Product Details

32 CHANNEL

What Is an EEG Machine?

An EEG (electroencephalogram) machine is a medical device that measures and records the electrical activity of the brain via electrodes placed on the scalp. The signals are captured as brain waves and displayed as waveforms for clinical interpretation.

An EEG recording helps detect abnormalities in brain function and is widely used in neurology.

⚙️ How It Works

1. Electrode Placement:
   Small metal discs (electrodes) are attached to the scalp, typically following the 10–20 international system to standardize positions.

2. Signal Detection:
   Electrodes detect tiny voltage changes resulting from the electrical activity of neurons in the cerebral cortex.

3. Amplification & Digitization:
   Signals are very weak (microvolts), so the machine uses amplifiers and A/D converters to digitize them.

4. Display & Analysis:
   The data are displayed as waveforms (peaks and troughs) on a screen or paper and analyzed by specialists.

📊 Typical Technical Specifications

Note: Specs vary by model and purpose (clinical vs research). Here are representative figures:

General Specs

• Channels: 16–256 (clinical commonly 19–32)

• Sampling Rate: 200–8192 Hz (high-frequency systems for research)

• Input Impedance: ≥10 MΩ or >100 MΩ

• CMRR: ≥90–100 dB (higher is better for noise rejection)

• Noise Level: <0.5–5 µV peak-to-peak

• Resolution: 12–24 bits

• Bandwidth: 0.01–120 Hz (or up to 500 Hz for specific needs)

• Filters: High-pass/low-pass filters to isolate relevant brain signals

• Connectivity: USB, Ethernet, Wi-Fi (varies by model)

Clinical Examples

• Portable systems with 16–32 channels, USB connectivity, rechargeable batteries, and common digital filters.

• High-end units may offer up to 48 channels and advanced signal processing.

🧩 Types of EEG Systems

1. Routine/Diagnostic EEG:
   Standard short recordings (20–60 min), used in clinics.

2. Ambulatory EEG:
   Wearable units for 24–72 hour monitoring at home.

3. Video-EEG Systems:
   EEG synchronized with video to correlate electrical activity with behavior.

4. Continuous ICU EEG (cEEG):
   Real-time, continuous monitoring for critical patients.

5. High-Density EEG:
   64–256+ channels for research and advanced brain mapping.

🧠 What EEG Measures

EEG machines record brain waves, representing the combined electrical activity of large groups of neurons. These include recognizable rhythms like alpha, beta, delta, and theta waves.

EEG has excellent temporal resolution (millisecond precision), though spatial resolution (exact location in the brain) is limited.

🧪 Common Clinical Uses

EEG machines are used to diagnose and monitor:

✔ Epilepsy and seizure disorders
✔ Sleep disorders
✔ Brain tumors and injuries
✔ Stroke and encephalopathy
✔ Monitoring brain activity during coma or anesthesia
✔ Assessing brain death
✔ Research in cognitive and neural science