3D human pose data augmentation using Generative Adversarial Networks for robotic-assisted movement quality assessment

In the realm of human motion recognition systems, the augmentation of 3D human pose data plays a pivotal role in enriching and enhancing the quality of original datasets through the generation of synthetic data. This augmentation is vital for addressing the current research gaps in diversity and complexity, particularly when dealing with rare or complex human movements. Our study introduces a groundbreaking approach employing Generative Adversarial Networks (GANs), coupled with Support Vector Machine (SVM) and DenseNet, further enhanced by robot-assisted technology to improve the precision and efficiency of data collection. The GANs in our model are responsible for generating highly realistic and diverse 3D human motion data, while SVM aids in the effective classification of this data. DenseNet is utilized for the extraction of key features, facilitating a comprehensive and integrated approach that significantly elevates both the data augmentation process and the model's ability to process and analyze complex human movements. The experimental outcomes underscore our model's exceptional performance in motion quality assessment, showcasing a substantial improvement over traditional methods in terms of classification accuracy and data processing efficiency. These results validate the effectiveness of our integrated network model, setting a solid foundation for future advancements in the field. Our research not only introduces innovative methodologies for 3D human pose data enhancement but also provides substantial technical support for practical applications across various domains, including sports science, rehabilitation medicine, and virtual reality. By combining advanced algorithmic strategies with robotic technologies, our work addresses key challenges in data augmentation and motion quality assessment, paving the way for new research and development opportunities in these critical areas.

Robotic-Assisted Versus Fluoroscopic-Guided Surgery on the Accuracy of Spine Pedicle Screw Placement: A Systematic Review and Meta-Analysis

Spinal fusion is a common method by which surgeons decrease instability and deformity of the spinal segment targeted. Pedicle screws are vital tools in fusion surgeries and advancements in technology have introduced several modalities of screw placement. Our objective was to evaluate the accuracy of pedicle screw placement in robot-assisted (RA) versus fluoroscopic-guided (FG) techniques. The PubMed and Cochrane Library databases were systematically reviewed from January 2007 through to August 8, 2022, to identify relevant studies. The accuracy of pedicle screw placement was determined using the Gertzbein-Robbins (GR) classification system. Facet joint violation (FJV), total case radiation dosage, total case radiation time, total operating room (OR) time, and total case blood loss were collected. Twenty-one articles fulfilled the inclusion criteria. Successful screw accuracy (GR Grade A or B) was found to be 1.02 (95% confidence interval: 1.01 - 1.04) times more likely with the RA technique. In defining accuracy solely based on the GR Grade A criteria, screws placed with RA were 1.10 (95% confidence interval: 1.06 - 1.15) times more likely to be accurate. There was no significant difference between the two techniques with respect to blood loss (Hedges' g: 1.16, 95% confidence interval: -0.75 to 3.06) or case radiation time (Hedges' g: -0.34, 95% CI: -1.22 to 0.53). FG techniques were associated with shorter operating room times (Hedges' g: -1.03, 95% confidence interval: -1.76 to -0.31), and higher case radiation dosage (Hedges' g: 1.61, 95% confidence interval: 1.11 to 2.10). This review suggests that RA may slightly increase pedicle screw accuracy and decrease per-case radiation dosage compared to FG techniques. However, total operating times for RA cases are greater than those for FG cases.

Robotic-assisted versus conventional laparoscopic approach in patients with large rectal endometriotic nodule: the evaluation of safety and complications

AIM

The aim was to compare postoperative complications in patients undergoing the excision of a rectal endometriotic nodule over 3 cm by a robotic-assisted versus a conventional laparoscopic approach.

METHODS

We conducted a retrospective cohort study evaluating prospectively collected data. The main interventions included rectal shaving, disc excision or colorectal resection. All the surgeries were performed in one endometriosis reference institute. To evaluate factors significantly associated with the risk of anastomosis leakage or fistula and bladder atony, we conducted a multivariate logistic regression model.

