forceps prongs. The forceps was used in 3 cadaveric brain experiments and forces applied by an experienced neurosurgeon for 10 surgical tasks across the 3 experiments were quantified. RESULTS: Maximal peak (effective) forces of 1.35 N and 1.16 N were observed for dissection (opening) and coagulation (closing) tasks, respectively. More than 70% of forces applied during the neurosurgical tasks were less than 0.3 N. Mean peak forces ranged between 0.10 N and 0.41 N for coagulation of scalp vessels and pia-arachnoid, respectively, and varied from 0.16 N for dissection of small cortical vessel to 0.65 N for dissection of the optic chiasm. CONCLUSIONS: The force-sensing bipolar forceps were able to successfully measure and record real-time tool-tissue interaction throughout the 3 experiments. This pilot study serves as a first step toward quantification of tool-tissue interaction forces in neurosurgery for training and improvement of instrument handling skills.