JP4135356B2 - Finger authentication device with biological state detection - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a personal authentication device using a living body, and more particularly to a biometric personal authentication device based on a blood vessel pattern of a finger.
[0002]
[Prior art]
In order to protect automobiles from theft and mischief, expectations for biometric authentication technology are increasing as a key system with higher security than conventional lock-type keys. A major feature of biometric authentication technology that uses a part of the human body as a key is that it is less likely to be lost or illegally used due to duplication. As biometric authentication technology for in-vehicle use, fingerprints are often used because of the ease of operation and low cost. However, as biometric authentication technology itself, iris and finger blood vessel patterns are used as a more secure authentication method. The proposed method has been proposed. Above all, the authentication method using the blood vessel pattern of the finger does not irradiate the eyeball directly like the iris, so there is little psychological resistance, and it reads the internal features instead of the surface of the living body There is an advantage that counterfeiting is difficult.
[0003]
Authentication using a finger blood vessel pattern is generally realized as follows. First, a light source that emits near-infrared light is prepared, and a camera is set up so that the light is photographed. The camera is equipped with an optical filter that passes only wavelengths in the near infrared region. At the time of authentication, a finger is inserted between the camera and the light source, and an image of the finger at that time is taken. Since hemoglobin in blood absorbs near-infrared light well, the blood vessel part appears dark without transmitting light. Collation is performed between the image of the blood vessel pattern photographed in this way and the image of the registered blood vessel pattern to perform personal authentication.
[0004]
On the other hand, the blood vessel state of the finger can be used not only for authentication but also as a clue to indicate the health state. As a well-known technique, there is a method of examining the state of the blood circulation system by the finger plethysmogram or its second derivative, the acceleration pulse group. The finger plethysmogram captures a change in the amount of blood flowing in the peripheral blood vessel of the fingertip, and measures the amount of blood using the light absorption characteristics of hemoglobin as described above.
[0005]
[Problems to be solved by the invention]
Conventionally, the key system of an automobile and the measurement of health status are treated as completely separate, and it is clear that starting the engine and locking / unlocking the door is a key, and that the health check of the driver is performed using medical equipment at home, hospital, etc. The role was divided. Also, the measurement site was different, and the fingerprint of the fingertip was measured as a key, and the arm was measured independently as a simple health check to measure blood pressure and pulse. On the other hand, as automobiles have become a daily foot and the number of accidents has remained high as in recent years, a mechanism to prevent accidents is increasingly desired. Many accidents are closely related to driver health, such as overwork. There is a possibility that accidents can be suppressed by knowing the health condition of the driver and controlling the car appropriately. However, it is troublesome for the driver to perform the key system and the health check independently, and the health check function may not be used after all.
[0006]
An object of the present invention is to simultaneously realize high security and high safety during driving by combining biometric authentication technology and health diagnosis technology. In particular, it is to realize an easy-to-use operability that allows the user to enjoy the benefits with few operations.
[0007]
[Means for Solving the Problems]
The object is to store blood vessel patterns from a storage means for storing personal data, a light source that emits near-infrared light, an imaging means that is sensitive to the near-infrared light, and a finger image captured by the imaging means. And the finger image captured by the imaging unit when the collation is matched by the collating unit, the electrode sensor, and the collating unit that collate the personal blood vessel pattern stored in the storage unit. The collation unit is configured to perform collation by estimating the individual's health condition from the time change of the signal, the signal of the electrode sensor, and the personal data specified by the collation unit stored in the storage unit. And an authentication unit that authenticates when the estimation unit estimates health, matches with the verification unit, and does not authenticate when the estimation unit does not estimate health In Ri is achieved.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail.
[0009]
FIG. 1 is an example of a schematic block diagram of a system configuration for realizing the present invention. Reference numeral 100 denotes a hand, and the finger is inserted between the light source 102 and the camera 104 to acquire an image signal of the blood vessel pattern. The image signal of the camera 104 is converted into digital data by the image input unit 106 and stored in the memory 112 via the input / output interface 114 of the computer 108. The switch 108 is provided via the input / output interface 114, and the on / off state of the switch is stored in the memory 210, or an interrupt signal is generated to the CPU 110 at the same time when the switch is turned on, whereby the authentication timing is set to the CPU. Can also be explicitly indicated. When the CPU 110 detects that a finger has been inserted by monitoring the image change of the switch 108 or the camera 104, the CPU 110 activates and executes a software program for authentication. Then, based on the processing result of the program, the result is displayed on the display 116, transmitted by voice through the speaker 120, or an appropriate signal is sent to the electric lock 122 or ECU (Engine Control Unit) 124. Various controls such as opening and closing the doors and locks and allowing the engine to start. The keyboard 118 is used, for example, for inputting auxiliary information related to authentication such as a password. 126 to 130 are general configurations of a pulse wave meter which is one method for detecting the health condition of the finger, and the optical sensor 126 converts the intensity of the light transmitted through the finger into an electrical signal by the light source 102. This electric signal is amplified through the amplifier 128 and the noise component is removed by the filter 130 and then stored in the memory 112 through the interface 114. Since the optical sensor is theoretically equivalent to a single pixel camera, all of 126 to 130 can be substituted by the camera 104 alone. It can be provided in the case of a sensitivity problem or when it is desired to simultaneously acquire a finger image and a pulse wave. In order to obtain the blood pressure from the pulse wave, it is generally necessary to know the contraction time of the heart, which is measured via 132 electrode sensors, an amplifier 134, a filter 136, and the like.
