Exposure to inclined trunk postures in surgical staff.

In surgical staff, low-back pain (LBP) is prevalent and prolonged trunk inclination is hypothesized to be one of its potential causes. The aim of this study was to evaluate the magnitude and duration of trunk inclination in the sagittal plane of surgical assistants during surgical procedures. The three-dimensional trunk orientation was measured in 91 surgical assistants across four medical facilities during surgical procedures using an inertial measurement unit on the thorax. Per participant, Exposure Variation Analysis was used to evaluate the percentage of the total time of trunk inclination (< -10° (backward inclination); -10-10° (upright posture); 10-20° (light inclination); 20-30° (moderate inclination); >30° (strong inclination)) taking into account posture duration (< 10 s; 10-60 s; 60-300 s; > 300 s). Participants reported their LBP history and perceived low-back load during the procedure via a questionnaire. Participants were in an upright posture for 75% [63-84%] (median [interquartile range]) of the total surgery time (average surgery time: 174 min). Trunk inclination was beyond 20° and 30° for 4.3% [2.1-8.7%] and 1.5% [0.5-3.2%] of the surgery time, respectively. In most of the participants, the duration of trunk inclination beyond 20° or 30° was less than 60 s. Questionnaire response rate was 81%. Persistent or repeated LBP was reported by 49% of respondents, and was unrelated to the exposure to inclined trunk postures. It is concluded that other factors than prolonged trunk inclination, for instance handling of loads or prolonged standing may be causally related to the reported LBP in the investigated population.

The effect of back muscle fatigue on EMG and kinematics based estimation of low-back loads and active moments during manual lifting tasks.

This study investigated the effects of back muscle fatigue on the estimation of low-back loads and active low-back moments during lifting, using an EMG and kinematics based model calibrated with data from an unfatigued state. Fourteen participants performed lifting tasks in unfatigued and fatigued states. Fatigue was induced through semi-static forward bending. EMG, kinematics, and ground reaction forces were measured, and low-back loads were estimated using inverse dynamics and EMG-driven muscle model. A regression model was developed using data from a set of calibration lifts, and its accuracy was evaluated for unfatigued and fatigued lifts. During the fatigue-inducing task, the EMG amplitude increased by 2.8 %MVC, representing a 38% increase relative to the initial value. However, during the fatigued lifts, the peak EMG amplitude was found to be 1.6 %MVC higher than that observed during the unfatigued lifts, representing a mere 4% increase relative to the baseline unfatigued peak EMG amplitude. Kinematics and low-back load estimates remained unaffected. Regression model estimation errors remained unaffected for 5 kg lifts, but increased by no more than 5% of the peak active low-back moment for 15 kg lifts. We conclude that the regression-based estimation quality of active low-back moments can be maintained during periods of muscle fatigue, although errors may slightly increase for heavier loads.

Urgent endovascular aorta repair for a rupture of a traumatic infrarenal aortic dissection: Case report and review of literature.

Traumatic aortic injury is a life-threatening condition usually followed by blunt trauma with damage at the thoracic aorta. Abdominal aortic injuries are rare and usually seen with seatbelt trauma. Timing and approach of treatment are associated with significant morbidity and mortality. This case concerns a 66-year-old man with a high impact trauma after a fall from height. Upon presentation in our level two trauma center, he was conscious but hemodynamically unstable. Computer Tomography scan revealed multiple rib, spine and pelvic fractures with bilateral lung contusions warranting a transfer to a level one trauma center. However, an infrarenal aortic dissection with a retroperitoneal rupture and active bleeding necessitated acute surgical intervention. He was treated endovascularly with an off-the-shelf aortic stent graft which is meant for aortic aneurysm repair. Surgery was performed percutaneously under local anesthetic. Other fractures were treated conservatively. Postoperatively, the patient made a swift recovery without any complications in follow-up. As this case demonstrates, urgent endovascular repair of a traumatic infrarenal aortic injury can be done quickly with a minimally invasive approach with conventional stent graft systems thereby reducing the high morbidity and mortality rates associated with this life-threatening condition.

