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Collision feedback about instrument and environment interaction is often lacking in robotic surgery training devices. The PoLaRS virtual reality simulator is a newly developed desk trainer that overcomes drawbacks of existing robot trainers for advanced laparoscopy. This study aimed to assess the effect of haptic and visual feedback during training on the performance of a robotic surgical task. Robotic surgery-naïve participants were randomized and equally divided into two training groups: Haptic and Visual Feedback (HVF) and No Haptic and Visual Feedback. Participants performed two basic virtual reality training tasks on the PoLaRS system as a pre- and post-test. The measurement parameters Time, Tip-to-tip distance, Path length Left/Right and Collisions Left/Right were used to analyze the learning curves and statistically compare the pre- and post-tests performances. In total, 198 trials performed by 22 participants were included. The visual and haptic feedback did not negatively influence the time to complete the tasks. Although no improvement in skill was observed between pre- and post-tests, the mean rank of the number of collisions of the right grasper (dominant hand) was significantly lower in the HVF feedback group during the second post-test (Mean Rank = 8.73 versus Mean Rank = 14.27, U = 30.00, p = 0.045). Haptic and visual feedback during the training on the PoLaRS system resulted in fewer instrument collisions. These results warrant the introduction of haptic feedback in subjects with no experience in robotic surgery. The PoLaRS system can be utilized to remotely optimize instrument handling before commencing robotic surgery in the operating room., Biomechanical Engineering, Medical Instruments & Bio-Inspired Technology

Background The operating room (OR) department is one of the most energy-intensive departments of a hospital. The majority of ORs in the Netherlands have an air-handling installation with an ultra-clean ventilation system. However, not all surgeries require an ultra-clean OR. Aim To determine the effect of reducing the air change rate on the ventilation effectiveness in ultra-clean ORs. Methods Lower air volume ventilation effectiveness (VELv) of conventional ventilation (CV), controlled dilution ventilation (cDV), temperature-controlled airflow (TcAF) and unidirectional airflow (UDAF) systems were evaluated within a 4 × 4 m measuring grid of 1 × 1 m. The VELv was defined as the recovery degree (RD), cleanliness recovery rate (CRR) and air change effectiveness (ACE). Findings The CV, cDVLv and TcAFLv ventilation systems showed a comparable mixing character in all areas (A, B and AB) when reducing the air change rate to 20/h. Ventilation effectiveness decreased when the air change rate was reduced, with the exception of the ACE. At all points for the UDAF-2Lv and at the centre point (C3) of the TcAFLv, higher RD10Lv and CRRLv were measured when compared with the other examined ventilation systems. Conclusions The ventilation effectiveness decreased when an ultra-clean OR with an ultra-clean ventilation air-supply system was switched to an air change rate of 20/h. Reducing the air change rate in the OR from an ultra-clean OR to a generic OR will reduce the recovery degree (RD10) by a factor of 10–100 and the local air change rate (CRR) by between 42% and 81%., Environmental & Climate Design, Medical Instruments & Bio-Inspired Technology

In this paper, we aim to design an automatic camera pose estimation pipeline for clinical spaces such as catheterization laboratories. Our proposed pipeline exploits Scaled-YOLOv4 to detect fixed objects. We adopt the self-supervised key-point detector SuperPoint in combination with SuperGlue, a keypoint matching technique based on graph neural networks. Thus, we match key-points on input images with annotated reference points. Reference points are chosen on fixed objects in the scene, such as corners of door posts or windows. The point-correspondences between the image coordinates and the 3D coordinates are applied to the Perspective-n-Point algorithm to estimate the pose of each camera. Compared with other camera pose estimation methods, the proposed pipeline does not require the construction of 3D point-cloud model of the scene or placing a polyhedron object in the scene before each required calibration. Using videos from real procedures, we show that the pipeline can estimate the camera pose with high accuracy., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Medical Instruments & Bio-Inspired Technology, Support Biomechanical Engineering, Signal Processing Systems

