Peter Hans Halldin

Peter Hans Halldin
KTH Royal Institute of Technology | KTH · School of Technology and Health (STH)

About

31
Publications
10,800
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
862
Citations

Publications

Publications (31)
Article
Full-text available
Bicycle helmets are shown to offer protection against head injuries. Rating methods and test standards are used to evaluate different helmet designs and safety performance. Both strain-based injury criteria obtained from finite element brain injury models and metrics derived from global kinematic responses can be used to evaluate helmet safety perf...
Conference Paper
Despite the fact that many new oblique impact test methods are emerging, with the aim of improving helmet design and reducing traumatic brain injury (TBI), comparative analysis of different test methods, particularly for helmet performance evaluation, is lacking. There is a multitude of variables and decisions to be made when designing a test metho...
Conference Paper
The impact velocity angle determined by the normal and tangential velocity has been shown to be an important description of head impact conditions but can vary in real-world accidents. The objective of this paper was to investigate the effect of impact velocity angle on helmeted head impact severity indicated by the brain tissue strain. The human b...
Article
Nowadays crash helmets are tested by dropping a free or unrestrained headform in Europe but a guided or restrained headform in the United States. It remains unclear whether the free fall and the guided fall produce similar impact kinematics that cause head injury. A finite element helmet model is developed and compared with experimental tests. The r...
Article
Full-text available
The objective of this study was to compare and evaluate the difference in head kinematics between the TNO and THUMS model in pedestrian accident situations. The TNO pedestrian model (version 7.4.2) and the THUMS pedestrian model (version 1.4) were compared in one experiment set up and fourteen different accident scenarios where the vehicle velocity...
Conference Paper
Full-text available
This paper exposes a critical analysis of current bicycle helmet standard tests and proposes an advanced test method. Different key aspects are considered consecutively, i.e. the bicyclist's head impact conditions in terms of velocity vector, head form boundary conditions, the headform itself with its instrumentation, the geometry of the impacted s...
Article
Full-text available
Pedestrians are one of the least protected groups in urban traffic and frequently suffer fatal head injuries. An important boundary condition for the head is the cervical spine, and it has previously been demonstrated that neck muscle activation is important for head kinematics during inertial loading. It has also been shown in a recent numerical s...
Article
Objective The objective of this study was to investigate the need for an updated specification for improved Downhill and Super-G helmet. One important aspect was to understand if the impact situations in the ski slope can generate high rotational accelerations and if so, how can the helmets be designed to absorb both translational and rotational en...
Article
Full-text available
Unprotected pedestrians are an exposed group in the rural traffic and the most vulnerable human body region is the head which is the source of many fatal injuries. This study was performed to gain a better understanding of the influence that the neck muscle tonus has on head kinematics during pedestrian accidents. This was done using a detailed who...
Article
Full-text available
In this pilot study we investigated how medical students evaluated a VIS practice session. Immediately after training 43 students answered a questionnaire on the training session. They evaluated VIS as a good interactive scenario based educational tool.
Article
Full-text available
Bicycle accidents have become the most common cause of serious injury in the traffic during the last couple of years in Sweden. The objective of this study was to investigate the effect of the input variables, initial velocity and head orientation, of a bicycle accident reconstruction on the strain levels in the brain using a detailed FE head model...
Article
Full-text available
Lateral impacts are of great concern for occupant safety. In order to design side protective systems, it is of importance that the timing of the body and the head should be well predicted. Today, experimental and numerical Anthropometric Test Devices (ATDs) are used as human substitutes to predict the human kinematics. As a complement to the ATDs,...
Article
A finite element (FE) model of the human neck was used to study the distribution of neck muscle loads during multidirectional impacts. The computed load distributions were compared to experimental electromyography (EMG) recordings. To quantify passive muscle loads in nonactive cervical muscles during impacts of varying direction and energy, using a...
Article
The numerical method of finite elements (FE) is a powerful tool for analysing stresses and strains in the human body. One area of increasing interest is the skeletal musculature. This study evaluated modelling of skeletal muscle tissue using a combination of passive non-linear, viscoelastic solid elements and active Hill-type truss elements, the su...
Article
The hypothesis that muscle tension protects the spine from injuries in helicopter scenarios was tested using a finite-element model of the human head and neck. It was compared with cadaver crash sled experiment with good correlation. Then, simulations were performed with a sinusoidal velocity (5–22 G) applied at T1 60° to the horizontal plane. The...
Article
A finite element (FE) model of the human neck with incorporated continuum or discrete muscles was used to simulate experimental impacts in rear, frontal, and lateral directions. The aim of this study was to determine how a continuum muscle model influences the impact behavior of a FE human neck model compared with a discrete muscle model. Most FE n...
Article
The Finite Element method is a powerful tool for analyzing the biomechanics of the human body. One area that has attracted increasing attention is the cervical musculature and its influence in neck injury mechanisms. Most cervical FE models of today use spring-elements as muscles and are limited to discrete geometries and nodal output results. A so...
Article
Full-text available
The objectives for the whole project were to: I. determine the relationships between head supported mass and the risk of neck injuries. The results should be used in a Graphical user interface. In this phase three report has also the Graphical User Interface (GUI) been evaluated and the question about the how the muscle activation affect the injury...
Article
Prevention of neck injuries due to complex loading, such as occurs in traffic accidents, requires knowledge of neck injury mechanisms and tolerances. The influence of muscle activation on outcome of the injuries is not clearly understood. Numerical simulations of neck injury accidents can contribute to increase the understanding of injury tolerance...
Article
Numeric techniques were used to study the upper cervical spine. To develop and validate an anatomic detailed finite element model of the ligamentous upper cervical spine and to analyze the effect of material properties of the ligaments on spinal kinematics. Cervical spinal injuries may be prevented with an increased knowledge of spinal behavior and...
Article
The most frequently sustained severe injuries in motorcycle crashes are injuries to the head, and many of these are caused by rotational force. Rotational force is most commonly the result of oblique impacts to the head. Good testing methods for evaluating the effects of such impacts are currently lacking. There is also a need for improving our und...
Article
Current requirements and regulations governing motorcycle helmets around the world are based on test results of purely radial impacts, which are statistically rare in real accidents. This study presents a new impact rig for subjecting test helmets to oblique impacts, which therefore is able to test impacts of increased statistical relevance to real...
Article
A new oblique impact test for motorcycle helmets is described, simulating a fall from a motorcycle on to the road surface or the windshield of a car. An instrumented headform falls vertically to impact a horizontally moving rigid rough or deformable surface. Both the impact site on the helmet, and the vertical and horizontal velocities, can be vari...
Article
Full-text available
A Finite Element (FE) model of isolated head and neck complex was developed aiming to investigate the mechanisms of injury from axial impacts, in the sagittal plane, and the injury thresholds from experimental studies reported in the literature. The model was validated on a local and a global level, showing a significant correlation with experiment...
Article
The Experimental Head Restraint Concept (EHRC), a 'safety belt' for the head, is designed to reduce forces to the head and neck, in frontal car crashes. The EHRC was evaluated experimentally in frontal collision for a crash severity of 11 m/s, and numerically in frontal collision for a crash severity of 11 and 15 m/s. Experimental data obtained fro...