Table 1.
Device name | Rat/mouse | Injury parameter (accuracy) | Calibration method | Dwell-time | Velocity (m/sec) | Target stabilization | Monitors | Reference |
---|---|---|---|---|---|---|---|---|
LISA | Y/Y | Displacement (±0.007 mm) | Non-contact laser sensor | 50 msec to 5 sec (±5 msec) | 0.5–2.0 | Mouse or rat stabilizer | Velocity Force Duration of compression | Present study |
NYU | Y/N | Velocity (±5%) | Contact (closed circuit) | Variable, depends on operator release | 0.3–0.9 | Two pairs of clamps on spinous processes | Velocity Height Movement of vertebra | Gruner et al., 1992 |
ESCID | Y/Y | Displacement (±0.008 mm) | Contact (Ling vibrator)a | 0.148 | Two pairs of forceps on spinous processes | Velocity Force Momentum | Stokes et al., 1992 | |
IH | Y/Y | Force (depends on background noise) | Internal | Immediately <5 msec | 0.1–0.13 | Two pairs of forceps on spinous processes | Force Displacement | Scheff et al., 2003 |
Weight drop | Y/Y | Velocity (NA) | Contact (visual observation) | Variable, depends on operator release | 0.3–0.9 | Two pairs of forceps on spinous processes | Strain Force | Gale et al., 1985 |
Modified aneurysm clips | Y/Y | Clip tension (depends on location of blades on the cord)a | NA | Variable, depends on operator release | NA | None needed | None | Rivlin et al., 1978 |
The importance of the closing velocity of the clip blades on the spinal cord was ignored. The outcome of injury can be dramatically different using the same clip but with dissimilar releasing methods (unpublished data).