Von Frey纖毛機械刺激針遵循Semmes-Weinstein（賽姆斯-韋恩斯坦）測試理論進行設計，可進行精細的觸覺檢查，可以測定從輕觸覺到深壓的感覺。

Von Frey纖毛機械刺激針也可叫做Touch-Test單絲測試盒、Semmes-Weinstein觸覺測量尼龍絲，能測試和評估感覺水平，Touch-Test?單絲的力量值在5%的標準偏差范圍內，測試感覺水平。

利用Touch-Test?單絲感覺測試套裝來測試感覺水平，可以準確報告正在減少或恢復的感覺；
測試根據預先設定力的5%的標準偏差進行；

當達到峰值力閾值時，測試筆的單絲呈彎曲形狀；
獨特的手柄設計，Touch-Test?單絲可以打開和回收90°角，方便測試和收納；
手指凹痕設計，具有牢固和舒適的手感；
單絲測試筆手柄上標有相應的壓力水平的顏色和編碼；
測試結果可以記錄在單獨出售的手部或腳部篩查表格上；
有5件套手部套件裝，6件套足部套件裝和20件套裝可供選擇；

20種單絲規格的力度值：

1.65（0.008g）、2.36（0.02g）、2.44（0.04g）、2.83（0.07g）、3.22（0.16g）、3.61（0.4g）、3.84（0.6g）、4.08（1.0g）、4.17（1.4g）、4.31（2.0g）、4.56（4.0g）、4.74（6.0g）、4.93（8.0g）、5.07（10.0g）、5.18（15.0g）、5.46（26.0g）、5.88（60.0g）、6.10（100.0g）、6.45（180.0g）、6.65（300.0g）。

不同顏色代碼表示不同的壓力級別：

1.65-2.83對應正常 Normal
3.22-3.61對應輕觸覺減退 Diminished Light Touch
3.84-4.31對應保護性感覺減退 Diminished Protective Sensation
4.56-6.45對應保護性感覺喪失Diminished Protective Sensation
6.65用于深層感覺檢測Deep Pressure Sensation Only
 
有手部感覺測試型、足部感覺測試型和全規格測試型可供選擇：
手部套件包含：2.83, 3.61, 4.31, 4.56 ,6.65 五種測試單絲，型號：NC12772
足部套件包含：2.83, 3.61, 4.31, 4.56, 5.07, 6.65六種測試單絲，型號：NC12773
全規格套件包含：所有二十種單絲測試---推薦配置，型號NC12775-99

Touch Test

The Semmes-Weinstein monofilaments provide an approximate 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. Subsets within the set of 20 probes distinguish pathologies on different parts of the body (foot, hand, lip, cheek,etc.).

Semmes-Weinstein Von Frey Aesthesiometer for touch assessment

Features

Set of 20 monofilaments based on the Semmes-Weinstein monofilament set

Features retractable filaments to protect the filament

Allows the researcher to carry a few in a pocket

The Semmes-Weinstein monofilaments provide an approximate 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. Subsets within the set of 20 probes distinguish pathologies on different parts of the body (foot, hand, lip, cheek,etc.).

Operating Principle When the tip of a fiber of given length and diameter is pressed against the skin at right angles, 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. This makes it possible for the researcher using a hand-held probe to apply a reproducible force, within a wide tolerance, to the skin surface.

Pre-Clinical Use Rodents exhibit a paw withdrawal reflex when the paw is unexpectedly touched. The Touch Test? Sensory Evaluator can be used on the Plantar surfaces of the foot of a rat or mouse. The animal indicates sensation by pulling back its paw. Individual filaments available.