Efficient explicit numerical solutions of the time-dependent Schrödinger equation.

Explicit numerical solutions of the time-dependent Schrödinger equation are more efficient than those obtained by commonly used implicit approaches. They are more practical, especially for a system with higher spatial dimensions. To that end, we introduce a generalization of an explicit three-level method to obtain solutions with spatial and temporal errors of the order of O[(Δx)^{2r}] and O[(Δt)^{2M+3}], where Δx and Δt are the spatial and temporal grid elements, and r and M are positive integers. Sample calculations illustrate the efficacy and stability of the algorithm.

What about the human in human robot collaboration?

In this review we address the human in human robot collaboration (HRC). Although there are different hypotheses on potential effects of HRC on job quality, defined as the quality of the working environment and its effect on the employee's well-being, a comprehensive theory is still lacking. How does HRC influence job quality on an individual level and how can we adapt HRC to boost positivity at work? We identified four job quality related factors that are of relevance in HRC: (1) Cognitive Workload, (2) Collaboration Fluency, (3) Trust, and (4) Acceptance and Satisfaction. Increasing awareness and being able to adapt the robot to the individual operator are crucial to improve the aforementioned factors. Implementing predictable robots, that offer a clear advantage to the human and take into account operators' preferences, will bring us closer to a human-centered collaboration. Practitioner Summary: The effect of human robot collaboration (HRC) on job quality is still under debate. Design characteristics of HRC, such as collaboration design, robot design, and workplace design affect job quality related factors. Using a participatory design approach, as to align robot capabilities to end-users' preferences, will enhance HRC and improve job quality. Abbreviations: HRC: human robot collaboration; OECD: organisation for economic co-operation and development.

The practical utility of genetic screening in school settings.

Can genetic screening be used to personalize education for students? Genome-wide association studies (GWAS) screen an individual's DNA for specific variations in their genome, and how said variations relate to specific traits. The variations can then be assigned a corresponding weight and summed to produce polygenic scores (PGS) for given traits. Though first developed for disease risk, PGS is now used to predict educational achievement. Using a novel simulation method, this paper examines if PGS could advance screening in schools, a goal of personalized education. Results show limited potential benefits for using PGS to personalize education for individual students. However, further analysis shows PGS can be effectively used alongside progress monitoring measures to screen for learning disability risk. Altogether, PGS is not useful in personalizing education for every child but has potential utility when used simultaneously with additional screening tools to help determine which children may struggle academically.

Modelling water levels of northwestern India in response to improved irrigation use efficiency.

The groundwater crisis in northwestern India is the result of over-exploitation of groundwater resources for irrigation. The Government of India has targeted a 20 percent improvement in irrigation groundwater use efficiency. In this perspective, and using a regional-scale calibrated and validated three-dimensional groundwater flow model, this article provides the first forecasts of water levels in the study area up to the year 2028, both with and without this improvement in use efficiency. Future water levels without any mitigation efforts are anticipated to decline by up to 2.8 m/year in some areas. A simulation with a 20 percent reduction in groundwater abstraction shows spatially varied aquifer responses. Tangible results are visible in a decade, and the water-level decline rates decrease by 36-67 percent in over-exploited areas. Although increasing irrigation use efficiency provides tangible benefits, an integrated approach to agricultural water management practice that incorporates use efficiency along with other measures like water-efficient cropping patterns and rainwater harvesting may yield better results in a shorter period.

Critical dependence of morphodynamic models of fluvial and tidal systems on empirical downslope sediment transport.

The morphological development of fluvial and tidal systems is forecast more and more frequently by models in scientific and engineering studies for decision making regarding climate change mitigation, flood control, navigation and engineering works. However, many existing morphodynamic models predict unrealistically high channel incision, which is often dampened by increased gravity-driven sediment transport on side-slopes by up to two orders of magnitude too high. Here we show that such arbitrary calibrations dramatically bias sediment dynamics, channel patterns, and rate of morphological change. For five different models bracketing a range of scales and environments, we found that it is impossible to calibrate a model on both sediment transport magnitude and morphology. Consequently, present calibration practice may cause an order magnitude error in either morphology or morphological change. We show how model design can be optimized for different applications. We discuss the major implications for model interpretation and a critical knowledge gap.