RESULTS

A total of 548 patients with rectal endometriotic nodule over 3 cm in diameter (#ENZIAN C3) were included in the final analysis. The demography and clinical characteristics of women managed by the robotic-assisted (n = 97) approach were similar to those of patients who underwent conventional laparoscopy (n = 451). The multivariate logistic regression demonstrated that the surgical approach (robotic-assisted vs. laparoscopic) was not associated with the rate of anastomosis leakage or fistula (adjusted odds ratio [aOR] 1.2, 95% confidence interval [CI] 0.3-4.0) and bladder dysfunction (aOR 0.5, 95% CI 0.1-1.8). A rectal nodule located lower than 6 cm from the anal verge was significantly associated with anastomosis leakage (aOR 4.1, 95% CI 1.4-10.8) and bladder atony (aOR 4.3, 95% CI 1.5-12.3). Anastomosis leakage was also associated with smoking (aOR 3.2, 95% CI 1.4-7.4), significant vaginal infiltration (aOR 2.7, 95% CI 1.2-6.7) and excision of nodules involving sacral roots (aOR 5.6, 95% CI 1.7-15.5).

CONCLUSION

The robotic-assisted approach was not associated with increased risk of main postoperative complications compared to conventional laparoscopy for the treatment of large rectal endometriotic nodules.

Effect of Robotic-Assisted Gait at Different Levels of Guidance and Body Weight Support on Lower Limb Joint Kinematics and Coordination

The Lokomat provides task-oriented therapy for patients with gait disorders. This robotic technology drives the lower limbs in the sagittal plane. However, normative gait also involves motions in the coronal and transverse planes. This study aimed to compare the Lokomat with Treadmill gait through three-dimensional (3D)-joint kinematics and inter-joint coordination. Lower limb kinematics was recorded in 18 healthy participants who walked at 3 km/h on a Treadmill or in a Lokomat with nine combinations of Guidance (30%, 50%, 70%) and bodyweight support (30%, 50%, 70%). Compared to the Treadmill, the Lokomat altered pelvic rotation, decreased pelvis obliquity and hip adduction, and increased ankle rotation. Moreover, the Lokomat resulted in significantly slower velocity at the hip, knee, and ankle flexion compared to the treadmill condition. Moderate to strong correlations were observed between the Treadmill and Lokomat conditions in terms of inter-joint coordination between hip-knee (r = 0.67-0.91), hip-ankle (r = 0.66-0.85), and knee-ankle (r = 0.90-0.95). This study showed that some gait determinants, such as pelvis obliquity, rotation, and hip adduction, are altered when walking with Lokomat in comparison to a Treadmill. Kinematic deviations induced by the Lokomat were most prominent at high levels of bodyweight support. Interestingly, different levels of Guidance did not affect gait kinematics. The present results can help therapists to adequately select settings during Lokomat therapy.

Comparison of Robot-Assisted and Manual Cannula Insertion in Simulated Big-Bubble Deep Anterior Lamellar Keratoplasty

This study aimed to compare the efficacy of robot-assisted and manual cannula insertion in simulated big-bubble deep anterior lamellar keratoplasty (DALK). Novice surgeons with no prior experience in performing DALK were trained to perform the procedure using manual or robot-assisted techniques. The results showed that both methods could generate an airtight tunnel in the porcine cornea, and result in successful generation of a deep stromal demarcation plane representing sufficient depth reached for big-bubble generation in most cases. However, the combination of intraoperative OCT and robotic assistance received a significant increase in the depth of achieved detachment in non-perforated cases, comprising a mean of 89% as opposed to 85% of the cornea in manual trials. This research suggests that robot-assisted DALK may offer certain advantages over manual techniques, particularly when used in conjunction with intraoperative OCT.

Movement therapy in lung transplantation candidates assisted by a lightweight wearable robot

The aim of this pilot-study was to investigate the safety, feasibility and tolerability of an assisted mobilization of patients with advanced pulmonary diseases, using a lightweight, exoskeleton-type robot (Myosuit, MyoSwiss AG, Zurich, Switzerland). Ten patients performed activities of daily life (ADL) both with and without the device. The mean age was 53.6 (±5.6) years; 70% were male. The assessment of outcome included the evaluation of vital signs, adverse events, rates of perceived exertion and dyspnea (PRE, PRD), the ability to perform ADL and the individual acceptability. Robotic-assisted mobilization was feasible in all patients. No adverse events occurred. RPE and RPD showed no significant difference with or without the Myosuit (mean difference in RPE -1.7, 95%-confidence interval (CI) -1.16, 4.49; p = 0.211; mean difference in RPD 0.00, 95%-CI -1.88, 1.88; p = 0.475). 80% of patients were interested to participate in a robotic-assisted training on a regular basis. A robotic exoskeleton-assisted mobilization is safe, feasible, well-tolerated and well-accepted. The results are highly encouraging to further pursue this highly innovative approach.

