Force-adjustable parallel-occlusion grasper.

BACKGROUND: During laparoscopic surgery, the operating surgeon grasps sections of the gastrointestinal tract (GIT), including delicate structures, with long (270 mm) 5 mm diameter graspers. These grasping instruments increase the risk of iatrogenic damage due to crushing of the grasped tissue. This risk is increased significantly by diseases such as bacterial peritonitis and inflammatory bowel disease and reduced but not abolished by using parallel-closing laparoscopic instruments. This study describes the design and laboratory testing of fully developed and tested smart graspers capable of reducing the grasping force used for inflamed tissues and hollow viscera. MATERIALS AND METHODS: In an ISO 13485-certified mechanical laboratory and CAD machine workshop, the authors have designed, developed, and evaluated a smart gasper capable of exerting a preselected uniform grasping force on the gastrointestinal tract and other structures/ tissues, through a mechanism incorporated in the handle of the instrument. This enables the control and graded reduction of the grasping force by the incorporation of a compression spring. The authors named the new instrument the force-adjustable parallel-occlusion grasper (FA-POG) because, in addition to applying a uniform force on the grasped bowel/tissue, it also enables the surgeon to select the force before grasping, depending on its physical condition, and pathological state. RESULTS: FA-POG differs from traditional pinch-occlusion grasper in two respects: it exerts a uniform force on the grasped tissue/bowel and enables the operating surgeon to select and apply a predetermined uniform grasping force, ranging from 1 to 5 N, depending on the pathological condition of the bowel/structure. The ISO 13485-certified and fully developed prototype has been subjected to various grasping in-vitro tests using freshly harvested porcine small-bowel segments obtained from a local abattoir, using Instron tensiometry. CONCLUSIONS: The authors designed and α/ß tested a parallel-occlusion gasper that enables the operating surgeon to select the force before grasping. This grasper design consists of end-effectors jaws with a 4-bar linkage mechanism for wide, uniform parallel-occlusion force, surpassing traditional scissor-type laparoscopic graspers. It incorporates a force-level controller knob, based on a spring-loaded mechanism, enabling surgeon-preselected grip force to prevent excessive grasping. The authors validated the design experimentally using porcine small-bowel segments, optimizing teeth for maximum grip friction to minimize slippage.

Delayed gastric emptying after pylorus-preserving pancreatoduodenectomy: Comparison between traditional open surgery and full-robotic approach with da Vinci Xi.

INTRODUCTION: Delayed gastric emptying (DGE) is a frequent complication after pancreatoduodenectomy, especially after pylorus preservation (Pp). We evaluated the effect of a fully robotic approach with da Vinci Xi on DGE after PpPD. METHODS: Open and robotic PDs were performed in 353 and 50 cases, respectively, from January 2009 to March 2022. We compared the clinical outcomes and incidence of clinically relevant DGE between robotic PpPD (R-PpPD) and open PpPD after one-to-one case-control matching. RESULTS: Each group consisted of 30 patients. Clinically relevant DGE was less common after R-PpPD (3/30 [10%] vs. 10/30 cases [33.3%], p = 0.028). The median length of hospital stay (LoS) was significantly lower in the R-PpPD group (10 vs. 15 days, p = 0.013). CONCLUSION: The reduced tissue trauma by the minimally invasive robotic approach is associated with a lower incidence of DGE, reducing the LoS and encouraging PpPD performed using the fully robotic approach.

Initial 50 consecutive full-robotic pancreatoduodenectomies without conversion by a single surgeon: a learning curve analysis from a tertiary referral high-volume center.