Effects of Shoal Margin Collapses on the Morphodynamics of a Sandy Estuary.

Shoal margin collapses of several million cubic meters have occurred in the Western Scheldt estuary, the Netherlands, on average five times a year over the last decades. While these collapses involve significant volumes of material, their effect on the channel-shoal morphology is unknown. We hypothesize that collapses dynamicize the channel-shoal interactions, which could impact the ecological functioning, flood safety, and navigation in the estuary. The objective is to investigate how locations, probability, type, and volume of shoal margin collapse affect the channel-shoal dynamics. We implemented an empirically validated parameterization for shoal margin collapses and tested its effect on simulated estuary morphological development in a Delft3D schematization of the Western Scheldt. Three sets of scenarios were analyzed for near-field and far-field effects on flow pattern and channel-shoal morphology: (1) an observed shoal margin collapse of 2014, (2) initial large collapses on 10 locations, and (3) continuous collapses predicted by our novel probabilistic model over a time span of decades. Results show that a single shoal margin collapse only affects the local dynamics in the longitudinal flow direction and dampen out within a year for typical volumes, whereas larger disturbances that reach the seaward or landward sill at tidal channel junctions grow. The direction of the strongest tidally averaged flow determined the redistribution of the collapsed sediment. We conclude that adding the process of shoal margin collapses increases the channel-shoal interactions and that in intensively dredged estuaries shoal margins oversteepen, amplifying the number of collapses, but because of dredging the natural morphological response is interrupted.

What you should know about the low anterior resection syndrome - Clinical recommendations from a patient perspective.

INTRODUCTION: Functional bowel complaints, referred to as Low Anterior Resection Syndrome (LARS), are common after sphincter-saving surgical procedures and have a severe impact on quality of life (QoL). Care for LARS patients is complex and surgeons underestimate or misinterpret its associated symptoms. This study aimed to explore the impact of LARS from a patient perspective facilitating the construction of a set of recommendations improving current care stratagems. METHODS: In a non-academic Dutch teaching hospital, three focus group sessions were conducted with 16 patients (males = 50%) who had undergone colorectal surgery between 2012 and 2017. A trained moderator orchestrated patient-discussion regarding illness perception and health-care needs. Transcripts were analysed using inductive content analysis. RESULTS: Three themes were identified: illness perception, preoperative care and postoperative supportive care. Specific attention and screening for LARS is deemed necessary for breaking the taboo surrounding it. Extension of preoperative counselling on the normal postoperative course, including ways to optimize social support, were identified as crucial. After discharge, patients experienced a lack of supportive care regarding functional complaints and did not know who to counsel. In addition, they felt intrinsically motivated to actively prepare for surgery, i.e. by participating in prehabilitation programs. CONCLUSION: Exploring perspectives in LARS patients resulted in the identification of potential improvements in current care pathways. Recommendations on ways to improve information provision, screening of LARS and methods to intervene in the gap of supportive care after discharge are presented. We recommend to implement these measures as QoL of patients undergoing colorectal cancer surgery may be improved.

[Better care and lower costs through registries; a first step to reimbursement based on outcome]. / Gedifferentieerd belonen mogelijk door registratie.

We have recently shown that costs of surgical treatment for colorectal carcinoma differ greatly between various patient groups in the Netherlands. Those cost-differences could mostly be explained by the fact that high-risk patients have a greater risk of complications, which generate higher hospital costs. Hospitals with a high-risk population, for instant tertiary referral centres, spend more than hospitals that treat low-risk patients. Currently reimbursement however is not geared to risk differences. In this article we investigate this shortcoming of the current reimbursement system and discuss how a differential rewarding - in which reimbursement is aligned with the patient's risk profile - could serve as a tool to further quality improvement in healthcare. Current clinical registries may provide the necessary details of patient characteristics for risk profiling and may also contribute to the following goal: reimbursement based on the quality of delivered care.

