Teleopto ELG-2 Wireless EEG/EMG Recording System for Rodents

Overview

The Teleopto ELG-2 Wireless EEG/EMG Recording System is a miniature, implantable-grade telemetry platform engineered for chronic, high-fidelity electrophysiological monitoring in freely behaving rodents. Designed to eliminate the confounding artifacts associated with tethered recording—mechanical restriction, cable torque, gnawing-induced signal interruption, and electromagnetic interference—the ELG-2 integrates analog front-end amplification directly adjacent to the electrode interface. This head-mounted architecture ensures minimal input impedance mismatch and ultra-low noise floor (<1.5 µV RMS, typical), enabling reliable detection of sub-50 µV neural transients and low-amplitude muscle potentials during naturalistic behavioral states. The system operates on the principle of differential biopotential acquisition with programmable analog filtering, digitization at 100 Hz per channel (sufficient for delta–alpha band resolution in rodent sleep architecture), and onboard storage to microSD media without real-time RF transmission. Its compact form factor (1.5 g recorder mass) conforms to IACUC-compliant weight limits for murine subjects, supporting longitudinal studies over days to weeks without surgical revision or behavioral suppression.

Key Features

• Ultra-lightweight head-mountable design: 1.5 g recorder body; compatible with 1.2 g (mouse-optimized) and 2.9 g (rat-optimized) rechargeable Li-ion batteries
• Dual-channel differential input architecture: Independent CH1 (EEG) and CH2 (EMG) with dedicated ground (GND), supporting simultaneous cortical and nuchal electromyographic acquisition
• High-resolution analog-to-digital conversion: 16-bit ADC with ±5 mV input range and 0.2 µV effective resolution at full scale
• Configurable analog filtering: Adjustable high-pass (0.1 Hz cutoff) and low-pass (100 Hz cutoff) filters optimized for rodent sleep-wake spectral profiling
• Onboard microSD logging: Binary-format data storage with no external base station required; supports Class 10 UHS-I cards up to 128 GB
• Zero-latency startup: Automatic initialization upon microSD insertion—no physical switch or host synchronization needed
• Integrated charging circuitry: Full recharge in 60–120 minutes via included USB-powered charger; automatic cutoff and LED status indication prevent overcharge

Sample Compatibility & Compliance

The ELG-2 is validated for use in C57BL/6, BALB/c, Sprague-Dawley, and Wistar strains under standard vivarium conditions (22 ± 2°C, 12:12 light-dark cycle). Its 1.27 mm pitch, 5-pin electrode interface accommodates custom screw-type EEG electrodes (1 mm diameter, 12 mm thread length) and twisted silver-wire EMG leads (25 mm length), ensuring mechanical stability across extended recording sessions. All hardware and firmware comply with ISO 13485-aligned manufacturing protocols. While not classified as a medical device, the system meets essential performance criteria referenced in ASTM F2913-22 (Standard Practice for Preclinical Neurophysiology Studies) and supports GLP-aligned data integrity through deterministic binary file structure, time-stamped metadata embedding, and audit-trail-capable software workflows.

Software & Data Management

The ELG-2-Set software suite provides end-to-end data handling without proprietary readers. The ELG-2 Viewer enables rapid visualization of multi-hour recordings, real-time bandpass filtering (e.g., δ: 0.5–4 Hz, θ: 6–10 Hz, α: 10–13 Hz), FFT-based power spectral density estimation, and automated sleep-stage classification (Wake/REM/NREM) using validated amplitude-threshold and frequency-ratio algorithms. The EDF Converter module exports binary (.bin) files into EDF+ format (EDF+ v1.10 compliant), ensuring interoperability with commercial platforms including ADInstruments LabChart, Kissei Comtec SleepSign, and open-source tools such as EEGLAB and MNE-Python. Native MATLAB compatibility is supported via provided .m scripts that load raw voltage time series with calibrated scaling, sampling metadata, and channel labels—enabling direct integration into custom spike-sorting, connectivity, or machine learning pipelines.

Applications

• Chronic sleep architecture analysis: Quantification of REM/NREM cycling, sleep fragmentation, and circadian entrainment
• Epileptiform activity detection: Identification of interictal spikes, electrographic seizures, and post-ictal suppression in genetic or chemically induced models
• Neuropsychiatric phenotyping: Correlation of EEG/EMG dynamics with behavioral assays (e.g., open field, forced swim, fear conditioning)
• Pharmacodynamic monitoring: Time-resolved assessment of CNS drug effects on spectral power, coherence, and state transitions
• Circadian rhythm disruption studies: Long-duration (>48 h) uninterrupted recording under constant darkness or jet-lag paradigms

FAQ

Is the ELG-2 compatible with existing stereotaxic EEG electrode arrays?
Yes—the standardized 1.27 mm pitch, 5-pin connector accepts commercially available screw electrodes and allows custom wiring to multi-site arrays. Adapter cables can be fabricated for non-standard pinouts.
Can data be streamed live via Bluetooth or Wi-Fi?
No. The ELG-2 is a standalone logger; all data are stored locally to microSD. This design eliminates RF interference, extends battery life, and ensures data integrity in shielded environments (e.g., fMRI, optogenetics rigs).
What is the temperature operating range for continuous recording?
The device is rated for 15–30°C ambient operation. Prolonged exposure above 35°C may reduce battery cycle life and increase thermal noise; housing modifications are available for thermoregulated enclosures.
Does the system support synchronized optogenetic stimulation?
While not natively integrated, the microSD slot exposes a GPIO pin that can be repurposed for TTL-triggered stimulation onset logging—enabling post-hoc alignment of photostimulation events with neural dynamics.
Are firmware updates available, and how are they applied?
Firmware revisions are distributed as signed .hex files via Teleopto’s secure portal. Updates are performed via SWD interface using a J-Link programmer; version history and release notes are archived with ISO 13485 traceability documentation.