Exact linearization and control of a mobile robot for the inspection of soil resources in Solanum tuberosum crops.

In recent years, the development of robots for agro-industrial applications, such as the cultivation of Solanum tuberosum potatoes, has aroused the interest of the academic and scientific communities. This is due, at least in part, to the complexity of modeling and robustly controlling some dynamics inherent to nonlinear behaviors normally attributed to the different technologies associated with the movement of these autonomous vehicles and their non-holonomic constraints. The different nonlinear dynamics of mobile robots are usually represented by state-space models. However, given some equilibrium and stability characteristics, the implementation of effective controllers for the robust parametric tracking and variation problem requires techniques that allow the operability of robots around regions of stable equilibrium. Feedback linearization control is one such technique that attempts to mathematically eliminate nonlinear expressions from the plant model. However, this technique requires an observable and controllable mathematical model. If there is some relationship between the model inputs and a controlled output that allows the relative degree of the control law to be determined, the controller design and implementation are posed as a linear issue. Flat filters developed from the generalized proportional integral control approach are an alternative that could facilitate the design of controllers for these linearized systems. From these flat filters, it is possible to obtain the transfer function of a controller without relying on the derivatives of the system output. This work proposes the design of a controller via exact linearization and its equivalent flat filter for a robot inspector of the soil resource of S. tuberosum crops in the department of Cundinamarca, Colombia. The actuator motion constraints resulted in a robot with two degrees of mobility and one non-holonomic constraint. Numerical validation of this system suggests that it can be an effective solution to the problem of tracking control at changing references by providing a system capable of navigating through crop rows. The results suggest correct tracking for linear and circular trajectories. However, the control lacks the ability to track spiral-type trajectories.

Peritoneal interposition flap reduces symptomatic lymphocele following transperitoneal robot-assisted radical prostatectomy and pelvic lymph node dissection: An updated meta-analysis.

Background: Robot-assisted radical prostatectomy with intraoperative pelvic lymph node dissection is the criterion standard for surgical treatment of nonmetastatic intermediate- and high-risk prostate cancer. However, this method is associated with symptomatic lymphocele (SLC), which is an important morbidity factor. To overcome this complication, several modifications of the technique have been developed, including the peritoneal interposition flap (PIF). We performed an updated systematic review and meta-analysis to investigate the efficacy and safety of this technique for preventing SLC and lymphocele (LC) formation. Materials and methods: Searches were performed using databases and references from included studies and previous systematic reviews. Only randomized controlled trials and nonrandomized cohorts were included. Primary outcomes were the incidence of SLC and LC formation, and safety outcomes were defined as operation time, estimated blood loss, length of hospital stay, and urinary incontinence. Quality assessment was performed using the Newcastle-Ottawa Scale and Cochrane Collaboration's tool. Pooled treatment effects were estimated using odds ratios with 95% confidence intervals (CIs) for binary endpoints. Heterogeneity was examined using Cochran's Q test and I 2 statistics; p values < 0.10 and I 2 > 25% were considered significant for heterogeneity. We used Mantel-Haenszel fixed-effect models in the analyses with low heterogeneity. Otherwise, the DerSimonian and Laird random-effects model was used. Results: The initial search yielded 510 results. After the removal of duplicate records and application of the exclusion criterion, 9 studies were fully reviewed for eligibility. Three randomized controlled trials and 5 retrospective cohorts met all the inclusion criteria, comprising 2261 patients, of whom 1073 (47.4%) underwent PIF. Six studies reported a significant reduction in SLC in the PIF group, and 3 of the 4 studies reported LC formation yielded significant results in preventing this complication. The incidence of SLC and LC formation in a follow-up of ≥3 months was significantly different between the PIF and no PIF group (odds ratio, 0.34 [95% CI, 0.16­0.74; p = 0.006] and 0.48 [95% CI, 0.31­0.74; p = 0.0008]), respectively. The safety outcomes did not differ significantly between the 2 groups. Conclusions: These results suggest that PIF is an effective and safe technique for preventing LC and SLC in patients undergoing transperitoneal robot-assisted radical prostatectomy and pelvic lymph node dissection.

