CPC A61B 5/1172 (2013.01) [G06V 40/12 (2022.01); G07C 9/257 (2020.01); G07C 9/37 (2020.01)] | 18 Claims |
10. An access control system comprising:
at least one fingerprint sensor, each fingerprint sensor having a sensor die and a bezel, the sensor die including a plurality of capacitive sensing elements, wherein a drive signal from the bezel is couplable to the sensor die by a finger;
a controller coupled to the fingerprint sensor; and
a fingerprint database coupled to the controller;
wherein
the fingerprint database includes:
a plurality of authorized person records, wherein each of the authorized person records contains fingerprint data corresponding to a particular authorized person; and
the controller is configured to:
receive a series of fingerprint signals from the at least one fingerprint sensor, each fingerprint signal generated from a plurality of electric charge intensity signals sensed by the plurality of capacitive sensing elements when the drive signal is coupled from the bezel to the sensor die;
authenticate the series of fingerprint signals by determining if each of the fingerprint signals in the series of fingerprint signals corresponds to the recorded fingerprint data for the particular authorized person;
verify that the series of fingerprint signals corresponds to a corresponding response signal for the particular authorized person;
determine if the fingerprint signals in the series of fingerprint signals correspond to live fingerprint signals by detecting a signal component of the fingerprint signals indicative of the fingerprint signals being received from a live human finger, wherein detecting the signal component indicative of the fingerprint signals being received from the live human finger comprises:
identifying variations in the received fingerprint signals;
determining that the variations comprise a rhythmic variation that corresponds to a heartbeat frequency of an expected heart rate; and
detecting the signal component indicative of the fingerprint signals being received from the live human finger in response to determining that the variations comprise the rhythmic variation; and
provide the corresponding response signal based on the series of fingerprint signals when the series of fingerprint signals are authenticated and verified, and the fingerprint signals correspond to live fingerprint signals.
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