# Non-Contact Heart Rate Detection Based on Hand Vein Transillumination Imaging
###### Abstract  
Vein recognition technology identifies human vein characteristics under near-infrared light and compares it with stored vein information for personal identification. Although this has high anti-counterfeiting performance, it is possible to fabricate artificial hands that simulate vein characteristics to deceive the identity authentication system. In view of this potential deficiency, we introduced heart rate information to vein authentication, a means of living body detection, which can further improve the anti-counterfeiting effect of vein authentication. A hand vein transillumination imaging experiment was designed to prove its effectiveness. In the proposed method, a near-infrared light source is used to transilluminate the hand, and the transillumination images are collected by a common camera. Then, the region of interest is selected for gray-scale image processing, the feature value of each frame is extracted by superimposing and averaging the images, and then the one-dimensional pulse wave is drawn. Furthermore, the baseline drift phenomenon is filtered by morphological methods, and the maximum percentage frequency is determined by Fast Fourier Transform, that is, the pulse wave frequency. The heart rate value is then calculated, and finally, the stability of the heart rate detection result is evaluated. The experiment shows that the method produces accurate and stable results, demonstrating that it can provide living information (heart rate value) for vein authentication, which has great application prospects and development opportunities in security systems. P 2  
surface and can be measured by electrodes on the skin surface. The arterial blood pressure method [8] uses a pressure sensor to convert the pressure signal corresponding to the regular fluctuation of arterial blood pressure into a heart rate signal. In 1938, [PERSON] proposed PPG [9], which detects the pulse by using light to transmit or reflect blood flowing in blood vessels. In 2000, [PERSON] et al. proposed iPPG [10] on the basis of PPG, which collects reflected light images with a black-and-white camera and analyzes the picture sequence to obtain pulse wave signals. Since traditional heart rate monitoring methods, such as electrocardiographic signal and arterial blood pressure methods, require contact with the skin, users may experience discomfort, and it is not suitable for obtaining heart rate parameters when applied in the field of biometrics. On the other hand, with the development of technology, cameras have become ubiquitous, so their use in heart rate detection has many potential applications. Biometric technology combines computers with high-tech approaches, such as optics, acoustics, biosensors, and biostatistics principles, and uses the inherent physiological characteristics of the human body (fingerprints, iris, gait, veins, etc.) to confirm a person's identity [11; 12; 13; 14]. Traditional identification methods include identification items (keys, certificates, ATM cards, etc. ), and security information (such as usernames and passwords). However, because these methods mainly rely on external objects or memory, once the identification item or security information that proves identity is stolen or forgotten, the individual can be easily impersonated or replaced by others. Biometrics is more secure, confidential and convenient than traditional identification methods. Biometric identification technology has several advantages: it does not require memorization, has good anti-counterfeiting performance, is difficult to forge or steal, and is \"carried\" with the individual, and is usable anytime, anywhere. Among these techniques, vein recognition technology [15] is highly effective against counterfeiting. Veins are hidden in the body, and are inherent features that are difficult to forge and steal. Vein authentication is a second-generation biometric recognition technology [16], with great application prospects and development opportunities in security fields.