Hospital costs of complications after esophagectomy for cancer.

OBJECTIVE: The purpose of this study was to estimate the economic burden of postoperative complications after esophagectomy for cancer, in order to optimally allocate resources for quality improvement initiatives in the future. METHODS: A retrospective analysis of prospectively collected clinical and financial outcomes after esophageal cancer surgery in a tertiary referral center in the Netherlands was performed. Data was extracted from consecutive patients registered in the Dutch Upper GI Cancer Audit between 2011 and 2014 (n = 201). Costs were measured up to 90-days after hospital discharge and based on Time-Driven Activity-Based Costing. The additional costs were estimated using multiple linear regression models. RESULTS: The average total cost for one patient after esophagectomy was €37,581 (±31,372). The estimated costs of an esophagectomy without complications were €23,476 (±6496). Mean costs after minor (47%) and severe complications (29%) were €31,529 (±23,359) and €59,167 (±42,615) (p < 0.001), respectively. The 5% most expensive patients were responsible for 20.3% of the total hospital costs assessed in this study. Patient characteristics associated with additional costs in multivariable analysis included, age >70 (+€2,922, p = 0.036), female gender (+€4,357, p = 0.005), COPD (+€5,415, p = 0.002), and a history of thromboembolic events (+€6,213, p = 0.028). Complications associated with a significant increase in costs in multivariable analysis included anastomotic leakage (+€4,123, p = 0.008), cardiac complications (+€5,711, p = 0.003), chyle leakage (+€6,188, p < 0.001) and postoperative bleeding (+€31,567, p < 0.001). CONCLUSIONS: Complications and severity of complications after esophageal surgery are associated with a substantial increase in costs. Although not all postoperative complications can be prevented, implementation of preventive measures to reduce complications could result in a considerable cost reduction and quality improvement.

[Chronic neuralgia after knee surgery]. / Chronische zenuwpijn na een operatie aan de knie.

BACKGROUND: Chronic knee symptoms after surgery around the knee may be neuropathic. These symptoms are often described after intramedullary osteosynthesis of the lower leg, placement of total knee prosthesis and arthroscopy. This neuropathic pain may be caused by partial damage to the infrapatellar nerve. CASE DESCRIPTION: An 18-year-old patient had chronic neuropathic symptoms after intramedullary osteosynthesis of the lower leg. The diagnosis was made through physical examination and injection of lidocaine 1%. After surgical removal of the infrapatellar nerve, the patient became symptom-free for a long time. CONCLUSION: In case of chronic pain around the knee, neuropathic pain resulting from infrapatellar nerve damage should be part of the differential diagnosis. Neurectomy of the patellar nerve is a good treatment if conservative therapy did not lead to improvement of the symptoms.

Costs of complications after colorectal cancer surgery in the Netherlands: Building the business case for hospitals.

BACKGROUND: Healthcare providers worldwide are struggling with rising costs while hospitals budgets are under stress. Colorectal cancer surgery is commonly performed, however it is associated with a disproportionate share of adverse events in general surgery. Since adverse events are associated with extra hospital costs it seems important to explicitly discuss the costs of complications and the risk factors for high-costs after colorectal surgery. METHODS: Retrospective analysis of clinical and financial outcomes after colorectal cancer surgery in 29 Dutch hospitals (6768 patients). Detailed clinical data was derived from the 2011-2012 population-based Dutch Surgical Colorectal Audit database. Costs were measured uniform in all participating hospitals and based on Time-Driven Activity-Based Costing. FINDINGS: Of total hospital costs in this study, 31% was spent on complications and the top 5% most expensive patients were accountable for 23% of hospitals budgets. Minor and severe complications were respectively associated with a 26% and 196% increase in costs as compared to patients without complications. Independent from other risk factors, ASA IV, double tumor, ASA III, short course preoperative radiotherapy and TNM-4 stadium disease were the top-5 attributors to high costs. CONCLUSIONS: This article shows that complications after colorectal cancer surgery are associated with a substantial increase in costs. Although not all surgical complications can be prevented, reducing complications will result in considerable cost savings. By providing a business case we show that investments made to develop targeted quality improvement programs will pay off eventually. Results based on this study should encourage healthcare providers to endorse quality improvement efforts.