BACKGROUND: Several studies report on a learning curve for robotic pancreatoduodenectomy (R-PD) ranging between 20 and 80 operations, with conversion rates varying between 1.1 and 35%. However, as these publications mostly refer to initial robotic experiences and do not take into account the previous surgical background in pancreatic surgery (PS) and in robotic-assisted surgery (RAS), the center's volume, as well as the platform used, we aimed to perform a surgical outcomes analysis with a particular view to these aspects. METHODS: Intraoperative and perioperative outcomes of the first 50 consecutive R-PD performed with the da Vinci Xi by the same surgeon, within a tertiary referral high-volume center, between January 2018 and March 2022, were analyzed. The surgeon was previously experienced in both PS and RAS. Shewhart control chart and cumulative sum (CUSUM) analysis were used to evaluate the learning curve of R-PD. RESULTS: All the operations were performed with a full-robotic technique, without any conversion to open surgery. Twenty of 50 patients (40%) had a BMI ≥ 25 kg/m2, while 24/50 (48%) had undergone previous abdominal surgery. Mean console time was 276.30 ± 31.16 min. The median post-operative length of hospital stay was 10 days, while 20/50 (40%) patients were discharged within post-operative day 8. Six patients (12%) had major complications (Clavien-Dindo grade 3 or above). There was no 30-day mortality. Shewhart control chart and CUSUM analysis did not show a significant learning curve during the study period. CONCLUSIONS: An extensive prior experience in both PS and RAS, within a tertiary referral high-volume center with availability of the da Vinci Xi platform, can significantly flatten the learning curve and, therefore, enable safe performance of challenging operations, i.e., pancreatoduodenectomies with a minimally invasive approach, with very low risk of conversion to open surgery, even in the first 50 operations.

5G in Healthcare: From COVID-19 to Future Challenges.

Worldwide up to May 2022 there have been 515 million cases of COVID-19 infection and over 6 million deaths. The World Health Organization estimated that 115,000 healthcare workers died from COVID-19 from January 2020 to May 2021. This toll on human lives prompted this review on 5G based networking primarily on major components of healthcare delivery: diagnosis, patient monitoring, contact tracing, diagnostic imaging tests, vaccines distribution, emergency medical services, telesurgery and robot-assisted tele-ultrasound. The positive impact of 5G as core technology for COVID-19 applications enabled exchange of huge data sets in fangcang (cabin) hospitals and real-time contact tracing, while the low latency enhanced robot-assisted tele-ultrasound, and telementoring during ophthalmic surgery. In other instances, 5G provided a supportive technology for applications related to COVID-19, e.g., patient monitoring. The feasibility of 5G telesurgery was proven, albeit by a few studies on real patients, in very low samples size in most instances. The important future applications of 5G in healthcare include surveillance of elderly people, the immunosuppressed, and nano- oncology for Internet of Nano Things (IoNT). Issues remain and these require resolution before routine clinical adoption. These include infrastructure and coverage; health risks; security and privacy protection of patients' data; 5G implementation with artificial intelligence, blockchain, and IoT; validation, patient acceptance and training of end-users on these technologies.

Breaking down the silos of artificial intelligence in surgery: glossary of terms.

BACKGROUND: The literature on artificial intelligence (AI) in surgery has advanced rapidly during the past few years. However, the published studies on AI are mostly reported by computer scientists using their own jargon which is unfamiliar to surgeons. METHODS: A literature search was conducted in using PubMed following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement. The primary outcome of this review is to provide a glossary with definitions of the commonly used AI terms in surgery to improve their understanding by surgeons. RESULTS: One hundred ninety-five studies were included in this review, and 38 AI terms related to surgery were retrieved. Convolutional neural networks were the most frequently culled term by the search, accounting for 74 studies on AI in surgery, followed by classification task (n = 62), artificial neural networks (n = 53), and regression (n = 49). Then, the most frequent expressions were supervised learning (reported in 24 articles), support vector machine (SVM) in 21, and logistic regression in 16. The rest of the 38 terms was seldom mentioned. CONCLUSIONS: The proposed glossary can be used by several stakeholders. First and foremost, by residents and attending consultant surgeons, both having to understand the fundamentals of AI when reading such articles. Secondly, junior researchers at the start of their career in Surgical Data Science and thirdly experts working in the regulatory sections of companies involved in the AI Business Software as a Medical Device (SaMD) preparing documents for submission to the Food and Drug Administration (FDA) or other agencies for approval.

Soft hybrid intrinsically motile robot for wireless small bowel enteroscopy.

