Based on the unique patterns of veins, vascular pattern recognition (VPR), or vein pattern recognition, provides the ease of use of hand geometry with much improved accuracy, smaller readers and a much more hygienic approach. It uses near-infrared light generated from a bank of LEDs projected through an individual’s skin to enable a high-contrast matching of vein patterns (e.g., vein branching points, vein thickness, and branching angles). VPR systems scan the de-oxygenated veins, extract key pattern features via contactless, near-infrared optical sensor systems, digitize the extracted pattern recognition, and then match the transaction templates to the respective pre-established enrollment template. By measuring the veins under the skin, it is very difficult for unauthorized persons to observe or capture this pattern, rendering VPR a highly secure method of identity verification.

Since 1997 Hitachi has been developing an original biometric, finger vein authentication technology, which uses the finger vein pattern obtained from passing light through a finger as a key. Its first commercial systems were deployed in 2004. In 2005, a grip-type finger vein authentication technology* was developed, enabling a door to be opened simply by gripping the handle. Since then, Hitachi has been working to develop an even more compact system to extend market applications.

As illustrated in the adjacent figure, near-infrared light generated by a bank of LEDs (light emitting diodes) penetrates the body tissue, it is reflected in the hemoglobin in the blood. A CCD camera (which uses a small, rectangular piece of silicon to receive incoming light) captures the image of the vein pattern through this reflected light. Image processing constructs a finger vein pattern from the camera image. This pattern is compressed and digitized so that it can be registered as a template for biometric authentication. Within a split second, the FV system filters the digitized image, produces a template or digitized image that it compares to the stored template of the user, and determines whether there is a match, using pattern-matching techniques. Variations in environmental temperature or a person’s blood pressure can sometimes cause fluctuations in the width and brightness of the blood vessels. The Hitachi finger vein system pinpoints the position of the center of each blood vessel so that those vein fluctuations do not affect the matching procedure.

Hitachi has delivered to the market a variety of finger vein scanning devices, depending on the application. Hitachi’s initial successes with VPR technology were with Japanese financial institutions and their ATM systems. HOTS (Hitachi Omron Terminal Solutions) designed a physical access module to be embedded in ATMS, kiosks, and turnstiles. Shown to the left, this module is highly accurate, and has a small portable form factor that enables it to be mounted inside a variety of larger devices. It has been successfully used at 65% of the Japanese banks and other ATM owners, including Japan Post, Mizuho Bank, Sumitomo Mitsui, and Daisan Bank, among others. The finger vein (FV) readers are quite small and support a template of approximately 500 bytes, small enough to support rapid processing and large enough to support both 1:1 and 1:N matching.