Linear_Impactor_MEC_v3.docx

Minimum Essential Characteristics – Linear Impactor and Sled A pneumatically driven linear impactor with the capability of replicating sports-related bodily collisions, military related exposures, and other biomechanical exposures is required. In general, the system must include a pneumatic impactor subsystem (with associated control equipment and pneumatic fittings) and a sled subsystem (with associated hardware). Minimum essential characteristics follow:

· In general, the linear impactor system must:

· Be able to achieve an impactor velocity of 13 meters per second (m/s) at a pressure level of 100 pounds per square inch (psi)

· Be able to achieve desired speeds with an accuracy of ±0.1 m/s

· Allow the use of different ram faces for multiple applications

· Be compatible with the neck base of a standard 50th percentile Hybrid III Anthropometric Test Device (ATD)

· Allow free travel of the head and neck on a sled following impact

· Allow five degree of freedoms in positioning of the head and neck (fore-aft tilt, twist, up/down, left/right, and fore/aft linear motion) to enable impacts to multiple sites (e.g., front, side, rear, chin, forehead, etc.).

· Include all appropriate pneumatic fittings, electrical fittings, power cables, control cables, control hardware, pneumatic hoses, and safety equipment for the normal use of the system.

· Include a minimum of a 12 month warranty for non-electronic equipment.

· Include a minimum of a 6 month warranty for electronic equipment.

· The pneumatic impactor subsystem must:

· Include a 14 kilogram (kg) ram

· Include appropriate safeguards against injury or misuse

· E.g., safety ball valve shut off, protective covers over the pneumatic ram, lock-out/tag-out controls for the system

· Include the ability to change the ram face simulating different impact conditions.

· Include a standard 38mm semi-rigid foam impact surface

· Include a ram braking chamber

· Provide the ability to retract the ram through the control system

· Include a precision pressure gauge

· Include a dual beam velocity gate to measure ram velocity

· Provide a 5V TTL signal from the velocity gate to trigger external data acquisition hardware.

· The sled subsystem must:

· Be compatible with a standard 50th percentile Hybrid III ATD neck and head.

· Provide five degrees of freedom in head position with measurement scales to document initial position of the head prior to impact

· Vertical movement (up/down)

· Lateral movement (left/right)

· Line of impact movement (fore/aft)

· Head/neck rotation (rotate about the z-axis or neck axis)

· Head nodding rotation (rotate about the sled Y-axis or fore-aft tilt of the head)

· Head nodding rotation must be on a continuous scale

· Use tool-less control of the vertical movement of the sled

· Include a mechanical stop for the sled