BACKGROUND: Difficulties in establishing diagnosis of small bowel (SB) disorders, prevented their effective treatment. This problem was largely resolved by wireless capsule endoscopy (WCE), which has since become the first line investigation for suspected SB disorders. Several types of WCE pills are now used in clinical practice, despite their limitations and complications. WCE pills are large, rigid and immotile capsules. When swallowed, they provide SB enteroscopy downloaded to a data logger carried by the patient. Most of the complications of WCEs result from lack of intrinsic locomotion: incomplete examination, capsule retention and impaction within strictures. In addition, the rigid nature and size of current generation of WCE pills is accompanied by 0.1% inability to swallow the pill by patients with normal esophageal motility. METHODS: The aim of this communication is to describe the initial prototype, P1, which is thinner and slightly longer than the current generation of WCEs. In addition, it exhibits intrinsic active locomotion, produced by vibrating silicon legs. These generate a controlled-skid locomotion on the small bowel mucosal surface, rendered slippery by surface mucus and intraluminal surfactant bile salts. We demonstrate the mechanism responsible for the active locomotion of P1, which we consider translatable into a working prototype, suitable for further R&D for eventual clinical translation. RESULTS: The shape and attachment of the rubber vibrating legs to vibrating actuators, have been designed specifically to produce a tight clockwise circular motion. When inserted inside a circular tube in vitro of equivalent diameter to human small intestine, the intrinsic circular clockwise motion of P1 translates into a linear locomotion by the constraints imposed by the surrounding circular walls of SB and rest of the gastrointestinal tract. This design ensures device stability during transit, essential for imaging and targeting lesions encountered during the enteroscopy. We preformed two experiments: (i) transit of P1 through a phantom consisting of a segment of PVC tube placed on a horizontal surface and (ii) transit through a transparent slippery nylon sleeve insufflated with air. In the PVC tube, its transit rate averages 15.6 mm/s, which is too fast for endoscopy: whereas inside the very slippery nylon sleeve insufflated with air, the average transit rate of P1 is reduced to 5.9 mm/s, i.e., ideal for inspection endoscopy. CONCLUSIONS: These in-vitro experiments indicate that the P1 hybrid soft robot prototype has the potential specifically for clinical translation for SB enteroscopy.

Ensemble deep learning for the prediction of proficiency at a virtual simulator for robot-assisted surgery.

BACKGROUND: Artificial intelligence (AI) has the potential to enhance patient safety in surgery, and all its aspects, including education and training, will derive considerable benefit from AI. In the present study, deep-learning models were used to predict the rates of proficiency acquisition in robot-assisted surgery (RAS), thereby providing surgical programs directors information on the levels of the innate ability of trainees to facilitate the implementation of flexible personalized training. METHODS: 176 medical students, without prior experience with surgical simulators, were trained to reach proficiency in five tasks on a virtual simulator for RAS. Ensemble deep neural networks (DNN) models were developed and compared with other ensemble AI algorithms, i.e., random forests and gradient boosted regression trees (GBRT). RESULTS: DNN models achieved a higher accuracy than random forests and GBRT in predicting time to proficiency, 0.84 vs. 0.70 and 0.77, respectively (Peg board 2), 0.83 vs. 0.79 and 0.78 (Ring walk 2), 0.81 vs 0.81 and 0.80 (Match board 1), 0.79 vs. 0.75 and 0.71 (Ring and rail 2), and 0.87 vs. 0.86 and 0.84 (Thread the rings 2). Ensemble DNN models outperformed random forests and GBRT in predicting number of attempts to proficiency, with an accuracy of 0.87 vs. 0.86 and 0.83, respectively (Peg board 2), 0.89 vs. 0.88 and 0.89 (Ring walk 2), 0.91 vs. 0.89 and 0.89 (Match board 1), 0.89 vs. 0.87 and 0.83 (Ring and rail 2), and 0.96 vs. 0.94 and 0.94 (Thread the rings 2). CONCLUSIONS: Ensemble DNN models can identify at an early stage the acquisition rates of surgical technical proficiency of trainees and identify those struggling to reach the required expected proficiency level.

A systematic review on artificial intelligence in robot-assisted surgery.

