The linear impactor was originally designed to simulate head-to-head collision between two NFL football players as a means of evaluating helmet effectiveness. While helmet tests are traditionally done using drop towers, the extreme closing speeds of player-to-player hits makes a drop test not feasible. The helmet being evaluated is positioned on the test headform, typically a Hybrid III automotive head and neck, instrumented to record linear and angular head acceleration as well as upper neck forces and torques. The machine is charged with a pre-determined set pressure to achieve a desired speed and the impact ram is propelled into the helmeted headform. The advantage of this system is that the headform is free to deflect and rebound in a natural way to study complete head kinematics.

 

This system has been demonstrated to be both repeatable and reliable and is adaptable to other situations where bodily impacts are desired in the 5-13 m/s range.

 

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Mouthguards may protect your teeth, but what about your brain? To investigate the protective aspects of mouth guards in relation to concussion, a headform with an articulating mandible has been developed. Based on the 50th percentile Hybrid III manikin skull, the new headform has a steel mandible with a steel upper and lower dentition and compliant temporomandibular joints (TMJ).

The TMJ provides a biofidelic range of motion to allow for the insertion of mouth guards. Mandible force-displacement response has been validated under direct chin impact against cadaver performance corridors recently developed at Wayne State University. The headform was developed in conjunction with the National Football League to assess the capacity of mouth guards to reduce concussion risk among helmeted players. However it may also be used for military and automotive research of mandible, TMJ and dentition injury.

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Biokinetics' static helmet retention tester (HRT-S) was designed specifically to comply with the DOT (FMVSS 218) motorcycle helmet test standard. It is used to verify that a motorcycle helmet's retention system meets a minimum strength requirement without excessive elongation. The test apparatus uses a pneumatic piston to apply the load and a linear potentiometer to measure the displacement of the chin simulator bars relative to the top of the helmet. Helmet testing and data reporting is greatly facilitated with use of the Helmet Test Software (HTS) suite.

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Biokinetics' quasi-static helmet retention tester (HRT-QS) was designed to evaluate the stretch of a retention system at a given load. Up to a 4000 N (900 lbf) of static load can be applied at a controlled rate. Elongation is measured electronically using a linear potentiometer. If the chin strap should break, or the buckle release, the exact force and displacement at the time of failure is recorded. Helmet testing and data reporting is greatly facilitated with use of the Helmet Test Software (HTS) suite.

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Biokinetics' dynamic helmet retention tester (HRT-D) incorporates two test methods into one apparatus. The first test evaluates the strength of a helmet's retention system under a dynamic load generated by a guided free falling mass dropped onto a catch plate that is connected to a helmet's chin strap. A linear potentiometer records the stretch of the strap during and after the loading event. The second test evaluates a helmet's stability by applying a dynamic load to the front or rear edges of a helmet that attempts to rotate the helmet off a test headform. Both methods are in compliance with most helmet performance test standards. Helmet testing and data reporting is greatly facilitated with use of the Helmet Test Software (HTS) suite.

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The Helmet Fatigue Tester (HFT) assesses the structural rigidity of a helmet or helmet component in any direction. It works by squeezing the helmet between two platens where the compression rate, measured force and number of compression cycles is computer programmed. The HFT has a peak compressive force of 4450 N (1000 lbf) and a maximum stroke length of 55 cm (22 in).

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Biokinetics' helmet impact tower (HIT) is used to evaluate the impact performance of helmets across a range of test conditions specified in standards such as the ASTM, CPSC, DoT, ECE and Snell. The self-supporting tower consists of a pedestal, linear bearing rail, lift carriage, drop carriage and lift motor. The drop carriage supports the locking ballarm and headform and is automatically raised to the user-defined height where upon command the helmet is released in guided free-fall onto one of many steel anvils. The forces transmitted to the headform are measured with an accelerometer located at the head's centre of gravity.

A full compliment of impact headforms, data acquisition and measurement systems is provided. Testing is streamlined and data reporting is greatly simplified with the integrated Helmet Test Software (HTS) and electro-mechanical systems.

The drop tower complies with many helmet test standards and it can be customized the client's exact needs.

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Biokinetics' Helmet Testing Software (HTS) is an easy to use program specifically designed for helmet testing. The HTS interfaces directly with all of Biokinetics' helmet test equipment via PC-based data acquisition and motion control. Test screens specific to each laboratory apparatus are provided allowing you to perform pre and post-test instrument checks followed by the entire helmet test sequence. Test results are instantly displayed both numerically and graphically and the data are automatically saved to disk for review at a later date. Once testing is completed, the HTS generates a test report and easily allows data file storage.

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