Designing cable harnesses can be time-consuming and complex due to many design and manufacturing aspects and rules. Automating the design process can help to fulfil these rules, speed up the process, ...and optimize the design. To accommodate this, we formulate a harness routing optimization problem to minimize cable lengths, maximize bundling by rewarding shared paths, and optimize the cables’ spatial location with respect to case-specific information of the routing environment, e.g., zones to avoid. A deterministic and computationally effective cable harness routing algorithm has been developed to solve the routing problem and is used to generate a set of cable harness topology candidates and approximate the Pareto front. Our approach was tested against a stochastic and an exact solver and our routing algorithm generated objective function values better than the stochastic approach and close to the exact solver. Our algorithm was able to find solutions, some of them being proven to be near-optimal, for three industrial-sized 3D cases within reasonable time (in magnitude of seconds to minutes) and the computation times were comparable to those of the stochastic approach.
•We present a multi-objective graph-based optimization model for cable harness routing.•The model is based on the shortest path problem and the Steiner tree problem.•We propose a novel routing algorithm for the cable harness routing problem.•Our method generates topologically different candidate solutions.
A subset of patients successfully treated for developmental dysplasia of the hip (DDH) as infants have symptomatic acetabular dysplasia at skeletal maturity leading to periacetabular osteotomy (PAO). ...The purpose of this study was to compare femoral and acetabular morphology in PAO patients with late acetabular dysplasia after previous treatment for DDH with PAO patients who do not have a history of DDH treatment.
A single surgeon's patients who underwent PAO between 2011 and 2021 were retrospectively reviewed. Patients previously treated for infantile DDH with a Pavlik harness, abduction brace, closed reduction and spica casting, or open reduction and spica casting were included. Patients with previous bony hip surgery were excluded. Preoperative radiographic measurements of each hip were recorded including lateral center edge angle, anterior center edge angle, and Femoro-Epiphyseal Acetabular Roof index. Computed tomography measurements included the coronal center edge angle, sagittal center edge angle, Tönnis angle, acetabular anteversion at 1, 2, and 3 o'clock, femoral neck-shaft angle, femoral version, and alpha angle. Control PAO cases without a history of DDH diagnosis or treatment were matched with the infantile DDH treatment group in a 2:1 ratio based on coronal center edge angle, age, and sex.
There were 21 hips in 18 patients previously treated for infantile DDH (13 patients Pavlik harness, 3 abduction brace, 1 closed reduction, and 1 open reduction). The control PAO cohort was 42 hips in 42 patients who did not have previous DDH treatment. There was no statistically significant difference in any of the recorded measurements between patients previously treated for DDH and those without previous treatment including femoral version (P=0.494), anteversion at 1 o'clock (P=0.820), anteversion at 2 o'clock (P=0.584), anteversion at 3 o'clock (P=0.137), neck-shaft angle (P=0.612), lateral center edge angle (P=0.433), Femoro-Epiphyseal Acetabular Roof index (P=0.144), and alpha angle (P=0.156).
Femoral and acetabular morphology is similar between PAO patients with persistent symptomatic acetabular dysplasia following DDH treatment and patients presenting after skeletal maturity with acetabular dysplasia and no previous history of DDH treatment.
Level III-case-control, prognostic study.
Tagging wildlife with transmitters is one of the most widely used techniques for research and monitoring. Knowing the possible impact of attaching transmitters to an animal has always concerned ...researchers; however, most assessments have been directed at the effects of transmitters on behaviour and fitness, and fewer have addressed possible injuries to the individuals. The present study evaluated the physical status of birds tagged with transmitters mounted with a Garcelon‐type backpack harness, from five species of large and medium‐sized soaring raptors in western Europe. The study also assessed the factors determining their duration and outcomes. We sent a survey to the managers of projects involving tagged raptors over a 24‐year period, concerning tracking results and veterinary analyses. We obtained information on 659 birds, of which 196 included clinical evaluation from birds in hand. None of the birds showed marks, injuries or abrasions on their feathers or skin caused by the harness or the transmitter. Therefore, this deployment technique is recommended for soaring birds in general and for others in which the use of a backpack harness is chosen. The duration of the system on the bird depended on the traits of the transmitter, being greater in platform transmitter terminal (PTT) satellites. The device lasted longer in larger species and for a shorter time when tagging nestlings. We propose the need for nestlings to be fitted with harnesses corresponding to the size of their adult conspecifics, distinguishing between males and females. Otherwise, the differential growth between sexes could cause discomfort and more frequent removal attempts of the harness. Our results are especially useful for managers and ethics committees to assess bird welfare risks before issuing official permits.
