For many years, medical professionals have relied on limited technology to locate the veins within their patients, however, this method has proven less effective for pediatric and elderly patients [1]. We propose a low-cost handheld scanner that determines the dorsal vein locations of a hand and uses the venous patterns to identify the patient. A hand dorsal vein pattern makes an excellent patient identification method in clinics or hospitals with more complex situations, as wearing personal protective equipment such as a mask can make it difficult to identify patients. The system also offers basic biological information about the patient, such as heart rate and blood oxygen saturation.

The scanner consists of 36 LEDs of red wavelength (625 nm) and NIR (near-infrared) wavelength (850 nm) which are used to display the dorsal vascular system. LED strips are incorporated into a 3D-printed jig that can be comfortably held by the patient. NIR LEDs are used as they are highly absorbed by oxygenated hemoglobin in the bloodstream, thus making veins more visible [2]. A webcam is used to capture the vascular pattern, which is then transferred and stored to the laptop computer for image processing and pattern recognition. The captured image is then processed through an algorithm consisting of multiple stages of filters to display dilated binary images of the vein patterns of the hand. As the light penetration rate of each patient's hand varies due to differences in skin color, thickness, and size, the scanner actively adjusts the intensity of the LEDs to increase the contrast of vein patterns. The images captured with different intensities of LED lights were subsequently analyzed using the algorithm developed to evaluate the ability to detect hand venous patterns.

In summary, we have developed a device and programmed an algorithm for processing an image of the dorsal venous network of the hand in real-time considering all possible hand characteristics. This device offers a new technological advancement for the medical field that could greatly benefit procedures used for vein finding in clinical settings in the future.

References

[1] V. M. Naik, S. S. P. Mantha, and B. K. Rayani, Indian Journal of Anaesthesia, 63, 737-745 (2019)

[2] A. Madrid García and P. R. Horche, Results in Physics, 11, 975-983 (2018)