Planning of Medical Flexible Needle Motion in Effective Area of Clinical Puncture

Lung cancer is the leading cause of cancer deaths worldwide. Although several lung cancer diagnostic methods are available for lung nodule biopsy, there are limitations in terms of accuracy, safety, and invasiveness. Transbronchial needle aspiration (TBNA) is a common method for diagnosing and treating lung cancer that involves a robot-assisted medical flexible needle moving along a curved three-dimensional trajectory, avoiding anatomical barriers to achieve clinically meaningful goals in humans. Inspired by the puncture angle between the needle tip and the vessel in venipuncture, we suggest that different orientations of the medical flexible needle puncture path affect the cost of the puncture trajectory and propose an effective puncture region based on the optimal puncture direction, which is a strategy based on imposing geometric constraints on the search space of the puncture direction, and based on this, we focused on the improved implementation of RCS*. Planning within the TBNA-based lung environment was performed using the rapidly exploring random tree (RRT), resolution-complete search (RCS), and RCS* (a resolution-optimal version of RCS) within an effective puncture region. The experimental results show that the optimal puncture direction corresponding to the lowest cost puncture trajectory is consistent among the three algorithms and RCS* is more efficient for planning. The experiments verified the feasibility and practicality of our proposed minimum puncture angle and puncture effective region and facilitated the study of the puncture direction of flexible needle puncture.

Computer-Navigated and Robotic-Assisted Total Knee Arthroplasty: Increasing in Popularity Without Increasing Complications

BACKGROUND

Data on the clinical impact of computer navigation (CN) and robotic assistance (RA) in total knee arthroplasty (TKA) are mixed. This study aims to describe modern utilization trends in CN-TKA, RA-TKA, and traditionally-instrumented (TD) TKA and to assess for differences in postoperative complications and opioid consumption by procedure type.

METHODS

A national database was queried to identify primary, elective TKA patients from 2015 to 2020. Trends in procedural utilization rates were assessed. Differences in 90-day postoperative complications and inpatient opioid consumption were assessed. Multivariate regression analyses were performed to account for potential confounders.

RESULTS

Of the 847,496 patients included, 49,317 (5.82%) and 24,460 (2.89%) underwent CN-TKA and RA-TKA, respectively. CN-TKA utilization increased from 5.64% (2015) to 6.41% (2020) and RA-TKA utilization increased from 0.84% (2015) to 5.89% (2020). After adjusting for confounders, CN-TKA was associated with lower periprosthetic joint infection (P = .001), pulmonary embolism (P < .001), and acute respiratory failure (P = .015) risk compared to traditional (TD) TKA. RA-TKA was associated with lower deep vein thrombosis (P < .001), myocardial infarction (P = .013), and pulmonary embolism (P = .001) risk than TD-TKA. Lower postoperative day 1 opioid usage was seen with CN-TKA and RA-TKA than TD-TKA (P < .001). Lower postoperative day 0 opioid consumption was also seen in RA-TKA (P < .001).

CONCLUSION

From 2015 to 2020, there was a relative 13.7% and 601.2% increase in CN-TKAs and RA-TKAs, respectively. This trend was associated with reductions in hospitalization duration, postoperative complications, and opioid consumption. These data support the safety of RA-TKA and CN-TKA compared to TD-TKA. Further investigation into the specific indications for these technology-assisted TKAs is warranted.

A Review of Exoskeletons Considering Nurses

Daily tasks of nurses include manual handling to assist patients. Repetitive manual handling leads to high risk of injuries due to the loads on nurses' bodies. Nurses, in hospitals and care homes, can benefit from the advances in exoskeleton technology assisting their manual handling tasks. There are already exoskeletons both in the market and in the research area made to assist physical workers to handle heavy loads. However, those exoskeletons are mostly designed for men, as most physical workers are men, whereas most nurses are women. In the case of nurses, they handle patients, a more delicate task than handling objects, and any such device used by nurses should easily be disinfected. In this study, the needs of nurses are examined, and a review of the state-of-the-art exoskeletons is conducted from the perspective of to what extent the existing technologies address the needs of nurses. Possible solutions and technologies and particularly the needs that have not been addressed by the existing technologies are discussed.