Routing of wire harnesses in complex machinery is a complicated problem. In this paper, we present an approach for computing all non-homotopic paths characteristic of all the homotopy classes ...associated with a pair of source–destination points embedded on the surface of the product. We introduce the notion of routing graphs, which are generated from specific non-trivial loops in the first homology group associated with the surface of the product. The routing graph, which is constructed only once, encodes the homotopy of the routing environment and is, therefore, used to find all the non-homotopic paths between multiple source–destination pairs. Based on the path embedding requirements, we classify the routing process into (1) On-Surface Routing, when the paths are constrained to the surface of the product, and (2) In-Air Routing, when the paths are allowed to venture into the product ambiance space. In the former case, the routing graph is defined by both the handle and tunnel loops in the first homology group, whereas in the latter case, it is defined by only the handle loops. We propose a linking number-based strategy for computing the handle and tunnel loops for a given closed surface. The methods are extended for routing in assemblies using the so-called shell structures associated with them. The results obtained demonstrate the efficacy of the proposed approach. The results show that the computation of the routing graph is very efficient, and the homotopy classes can be generated in very little time using the proposed approach.
•A topological method for 3D wire harness routing is developed.•The method generates all the homotopy classes associated with a pair of terminals.•The approach works for both – (1) On-surface and (2) In-air routing.•The method is extended for routing on assemblies.•An algorithm for computing handle & tunnel loops on closed surfaces is described.
Harnesses are used in wearable robots in safety, sports, medical, and industrial environments. Wearable robot harnesses for lower extremities should be designed to prevent musculoskeletal disorders ...caused by excessive strain on the spine and lower extremities when users wear these robots for prolonged periods. Therefore, this study compares and analyzes the usability of the two harnesses—the former (old design) and the latter (new design)—for the Hyundai chairless exoskeleton (CEX). In total, 27 participants took part in this study. The wearability, stability, and overall wearing satisfaction of the former and the latter harnesses were compared. We conducted an experiment where the participants wore the former and the latter harnesses while completing a series of tasks that resembled the ones performed by the workers on a front-end module assembling line of an automobile factory. After the experiment, the participants took part in a survey and semi-structured interviews. The data was analyses by t-test, correlation, and regression analyses. The survey results demonstrated that for the latter harness the cushioning sensation (thigh r = 0.539; calf r = 0.516) had the strongest effect on the overall wearing satisfaction. In addition, the latter harness scored higher in overall wear satisfaction than the previous harness. This study was able to verify the difference between the new and old designs according to the usability evaluation of the harness. The results of this study are considered to be helpful in design to improve the usability of the harness in the future.
•Results indicate that usability test on harness for wearable robots.•The wearability, stability, and comfort of the former and latter harnesses were compared.•This study contributes to make progress on the future harnesses.
Numerous mouth injuries have been reported in relation to bit use in horses. Rein tension is a potential risk factor, as it exerts pressure on the rostral parts of the mouth via the bit. The aim of ...this pilot study was to investigate rein tension during driving and its association with horse behaviour and mouth injuries.
Eight horses were driven clockwise on a 1000m oval racetrack for 3–4km at walk and trot. Rein tension was measured with two IPOS rein sensors. Researchers filmed the horse’s behaviour from a vehicle moving alongside the horse on the outer track. The bit area of the mouth was examined before and after the session. One observer, blinded to the rein tension and mouth injury results, coded behaviours from videos according to a predefined ethogram.
Median rein tensions in one rein ranged from 5N to 36N. Maximum rein tensions ranged from 106N to 236N. Five 30-second data subsets, representing samples of Low, Medium1, Medium2, High and Peak tension, were visually selected from the rein tension graphs to investigate behaviour differences during different rein tension levels. The durations of unrushed walk (P < 0.001) and mouth closed (P = 0.003) were longer in the Low rein tension subset. The durations of slow (P = 0.01) and fast trot (P = 0.003), mouth widely (P = 0.02) or repeatedly open (P = 0.03) were longer in the higher rein tension subsets.
None of the horses had any prior mouth injuries in the bit area. After driving, three horses experienced moderate bruising. Their median rein tension was numerically higher (left 35N; right 34N) than that in horses without injuries (22N; 18N), and they showed longer periods of rushed walk (P = 0.04).
Rein tensions were quite high, as previous studies suggest that horses find tensions above 6–10N aversive. Horse trainers should monitor the horse's mouth behaviour, arousal state and ability to walk calmly and modify training accordingly, as mouth widely or repeatedly open at higher rein tensions may indicate aversion (mouth discomfort/pain) and rushed walk may indicate high arousal, which in turn may increase the risk for mouth injury.
•Rein tension in trotters may be high.•With higher rein tension, horses showed longer duration of mouth widely or repeatedly open.•Three of eight horses had moderate bruises after 8–16-minute drive session on the track.•Median rein tension was numerically higher in horses with mouth injuries.•Horses with mouth injuries stayed in rushed walk for longer periods than horses without injuries.
