Assessment of a low-cost LED vein detection method

Venepuncture is one of the most common invasive procedures in medical healthcare worldwide, however failure rates are still relatively high, particularly for paediatric, geriatric, darker skinned, and obese patients. Visualisation of the veins has been shown to decrease failure rates and can be achieved through trans-illumination, near infrared reflectance, or sonography. However, these techniques are either not reliable or very expensive, resulting in them not being commonly used in the clinical workplace. This paper develops a proof of concept low-cost LED vein detection device using photocurrent generated by LEDs in reverse bias. The prototype uses two emitting LEDs and one detecting LED to identify the location of a vein via trans-illuminance and reflectance. Various light intensities and wavelengths of the LEDs are tested in regard to resolution, noise, and signal peaks. A balance between system noise and resolution is identified for each LED in relation to the emitted intensity. No significant difference was observed in relative peak height when different wavelengths were used to identify the same superficial veins. The initial proof of concept proves the LED vein detection method and provides the foundation for further low-cost LED vein detection devices to be developed.