Robotic Light Touch Assists Human Balance Control During Maximum Forward Reaching

OBJECTIVE

We investigated how light interpersonal touch (IPT) provided by a robotic system supports human individuals performing a challenging balance task compared to IPT provided by a human partner.

BACKGROUND

IPT augments the control of body balance in contact receivers without a provision of mechanical body weight support. The nature of the processes governing the social haptic interaction, whether they are predominantly reactive or predictive, is uncertain.

METHOD

Ten healthy adult individuals performed maximum forward reaching (MFR) without visual feedback while standing upright. We evaluated their control of reaching behavior and of body balance during IPT provided by either another human individual or by a robotic system in two alternative control modes (reactive vs. predictive).

RESULTS

Reaching amplitude was not altered by any condition but all IPT conditions showed reduced body sway in the MFR end-state. Changes in reaching behavior under robotic IPT conditions, such as lower speed and straighter direction, were linked to reduced body sway. An Index of Performance expressed a potential trade-off between speed and accuracy with lower bitrate in the IPT conditions.

CONCLUSION

The robotic IPT system was as supportive as human IPT. Robotic IPT seemed to afford more specific adjustments in the human contact receiver, such as trading reduced speed for increased accuracy, to meet the intrinsic demands and constraints of the robotic system or the demands of the social context when in contact with a human contact provider.

MAZOR-X robotic-navigated percutaneous C2 screw placement for hangman's fracture: a case report

Robotic-navigated screw placement has potential for higher precision and accuracy. Robotic assistance is well-described in the lumbar spine, however only few studies have evaluated its use in the cervical spine. Surgical treatment for hangman's fractures after nonunion typically involves C2-3 anterior fusion or posterior occipito-cervical fusion. However, occipito-cervical fusion involves loss of mobility in the cervical spine with associated morbidity. We have previously described a minimally invasive approach using percutaneous screw fixation with X-ray navigation. Robotic assistance is ideally suited for cervical fusion given smaller bony anatomy and adjacent critical structures. We describe a young healthy patient who presented with a hangman's fracture initially managed conservatively with immobilization. She presented with nonunion and persistent symptoms. Surgical options considered included anterior cervical discectomy and fusion, or posterior cervical fusion with or without extension to the occiput. These options would have involved some loss of flexion/extension and rotational motion with associated morbidity. We performed percutaneous screw fixation of the hangman's fracture using MAZOR-X robotic navigation and achieved good radiographic fracture reduction with accurate screw placement. To our knowledge this is the first case of a robotic-assisted percutaneous screw fixation for a hangman's fracture. Robotic-navigated screw placement can be used safely and accurately for cervical spine fractures.

Virtual Reality-Based Framework to Simulate Control Algorithms for Robotic Assistance and Rehabilitation Tasks through a Standing Wheelchair

The implementation of control algorithms oriented to robotic assistance and rehabilitation tasks for people with motor disabilities has been of increasing interest in recent years. However, practical implementation cannot be carried out unless one has the real robotic system availability. To overcome this drawback, this article presents the development of an interactive virtual reality (VR)-based framework that allows one to simulate the execution of rehabilitation tasks and robotic assistance through a robotic standing wheelchair. The virtual environment developed considers the kinematic and dynamic model of the standing human–wheelchair system with a displaced center of mass, since it can be displaced for different reasons, e.g.,: bad posture, limb amputations, obesity, etc. The standing wheelchair autonomous control scheme has been implemented through the Full Simulation (FS) and Hardware in the Loop (HIL) techniques. Finally, the performance of the virtual control schemes has been shown by means of several experiments based on robotic assistance and rehabilitation for people with motor disabilities.

Promoting Motor Variability During Robotic Assistance Enhances Motor Learning of Dynamic Tasks