•Suspension comfort and tolerable suspension time vary with harness type.•60 human subjects underwent 10-minute motionless suspension.•Strap pressure, subject psychophysical and physiological ...responses were measured.•Traditional H-configuration harnesses are the least tolerable for suspension.•Y-configuration harnesses have the best performance in suspension.
Falls from height are still a major occupational hazard, particularly in the construction industry, where it is the leading cause of fatal injuries. When opting for personal fall arrest systems, the use of a safety harness is mandatory. Following a fall arrest, motionless suspension in a full-body harness can be hazardous and lead to death. This paper investigates the effect of harness type, gender, and somatotype on perceived discomfort, the pressure exerted by the harness straps, and the evolution of physiological parameters in motionless suspension.
For this study, 30 male and 30 female students (10 ectomorph, 10 mesomorph, and 10 endomorph for each gender) were suspended for a maximum of ten minutes from the dorsal D-ring, in four different harnesses. The selected harnesses for this study are commercially available, one of them is X-configuration, another is Y-configuration, and the other two are the more traditional H-configuration. The results show that the H-configuration harnesses, which are very common in the industry and often the cheapest models, are perceived as the least tolerable in suspension. Moreover, H-configuration harnesses lead to greater reduction in muscular blood oxygenation and greater increase in the heart rate, which could make this type of harness hazardous. The Y-configuration harness seems to be the best performer in suspension. The influence of the sub-pelvic strap on suspension tolerance is not very clear and could be studied further. Those results could be useful to develop new harness models that would increase the suspension time tolerance.
Falls from heights (FFH) are major contributors of injuries and deaths in construction. Yet, despite workers being made aware of the dangers associated with not wearing a safety harness, many forget ...or purposefully do not wear them when working at heights. To address this problem, this paper develops an automated computer vision-based method that uses two convolutional neural network (CNN) models to determine if workers are wearing their harness when performing tasks while working at heights. The algorithms developed are: (1) a Faster-R-CNN to detect the presence of a worker; and (2) a deep CNN model to identify the harness. A database of photographs of people working at heights was created from activities undertaken on several construction projects in Wuhan, China. The database was then used to test and train the developed networks. The precision and recall rates for the Faster R-CNN were 99% and 95%, and the CNN models 80% and 98%, respectively. The results demonstrate that the developed method can accurately detect workers not wearing their harness. Thus, the computer vision-based approach developed can be used by construction and safety managers as a mechanism to proactively identify unsafe behavior and therefore take immediate action to mitigate the likelihood of a FFH occurring.
•A Faster-R-CNN and deep CNN model is developed to identify workers and their harness.•Precision and recall rates for the Faster R-CNN to detect workers were 99% and 95%, respectively.•Precision and recall rates for the CNN to detect those not wearing their safety harness were 80% and 98%, respectively.
BACKGROUND:Current dogma contends that prolonged treatment of a dislocated hip in Pavlik harness beyond 3 weeks will cause “Pavlik harness disease.” To our knowledge, however, no previous studies ...have documented objective morphologic changes to the acetabulum from continued treatment of a persistently dislocated hip.
METHODS:We retrospectively reviewed a consecutive series of infants with developmental dysplasia of the hip, below 6 months old, who failed Pavlik treatment from a single, tertiary-care pediatric hospital and a multicenter, international study group. Inclusion criteria were dislocated hips confirmed by ultrasound (both initially and at Pavlik termination) and a minimum of 2 ultrasounds during harness treatment at least 3 weeks apart. As a global measure of acetabular morphology, α angle (AA) was compared between initial and final ultrasound. The final means of obtaining successful hip reduction was recorded from the medical records.
RESULTS:Forty-nine hips in 38 patients were identified. Median age at Pavlik initiation was 4 weeks (range, 0 to 18 wk); median time in harness was 6 weeks (range, 3 to 14 wk). Surprisingly, a mean of 4 degrees improvement in AA (95% CI, 2-6 degrees; P=0.001) was observed between first and final ultrasound. We found no difference in AA change between those in harness 3 to 5 weeks and those with prolonged wear >5 weeks (P=0.817). There was no significant association between change in AA and time in harness (P=0.545), age at Pavlik initiation (P=0.199), clinical reducibility of the hip (P=0.202), or initial percent femoral head coverage (P=0.956). Following harness failure, 22/49 hips (45%) were successfully treated with rigid abduction bracing, 16 (33%) by closed reduction/spica casting, and 10 (20%) by open reduction; 1 hip (2%) spontaneously reduced and required no further treatment.
CONCLUSIONS:On the basis of the lengths of harness treatment in our series, most hips did not exhibit negative changes in the acetabular AA in response to prolonged treatment of a dislocated hip in harness. Furthermore, 80% of hips failing Pavlik treatment were successfully reduced through closed means, indicating that subsequent treatment was not compromised.
LEVEL OF EVIDENCE:Level IV—retrospective case series.
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