[0010]
FIG. 2 shows an example of a software flow executed by the hardware, particularly the CPU 110. In process 200, initial values are substituted into temporary variables necessary for initialization of the entire hardware and program execution. When the transition to the initial state is completed, the program enters an idling state and waits for the finger to be inserted into the imageable range (202). Finger insertion can be detected by a sensor, or the operator can explicitly press the switch 108, and can continue to input images from the camera and wait for image changes that accompany finger insertion. You can also. When the insertion of a finger is detected, the camera 104 captures the finger and captures the image in the memory 210 (204). In the captured finger image, since the hemoglobin absorbs near-infrared rays, the blood vessel portion appears to be black. Image processing is performed on the image data to extract the features of the blood vessel pattern (206), and a collation search is performed to see if there is a match with the already registered pattern (208). If there is a matching pattern (210), the process proceeds to the next medical examination. In this embodiment, an example of performing a health check based on a pulse wave is shown. The pulse wave is generally measured by using the optical sensor 126. Here, a method for obtaining a pulse wave from a camera image will be described. By sharing the camera with authentication, the system cost can be reduced. From the same point of view, the light source for measuring the pulse wave is not a light source having a dedicated wavelength, but a common example. When importance is attached to accuracy, a plurality of light sources with optimally adjusted wavelengths may be prepared and switched as necessary. Alternatively, a method using a pressure sensor instead of an optical sensor is also known. As a method for optically obtaining a pulse wave, a method for observing a change in arterial oxygen saturation (SpO2) is known. In the arterial blood that is sent to the fingertips and other peripheral tissues at every heartbeat, there is a large amount of hemoglobin combined with oxygen, and oxygen in the body tissue is deprived, and the number of oxyhemoglobin gradually decreases. Since hemoglobin has different near-infrared light absorbance depending on the presence or absence of oxidation, the amount of hemoglobin bound to oxygen can be measured. This time change forms a sine wave-like waveform having periodic peaks and valleys in conjunction with the pulse. The mountain cycle indicates a pulse. The time difference between the lowest valley point in one cycle and the R point in the electrocardiogram is the time from when the heart contracts until the blood reaches the end, and the pulse wave propagation time (PWTT) : Pulse Wave Transmit Time), and correlation with blood pressure has been confirmed. Since the R point of the electrocardiogram can be easily obtained by the electrode sensor 132, the pulse and blood pressure can be obtained simultaneously. In addition, the temporal change pattern is correlated with physical condition, and can be used as an index of fatigue level. There are individual differences in the relationship between the pulse wave, blood pressure, and health. However, since the person is identified by the authentication process in the previous stage, it can be appropriately handled by referring to the personal data registered in advance. In actual processing, first, in processing 212, in the finger image acquired in 204, the sum of the luminances of the pixels constituting the region is obtained for the entire finger region excluding the background or a part thereof. Of course, if the background is constant, it is not necessary to limit and extract only the finger area. Further, the finger image is input again in the same manner as in the process 204, and the sum of luminance is obtained in the same manner. This is repeated for a certain period, and the temporal change of the luminance sum is measured. The total luminance here may be normalized or an average value may be used. As a result, a measurement result equivalent to the pulse wave measurement using the optical sensor can be obtained. From the obtained pattern of measurement results, the health condition such as pulse, blood pressure, and physical condition can be estimated as described above (214). The obtained health condition is displayed on the display 116 or outputted from the speaker 120 by voice. It may be a notification or warning message related to the health condition itself. If there is no fatal health problem such as showing data that is significantly different from past results or if drinking is detected (216), a confirmation signal to the effect of authentication is sent to the electric lock or ECU, and the door is unlocked / unlocked And start the engine (218). At this time, by sending the health condition information to the ECU, the ECU can perform vehicle control in accordance with the health condition of the driver as shown in FIG.
