Andrew J. Taylor

A multi-body head-and-neck model for simulation of rear impact in cars

Abstract This paper presents the development and validation of a 50th percentile male multi-body head-and-neck model, aimed primarily at analysing rear impact and the resulting whiplash injury effects. The objective is to design a computationally efficient model behaving like a human head and neck in the case of a rear impact. The volunteer sled tests performed by the Japanese Automobile Research Institute (JARI) have been used for the validation of the head-neck model for low-speed rear-impact analysis. The presented approach for the multi-body head-and-neck model is simple, effective, and capable of producing biofidelic responses. The results show that the model can represent with a high degree of accuracy the rear-impact response of a human.

Energy-Absorbing Car Seat Designs for Reducing Whiplash

Objectives: This study presents an investigation of anti-whiplash features that can be implemented in a car seat to reduce whiplash injuries in the case of a rear impact. The main emphasis is on achieving a seat design with good energy absorption properties. Methods: A biofidelic 50th percentile male multi-body human model for rear impact is developed to evaluate the performance of car seat design concepts. The model is validated using the responses of 7 volunteers from the Japanese Automobile Research Institute (JARI) sled tests, which were performed at an impact speed of 8 kph with a rigid seat and without head restraint and seatbelt. A generic multi-body car seat model is also developed to implement various seatback and recliner properties, anti-whiplash devices, and head restraints. Using the same driving posture and the rigid seat in the JARI sled tests as the basic configuration, several anti-whiplash seats are designed to allow different types of motion for the seatback and seat-pan. Results: The anti-whiplash car seat design concepts limit neck internal motion successfully until the head-to–head restraint contact occurs and they exhibit low NICmax values (7 m2/s2 on average). They are also effective in reducing neck compression forces and T1 forward accelerations. In principle, these car seat design concepts employ controlled recliner rotation and seat-pan displacement to limit the formation of S-shape. This is accomplished by using anti-whiplash devices that absorb the crash energy in such a way that an optimum protection is provided at different severities. Conclusions: The results indicate that the energy absorbing car seat design concepts all demonstrate good whiplash-reducing performances at the IIWPG standard pulse. Especially in higher severity rear impacts, two of the car seat design concepts reduce the ramping of the occupant considerably.

Design issues for underwater manipulator systems

Abstract Underwater manipulators have developed from the crude grabbers first fitted to submersibles in the 1970s to become advanced systems capable of a diverse range of tasks, operating dependably in a hostile and unstructured environment. However, many difficulties still exist in this field and new manipulators with enhanced capabilities, particularly in terms of intelligent control, will be required within the next few years if the efforts to replace the diver are to continue to advance. The wide range of technologies embodied in manipulator systems, together with inherent non-quantifiable and human factors considerations, necessitates a mechatronics approach to design for all but the crudest of arms. Many of the design criteria for underwater systems contrast sharply with those in the better known industrial robotics context. This paper provides an overview of underwater manipulator technology, and discusses the broad range of design problems associated with subsea operation which must be considered for any new design.

A multi-body human model for rear-impact simulation

Abstract This paper presents the validation of a 50th-percentile male multi-body human model specifically developed for rear-impact simulation. The aim is to develop a biofidelic model with the simplest architecture that can simulate the interaction of the human body with the seat during rear impact. The model was validated using the head-and-neck and torso responses of seven volunteers from the Japanese Automobile Research Institute sled tests, which were performed at an impact speed of 8km/h with a rigid seat and without head restraint and seat belt. The results indicate that the human-body model can effectively mimic the rear-impact response of a 50th-percentile male with a good level of accuracy and has the potential to predict whiplash injury.

X-ray-based machine vision system for distal locking of intramedullary nails

Abstract In surgical procedures for femoral shaft fracture treatment, current techniques for locking the distal end of intramedullary nails, using two screws, rely heavily on the use of two-dimensional X-ray images to guide three-dimensional bone drilling processes. Therefore, a large number of X-ray images are required, as the surgeon uses his/her skills and experience to locate the distal hole axes on the intramedullary nail. The long-term effects of X-ray radiation and their relation to different types of cancer still remain uncertain. Therefore, there is a need to develop a surgical technique that can limit the use of X-rays during the distal locking procedure. A robotic-assisted orthopaedic surgery system has been developed at Loughborough University to assist orthopaedic surgeons by reducing the irradiation involved in such operations. The system simplifies the current approach as it uses only two near-orthogonal X-ray images to determine the drilling trajectory of the distal locking holes, thereby considerably reducing irradiation to both the surgeon and patient. Furthermore, the system uses robust machine vision features to reduce the surgeons interaction with the system, thus reducing the overall operating time. Laboratory test results have shown that the proposed system is very robust in the presence of variable noise and contrast in the X-ray images.