Despite recent advances in robot-assisted training, the benefits of haptic guidance on motor (re)learning are still limited. While haptic guidance may increase task performance during training, it may also decrease participants' effort and interfere with the perception of the environment dynamics, hindering somatosensory information crucial for motor learning. Importantly, haptic guidance limits motor variability, a factor considered essential for learning. We propose that Model Predictive Controllers (MPC) might be good alternatives to haptic guidance since they minimize the assisting forces and promote motor variability during training. We conducted a study with 40 healthy participants to investigate the effectiveness of MPCs on learning a dynamic task. The task consisted of swinging a virtual pendulum to hit incoming targets with the pendulum ball. The environment was haptically rendered using a Delta robot. We designed two MPCs: the first MPC-end-effector MPC-applied the optimal assisting forces on the end-effector. A second MPC-ball MPC-applied its forces on the virtual pendulum ball to further reduce the assisting forces. The participants' performance during training and learning at short- and long-term retention tests were compared to a control group who trained without assistance, and a group that trained with conventional haptic guidance. We hypothesized that the end-effector MPC would promote motor variability and minimize the assisting forces during training, and thus, promote learning. Moreover, we hypothesized that the ball MPC would enhance the performance and motivation during training but limit the motor variability and sense of agency (i.e., the feeling of having control over their movements), and therefore, limit learning. We found that the MPCs reduce the assisting forces compared to haptic guidance. Training with the end-effector MPC increases the movement variability and does not hinder the pendulum swing variability during training, ultimately enhancing the learning of the task dynamics compared to the other groups. Finally, we observed that increases in the sense of agency seemed to be associated with learning when training with the end-effector MPC. In conclusion, training with MPCs enhances motor learning of tasks with complex dynamics and are promising strategies to improve robotic training outcomes in neurological patients.

Analysis of Compensatory Movements Using a Supernumerary Robotic Hand for Upper Limb Assistance

Recently, extratheses, aka Supernumerary Robotic Limbs (SRLs), are emerging as a new trend in the field of assistive and rehabilitation devices. We proposed the SoftHand X, a system composed of an anthropomorphic soft hand extrathesis, with a gravity support boom and a control interface for the patient. In preliminary tests, the system exhibited a positive outlook toward assisting impaired people during daily life activities and fighting learned-non-use of the impaired arm. However, similar to many robot-aided therapies, the use of the system may induce side effects that can be detrimental and worsen patients' conditions. One of the most common is the onset of alternative grasping strategies and compensatory movements, which clinicians absolutely need to counter in physical therapy. Before embarking in systematic experimentation with the SoftHand X on patients, it is essential that the system is demonstrated not to lead to an increase of compensation habits. This paper provides a detailed description of the compensatory movements performed by healthy subjects using the SoftHand X. Eleven right-handed healthy subjects were involved within an experimental protocol in which kinematic data of the upper body and EMG signals of the arm were acquired. Each subject executed tasks with and without the robotic system, considering this last situation as reference of optimal behavior. A comparison between two different configurations of the robotic hand was performed to understand if this aspect may affect the compensatory movements. Results demonstrated that the use of the apparatus reduces the range of motion of the wrist, elbow and shoulder, while it increases the range of the trunk and head movements. On the other hand, EMG analysis indicated that muscle activation was very similar among all the conditions. Results obtained suggest that the system may be used as assistive device without causing an over-use of the arm joints, and opens the way to clinical trials with patients.

Bimanual motor skill learning and robotic assistance for chronic hemiparetic stroke: a randomized controlled trial

Using robotic devices might improve recovery post-stroke, but the optimal way to apply robotic assistance has yet to be determined. The current study aimed to investigate whether training under the robotic active-assisted mode improves bimanual motor skill learning (biMSkL) more than training under the active mode in stroke patients. Twenty-six healthy individuals (HI) and 23 chronic hemiparetic stroke patients with a detectable lesion on MRI or CT scan, who demonstrated motor deficits in the upper limb, were randomly allocated to two parallel groups. The protocol included a two-day training on a new bimanual cooperative task, LIFT-THE-TRAY, under either the active or active-assisted modes (where assistance decreased in a pre-determined stepwise fashion) with the bimanual version of the REAplan® robotic device. The hypothesis was that the active-assisted mode would result in greater biMSkL than the active mode. The biMSkL was quantified by a speed-accuracy trade-off (SAT) before (T1) and immediately after (T2) training on days 1 and 2 (T3 and T4). The change in SAT after 2 days of training (T4/T1) indicated that both HI and stroke patients learned and retained the bimanual cooperative task. After 2 days of training, the active-assisted mode did not improve biMSkL more than the active mode (T4/T1) in HI nor stroke patients. Whereas HI generalized the learned bimanual skill to different execution speeds in both the active and active-assisted subgroups, the stroke patients generalized the learned skill only in the active subgroup. Taken together, the active-assisted mode, applied in a pre-determined stepwise decreasing fashion, did not improve biMSkL more than the active mode in HI and stroke subjects. Stroke subjects might benefit more from robotic assistance when applied “as-needed.” This study was approved by the local ethical committee (Comité d’éthique médicale, CHU UCL Namur, Mont-Godinne, Yvoir, Belgium; Internal number: 54/2010, EudraCT number: NUB B039201317382) on July 14, 2016 and was registered with ClinicalTrials.gov (Identifier: NCT03974750) on June 5, 2019.