When making a decision on the operating room air handling installation and type of air supply system, it is relevant to know the expenditures of the different air handling installations and air supply systems. The aim of this study was to determine the capital and operational expenditures of air handling installations equipped with an ultra-clean or with a conventional system. To compare the technical requirements of Dutch air handling installations with European standards and guidelines, and evaluate the costs of surgical site infections in comparison with the capital expenditures. This study fills a gap in knowledge, detailed technical information and costs of air handling installations and air supply systems from multiple completed projects of 24 hospitals were collected, analyzed and compared. Per OR capital expenditures increase by €62,491 to €139,018 when an air handling installation with an ultra-clean system is compared to a conventional system, which is 3%–7% of the total construction costs of a completely new OR department. The yearly increase in operational expenditures per OR with an ultra-clean system compared to a conventional system was €673 to €1,896. The capital and operational expenditures of air handling installations with an ultra-clean system are higher than those with a conventional system. The technical specifications of the ORs studied in the Netherlands correspond to European standards and guidelines. When the impact on patient suffering and costs associated with surgical site infections are weighed against the investment required for an air handling installation with an ultra-clean system, it is worth considering., Environmental & Climate Design, Medical Instruments & Bio-Inspired Technology, Support Biomechanical Engineering

Ultra-clean ventilation systems are used in the operating room (OR) to reduce the quantity of airborne bacteria in the ultra-clean area, and reduce the incidence of surgical site infections (SSIs). When the number of colony-forming units (CFUs) in the ultra-clean (protected) area is too high, this is considered a risk factor for SSIs., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Environmental & Climate Design, Medical Instruments & Bio-Inspired Technology

Workflow analysis is a young research field that has been gaining traction in recent years. Work in this field aims to improve the efficiency and safety in operating rooms by analysing surgical processes and providing feedback or support, where observations are made and evaluated by algorithms rather than human experts. For our study, we mount five cameras from different angles in a Catheterization Laboratory (CathLab) to observe and analyse Cardiac Angiogram procedures. To automate the classification of workflow and personnel activities, we propose a pipeline that first automates the camera calibration of the 5-camera network then detect locations of medical equipment and track personnel activities..., Medical Instruments & Bio-Inspired Technology, Circuits and Systems, Support Biomechanical Engineering

BACKGROUND: Patients at the end-of-life may experience refractory symptoms of which pain, delirium, vomiting and dyspnea are the most frequent. Palliative sedation can be considered a last resort option to alleviate one or more refractory symptoms. There are only a limited number of (qualitative) studies exploring the experiences of relatives of sedated patients and their health care professionals (HCPs). The aims of this study protocol are: 1) to elicit the experiences of bereaved relatives and health care professionals of patients treated with palliative sedation and 2) to explore the understanding of the decision-making process to start palliative sedation across care settings in 5 European countries. METHODS: This study protocol is part of the larger HORIZON 2020 Palliative Sedation project. Organisational case study methodology will be used to guide the study design. In total, 50 cases will be conducted in five European countries (10 per country). A case involves a semi-structured interview with a relative and an HCP closely involved in the care of a deceased patient who received some type of palliative sedation at the end-of-life. Relatives and health care professionals of deceased patients participating in a linked observational cohort study of sedated patients cared for in hospital wards, palliative care units and hospices will be recruited. The data will be analyzed using a framework analysis approach. The first full case will be analyzed by all researchers after being translated into English using a pre-prepared code book. Afterwards, bimonthly meetings will be organized to coordinate the data analysis. DISCUSSION: The study aims to have a better understanding of the experiences of relatives and professional caregivers regarding palliative sedation and this within different settings and countries. Some limitations are: 1) the sensitivity of the topic may deter some relatives from participation, 2) since the data collection and analysis will be performed by

The authors regret that they have missed during the review process that the legend belonging to figure 6a, 6b, 6c and 6d is not shown. It is necessary to show the legenda otherwise the readers cannot interpret the graphs. Apologies that we missed it during the review process of the article. The legend belonging to figure 6 is:[Formula presented] The authors would like to apologize for any inconvenience caused., Building Services, Medical Instruments & Bio-Inspired Technology, Support Biomechanical Engineering