Robot-assisted versus laparoscopic ileal ureteral replacement: systematic review and meta-analysis.

Introduction: Robot-assisted laparoscopic surgery (RALS) and conventional laparoscopic surgery (LS) are the main options for ileal ureteral replacement (IUR). It is not clear which option is superior. The purpose of this study is to compare RALS and LS for IUR. Material and methods: We searched MEDLINE, Embase, Web of Science, Scopus, Cochrane Central, and Google Scholar for studies comparing RALS and LS for IUR. The outcomes of interest are operative time, blood loss, postoperative stay, and Clavien-Dindo complications. Meta-analysis was performed with Rev Man version 5.4. Results: We included 36 patients from 3 studies. The mean age was 44 years, with 53% male patients. Blood loss (MD -89.13 cc, CI -129.03 to -49.22, I2 = 0%) was significantly lower in patients undergoing RALS when comparing with LS. No differences were observed when comparing operative time (MD -10.99 minutes, CI -85.66 to 63.59, p = 0.77, I2 = 64%), postoperative stay (MD -2.56 days, CI -8.24 to 3.13, p = 0.38, I2 = 30%), and postoperative complications (OR 1.63, CI 0.27 to 10.02, p = 0.60, I2 = 0%). Conclusions: Overall, we conclude that the robot-assisted technique showed less bleeding compared to the laparoscopic technique.

Validity and reliability of the Chinese version of human-robot interaction self-efficacy scale in Chinese adults.

BACKGROUND: With the fast-paced advancements of robot technology, human-robot interaction (HRI) has become increasingly popular and complex, and self-efficacy in HRI has received extensive attention. Despite its popularity, this topic remains understudied in China. OBJECTIVE: In order to provide a psychometrically sound instrument in China, this study aimed to translate and validate the Self-Efficacy in Human-Robot Interaction Scale (SE-HRI) in two Chinese adult samples (N1 = 300, N2 = 500). METHODS: The data was analyzed by SPSS 26.0 and Amos 24.0. Item analysis and exploratory factor analysis were conducted using Sample 1 data. Confirmatory factor analysis, criterion-related validity analysis, and reliability analysis were then performed using Sample 2 data. RESULTS: The results revealed that the Chinese SE-HRI scale consisted of 13 items in a two-factor model, suggesting a good model fit. Moreover, general self-efficacy and willingness to accept the use of artificial intelligence (AI) were both positively correlated with self-efficacy in HRI, while negative attitudes toward robots showed an inverse correlation, proving the Chinese SE-HRI scale exhibited excellent criterion-related validity. CONCLUSION: The Chinese SE-HRI scale is a reliable assessment tool for evaluating self-efficacy in HRI in China. The study discussed implications and limitations, and suggested future directions.

Enhancing Operational Efficiency and Service Delivery through a Robotic Dispensing System: A Case Study from a Retail Pharmacy in Brazil.

Drug dispensing in retail pharmacies typically involves several manual tasks that often lead to inefficiencies and errors. This is the first published quality improvement study in Latin America, specifically in Brazil, investigating the operational impacts of implementing a robotic dispensing system in a retail pharmacy. Through observational techniques, we measured the time required for the following pharmacy workflows before and after implementing the robotic dispensing system: customer service, receiving stock, stocking inventory, separation, invoicing, and packaging of online orders for delivery. Time savings were observed across all workflows within the pharmacy, notably in receiving stock and online order separation, which experienced 70% and 75% reductions in total time, respectively. Furthermore, customer service, stocking, invoicing, and packaging of online orders, also saw total time reductions from 36% to 53% after implementation of the robotic dispensing system. This study demonstrates an improvement in the pharmacy's operational efficiency post-implementation of the robotic dispensing system. These findings highlight the potential for such automated systems to streamline pharmacy operations, improve staff time efficiency, and enhance service delivery.

Navigating challenges in anesthesia for robotic urological surgery: a comprehensive guide.