Improvement of the primary efficacy of microwave ablation of malignant liver tumors by using a robotic navigation system

Background The aim of the study was to assess the primary efficacy of robot-assisted microwave ablation and compare it to manually guided microwave ablation for percutaneous ablation of liver malignancies. Patients and methods We performed a retrospective single center evaluation of microwave ablations of 368 liver tumors in 192 patients (36 female, 156 male, mean age 63 years). One hundred and nineteen ablations were performed between 08/2011 and 03/2014 with manual guidance, whereas 249 ablations were performed between 04/2014 and 11/2018 using robotic guidance. A 6-week follow-up (ultrasound, computed tomography and magnetic resonance imaging) was performed on all patients. Results The primary technique efficacy outcome of the group treated by robotic guidance was significantly higher than that of the manually guided group (88% vs. 76%; p = 0.013). Multiple logistic regression analysis indicated that a small tumor size (≤ 3 cm) and robotic guidance were significant favorable prognostic factors for complete ablation. Conclusions In addition to a small tumor size, robotic navigation was a major positive prognostic factor for primary technique efficacy.

Work with me, not for me: Relationship between robotic assistance and performance in subacute and chronic stroke patients

Introduction

Studies in robotic therapy which applied the performance enhancement approach report improvements in motor performance during training, though these improvements do not always transfer to motor learning.

Objectives

We postulate that there exists an assistance threshold for which performance saturates. Above this threshold, the robot’s input outweighs the patient’s input and likely learning is not fostered. This study investigated the relationship between assistance and performance changes in stroke patients to find the assistance threshold for performance saturation.

Methods

Twelve subacute and chronic stroke patients engaged in five sessions (over two weeks, each 60 min) in which they performed a reaching task with the rehabilitation robot H-Man in presence of varying levels of haptic assistance (50 N/m to 290 N/m, randomized order). In two additional sessions, a therapist manually tuned the assistance to promote maximal motor learning.

Results

Higher levels of assistance resulted in smoother and faster performance that saturated at assistance levels with K ≥ 110 N/m. Also, the therapist selected assistance levels of K = 175 N/m or below.

Conclusion

The findings of the study indicate that low levels of assistance (K ≤ 175 N/m) can sufficiently induce a significant change in performance.

How Tool-Use Shapes Body Metric Representation: Evidence From Motor Training With and Without Robotic Assistance

Previous evidence has shown that tool-use can reshape one's own body schema, extending peripersonal space and modulating the representation of related body parts. Here, we investigated the role of tool action in shaping the body metric representation, by contrasting two different views. According to a first view, the shaping would rely on the mere execution of tool action, while the second view suggests that the shaping induced by tool action on body representation would primarily depend on the representation of the action goals to be accomplished. To this aim, we contrasted a condition in which participants voluntarily accomplish the movement by representing the program and goal of a tool action (i.e., active tool-use training) with a condition in which the tool-use training was produced without any prior goal representation (i.e., passive tool-use training by means of robotic assistance). If the body metric representation primarily depends on the coexistence between goal representation and bodily movements, we would expect an increase of the perceived forearm length in the post- with respect to the pre-training phase after the active training phase only. Healthy participants were asked to estimate the midpoint of their right forearm before and after 20 min of tool-use training. In the active condition, subjects performed "enfold-and-push" movements using a rake to prolong their arm. In the passive condition, subjects were asked to be completely relaxed while the movements were performed with robotic assistance. Results showed a significant increase in the perceived arm length in the post- with respect to the pre-training phase only in the active task. Interestingly, only in the post-training phase, a significant difference was found between active and passive conditions, with a higher perceived arm length in the former than in the latter. From a theoretical perspective, these findings suggest that tool-use may shape body metric representation only when action programs are motorically represented and not merely produced. From a clinical perspective, these results support the use of robots for the rehabilitation of brain-damaged hemiplegic patients, provided that robot assistance during the exercises is present only "as-needed" and that patients' motor representation is actively involved.