BACKGROUND: Despite the extensive published literature on the significant potential of artificial intelligence (AI) there are no reports on its efficacy in improving patient safety in robot-assisted surgery (RAS). The purposes of this work are to systematically review the published literature on AI in RAS, and to identify and discuss current limitations and challenges. MATERIALS AND METHODS: A literature search was conducted on PubMed, Web of Science, Scopus, and IEEExplore according to PRISMA 2020 statement. Eligible articles were peer-review studies published in English language from January 1, 2016 to December 31, 2020. Amstar 2 was used for quality assessment. Risk of bias was evaluated with the Newcastle Ottawa Quality assessment tool. Data of the studies were visually presented in tables using SPIDER tool. RESULTS: Thirty-five publications, representing 3436 patients, met the search criteria and were included in the analysis. The selected reports concern: motion analysis (n = 17), urology (n = 12), gynecology (n = 1), other specialties (n = 1), training (n = 3), and tissue retraction (n = 1). Precision for surgical tools detection varied from 76.0% to 90.6%. Mean absolute error on prediction of urinary continence after robot-assisted radical prostatectomy (RARP) ranged from 85.9 to 134.7 days. Accuracy on prediction of length of stay after RARP was 88.5%. Accuracy on recognition of the next surgical task during robot-assisted partial nephrectomy (RAPN) achieved 75.7%. CONCLUSION: The reviewed studies were of low quality. The findings are limited by the small size of the datasets. Comparison between studies on the same topic was restricted due to algorithms and datasets heterogeneity. There is no proof that currently AI can identify the critical tasks of RAS operations, which determine patient outcome. There is an urgent need for studies on large datasets and external validation of the AI algorithms used. Furthermore, the results should be transparent and meaningful to surgeons, enabling them to inform patients in layman's words. REGISTRATION: Review Registry Unique Identifying Number: reviewregistry1225.

Use of barbed suture without fashioning the "classical" Wirsung-jejunostomy in a modified end-to-side robotic pancreatojejunostomy.

BACKGROUND: The treatment of the pancreatic stump is a critical step of pancreatoduodenectomy (PD). Robot-assisted surgery (RAS) can facilitate minimally invasive challenging abdominal procedures, including pancreatojejunostomy. However, one of the major limitations of RAS stems from its lack of tactile feedback that can lead to pancreatic parenchyma laceration during knot tying or during traction on the suture. Moreover, a Wirsung-jejunostomy is not always easy to execute, especially in cases with small diameter duct. Herein, we describe and video-report the technical details of a robotic modified end-to-side invaginated robotic pancreatojejunostomy (RmPJ) with the use of barbed suture instead of the "classical" Wirsung-jejunostomy. METHODS: The RmPJ technique consists of a double layer of absorbable monofilament running barbed suture (3-0 V-Loc), the outer layer is used to invaginate the pancreatic stump. Thereafter, a small enterotomy is made in the jejunum exactly opposite to the location of the pancreatic duct for stent insertion (usually 5 Fr) inside the duct. The internal layer provides a second barbed running suture placed between the pancreatic capsule/parenchyma and the jejunal seromuscular layer. RESULTS: A total of 14 patients underwent robotic PD with RmPJ at our Institution. The mean console time was (281.36 ± 31.50 min), while the mean operative time for fashioning the RmPJ was 37.31 ± 7.80 min. Ten out of 14 patients were discharged within postoperative day 8. No clinically relevant pancreatic fistulas were encountered, while two patients developed biochemical leaks. CONCLUSIONS: RmPJ is feasible and reproducible irrespective of pancreatic duct size and parenchyma, and can enhance the surgical workflow of this operation. Specifically, the use of barbed sutures allows the exploitation of the potential advantages of the RAS, while minimizing the negative effect caused by the main disadvantage of the robotic approach, its absence of tactile feedback, by ensuring uniform tension on the continuous suture lines used, especially during the reconstructive phase of the operation.

Hydro-jet propelled colonoscopy: proof of concept in a phantom colon.

