Background

• The automated Dynamic Plantar Aesthesiometer (DPA) is a quick, accurate way of delivering mechanical stimulation and measuring a response.
• Impaired cutaneous sensation is usually first manifested in a loss of light touch detection. Mechanical stimulation is used clinically to diagnose pathologies of hyper- or hypo-aesthesia, brought about by drugs, neural pathology or experimental lesions.

Application & Disease Models

• Automatically detects and records latency time, and actual force at the time of paw withdrawal reflex. 
• A movable force actuator is positioned below the plantar surface of the animal. The desired force and force speed (ramp) is applied, as pre-set by the operator.  
• Increasing force is exerted by rigid Von Frey filament (0.5mm tip) until the animal twitches its paw. 
• Adjustable touching force and touching pause (to control the stimulus approaching phase).
• Paw withdrawal detection is automatic. Manual detection is also available (useful if animal motor response is unusual).
• The device comprises:
  • A movable touch-stimulator unit complete with filament actuator and adjustable angled-mirror
  • A microprocessor controlled electronic unit with touch screen, graphic display, internal memory for data storage, USB key and optional printer
  • Large testing surface (perforated metal platform), laser cut for smooth and precise grid spacing
  • Modular animal enclosure offering from 3 to 12 spaces is convenient for holding rats and mice
• Supplied with accessories to work with both mice and rats. 
• Data can be transferred to a computer via the memory stick.
• TTL outputs for Start/Stop and Detection (Manual/Automatic) as well as TTL Input for external start provide easy interface to external instruments such as DAQs. Analog output is also available.

Impaired cutaneous sensation is usually first manifested in a loss of light touch detection. So “mechanical” stimulation has a long history of effective clinical use to diagnose pa-thologies of hyper- or hypo-aesthesia, brought about by drugs, neural pathology or experimental lesions, etc.

The Dynamic Plantar Aesthesiometer was developed to apply a reproducible light touch to the rodent plantar surface, and quantify the force which causes the animal to react by withdrawing the paw.