Electronic Von Frey - e-VF handheld
Touch sensitivity in unrestrained animals is traditionally tested with Von Frey filaments, which is a tedious and experimenter-dependent assay.
The Electronic Von Frey system solves the multiple measurement (i.e. multiple filaments) issue and the experimenter bias by using a hand-held force sensor with a rigid metal. The scientist gradually increases the force applied to the animal paw, until the peak detector scores the animal paw withdrawal (or the user scores it manually with the included pedal).
Force ranges are selectable in the 0-50, 0-200 and 0-1500 grams with a 0.1 grams sensitivity and software tools are included to aid a linear application of the force (rate-meter and slope).
The system is battery or mains powered and comes with software included and data export in CSV. One model for Mice or Rats in modular enclosures (up to 6 rats or 12 mice).
The Electronic Von Frey has been used in a variety of neuropathy applications in nerve injury, from partial sciatic nerve ligation (PNL, to chronic constriction injury (CCI) and spinal nerve ligation (SNL) to screen phenotypes and drugs to treat allodynia and hyperalgesia.
Altogether this brings about a high reproducibility, sensitivity and accuracy which no other mechanical stimulation application can provide. The sensitivity is by far the result of the fact that the force application does not rely on hand movement.
Moreover, the Dynamic Plantar Aesthesiometer, differently than Von Frey filaments, provide a linear and not logarithmic scale of stimulation.
Background of Von Frey test
- Von Frey filaments are still a productive way to evaluate behavioral responses of neuropathic pain in preclinical and clinical research
- Von Frey tests are time consuming and subject to experimenter bias, for this reason Ugo Basile developed a hand held Electronic Von Frey test with automated paw withdrawal detector
- It is important that the application of the force is always perpendicular, with a preset amount of grams and at a predefined rate, which can be controlled with the provided tools (rate-meter on the control unit and slope on the software)
- The Electronic Von Frey is based on a force sensor and a peak detection algorithm to automatically score paw withdrawal (a foot pedal for manual score is also included)
- One key feature of this device is the possibility to visually control the rate of application of the force by keeping the signal on the slope via software or using the rate-meter on the electronic unit
System components and main features
The Electronic Von Frey Ugo Basile system comes complete with:
- An electronic unit battery powered via USB or the provided charger
- A rigid stimulator filament in nitinol (metal) and a prism to aid paw targeting
- A plastic (Eppendorf tip) stimulator tip
- A pedal for manual scoring
- A software for saving force curves, peaks and export data into CSV for Excel
- A large testing grid surface with 5x5 mm2 holes (option)
- A modular set of animal enclosures to hold up to 6 rats and 12 mice (option)
Features includes
- 0-50, 0-200, 0-1500 grams ranges to maximize device dynamic range
- 0.1 gram sensitivity and time resolution of 0.1 seconds
- Automatic peak detector and foot pedal
- Software included for rate control, waveform saving and CSV data export
- Small and handy battery powered electronic unit
Features&benefits of electroni Von Frey system
Emedded force sensor: no need for multiple filament measurements but just one application of the force
Force Peak detector for automated scoring of paw withdrawal: higher throughput and improved accuracy, thanks to decrease in experimenter bias
Large force range (0-1500 grams) and high time resolution (0.1 seconds): flexibility for performing many types of experiments from severe allodynia to hyperalgesia
Battery powered, small electronic unit with display for settings and results: the system can be easily positioned even away from the mains and can be used with or without software
Grid platform and animal enclosures (optional): can be provided as a complete, “ready to go system”
Optional manual scoring of paw withdrawal: allows for scoring animals which present an unusual position of the paw, and do require the experimenter to visually score
Painted metal grid and modular animal cages: works with rats and mice in high throughput (6 rats and 12 mice at the time) and it is easy to clean
- 38450-001 Electronic unit
- 38450-004 Von Frey Applicator, with Prism to locate the aimed area on the animal paw. Complete with transducer
- 38450-310 Glass prism
- 38450-330 Filament, with magnetic fixing
- 37215-323 Pedal switch
- 52010-325 USB lead
- E-AU 059 Universal power supply
- E-AU 101 USB pen-drive, including instruction manual and software
- 37450-278 Base assembly for plantar stimulation, including support with columns, perforated metal sheet and multiple-configuration animal-enclosure, from 3 to 12 spaces
- 37450-005 Large perforated metal sheet
- 37450-045 Large perforated metal sheet, with 4 legs, 40cm height (animal enclosure 37000-007 is not included and should be ordered separately)
- 37450-085 Large perforated metal sheet, with 4 legs, 80cm height (animal enclosure 37000-007 is not included and should be ordered separately)
- 38450-331 Filament in plastic, Eppendorf