BACKGROUND: Colonoscopy is a widely used and effective procedure, but it often causes patient discomfort and its execution requires considerable skill and training. We demonstrate an alternative approach to colonoscope propulsion with the potential to minimise patient discomfort by reducing the forces exerted on the colonic wall and mesentery, and to reduce the level of skill required for execution. METHODS: A prototype colonoscopic device is described, consisting of a tethered capsule that is propelled and manoeuvred through a water-filled colon (hydro-colonoscopy) by an array of water jets. As an initial proof of concept, experiments were performed to assess the ability of the device to navigate through a simplified PVA cryogel human colon phantom arranged in various anatomical configurations. RESULTS: The prototype was capable of successfully navigating through three out of four colon configurations: a simple layout, alpha loop and reverse alpha loop. It was unable to negotiate the fourth configuration involving an "N loop", but this was attributed to problems with the colon phantom. In the successful test replicates, mean complete insertion (i.e. caecal intubation) time was 4.7 min. Measured pressures, temperatures and forces exerted on the colon appeared to be within a physiologically acceptable range. The results demonstrate the viability of propelling a colonoscope through a colon phantom using hydro-jets. CONCLUSIONS: Results indicate that this approach has the potential to enable rapid and safe caecal intubation. This suggests that further development towards clinical translation is worthwhile.

Objective assessment of surgical operative performance by observational clinical human reliability analysis (OCHRA): a systematic review.

BACKGROUND: Both morbidity and mortality data (MMD) and learning curves (LCs) do not provide information on the nature of intraoperative errors and their mechanisms when these adversely impact on patient outcome. OCHRA was developed specifically to address the unmet surgical need for an objective assessment technique of the quality of technical execution of operations at individual operator level. The aim of this systematic review was to review of OCHRA as a method of objective assessment of surgical operative performance. METHODS: Systematic review based on searching 4 databases for articles published from January 1998 to January 2019. The review complies with Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and includes original publications on surgical task performance based on technical errors during operations across several surgical specialties. RESULTS: Only 26 published studies met the search criteria, indicating that the uptake of OCHRA during the study period has been low. In 31% of reported studies, the operations were performed by fully qualified consultant/attending surgeons and by surgical trainees in 69% in approved training programs. OCHRA identified 7869 consequential errors (CE) during the conduct of 719 clinical operations (mean = 11 CEs). It also identified 'hazard zones' of operations and proficiency-gain curves (P-GCs) that confirm attainment of persistent competent execution of specific operations by individual trainee surgeons. P-GCs are both surgeon and operation specific. CONCLUSIONS: Increased OCHRA use has the potential to improve patient outcome after surgery, but this is a contingent progress towards automatic assessment of unedited videos of operations. The low uptake of OCHRA is attributed to its labor-intensive nature involving human factors (cognitive engineering) expertise. Aside from faster and more objective peer-based assessment, this development should accelerate increased clinical uptake and use of the technique in both routine surgical practice and surgical training.

Robotic-assisted versus open left pancreatectomy for cystic tumours: A single-centre experience.

BACKGROUND: Cystic pancreatic lesions (CPLs) are being identified increasingly, and some benefit from surgical treatment. With the increasing use of robotic-assisted surgery (RAS) for neoplasms of the pancreas, the aim of the present comparative study is to establish whether the RAS offered any advantages over conventional open surgery (OS) in the management of CPLs. PATIENTS AND METHODS: Twenty-seven out of 37 robot-assisted left-sided pancreatectomy (LSP) performed between January 2010 and April 2017 were carried out for CPLs. The surgical outcome and histopathology were compared retrospectively with a control group of 27 patients who had undergone open LSP for CPLs, selected using a one-to-one case-matched methodology (OS-Group) from the prospectively collected institutional database. RESULTS: The spleen was preserved in a significantly higher percentage of patients in the RAS-group (63% vs. 33.3%,P < 0.05). There was no difference in the post-operative course (pancreatic fistula and morbidity) between the two groups. The median post-operative hospital stay was significantly shorter in the RAS-group: 8 days (range 3-25) versus 12 days (range 7-26) in the OS-group (P < 0.01). No conversion to open approach was reported in the RAS-group. CONCLUSIONS: Robotically assisted LSP is a safe and effective procedure. It is accompanied by a significantly higher spleen preservation rate compared to the open approach. In addition, because of the reduced trauma, RAS incurred a shorter post-operative hospital stay and faster return to full recovery, particularly important in patients undergoing surgery for relative indications. However, these benefits of RAS for LSP require confirmation by prospective randomised controlled studies.