Robotic surgery has emerged as a cornerstone in urological interventions, offering effectiveness and safety for patients. For anesthesiologists, this technological advancement presents a myriad of new challenges, spanning from patient selection and assessment to intraoperative dynamics and post-surgical pain management. This article aims to elucidate these challenges and provide guidance for anesthesiologists in navigating the complexities of anesthesia administration in robotic urological procedures. Through a detailed exploration of patient optimization, team coordination, intraoperative adjustments, and post-surgical care, this article serves as a valuable resource for ensuring the success of such interventions.

Efficacy between Conventional Laparoscopy and Robotic Surgery in Mexican Patients with Endometriosis: A Comparative Study.

Background. Surgical management of endometriosis is essential, and deep endometriosis involves the invasion of endometrial tissue into other organs such as the bladder, ureters, and rectum. In Latin American countries, significant expertise has been achieved in conventional laparoscopy (CL); however, there is less experience in robot-assisted laparoscopy (RAL) because of the high cost of this technique. For this reason, studies comparing CL and RAL for the treatment of deep endometriosis in patients are scarce, making this study the first to share the experience of Mexican patients. Aim. The efficacy of CL vs. RAL in the management of deep endometriosis in Mexican patients was compared. Materials and Methods. We performed a retrospective and comparative study. We considered all patients treated with minimally invasive surgery for deep endometriosis between 2015 and 2023. Results. A total of 93 patients were included; 56 patients were treated with CL, and 37 patients were treated with RAL. A significant difference (p < 0.05) was observed in the postoperative length of stay, which was longer in patients treated with CL compared with those treated with RAL. Additionally, postoperative pain was less frequent in patients treated with RAL than in those treated with CL (p < 0.05). We did not observe a significant difference in operative time, blood loss, or perioperative complications between the two surgical techniques (p < 0.05). Conclusions. CL and RAL are effective methods for managing endometriosis in Mexican patients; however, RAL is beneficial for the treatment of deep endometriosis because patients experience postoperative pain less frequently than CL patients and have a shorter postoperative length of stay.

Acinonyx jubatus-Inspired Quadruped Robotics: Integrating Neural Oscillators for Enhanced Locomotion Control.

This study presents the design, simulation, and prototype creation of a quadruped robot inspired by the Acinonyx jubatus (cheetah), specifically designed to replicate its distinctive walking, trotting, and galloping locomotion patterns. Following a detailed examination of the cheetah's skeletal muscle anatomy and biomechanics, a simplified model of the robot with 12 degrees of freedom was conducted. The mathematical transformation hierarchy model was established, and direct kinematics were simulated. A bio-inspired control approach was introduced, employing a Central Pattern Generator model based on Wilson-Cowan neural oscillators for each limb, interconnected by synaptic weights. This approach assisted in the simulation of oscillatory signals for relative phases corresponding to four distinct gaits in a system-level simulation platform. The design phase was conducted using CAD software (SolidWorks 2018), resulting in a 1:3-scale robot mirroring the cheetah's actual proportions. Movement simulations were performed in a virtual mechanics software environment, leading to the construction of a prototype measuring 35.5 cm in length, 21 cm in width, 27 cm in height (when standing), and weighing approximately 2.1 kg. The experimental validation of the prototype's limb angular positions and trajectories was achieved through the image processing of video-recorded movements, demonstrating a high correlation (0.9025 to 0.9560) in joint angular positions, except for the knee joint, where a correlation of 0.7071 was noted. This comprehensive approach from theoretical analysis to practical implementation showcases the potential of bio-inspired robotics in emulating complex biological locomotion.

Implementation of a Long Short-Term Memory Neural Network-Based Algorithm for Dynamic Obstacle Avoidance.