Control lines are connected from the ECU 124 to the engine 300, the suspension 302, the air conditioner 304, the steering wheel 306, the seat 308, and the car navigation system 310. As a specific example of vehicle control, for example, by controlling an electronically controlled suspension, it is possible to wake up by setting a soft setting with less vibration when physical condition is bad, and conversely stiffening when drowsiness is strong. It is done. Similarly, by adjusting the engine speed, the weight of the steering wheel and brake pedal, the shift timing, the air condition, the seat position, etc., it is possible to provide a driving environment suitable for the health condition of the driver. If it is clear that the disease is obvious, it is possible to show the route to the hospital or clinic closest to the current vehicle position in conjunction with the car navigation system. In addition, even if the health diagnosis result does not interfere with the operation of the vehicle, a warning message may be actively transmitted for the purpose of early detection of the disease.
[0011]
In the above description, the in-vehicle biometric authentication device has been described as an example. However, the present invention is not limited thereto, and the health management function is provided even when the biometric authentication device is used in an entry / exit room or a time card. There are advantages that can be provided without additional operating steps. Alternatively, by incorporating biometric authentication technology into a medical instrument such as a fingertip blood pressure monitor or pulse wave meter, individual identification can be automatically performed, and labor saving of history management of measurement data for each individual can be achieved. As for the biometric authentication method, a fingerprint or the like may be used instead of the blood vessel pattern. Furthermore, as long as measurement data for both authentication and health check can be obtained at the same time for other living body parts, the parts can also be used for the same purpose as the present invention.
[0012]
【The invention's effect】
According to the present invention, high security and driving safety can be realized simultaneously with a simple operation.
[Brief description of the drawings]
FIG. 1 is an example of an apparatus system configuration for realizing the present invention.
FIG. 2 is an example of a software flow for realizing the present invention.
FIG. 3 is an example showing a connection between an ECU and a vehicle component.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 ... Hand, 102 ... Light source, 104 ... Camera, 106 ... Image input device, 108 ... Button switch, 110 ... CPU, 112 ... Memory, 114 ... Input / output interface, 116 ... Display device, 118 ... Keyboard, 120 ... Speaker, 122 ... Electric lock, 124 ... Engine control computer, 126 ... Optical sensor, 128, 134 ... Amplifier, 130, 136 ... Filter, 132 ... Electrode sensor.

Claims (10)

Storage means for storing personal data;
A light source that emits near-infrared light;
Imaging means sensitive to the near-infrared light;
A blood vessel pattern is extracted from an image of a finger imaged by the image pickup means, and a matching means for matching this with an individual blood vessel pattern stored in the storage means;
An electrode sensor;
When the collation is matched by the collating means, the time change of the image of the finger imaged by the imaging means, the signal of the electrode sensor, and the personal data specified by the collating means stored in the storage means from the estimation means for estimating the state of health of the individual,
Authentication means that authenticates when the collation is matched by the collating means and the estimating means estimates health, and does not authenticate when the collation is matched by the collating means and the estimating means does not estimate health And a finger authentication device. The finger authentication device according to claim 1, wherein
A finger authentication device characterized in that, when it is estimated that controlling a specific mechanism after authentication leads to an illegal state such as drunk driving from the measurement result of the biological state, the authentication can be canceled. The finger authentication device according to claim 1, wherein
Health and the biological condition certain period recording of such physical condition, if the measured biological condition is significantly different from past information is a finger authentication device, characterized in that to cancel the authentication. The finger authentication device according to claim 3,
A finger authentication device that records and organizes each state identified by authentication when recording a biological state such as health and physical condition for a certain period of time. The finger authentication device according to claim 1, wherein
The finger authentication device characterized in that the mechanism control performed according to the measurement result of the biological state is the hardness of the suspension of the vehicle. The finger authentication device according to claim 1, wherein
The finger authentication device characterized in that the mechanism control performed according to the measurement result of the biological state is a shift timing of the transmission of the vehicle. The finger authentication device according to claim 1, wherein
The finger authentication device characterized in that the mechanism control performed according to the measurement result of the biological state is the engine speed of the vehicle. The finger authentication device according to claim 1, wherein
The finger authentication apparatus characterized in that the mechanism control performed according to the measurement result of the biological state is a vehicle air conditioner.   The finger authentication apparatus according to claim 1, wherein the mechanism control performed according to the measurement result of the biological state is an introduction of a nearest facility such as a hospital estimated to be necessary in conjunction with the car navigation system. Finger authentication device. The finger authentication device according to claim 1, wherein
A right that has means for storing in advance personal biometric information of one or more right holders who can use the authentication device, and is authenticated by the characteristics of the blood vessel pattern in the analysis of the biometric information of the finger or its temporal change A finger authentication device characterized by estimating a biological state such as health and physical condition using the personal biological information of a person.

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