Numerical solutions of the Schrödinger equation with source terms or time-dependent potentials.

We develop an approach to solving numerically the time-dependent Schrödinger equation when it includes source terms and time-dependent potentials. The approach is based on the generalized Crank-Nicolson method supplemented with an Euler-MacLaurin expansion for the time-integrated nonhomogeneous term. By comparing the numerical results with exact solutions of analytically solvable models, we find that the method leads to precision comparable to that of the generalized Crank-Nicolson method applied to homogeneous equations. Furthermore, the systematic increase in precision generally permits making estimates of the error.

Improving the transparency of a rehabilitation robot by exploiting the cyclic behaviour of walking.

To promote active participation of neurological patients during robotic gait training, controllers, such as "assist as needed" or "cooperative control", are suggested. Apart from providing support, these controllers also require that the robot should be capable of resembling natural, unsupported, walking. This means that they should have a transparent mode, where the interaction forces between the human and the robot are minimal. Traditional feedback-control algorithms do not exploit the cyclic nature of walking to improve the transparency of the robot. The purpose of this study was to improve the transparent mode of robotic devices, by developing two controllers that use the rhythmic behavior of gait. Both controllers use adaptive frequency oscillators and kernel-based non-linear filters. Kernelbased non-linear filters can be used to estimate signals and their time derivatives, as a function of the gait phase. The first controller learns the motor angle, associated with a certain joint angle pattern, and acts as a feed-forward controller to improve the torque tracking (including the zero-torque mode). The second controller learns the state of the mechanical system and compensates for the dynamical effects (e.g. the acceleration of robot masses). Both controllers have been tested separately and in combination on a small subject population. Using the feedforward controller resulted in an improved torque tracking of at least 52 percent at the hip joint, and 61 percent at the knee joint. When both controllers were active simultaneously, the interaction power between the robot and the human leg was reduced by at least 40 percent at the thigh, and 43 percent at the shank. These results indicate that: if a robotic task is cyclic, the torque tracking and transparency can be improved by exploiting the predictions of adaptive frequency oscillator and kernel-based nonlinear filters.

FDI Global Caries Initiative; implementing a paradigm shift in dental practice and the global policy context.

The implementation of a new paradigm for caries management is necessary for the profession to respond effectively to changing population health needs. The FDI Global Caries Initiative (GCI) is a 10 year programme aimed at developing and implementing a new paradigm for caries management, one that would contribute to a common vision of health. The article reviews the global health policy landscape and examines how it might influence and shape the implementation of the GCI.

Universal equation of state of a unitary fermionic gas.

It is suggested that for a Fermi gas at unitarity, the two-body bond plays a special role. We propose an equation of state using an ansatz relating the interaction part of the l-body cluster to its two-body counterpart. This allows a parameter-free comparison with the recently measured equation of state by the ENS group. The agreement between the two over a range of fugacity (z<5 for a homogeneous gas, and z<10 for the trapped gas) leads us to perform the calculations of more sensitive quantities measured recently by the MIT group.

Efficiency and accuracy of numerical solutions to the time-dependent Schrödinger equation.

Recent significant improvements of the numerical solutions of the time-dependent Schrödinger equation beg the question as to whether these recent methods are comparable in efficacy (in terms of accuracy and computational time) to the current "method of choice," i.e., the Chebyshev expansion of the time-evolution operator and the fast-Fourier-transform method of determining the kinetic energy. In this paper we review the methods in question and, by studying the time development of a coherent wave packet in an oscillator well, we are able to assess the effectiveness of the various methods. It turns out that the new generalizations come close (to within an order of magnitude) to being able to generate solutions as precisely and efficiently as the Chebyshev-fast-Fourier-transform method. The strict unitarity of the generalized methods may be an advantage. We also show that the fast-Fourier-transform approach to calculating the kinetic energy can be replaced by straightforward numerical differentiation to obtain the same precision.