Autonomous mobile robots are essential to the industry, and human-robot interactions are becoming more common nowadays. These interactions require that the robots navigate scenarios with static and dynamic obstacles in a safely manner, avoiding collisions. This paper presents a physical implementation of a method for dynamic obstacle avoidance using a long short-term memory (LSTM) neural network that obtains information from the mobile robot's LiDAR for it to be capable of navigating through scenarios with static and dynamic obstacles while avoiding collisions and reaching its goal. The model is implemented using a TurtleBot3 mobile robot within an OptiTrack motion capture (MoCap) system for obtaining its position at any given time. The user operates the robot through these scenarios, recording its LiDAR readings, target point, position inside the MoCap system, and its linear and angular velocities, all of which serve as the input for the LSTM network. The model is trained on data from multiple user-operated trajectories across five different scenarios, outputting the linear and angular velocities for the mobile robot. Physical experiments prove that the model is successful in allowing the mobile robot to reach the target point in each scenario while avoiding the dynamic obstacle, with a validation accuracy of 98.02%.

Soft Sensory-Motor System Based on Ionic Solution for Robotic Applications.

Soft robots claim the architecture of actuators, sensors, and computation demands with their soft bodies by obtaining fast responses and adapting to the environment. Sensory-motor coordination is one of the main design principles utilized for soft robots because it allows the capability to sense and actuate mutually in the environment, thereby achieving rapid response performance. This work intends to study the response for a system that presents coupled actuation and sensing functions simultaneously and is integrated in an arbitrary elastic structure with ionic conduction elements, called as soft sensory-motor system based on ionic solution (SSMS-IS). This study provides a comparative analysis of the performance of SSMS-IS prototypes with three diverse designs: toroidal, semi-toroidal, and rectangular geometries, based on a series of performance experiments, such as sensitivity, drift, and durability. The design with the best performance was the rectangular SSMS-IS using silicon rubber RPRO20 for both internal and external pressures applied in the system. Moreover, this work explores the performance of a bioinspired soft robot using rectangular SSMS-IS elements integrated in its body. Further, it investigated the feasibility of the robot to adapt its morphology online for environment variability, responding to external stimuli from the environment with different levels of stiffness and damping.

Perioperative, Oncological, and Functional Outcomes Between Robot-Assisted Laparoscopic Prostatectomy and Open Radical Retropubic Prostatectomy: A Randomized Clinical Trial.

PURPOSE: Limited high-quality studies have compared robot-assisted laparoscopic prostatectomy (RALP) vs open retropubic radical prostatectomy. We sought to compare their postoperative outcomes in a randomized setting. MATERIALS AND METHODS: In a single center, 354 men with newly diagnosed prostate cancer were assessed for eligibility; 342 were randomized (1:1). The primary outcome was 90-day complication rates. Functional outcomes and quality of life were assessed over 18 months, and oncological outcomes, biochemical recurrence-free survival, and additional treatment over 36 months. RESULTS: From 2014 to 18, 327 patients underwent surgery (retropubic radical prostatectomy = 156, RALP = 171). Complications occurred in 27 (17.3%) vs 19 (11.1%; P = .107). Patients undergoing RALP experienced lower median bleeding (250.0 vs 719.5 mL; P < .001) and shorter hospitalization time. Urinary EPIC (Expanded Prostate Cancer Index Composite) median scores were better for RALP over 18 months, with higher continence rate at 3 months (80.5% vs 64.7%; P = .002), 6 months (90.1% vs 81.6%; P = .036) and 18 months (95.4% vs 78.8%; P < .001). Sexual EPIC and Sexual Health Inventory for Men median scores were higher with RALP up to 12 months, while the potency rate was superior at 3 months (23.9% vs 5.3%; P = .001) and 6 months (30.6% vs 6.9%; P < .001). Quality of life over the 18 months and oncological outcomes over 36 months were not significantly different between arms. CONCLUSIONS: Complications at 90 days were similar. RALP showed superior sexual outcomes at 1 year, improved urinary outcomes at 18 months, and comparable oncological outcomes at 36 months. TRIAL REGISTRATION: Prospective Analysis of Robot-Assisted Surgery; NCT02292914. https://clinicaltrials.gov/ct2/show/NCT02292914?cond=NCT02292914&draw=2&rank=1.

How Do Escape Distance Behavior of Broiler Chickens Change in Response to a Mobile Robot Moving at Two Different Speeds?

