## Common ground
All are electrodes designed for medical or surgical applications, used to detect or deliver electrical signals.
## Options at a glance
**9018.11 – disposable ECG electrodes**
- **Defining trait:** Designed specifically for non-invasive heart signal detection during ECG exams, intended for single use.
- **Typical examples:** Adhesive pads placed on chest/limbs for standard ECG recordings.
- **Best fit when:** Used in routine cardiac monitoring or diagnostics with disposable, patient-specific application.
**9018.19 – ECG/EMG signal detection electrodes**
- **Defining trait:** General-purpose electrodes for detecting electrical activity from heart (ECG) or muscles (EMG), not limited to one type of signal.
- **Typical examples:** Reusable surface electrodes used in physiotherapy or neuromuscular testing.
- **Best fit when:** Measuring both cardiac and muscle signals, especially in research or rehabilitation settings.
**9018.50 – non-optical ophthalmological instrument electrodes (e.g. ECG ear electrodes)**
- **Defining trait:** Used in ophthalmological devices (like electroretinography), often placed on ears or skin near eyes; not for general ECG/EMG.
- **Typical examples:** Ear electrodes used during eye function tests, or skin electrodes for retinal response measurement.
- **Best fit when:** Integrated into specialized eye-testing equipment, especially where non-optical signal detection is required.
**9018.90 – surgical electrosurgical electrodes**
- **Defining trait:** Designed to deliver high-frequency electrical current during surgery (e.g., cutting or coagulating tissue).
- **Typical examples:** Monopolar or bipolar probes used in laparoscopic or open surgery.
- **Best fit when:** Used for tissue ablation, cutting, or sealing during surgical procedures.
## Key differences
| Feature | 9018.11 | 9018.19 | 9018.50 | 9018.90 |
|-----------------------|------------------|-------------------|----------------------|---------------------|
| Primary use | ECG monitoring | ECG/EMG detection | Ophthalmological test | Surgery (cutting/coagulation) |
| Signal type | Cardiac only | Cardiac or muscle | Eye-related signals | High-frequency energy delivery |
| Reusability | Disposable | Often reusable | Varies | Usually single-use or sterilizable |
## How to choose
- Is it used for heart monitoring only? → 9018.11
- Does it detect both heart and muscle signals? → 9018.19
- Is it part of an eye-testing device (e.g., ear electrode)? → 9018.50
- Is it used to cut or seal tissue during surgery? → 9018.90
## Overlaps & pitfalls
- A disposable ECG electrode could also be used in EMG testing, so 9018.11 and 9018.19 may overlap if not strictly defined by use.
- 9018.50 includes "ECG ear electrodes" as an example, which might confuse users thinking it's for general ECG—clarify that it’s for ophthalmological systems only.
- No option takes priority; choose based on the **main function** of the electrode