CCI, CHI, SCI, or CHIMERA models

The Neuropactor has several key advantages over other means of experimental TBI in laboratory animals.  

With the actuator mounted on a stereotaxic instrument, the Neuropactor™ is optimized for reproducible impacts in a group of animals, yielding low variability in anatomical damage and resulting functional damage.  With the actuator mounted on a stereotaxic instrument, precisely positioned and reproducible impacts may be made open head, closed head, or spinally from any angle at a preset velocity, dwell time (time in contact before automatic withdrawal), and depth.   

Alternatively, the same actuator can be mounted on the optional Neuropactor™ CHIMERA Table,  which has  restraint for the body but not the head.  Impact through the table from below with the animal dorsal side down and with the head free to move more closely models common types of accident injury (Namjoshi, Cheng, & McInnes et. al., 2014).

ADVANTAGES of the NEUROPACTOR™ over previous models:

ADVANTAGES of the NEUROPACTOR™ ACTUATOR:

• The wires to the piston pass through the side of the cylinder, rather than wrap around the end.  This prevents accidental tightening of the wires, which will prevent full retraction of the piston and attenuate its impact, possibly without notice by the experimenter.
• The set of 5 impact tips that are included screw into the piston end tightly, and will not work loose after repeated impacts.  The piston end has a thread arrangement designed to prevent vibration from loosening fasteners.
• Piston will not rotate to strain wires as probes are being screwed in.
• Piston material resists  swelling due to either temperature or humidity.  The piston will not lock against the cylinder interior.   Even prolonged incorrect switch position will not cause lockup.
• The piston fits snugly in the cylinder, to reduce wobble.
• Impact velocity can be set from 1.0 to 6 meters/sec. 
• May be mounted on common makes of stereotaxic instruments, or the Neuropactor™ CHIMERA table, to meet the experiments goals.

ADVANTAGES of the NEUROPACTOR™ CONTROL BOX:

• Since heat is no longer a problem in the actuator, additional voltage has been added to ensure the tip will always retract when it is supposed to.  It should not affect operation if the switch is left in “Retract” or “Extend” for long periods.  Just for energy efficiency, it is still good practice to leave it in the central neutral position, but you will not incur any operational penalty if a student forgets.
• The Controller is calibrated to achieve a factory standard impact for the given actuator.  Calibration does not shift over time, there is no need for periodic recalibration.  Any change of actuator does require factory recalibration of the controller. 

OPERATION:

Velocity is preset over a range of 1.0- 6.0 meters/second with a large rotary knob, and  is displayed in advance on a large digital display, for any application.

Dwell time, the time the tip remains in contact with the head before automatic withdrawal, used with CCI and CHI, may be preset between 0.1 and 9.9 sec.  For CHIMERA it is set to zero. 

Depth of penetration is set by operating the DV drive on the stereotaxic instrument to lower the actuator, with tip extended, to just contact the head, then retract the tip.  Lower the actuator with the stereotaxic instrument by the amount the tip should be allowed to travel past the impact point, and the instrument is ready to fire an impact. The Neuropactor™ comes with a set of 5 interchangeable impact tip head sizes (1, 1.5, 2, 3, and 5 mm).  Special threads are used that do not work loose with repeated impacts.  The coil does not rotate as tips are installed or removed.  Custom tips can be made, contact us to discuss your needs.

Contact sensor beeps when extended tip just touches the animal. Tip is then retracted, and the actuator lowered with the stereotaxic instrument the amount the tip should be allowed to go past first contact, controlling the depth of penetration.