In poultry farming, robots are considered by birds as intruder elements to their environment, because animals escape due to their movement. Their escape is measured using the escape distance (ED) technique. This study analyzes the behavior of animals in relation to their ED through the use of a robot with two speeds: 12 rpm and 26 rpm. The objective is to understand whether the speeds cause variations in ED and their implications for animal stress. A broiler breeding cycle was analyzed (six weeks) through the introduction of the robot weekly. ED analyses were carried out on static images generated from footage of the robot running. The results indicate higher escape distance rates (p < 0.05) peaking midway through the production cycle, notably in the third week. Conversely, the final weeks saw the lowest ED, with the most significant reduction occurring in the last week. This pattern indicates a gradual escalation of ED up to the fourth week, followed by a subsequent decline. Despite RPM12 having shown low ED results, it did not show enough ED to move the animals away from their path of travel, causing bumps and collisions. RPM26 showed higher ED in all breeding phases, but showed ED with no bumps and collisions.

Extracción de miomas por colpotomía posterior en miomectomía laparoscópica asistida por robot (HUGO RAS)

Video de sección Imágenes en ginecología y obstetricia donde se observa la extracción de miomas por colpotomía posterior en miomectomía laparoscópica asistida por robot (HUGO RAS). (provisto por Infomedic International)

Video from the section Images in gynecology and obstetrics showing the removal of myomas by posterior colpotomy in robot-assisted laparoscopic myomectomy (HUGO RAS). (provided by Infomedic International)

Dynamics of changes in broiler spatial distribution induced by a robot with autonomous navigation along the growing cycle.

Welfare problems in broiler chickens are associated with accelerated growth in high density and barren environments. Encouraging broiler movement yields benefits by increasing locomotion, foraging, and environmental exploration. Robot sensors with autonomous navigation capabilities developed to collect husbandry information could collaterally induce movement of birds while traversing the chicken houses. This study examines the short-time dynamic of changes in broiler spatial distribution within the robot's zone of influence throughout the growing cycle. Two batches of mixed-sex Cobb-500 were raised in a commercial broiler farm until 42 d of age, in 2 houses divided into 4 equally sized sectors. In half of the sectors an AviSense robot sustained 2-h per day of autonomous navigation. The minute prior and the 4 min following the robot entering the zone of influence were video recorded weekly. Control sectors without a robot were analyzed equivalently. Number of individuals within the zone of influence of the robot were obtained at 1-s intervals and relative density (%) was estimated. Physical interactions between broilers and the robot, as well as interactions with the environment were also recorded. The entrance of the robot triggers within seconds a strong depopulation of the zone with birds walking to neighboring areas (P < 0.03, in all ages). The decreases in relative density induced by the robot appears more pronounced, and repopulation of the zone was slower, in younger than in older birds (P < 0.05). Broilers´ showed physical interactions towards the robot and were also touched and/or slightly pushed by the robots (19 and 84% of videos recorded, respectively). They were also found scratching and/or pecking the ground after the robot passed (64% of videos). Findings strongly suggest that robots, beyond their specific capabilities as environmental sensors, were effective in promoting increased movement in broilers along the growing cycle and could also favor additional exploratory behaviors. Thus, these robots could be considered as environmental enrichment elements that contribute to welfare improvements during intensive rearing.

Erectile dysfunction criteria of 131,350 patients after open, laparoscopic, and robotic radical prostatectomy.

