Ugo Basile 38450 e-VF Automated Von Frey Tactile Sensory Analyzer

Overview

The Ugo Basile 38450 e-VF Automated Von Frey Tactile Sensory Analyzer is an electromechanical instrument engineered for quantitative assessment of mechanical allodynia and hyperalgesia in rodent models—primarily mice and rats. It operates on the principle of calibrated monofilament stimulation combined with objective behavioral response detection. Unlike manual von Frey testing, the e-VF system applies controlled, linearly increasing mechanical force to the plantar surface of the hind paw via a precision-driven actuator. The device detects withdrawal reflex onset either automatically through real-time force–displacement monitoring or manually via footswitch input, ensuring temporal alignment between stimulus delivery and behavioral endpoint. Its integrated triangular prism optical system provides unobstructed, parallax-free visualization of the paw–filament contact zone—a critical design feature for accurate positioning and consistent application geometry across repeated trials. The system is purpose-built for longitudinal pain phenotyping, preclinical pharmacodynamic evaluation, and mechanistic studies involving peripheral and central sensitization pathways.

Key Features

• Precision force actuation with 0.1 g resolution and full-scale range up to 1000 g—enabling high-fidelity quantification across both low-threshold tactile sensitivity and high-threshold nociceptive thresholds.
• Programmable stimulus ramp rate (g/s) and inter-trial interval—supporting standardized protocols aligned with IASP and NIH guidelines for rodent pain behavior assessment.
• Onboard data logging with timestamped force–time curves, withdrawal latency, and trial metadata—each session stored with unique animal ID, operator code, and date/time stamp.
• Dual-mode response detection: automatic electronic sensing of paw withdrawal based on sudden load drop (>5% threshold deviation within 100 ms), plus optional footswitch-triggered manual confirmation for ambiguous responses.
• Ergonomic triangular prism viewing module—engineered to eliminate occlusion during stimulation while maintaining natural weight-bearing posture; compatible with standard rodent restraint tubes and elevated mesh platforms.
• Modular accessory support including optional grip bar for consistent body positioning, laser-perforated stainless-steel mesh floor (5 × 5 mm² apertures, 1 mm center-to-center spacing), and corrosion-resistant epoxy coating for routine disinfection.

Sample Compatibility & Compliance

The e-VF 38450 is validated for use with adult C57BL/6, CD-1, Sprague-Dawley, and Wistar rats and mice (body weight ≥18 g). It supports both acute and chronic pain models—including CCI, SNI, STZ-induced neuropathy, CFA-mediated inflammation, and chemotherapy-induced peripheral neuropathy (CIPN). All hardware and firmware comply with CE marking requirements under Directive 2014/30/EU (EMC) and 2014/35/EU (LVD). Data export formats (CSV, Excel-compatible) meet minimum requirements for audit trails under GLP Annexes and FDA 21 CFR Part 11 when used with validated laboratory information management systems (LIMS). The system does not require calibration certificates traceable to NIST, but includes internal self-check routines prior to each test session.

Software & Data Management

The e-VF is operated via Ugo Basile’s proprietary e-VF Control Suite (v3.2+), a Windows-based application supporting protocol templating, multi-animal batch scheduling, and real-time force–time waveform display. Raw data files contain full analog traces sampled at 100 Hz, annotated with operator-defined event markers (e.g., “first contact”, “withdrawal”, “reposition”). Exported datasets include calculated metrics: 50% withdrawal threshold (via Dixon up-down method), mean latency, coefficient of variation across replicates, and inter-limb asymmetry index. Audit logs record user login, parameter changes, and file export events—retained for ≥36 months unless manually purged. Data integrity is preserved through write-once file generation and SHA-256 checksum validation upon export.

Applications

• Quantitative assessment of mechanical allodynia in transgenic mouse models of neuropathic pain (e.g., Nav1.7 KO, TRPA1 overexpression).
• Pharmacological profiling of novel analgesics targeting voltage-gated sodium channels, ASICs, or mechanosensitive Piezo receptors.
• Validation of dorsal root ganglion (DRG) neuron excitability changes following intrathecal siRNA or CRISPR interference.
• Longitudinal tracking of sensory recovery post-spinal cord injury or peripheral nerve repair.
• Standardized endpoint measurement in contract research organization (CRO) studies requiring OECD TG 407 or ICH S7B-compliant pain assays.
• Integration with complementary modalities such as dynamic weight bearing (DWB), Hargreaves thermal test, or automated gait analysis (CatWalk XT).

FAQ

What filament sets are compatible with the e-VF 38450?
The system is fully compatible with Ugo Basile’s calibrated von Frey filament kits (models 37450 and 277), covering forces from 0.008 g to 300 g. These filaments conform to Semmes-Weinstein monofilament standards and are supplied with individual NIST-traceable calibration certificates.
Can the e-VF be used without the triangular prism platform?
Yes—the actuator module may be mounted on third-party elevated mesh floors or custom behavioral arenas, provided the vertical clearance (≥25 mm) and lateral stability meet ISO 13485 mechanical interface specifications.
Is the software validated for 21 CFR Part 11 compliance?
The e-VF Control Suite itself is not individually 21 CFR Part 11 certified; however, it generates ALCOA+ compliant data when deployed within a validated LIMS environment that enforces electronic signatures, audit trail retention, and role-based access control.
How often does the system require recalibration?
Annual verification against certified dead-weight standards is recommended per ISO/IEC 17025. Internal diagnostics verify linearity, hysteresis, and zero drift before each experimental session.
Does the e-VF support integration with video tracking systems?
Yes—via TTL output triggers synchronized to stimulus onset and withdrawal detection events, enabling frame-accurate alignment with EthoVision XT, Noldus, or DeepLabCut-generated pose estimation outputs.