Von Frey Hairs, Semmes-Weinstein set of monofilaments

Product Code:37450-275

Used to measure the paw withdrawal reflex when the mouse or rat paw is unexpectedly touched. For evaluating mechanical allodynia and cutaneous sensation levels. Popular non-invasive technique.

Aesthesio® set of 20 monofilaments based on the Semmes Weinstein monofilament set. An ascending series of increasingly stiff filaments (from 0.008 to 300 grams). Features retractable head to protect the filaments, allowing a researcher to carry a few around in a pocket. An optional perforated metal grid platform is available that is comfortable for the animal and easy for viewing the target area.

Especially suggested for sub-gram forces (i.e., severe allodynia) although very time consuming and operator dependent.

Detailed description +-

Background

Von Frey hairs (named after the German physiologist Max von Frey, 1852–1932). They have a long history of effective use in clinical settings, and can be used to diagnose pathologies of hyper- or hypo-aesthesia.
The diameter of the nylon monofilaments determines the resistance of the monofilament to bending.
For use on the plantar surfaces of the foot of a rat or mouse. The animal will indicate sensation by pulling back its paw.
A defensive response indicates using a lower filament force for the next test, while lack of a response indicates the need for a higher strength filament.
Based on the Semmes Weinstein monofilament set.
Subsets within the set of 20 probes distinguish pathologies on different parts of the body (foot, hand, lip, cheek, etc.)

Dynamic experiments, easy control

The filaments are individually calibrated to deliver a target force, from 0.008 grams to 300 grams.
The set provides an approximate logarithmic scale of actual force, and a linear scale of perceived intensity (refer to specification table)
Get a complete set up by adding the metal platform. Laser-cut perforations form a mesh-like open grid of square holes ~5X5mm can be very useful when testing the rodent plantar surface. The framework of the metal grid is approximately 1mm wide, comfortable to the animal and easy to view the target area of the paw. The platform is coated with a polymer resin that is easy to clean and which will not be spoiled by fluids or waste materials.

Features & Benefits +-

Feature	Benefit
Retractable filament	Easy to carry and protected from damage
Effective use in clinical setting	Used to diagnose pathologies of hyper- or hypo-aesthesia
Optional perforated platform available	For convenient stimulation of rodent plantar-surface

Specifications +-

Aesthesio® Tactile Sensory Evaluator Data Chart

Application +-

When the tip of a fiber of given length and diameter is pressed against the skin at right angle, the force of application increases as long as the researcher continues to advance the probe, until the fiber bends. After the fiber bends, continued advance creates more bend, but not more force of application. The Semmes Weinstein set of monofilaments provides an approximately logarithmic scale of actual force, and a linear scale of perceived intensity. They have a long history of effective use in clinical settings, and can be used to diagnose pathologies of hyper- or hypo-aesthesia.

Ordering informations +-

Color	Evaluator Size	Catalogue item Number	Target Force (grams)	*Target Force (milliNewtons)**	Theoretical Pressure Grams/Sq. mm	Hand & Dorsal Foot Thresholds	Plantar Threshold
Green	1.65	514001	0.008	0.08	2.53	normal	normal
	2.36	514002	0.02	0.20	4.39	normal	normal
	2.44	514003	0.04	0.40	4.93	normal	normal
	2.83	514004	0.07	0.70	5.53	normal	normal
Blue	3.22	514005	0.16	1.6	8.77	Diminished Light Touch	normal
Blue	3.61	514006	0.40	3.9	16.1	Diminished Light Touch	Diminished Light Touch
Purple	3.84	514007	0.60	5.9	18.4	Diminished Light Touch	Diminished Light Touch
	4.08	514008	1.0	9.8	24.4	Diminished Light Touch	Diminished Light Touch
	4.17	514009	1.4	13.7	27.9	Diminished Light Touch	Diminished Light Touch
	4.31	514010

Product
37450-275	Von Frey Hairs - Set of 20 Monofilaments
Optional
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)