A Soft Pneumatic Inchworm Double balloon (SPID) for colonoscopy.

The design of a smart robot for colonoscopy is challenging because of the limited available space, slippery internal surfaces, and tortuous 3D shape of the human colon. Locomotion forces applied by an endoscopic robot may damage the colonic wall and/or cause pain and discomfort to patients. This study reports a Soft Pneumatic Inchworm Double balloon (SPID) mini-robot for colonoscopy consisting of two balloons connected by a 3 degrees of freedom soft pneumatic actuator. SPID has an external diameter of 18 mm, a total length of 60 mm, and weighs 10 g. The balloons provide anchorage into the colonic wall for a bio-inspired inchworm locomotion. The proposed design reduces the pressure applied to the colonic wall and consequently pain and discomfort during the procedure. The mini-robot has been tested in a deformable plastic colon phantom of similar shape and dimensions to the human anatomy, exhibiting efficient locomotion by its ability to deform and negotiate flexures and bends. The mini-robot is made of elastomer and constructed from 3D printed components, hence with low production costs essential for a disposable device.

The Safer Prescription of Opioids Tool (SPOT): A Novel Clinical Decision Support Digital Health Platform for Opioid Conversion in Palliative and End of Life Care-A Single-Centre Pilot Study.

Opioid errors are a leading cause of patient harm. Active failures in opioid dose conversion can contribute to error. Conversion is complex and is currently performed manually using tables of approximate equivalence. Apps that offer opioid dose double-checking are available but there are concerns about their accuracy and clinical validation. This study evaluated a novel opioid dose conversion app, The Safer Prescription of Opioids Tool (SPOT), a CE-marked Class I medical device, as a clinician decision support (CDS) platform. This single-centre prospective clinical utility pilot study followed a mixed methods design. Prescribers completed an initial survey exploring their current opioid prescribing practice. Thereafter prescribers used SPOT for opioid dosage conversions in parallel to their usual clinical practice, then evaluated SPOT through a survey and focus group. SPOT matched the Gold Standard result in 258 of 268 (96.3%) calculations. The 10 instances (3.7%) when SPOT did not match were due to a rounding error. Users had a statistically significant increase in confidence in prescribing opioids after using SPOT. Focus group feedback highlighted benefits in Quality Improvement and Safety when using SPOT. SPOT is a safe, reliable and validated CDS that has potential to reduce harms from opioid dosing errors.

Gastrointestinal stromal tumours of stomach: Robot-assisted excision with the da Vinci Surgical System regardless of size and location site.

Aims: The role of minimally invasive surgery of gastrointestinal stromal tumours (GISTs) of the stomach remains uncertain especially for large and/or difficult located tumours. We are hereby presenting a single-centre series of robot-assisted resections using the da Vinci Surgical System (Si or Xi). Subjects and Methods: Data of patients undergoing robot-assisted treatment of gastric GIST were retrieved from the prospectively collected institutional database and a retrospective analysis was performed. Patients were stratified according to size and location of the tumour. Difficult cases (DCs) were considered for size if tumour was >50 mm and/or for location if the tumour was Type II, III or IV sec. Privette/Al-Thani classification. Results: Between May 2010 and February 2017, 12 consecutive patients underwent robot-assisted treatment of GIST at our institution. DCs were 10/12 cases (83.3%), of which 6/10 (50%) for location, 2/10 (25%) for size and 2/10 (25%) for both. The da Vinci Si was used in 8 patients, of which 6 (75%) were DC, and the da Vinci Xi in 4, all of which (100%) were DC. In all patients, excision was by wedge resection. All lesions had microscopically negative resection margins. There was no conversion to open surgery, no tumour ruptures or spillage and no intraoperative complications. Conclusion: Our experience suggests a positive role of the robot da Vinci in getting gastric GIST removal with a conservative approach, regardless of size and location site. Comparative studies with a greater number of patients are necessary for a more robust assessment.

Structured cost analysis of robotic TME resection for rectal cancer: a comparison between the da Vinci Si and Xi in a single surgeon's experience.