Background: As global use of surgical robotic systems is steadily increasing, surgical simulation can be an excellent way for robotic surgeons to acquire and retain their skills in a safe environment. To address the need for training in less wealthy parts of the world, an affordable surgical robot simulator (PoLaRS) was designed. Methods: The aim of this pilot study is to compare learning curve data of the PoLaRS prototype with those of Intuitive Surgical’s da Vinci Skills Simulator (dVSS) and to establish face- and construct validity. Medical students were divided into two groups; the test group (n = 18) performing tasks on PoLaRS and dVSS, and the control group (n = 20) only performing tasks on the dVSS. The performance parameters were Time, Path length, and the number of collisions. Afterwards, the test group participants filled in a questionnaire regarding both systems. Results: A total of 528 trials executed by 38 participants were measured and included for analyses. The test group significantly improved in Time, Path Length and Collisions during the PoLaRS test phase (P ≤ 0.028). No differences was found between the test group and the control group in the dVSS performances during the post-test phase. Learning curves showed similar shapes between both systems, and between both groups. Participants recognized the potential benefits of simulation training on the PoLaRS system. Conclusions: Robotic surgical skills improved during training with PoLaRS. This shows the potential of PoLaRS to become an affordable alternative to current surgical robot simulators. Validation with similar tasks and different expert levels is needed before implementing the training system into robotic training curricula., Medical Instruments & Bio-Inspired Technology, Support Biomechanical Engineering

Background: Entrainment test methods are described in most European standards and guidelines to determine the protected area for ultra-clean ventilation (UCV) systems. New UCV systems, such as temperature-controlled airflow (TcAF) and controlled dilution ventilation (cDV) systems, claim the whole operating room (OR) to be ultra-clean. However, current test standards were not developed to assess ventilation effectiveness outside the standard protected area. Aim: To assess and compare the ventilation effectiveness of four types of OR ventilation systems in the ultra-clean area using a uniform test grid. Methods: Ventilation effectiveness of four ventilation systems was evaluated for three different ultra-clean (protected) areas: the standard protected area (A); the area outside the standard protected area (B); and a large protected area (AB). Ventilation effectiveness was assessed using recovery degree (RD), cleanliness recovery rate (CRR) and air change effectiveness (ACE). Findings: RD, CRR and ACE were significantly higher for the unidirectional air flow (UDAF) system compared with the other systems in area A. In area B, the UDAF and cDV systems were comparable for RD and CRR, and the UDAF and conventional ventilation (CV) systems were comparable for ACE. In area AB, the UDAF and cDV systems were comparable for CRR and ACE, but significant differences were found in RD. Conclusion: In area A, the ventilation effectiveness of the UDAF system outperformed other ventilation systems. In area B, the cDV system was best, followed by the UDAF, TcAF and CV systems. In area AB, the UDAF system was best, followed by the cDV, TcAF and CV systems., Building Services, Medical Instruments & Bio-Inspired Technology, Support Biomechanical Engineering

Introduction Hospitals in the Netherlands generate approximately 1.3 million kg of waste from the polypropylene (PP) wrapping paper (WP) used to wrap surgical instruments each year. The aim of this study was to develop a method to recycle WP waste into new medical devices. Methods WP was recovered from Maasstad Hospital, Netherlands. The WP was melted into bars, granulated, and mixed with virgin material at different ratios and temperatures. Dog bones were injection-molded from volume (v.%) virgin, mixed (%R), and recycled (100%R) granulate, and a tensile testing machine was used to compare the material properties before and after ten disinfection cycles at the sterilization department. Then, 25 instrument openers were made from the 50%R material and circulated for four weeks. Results The data indicated no significant differences in the mechanical properties at different melting temperatures. For dog bones made from the 100%R, 50%R, and virgin granulate, the Young's moduli were 1021 (SD13), 879 (SD13), and 795 (SD14) MPa, and the strains were 8%, 12%, and 14%. Ten disinfection cycles did not significantly change the material properties. After one month, the openers did not show any deterioration or damage other than surface scratches. Discussion The results indicated that the initial WP melting temperature did not influence the mechanical properties. Although devices could be produced directly from the recycled WP granulate, increasing the recycled granulate in the mix ratio increased the strength and brittleness. Conclusions It is feasible to recycle WP waste into a high-quality raw material for the injection molding of medical devices without using additives. This would allow hospitals to become more compliant with the circular economy enabling economically viable and circular processes that positively contribute to cleaner technical processes, sustainable products, and the reduction of medical waste., Medical Instruments & Bio-Inspired Technology, Support Biomechanical Engineering

