RWD 68302 Hollow 45° Rat Ear Bar (Customizable)

Overview

The RWD 68302 Hollow 45° Rat Ear Bar is a precision-engineered stereotaxic accessory designed for secure, reproducible head fixation of adult rats during neuroscientific procedures—including electrophysiology, microinjection, optogenetics, and in vivo imaging. Its 45° angled, hollow stainless-steel construction enables unobstructed ventral access to the skull base and brainstem while maintaining optimal alignment with standard stereotaxic frames (e.g., David Kopf, Stoelting, or RWD-compatible systems). The hollow design reduces weight and thermal mass, minimizing conductive heat transfer during prolonged experiments—a critical factor in thermosensitive protocols. Unlike solid ear bars, this configuration accommodates integrated temperature probes, fiber-optic cannulas, or miniature pressure sensors without mechanical interference.

Key Features

• 45° fixed angular geometry optimized for rat cranial anatomy—ensures consistent bregma-lambda alignment across subjects and sessions.
• Hollow cylindrical shaft (inner diameter ≥1.2 mm) allows concurrent passage of calibrated thermistors, optical fibers (up to Ø1.0 mm), or microdialysis tubing.
• Laser-etched linear scale (0–50 mm) along the shaft with 1 mm resolution for precise depth calibration relative to the external auditory meatus.
• Corrosion-resistant medical-grade 316L stainless steel; passivated per ASTM F86 and ISO 10993-1 for biocompatibility and repeated autoclaving (134°C, 18 min, 20 cycles).
• Integrated compatibility with RWD 68000-series stereotaxic adapters (e.g., 68010 Universal Adapter Plate) and third-party clamping mechanisms via standardized M4 threaded interface.
• Customization options include surface finish (electropolished vs. matte), length extension (+20 mm increments), and optional radiopaque tungsten markers for intraoperative X-ray or µCT co-registration.

Sample Compatibility & Compliance

The 68302 ear bar is validated for use with Sprague-Dawley, Wistar, and Long-Evans rats (250–500 g). It conforms to institutional animal care requirements under AAALAC International standards and supports GLP-compliant surgical workflows when used with traceable calibration logs. All dimensional tolerances adhere to ISO 2768-mK general tolerancing for machined parts. The 1 mm刻度 (scale graduation) meets ANSI/ASME B89.1.12M metrological guidelines for laboratory measurement tools used in preclinical research. No CE marking or FDA 510(k) clearance applies, as this is a Class I non-invasive, non-powered surgical accessory under 21 CFR §892.1000.

Software & Data Management

While the ear bar itself is hardware-only, its scale markings are directly integratable into digital stereotaxic workflows. When paired with RWD’s NeuroStar™ Stereotaxic Suite (v3.2+), users may input calibrated zero-reference points (e.g., external auditory meatus at 0 mm) to auto-calculate target coordinates in Paxinos & Watson space. Audit trails—including operator ID, date/time stamp, and adapter serial number—are retained in compliance with 21 CFR Part 11 when using validated electronic lab notebooks (ELNs) such as LabArchives or Benchling. Calibration certificates (traceable to NIM China) are available upon request for ISO/IEC 17025-accredited labs.

Applications

• Precise targeting of subcortical structures (e.g., VTA, SNc, DRN) requiring ventral approach angles.
• Chronic implantation of bilateral electrode arrays where symmetric ear bar torque minimizes midline deviation.
• Intraoperative MRI or CT-guided interventions requiring uncluttered inferior field-of-view.
• Thermoregulation studies involving simultaneous brain surface temperature monitoring and intracranial manipulation.
• High-throughput behavioral phenotyping rigs integrating automated head-fixation and motion tracking.

FAQ

Is the 68302 compatible with non-RWD stereotaxic frames?
Yes—mechanical interface follows ISO 8015 universal mounting specifications; adapter plates for Kopf (Model 968) and Stoelting (Model 51725) are available separately.
Can the hollow channel accommodate a 200-µm optical fiber with FC/PC connector?
Yes, provided the connector is detached prior to insertion; the internal bore supports Ø1.0 mm rigid components up to 45 mm insertion depth.
What is the maximum recommended torque for tightening the ear bar into the adapter?
0.5–0.7 N·m—exceeding 0.8 N·m risks thread deformation in aluminum adapters; a calibrated torque screwdriver (e.g., Wiha 27200) is advised.
Does RWD provide validation documentation for GLP audits?
Yes—upon order confirmation, customers receive a Device Master Record (DMR) excerpt including material certifications, dimensional inspection reports, and sterilization validation summaries.
Are custom angles (e.g., 30° or 60°) available under OEM agreement?
Yes—RWD offers full mechanical redesign services under NDA, including FEA stress analysis and prototype testing per ISO 14155 for preclinical device evaluation.