BACKGROUND: Robotic-assisted surgery by the da Vinci Si appears to benefit rectal cancer surgery in selected patients, but still has some limitations, one of which is its high costs. Preliminary studies have indicated that the use of the new da Vinci Xi provides some added advantages, but their impact on cost is unknown. The aim of the present study is to compare surgical outcomes and costs of rectal cancer resection by the two platforms, in a single surgeon's experience. METHODS: From April 2010 to April 2017, 90 robotic rectal resections were performed, with either the da Vinci Si (Si-RobTME) or the da Vinci Xi (Xi-RobTME). Based on CUSUM analysis, two comparable groups of 40 consecutive Si-RobTME and 40 consecutive Xi-RobTME were obtained from the prospectively collected database and used for the present retrospective comparative study. Data costs were analysed based on the level of experience on the proficiency-gain curve (p-g curve) by the surgeon with each platform. RESULTS: In both groups, two homogeneous phases of the p-g curve were identified: Si1 and Xi1: cases 1-19, Si2 and Xi2: cases 20-40. A significantly higher number of full RAS operations were achieved in the Xi-RobTME group (p < 0.001). A statistically significant reduction in operating time (OT) during Si2 and Xi2 phase was observed (p < 0.001), accompanied by reduced overall variable costs (OVC), personnel costs (PC) and consumable costs (CC) (p < 0.001). All costs were lower in the Xi2 phase compared to Si2 phase: OT 265 versus 290 min (p = 0.052); OVC 7983 versus 10231.9 (p = 0.009); PC 1151.6 versus 1260.2 (p = 0.052), CC 3464.4 versus 3869.7 (p < 0.001). CONCLUSIONS: Our experience confirms a significant reduction of costs with increasing surgeon's experience with both platforms. However, the economic gain was higher with the Xi with shorter OT, reduced PC and CC, in addition to a significantly larger number of cases performed by the fully robotic approach.

Piconewton Mechanical Forces Promote Neurite Growth.

Investigations over half a century have indicated that mechanical forces induce neurite growth, with neurites elongating at a rate of 0.1-0.3 µm h-1 pN-1 when mechanical force exceeds a threshold, with this being identified as 400-1000 pN for neurites of PC12 cells. In this article, we demonstrate that neurite elongation of PC12 cells proceeds at the same previously identified rate on application of mechanical tension of ∼1 pN, which is significantly lower than the force generated in vivo by axons and growth cones. This observation raises the possibility that mechanical tension may act as an endogenous signal used by neurons for promoting neurite elongation.

Design of a 2 DOFs Mini Hollow Joint Actuated with SMA Wires.

Shape memory alloys (SMAs) are smart materials used in robotics because of its light weight and high force-to-weight ratio. The low energy efficiency, up to 5%, has limited their use for large actuators. However, they have shown advantages in the design of mini-robots because of the limited volume required for the actuation system. The present study reports the design and construction of a mini compliant joint (MCJ) with a 2 degrees of freedom (DOFs) intersecting axis. The MCJ prototype has a 20 mm external diameter surrounding a cavity of 8 mm, weighs 2 g, is 20 mm high and can perform an angle rotation of 30 ∘ in less than 260 ms. It uses SMA NiTi wires in antagonistic configuration and springs to reduce the energy consumption and minimise heat production. The design methods and experimental results of the manufactured prototype are reported and discussed.

Nano-topography: Quicksand for cell cycle progression?

The 3-D spatial and mechanical features of nano-topography can create alternative environments, which influence cellular response. In this paper, murine fibroblast cells were grown on surfaces characterized by protruding nanotubes. Cells cultured on such nano-structured surface exhibit stronger cellular adhesion compared to control groups, but despite the fact that stronger adhesion is generally believed to promote cell cycle progression, the time cells spend in G1 phase is doubled. This apparent contradiction is solved by confocal microscopy analysis, which shows that the nano-topography inhibits actin stress fiber formation. In turn, this impairs RhoA activation, which is required to suppress the inhibition of cell cycle progression imposed by p21/p27. This finding suggests that the generation of stress fibers, required to impose the homeostatic intracellular tension, rather than cell adhesion/spreading is the limiting factor for cell cycle progression. Indeed, nano-topography could represent a unique tool to inhibit proliferation in adherent well-spread cells.