Context: Near the end of life when patients experience refractory symptoms, palliative sedation may be considered as a last treatment. Clinical guidelines have been developed, but they are mainly based on expert opinion or retrospective chart reviews. Therefore, evidence for the clinical aspects of palliative sedation is needed. Objectives: To explore clinical aspects of palliative sedation in recent prospective studies. Methods: Systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and registered at PROSPERO. PubMed, CINAHL, Cochrane, MEDLINE, and EMBASE were searched (January 2014–December 2019), combining sedation, palliative care, and prospective. Article quality was assessed. Results: Ten prospective articles were included, involving predominantly patients with cancer. Most frequently reported refractory symptoms were delirium (41%–83%), pain (25%–65%), and dyspnea (16%–59%). In some articles, psychological and existential distress were mentioned (16%–59%). Only a few articles specified the tools used to assess symptoms. Level of sedation assessment tools were the Richmond Agitation Sedation Scale, Ramsay Sedation Scale, Glasgow Coma Scale, and Bispectral Index monitoring. The palliative sedation practice shows an underlying need for proportionality in relation to symptom intensity. Midazolam was the main sedative used. Other reported medications were phenobarbital, promethazine, and anesthetic medication—propofol. The only study that reported level of patient's discomfort as a palliative sedation outcome showed a decrease in patient discomfort. Conclusion: Assessment of refractory symptoms should include physical evaluation with standardized tools applied and interviews for psychological and existential evaluation by expert clinicians working in teams. Future research needs to evaluate the effectiveness of palliative sedation for refractory symptom relief. © 2020 The Authors

Context: Near the end of life when patients experience refractory symptoms, palliative sedation may be considered as a last treatment. Clinical guidelines have been developed, but they are mainly based on expert opinion or retrospective chart reviews. Therefore, evidence for the clinical aspects of palliative sedation is needed. Objectives: To explore clinical aspects of palliative sedation in recent prospective studies. Methods: Systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and registered at PROSPERO. PubMed, CINAHL, Cochrane, MEDLINE, and EMBASE were searched (January 2014–December 2019), combining sedation, palliative care, and prospective. Article quality was assessed. Results: Ten prospective articles were included, involving predominantly patients with cancer. Most frequently reported refractory symptoms were delirium (41%–83%), pain (25%–65%), and dyspnea (16%–59%). In some articles, psychological and existential distress were mentioned (16%–59%). Only a few articles specified the tools used to assess symptoms. Level of sedation assessment tools were the Richmond Agitation Sedation Scale, Ramsay Sedation Scale, Glasgow Coma Scale, and Bispectral Index monitoring. The palliative sedation practice shows an underlying need for proportionality in relation to symptom intensity. Midazolam was the main sedative used. Other reported medications were phenobarbital, promethazine, and anesthetic medication—propofol. The only study that reported level of patient's discomfort as a palliative sedation outcome showed a decrease in patient discomfort. Conclusion: Assessment of refractory symptoms should include physical evaluation with standardized tools applied and interviews for psychological and existential evaluation by expert clinicians working in teams. Future research needs to evaluate the effectiveness of palliative sedation for refractory symptom relief. © 2020 The Authors