PURPOSE: Comparing post-radical prostatectomy erectile function rates among different techniques has always been a challenge in urology. This difficulty is due to the heterogeneity of studies, mainly in relation to the type of erectile function classification criteria used. The aim is to apply a new evidence-gathering methodology, called reverse systematic review, to compare erectile function rates among retropubic radical prostatectomy, laparoscopic radical prostatectomy, and robot-assisted radical prostatectomy, considering the diversity of classification criteria. METHODS: A search was carried out in eight databases between 2000 and 2020 through systematic review studies referring to retropubic radical prostatectomy, laparoscopic radical prostatectomy, or robot-assisted radical prostatectomy (80 systematic reviews). All references used in these systematic reviews were captured by referring to 910 papers in a global database called EVIDENCE. A total of 268 studies related to post-prostatectomy erectile function rates were selected for the final analysis, totaling 465 cohorts or reports referring to 131,350 patients. RESULTS: Note that, 119 (25.6%) reports for retropubic radical prostatectomy, 143 (30.7%) reports for laparoscopic radical prostatectomy, and 203 (43.7%) reports for robot-assisted radical prostatectomy were found. Mean overall erectile function rates, respectively for retropubic radical prostatectomy, laparoscopic radical prostatectomy, and robot-assisted radical prostatectomy, were: 16%, 12%, and 35% at 1 month, 22%, 26%, and 42% in 3 months; 30%, 44%, and 54% at 6 months, 41%, 55%, and 59% at 12 months, and 58%, 52%, and 67% at more than 18 months. The most used erectile function criterion was Erection Sufficient for Intercourse (74.1%), followed by Sexual Health Inventory for Men > 21 (5.5%), and Sexual Health Inventory for Men > 16 (3.7%). Erection Sufficient for Intercourse showed the lowest discrepancy in erectile function rates in each period compared to the global average, for each technique, demonstrating less ability to influence the final results, favoring any of the techniques. CONCLUSIONS: The reverse systematic review demonstrated that the robot-assisted radical prostatectomy showed higher rates of erectile function recovery at all times analyzed (1->18 months), in relation to the retropubic radical prostatectomy and laparoscopic radical prostatectomy. The Erection Sufficient for Intercourse criterion was the most used in the literature and showed the lowest bias capable of influencing the results and favoring any of the techniques and might be the fairest option for future comparisons.

Snake Robot with Motion Based on Shape Memory Alloy Spring-Shaped Actuators.

This study presents the design and evaluation of a prototype snake-like robot that possesses an actuation system based on shape memory alloys (SMAs). The device is constructed based on a modular structure of links connected by two degrees of freedom links utilizing Cardan joints, where each degree of freedom is actuated by an agonist-antagonist mechanism using the SMA spring-shaped actuators to generate motion, which can be easily replaced once they reach a degradation point. The methodology for programming the spring shape into the SMA material is described in this work, as well as the instrumentation required for the monitoring and control of the actuators. A simplified design is presented to describe the way in which the motion is performed and the technical difficulties faced in manufacturing. Based on this information, the way in which the design is adapted to generate a feasible robotic system is described, and a mathematical model for the robot is developed to implement an independent joint controller. The feasibility of the implementation of the SMA actuators regarding the motion of the links is verified for the case of a joint, and the change in the shape of the snake robot is verified through the implementation of a set of tracking references based on a central pattern generator. The generated tracking results confirm the feasibility of the proposed mechanism in terms of performing snake gaits, as well as highlighting some of the drawbacks that should be considered in further studies.

Novel Technique to Increase the Effective Workspace of a Soft Robot.

This article presents a novel technique for a class 2 tensegrity robot, also classified as a soft robot, to increase workspace by increasing the number of geometric equilibrium configurations of the robot. The proposed modification, unlike the strategies reported in the literature, consists of increasing the number of points where the flexible and rigid elements that make up the robot come into contact without the need to increase the number of actuators, the number of flexible elements, or modify the geometry of the rigid elements. The form-finding methodology combines the basic principles of statics with the direct and inverse kinematic position analysis to determine the number of equilibrium positions of the modified robot. In addition, numerical experiments were carried out using the commercial software ANSYS®, R18.2 based on the finite element theory, to corroborate the results obtained with them. With the proposed modification, an increase of 23.369% in the number of geometric equilibrium configurations is achieved, which integrates the workspace of the modified class 2 tensegrity robot. The novel technique applied to tensegrity robots and the tools developed to increase their workspace apply perfectly to scale the robots presented in this paper.

Qhali: A Humanoid Robot for Assisting in Mental Health Treatment.