Car seat design to improve rear-impact protection:

This study presents car seat concepts which are designed to mitigate whiplash injuries through coordinated motion of seat components for a wide range of crash severities. In order to evaluate the effectiveness of the proposed car seat concepts, computational multibody models of a generic car seat and a biofidelic 50th-percentile male human model for rear impact are developed. A number of car seat concepts are shown to reduce the risk of whiplash injuries by utilizing head restraint support and energy-absorbing features, which remain reusable after impact.

Driver tracking and posture detection using low-resolution infrared sensing

Abstract Intelligent sensors are playing an ever-increasing role in automotive safety. This paper describes the development of a low-resolution infrared (IR) imaging system for continuous tracking and identification of driver postures and movements. The resolution of the imager is unusually low at 16 − 16 pixels. An image processing technique has been developed using neural networks operating on a segmented thermographic image to categorize driver postures. The system is able reliably to identify 18 different driver positions, and results have been verified experimentally with 20 subjects driving in a car simulator. IR imaging offers several advantages over visual sensors; it will operate in any lighting conditions and is less intrusive in terms of the privacy of the occupants. Hardware costs for the low-resolution sensor are an order of magnitude lower than those of conventional IR imaging systems. The system has been shown to have the potential to play a significant role in future intelligent safety systems.

Feedback Device for Improvement of Coordination of Reach-to-Grasp After Stroke

OBJECTIVEnTo describe a novel feedback device (Grasp Rehabilitation Accessory for Stroke Patients [GRASP]) that gives feedback on the time lag between the start of hand opening and the start of transport during reach-to-grasp movements, and to report the results of a preliminary series of single case studies to assess the utility of the device for improving the coordination of arm and hand at the beginning of a reach-to-grasp movement.nnnDESIGNnA multiple baseline design across 6 subjects was used, with each subject performing 40 repetitions of reaching to grasp a jar. Two subjects each performed 10, 15, or 20 randomly assigned baseline repetitions.nnnSETTINGnPhysiotherapy department or at the participants home.nnnPARTICIPANTSnParticipants with middle cerebral artery or parietal stroke (n=6) were consecutively recruited from physiotherapy departments. Additional inclusion criteria were a Rivermead Motor Assessment score of 5 or more and time between start of hand opening and transport of more than 60ms.nnnINTERVENTIONSnDuring the intervention phase, feedback on time between start of transport and start of grasp was communicated via GRASP. Participants were encouraged to reduce the time.nnnMAIN OUTCOME MEASUREnThe outcome measure was the time between start of transport and start of grasp, measured with GRASP.nnnRESULTSnAll participants decreased the mean time lag during the intervention phase compared with the baseline phase. Participants 1 to 6 showed decreases of 35, 296, 34, 34, 1212, and 114ms, respectively. Two out of 6 participants demonstrated a significant decrease in time lag in the intervention compared with the baseline phase.nnnCONCLUSIONSnGRASP is potentially beneficial as an adjunct to physiotherapy training of reach-to-grasp coordination after stroke.

Whiplash Protection by Energy Absorbing Car-Seat Concepts

Whiplash injury/disorder is a common neck-injury in road traffic accidents. This paper introduces energy absorbing car-seat concepts which can reduce the risk of whiplash injuries. Computational multi-body models of a generic car seat and a biofidelic 50th-percentile male human model for rear impact are developed to assess the effectiveness of the proposed car-seat concepts. The numerical sled-test-simulations show that the proposed car-seat concepts can successfully mitigate whiplash injuries for a wide range of crash severity by utilising energy absorbing devices which can remain reusable after a rear-impact. A physical model of a proposed car-seat concept is built and tested to verify the computational models.Copyright