The Japanese firm Fujitsu, a leader in biometric-based recognition systems for the pattern of palm veins, has requested new US patents for technological advances in relation to this type of authentication.
A vascular patterns reader is based on the infrared light emission whose wavelength is close to 760 mm. Blood is able to absorb light at this spectrum range, while other body tissues (bones, skin, muscles, etc.) do not. This is due to the presence of hemoglobin in the blood that can absorb some of these rays, thereby reducing the percentage of reflected rays and causing the veins to appear as a black pattern in the captured image.
Using an appropriated and specific sensor, it can be obtained an image where the blood vessels are visible as dark lines and the rest of the finger or hand appears in a lighter color. These lines build a particular unique vein diagram for each person, generating an individual biometric pattern.
This technique is usually used to find vein patterns located in the palm or the back of the hand, wrist, or in any of the fingers. It has the advantage that the device is not touched by individuals during the identification process. The application includes a pre-collection of information to feed a database that will serve for future identifications.
Fujitzu has patented the development of a technology where pixels values of the captured image can be converted into frequency components. The device filters the frequency components of the image depending on the vascular structure, which is unique to each person.
The firm has also filed another patent to develop a device which includes an acquisition unit configured to repeatedly image a biological part of an authenticated person, while changing a relative position with respect to the biological part thereby acquiring time-series biological images.
The system was designed to improve precision of this authentication method, decreasing the impact of surface reflection that can be created when light reflects off of the palm of an individual. The series of images captured by the system compose a final image with no surface reflection. In this way a precise, unique and practically “impossible to replace” system was achieved.