Robotic Assistance for Upper Limbs May Induce Slight Changes in Motor Modules Compared With Free Movements in Stroke Survivors: A Cluster-Based Muscle Synergy Analysis

Background: The efficacy of robot-assisted rehabilitation as a technique for achieving motor recovery is still being debated. The effects of robotic assistance are generally measured using standard clinical assessments. Few studies have investigated the value of human-centered instrumental analysis, taking the modular organization of the human neuromotor system into account in assessing how stroke survivors interact with robotic set-ups. In this paper, muscle synergy analysis was coupled with clustering procedures to elucidate the effect of human-robot interaction on the spatial and temporal features, and directional tuning of motor modules during robot-assisted movements. Methods: Twenty-two stroke survivors completed a session comprising a series of hand-to-mouth movements with and without robotic assistance. Patients were assessed instrumentally, recording kinematic, and electromyographic data to extract spatial muscle synergies and their temporal components. Patients' spatial synergies were grouped by means of a cluster analysis, matched pairwise across conditions (free and robot-assisted movement), and compared in terms of their spatial and temporal features, and directional tuning, to examine how robotic assistance altered their motor modules. Results: Motor synergies were successfully extracted for all 22 patients in both conditions. Seven clusters (spatial synergies) could describe the original datasets, in both free and robot-assisted movements. Interacting with the robot slightly altered the spatial synergies' features (to a variable extent), as well as their temporal components and directional tuning. Conclusions: Slight differences were identified in the characteristics of spatial synergies, temporal components and directional tuning of the motor modules of stroke survivors engaging in free and robot-assisted movements. Such effects are worth investigating in the framework of a modular description of the neuromusculoskeletal system to shed more light on human-robot interaction, and the effects of robotic assistance and rehabilitation.

Component Placement Accuracy in Unicompartmental Knee Arthroplasty Is Improved with Robotic-Assisted Surgery: Will It Have an Effect on Outcomes?

Bell et al.'s "Improved Accuracy of Component Positioning with Robotic-Assisted Unicompartmental Knee Arthroplasty: Data from a Prospective, Randomized Controlled Study" compared the accuracy of a robotic-assisted unicompartmental knee arthroplasty (UKA) using the MAKO Robotic Interactive Orthopedic Arm (RIO) system to a conventional UKA using standardized instrumentation. This review examines the authors' findings and their relevance to clinical practice. Bell et al. conclude that the MAKO RIO system leads to more accurate implantation of both the tibial and femoral components in UKA in the sagittal, coronal, and axial planes. This well-designed, level I study suggests what many arthroplasty surgeons assume about robotic assistance, which admittedly is of unknown clinical significance at this time. Evaluating this article in the context of the current literature provides valuable insight into areas in need of future investigation. The effect of implant positioning on long-term clinical outcomes and implant survivorship remains unclear. Long-term follow-up studies are needed to determine the role of robotic-assisted arthroplasty in the future.

Robot-assisted vitreoretinal surgery: current perspectives

Vitreoretinal microsurgery is among the most technically challenging of the minimally invasive surgical techniques. Exceptional precision is required to operate on micron scale targets presented by the retina while also maneuvering in a tightly constrained and fragile workspace. These challenges are compounded by inherent limitations of the unassisted human hand with regard to dexterity, tremor and precision in positioning instruments. The limited human ability to visually resolve targets on the single-digit micron scale is a further limitation. The inherent attributes of robotic approaches therefore, provide logical, strategic and promising solutions to the numerous challenges associated with retinal microsurgery. Robotic retinal surgery is a rapidly emerging technology that has witnessed an exponential growth in capabilities and applications over the last decade. There is now a worldwide movement toward evaluating robotic systems in an expanding number of clinical applications. Coincident with this expanding application is growth in the number of laboratories committed to "robotic medicine". Recent technological advances in conventional retina surgery have also led to tremendous progress in the surgeon's capabilities, enhanced outcomes, a reduction of patient discomfort, limited hospitalization and improved safety. The emergence of robotic technology into this rapidly advancing domain is expected to further enhance important aspects of the retinal surgery experience for the patients, surgeons and society.

Can Robot-Assisted Unicompartmental Knee Arthroplasty Be Cost-Effective? A Markov Decision Analysis

BACKGROUND

Unicompartmental knee arthroplasty (UKA) is a treatment option for single-compartment knee osteoarthritis. Robotic assistance may improve survival rates of UKA, but the cost-effectiveness of robot-assisted UKA is unknown. The purpose of this study was to delineate the revision rate, hospital volume, and robotic system costs for which this technology would be cost-effective.