In recent years, social assistive robots have gained significant acceptance in healthcare settings, particularly for tasks such as patient care and monitoring. This paper offers a comprehensive overview of the expressive humanoid robot, Qhali, with a focus on its industrial design, essential components, and validation in a controlled environment. The industrial design phase encompasses research, ideation, design, manufacturing, and implementation. Subsequently, the mechatronic system is detailed, covering sensing, actuation, control, energy, and software interface. Qhali's capabilities include autonomous execution of routines for mental health promotion and psychological testing. The software platform enables therapist-directed interventions, allowing the robot to convey emotional gestures through joint and head movements and simulate various facial expressions for more engaging interactions. Finally, with the robot fully operational, an initial behavioral experiment was conducted to validate Qhali's capability to deliver telepsychological interventions. The findings from this preliminary study indicate that participants reported enhancements in their emotional well-being, along with positive outcomes in their perception of the psychological intervention conducted with the humanoid robot.

Supervised learning for improving the accuracy of robot-mounted 3D camera applied to human gait analysis.

BACKGROUND AND OBJECTIVE: the use of 3D cameras for gait analysis has been highly questioned due to the low accuracy they have demonstrated in the past. The objective of the study presented in this paper is to improve the accuracy of the estimations made by robot-mounted 3D cameras in human gait analysis by applying a supervised learning stage. METHODS: the 3D camera was mounted in a mobile robot to obtain a longer walking distance. This study shows an improvement in detection of kinematic gait signals and gait descriptors by post-processing the raw estimations of the camera using artificial neural networks trained with the data obtained from a certified Vicon system. To achieve this, 37 healthy participants were recruited and data of 207 gait sequences were collected using an Orbbec Astra 3D camera. There are two basic possible approaches for training and both have been studied in order to see which one achieves a better result. The artificial neural network can be trained either to obtain more accurate kinematic gait signals or to improve the gait descriptors obtained after initial processing. The former seeks to improve the waveforms of kinematic gait signals by reducing the error and increasing the correlation with respect to the Vicon system. The second is a more direct approach, focusing on training the artificial neural networks using gait descriptors directly. RESULTS: the accuracy of the 3D camera to objectify human gait was measured before and after training. In both training approaches, a considerable improvement was observed. Kinematic gait signals showed lower errors and higher correlations with respect to the ground truth. The accuracy of the system to detect gait descriptors also showed a substantial improvement, mostly for kinematic descriptors rather than spatio-temporal. When comparing both training approaches, it was not possible to define which was the absolute best. CONCLUSIONS: supervised learning improves the accuracy of 3D cameras but the selection of the training approach will depend on the purpose of the study to be conducted. This study reveals the great potential of 3D cameras and encourages the research community to continue exploring their use in gait analysis.

Colorectal resections for malignancy: A pilot study comparing conventional vs freehand robot-assisted laparoscopic colectomy.

BACKGROUND: Laparoscopic colectomy is widely accepted as a safe operation for colorectal cancer, but we have experienced resistance to the introduction of the FreeHand® robotic camera holder to augment laparoscopic colorectal surgery. AIM: To compare the initial results between conventional and FreeHand® robot-assisted laparoscopic colectomy in Trinidad and Tobago. METHODS: This was a prospective study of outcomes from all laparoscopic colectomies performed for colorectal carcinoma from November 29, 2021 to May 30, 2022. The following data were recorded: Operating time, conversions, estimated blood loss, hospitalization, morbidity, surgical resection margins and number of nodes harvested. All data were entered into an excel database and the data were analyzed using SPSS ver 20.0. RESULTS: There were 23 patients undergoing colectomies for malignant disease: 8 (35%) FreeHand®-assisted and 15 (65%) conventional laparoscopic colectomies. There were no conversions. Operating time was significantly lower in patients undergoing robot-assisted laparoscopic colectomy (95.13 ± 9.22 vs 105.67 ± 11.48 min; P = 0.045). Otherwise, there was no difference in estimated blood loss, nodal harvest, hospitalization, morbidity or mortality. CONCLUSION: The FreeHand® robot for colectomies is safe, provides some advantages over conventional laparoscopy and does not compromise oncologic standards in the resource-poor Caribbean setting.