METHODS

We created a Markov decision analysis to evaluate the costs, outcomes, and incremental cost-effectiveness of robot-assisted UKA in 64-year-old patients with end-stage unicompartmental knee osteoarthritis.

RESULTS

Robot-assisted UKA was more costly than traditional UKA, but offered a slightly better outcome with 0.06 additional quality-adjusted life-years at an incremental cost of $47,180 per quality-adjusted life-years, given a case volume of 100 cases annually. The system was cost-effective when case volume exceeded 94 cases per year, 2-year failure rates were below 1.2%, and total system costs were <$1.426 million.

CONCLUSION

Robot-assisted UKA is cost-effective compared with traditional UKA when annual case volume exceeds 94 cases per year. It is not cost-effective at low-volume or medium-volume arthroplasty centers.

Robotic assisted kidney transplantation

Kidney transplantation is the standard of care for patients with end stage renal disease. While open surgery remains the gold standard, minimally invasive surgery has recently been introduced for the recipient undergoing kidney transplantation. We review the evolution of techniques of minimally invasive surgery for kidney transplantation with specific emphasis on technical aspects of robotic assisted kidney transplantation.

Robotic assisted excision of retrovesical angiomyxoma in a male patient

Angiomyxoma is a rare tumour found predominantly in pelvis of young females. Less than 150 cases have been reported, more than 90% in females and only few cases in males. Its surgical excision is a big challenge and usually leads to recurrence due to incomplete excision. We report a case of retrovesical Angiomyxoma in an elderly male. The aim of this report is to highlight the rarity of this disease, especially in males, and robotic assisted excision as an evolving option of treatment.

MRI-safe robot for targeted transrectal prostate biopsy: animal experiments

OBJECTIVES

To study the feasibility and safety of using a magnetic resonance imaging (MRI)-safe robot for assisting MRI-guided transrectal needle placement and biopsy in the prostate, using a canine model. To determine the accuracy and precision afforded by the use of the robot while targeting a desired location in the organ.

MATERIALS AND METHODS

In a study approved by the Institutional Animal Care and Use Committee, six healthy adult male beagles with prostates of at least 15 × 15 mm in size at the largest transverse section were chosen for the procedure. The probe portion of the robot was placed into the rectum of the dog, images were acquired and image-to-robot registration was performed. Images acquired after placement of the robot were reviewed and a radiologist selected targets for needle placement in the gland. Depending on the size of the prostate, up to a maximum of six needle placements were performed on each dog. After needle placement, robot-assisted core biopsies were performed on four dogs that had larger prostate volumes and extracted cores were analysed for potential diagnostic value.

RESULTS

Robot-assisted MRI-guided needle placements were performed to target a total of 30 locations in six dogs, achieving a targeting accuracy of 2.58 mm (mean) and precision of 1.31 mm (SD). All needle placements were successfully completed on the first attempt. The mean time required to select a desired target location in the prostate, align the needle guide to that point, insert the needle and perform the biopsy was ∼ 3 min. For this targeting accuracy study, the inserted needle was also imaged after its placement in the prostate, which took an additional 6-8 min. Signal-to-noise ratio analysis indicated that the presence of the robot within the scanner bore had minimal impact on the quality of the images acquired. Analysis of intact biopsy core samples indicated that the samples contained prostatic tissues, appropriate for making a potential diagnosis. Dogs used in the study did not experience device- or procedure-related complications.

CONCLUSIONS

Results from this preclinical pilot animal study suggest that MRI-targeted transrectal biopsies are feasible to perform and this procedure may be safely assisted by an MRI-safe robotic device.

The role of biomechanics and engineering in total hip replacement. Why surgeons need technical help

Implanting the acetabular cup of hard-on-hard bearings, like metal-on-metal or ceramic-on-ceramic, requires considerable surgeon skill to avoid the complications associated with edge loading. Successful cup positioning instruments have been designed in the past by pioneering surgeons, like Peter Ring and Michael Freeman, and these are re-visited in this article. An advantage of these instruments is that they could position the acetabular cup without defining a reference pelvic plane. Computer-assisted cup orientation is able to reduce outliers in cup orientation, but the technology has not been widely adopted. There may be an opportunity to improve the uptake of computer-assisted surgery by incorporating some of the concepts from historically successful manual instruments.