Abstract: In some aspects, a user device may initiate a biometric measurement operation relating to a user of the user device. The user device may monitor, using a pressure sensor of the user device, whether a pressure at an interface between a body of the user and the user device is within a range used for obtaining data for a biometric measurement. The user device may provide an indication of whether the user is to adjust the pressure based on whether the pressure is within the range. The user device may obtain the data for the biometric measurement. Numerous other aspects are described.

Abstract: The described techniques support a sensing scheme for electromagnetic excitation in ultrasonic imaging sensors. A biological tissue may be sensed and imaged using an electromagnetic excitation process to generate ultrasonic waves, such as, within the tissue. A component of a device may generate one or more pulses of electromagnetic waves, which may encounter and enter the biological tissue. The electromagnetic waves may excite the biological tissue and generate ultrasonic waves via expansion and contraction of the tissue upon heating. The ultrasonic waves may propagate within the biological tissue and may be sensed by an ultrasonic receiver array. The ultrasonic waves may be converted to pixel image data of a biometric image and may be used for biometric authentication. This process may be repeated to reconstruct an image of the finger at multiple plane slices of the finger.

Abstract: Some disclosed methods involve controlling, via a control system, a light source system to emit a plurality of light pulses into biological tissue at a pulse repetition frequency, the biological tissue including blood and blood vessels at depths within the biological tissue. Such methods may involve receiving, by the control system, signals from the piezoelectric receiver corresponding to acoustic waves emitted from portions of the biological tissue, the acoustic waves corresponding to photoacoustic emissions from the blood and the blood vessels caused by the plurality of light pulses. Such methods may involve detecting, by the control system, heart rate waveforms in the signals, determining, by the control system, a first subset of detected heart rate waveforms corresponding to vein heart rate waveforms and determining, by the control system, a second subset of detected heart rate waveforms corresponding to artery heart rate waveforms.

Abstract: An object having an outer surface (e.g. a friction-ridge surface of a finger) and internal parts (e.g. tissue layer, papillae, blood vessels, fat, muscle, nail and bone) is scanned by a system having a transmitter, receiver and computer. One such system has a substantially planar piezoelectric transmit-layer, an ultrasonic receiver array having a plurality of receivers, and a platen. The transmit layer is caused to produce an ultrasound plane-wave traveling toward the object residing on the platen. Using the ultrasonic receiver, ultrasonic energy that has been reflected from the object is detected. The detected ultrasonic energy is analyzed to provide an analysis result, and the analysis result is compared to a template. A determination is made as to whether the analysis result and the template are similar, and the object is declared to be alive if the analysis result is determined to be similar to the template.

Abstract: An apparatus may include a cover layer, a layer of first metamaterial proximate (or in) the cover layer, a light source system configured for providing light to the layer of first metamaterial and a receiver system. The first metamaterial may include nanoparticles configured to create ultrasonic waves when illuminated by light. The receiver system may include an ultrasonic receiver system configured to receive ultrasonic waves reflected from a target object in contact with, or proximate, a surface of the cover layer. The control system may be configured to receive ultrasonic receiver signals from the ultrasonic receiver system corresponding to the ultrasonic waves reflected from the target object and to perform an authentication process and/or an imaging process that is based, at least in part, on the ultrasonic receiver signals.

Abstract: An ultrasound cardiovascular measuring device may include an ultrasonic sensor system having an ultrasound transmitter layer configured to generate ultrasonic plane waves and a focusing layer that includes one or more lenses. One or more of the lenses may be configured to generate output signals corresponding to detected ultrasonic reflections. The measuring device may include a control system capable of processing the output signals to calculate values corresponding to one or more cardiovascular properties.

Abstract: An apparatus may include a cover layer, a layer of first metamaterial proximate (or in) the cover layer, a light source system configured for providing light to the layer of first metamaterial and a receiver system. The first metamaterial may include nanoparticles configured to create ultrasonic waves when illuminated by light. The receiver system may include an ultrasonic receiver system configured to receive ultrasonic waves reflected from a target object in contact with, or proximate, a surface of the cover layer. The control system may be configured to receive ultrasonic receiver signals from the ultrasonic receiver system corresponding to the ultrasonic waves reflected from the target object and to perform an authentication process and/or an imaging process that is based, at least in part, on the ultrasonic receiver signals.

Abstract: The described techniques support a sensing scheme for electromagnetic excitation in ultrasonic imaging sensors. A biological tissue may be sensed and imaged using an electromagnetic excitation process to generate ultrasonic waves, such as, within the tissue. A component of a device may generate one or more pulses of electromagnetic waves, which may encounter and enter the biological tissue. In some examples, the component may be a display interface or may be different from a display interface of the device. The electromagnetic waves may excite the biological tissue and generate ultrasonic waves via expansion and contraction of the tissue upon heating. The ultrasonic waves may propagate within the biological tissue and may be sensed by an ultrasonic receiver array. The sensed ultrasonic waves may be converted to pixel image data of a biometric image and may be used for biometric authentication.

Abstract: An apparatus may include an ultrasonic sensor array and a control system. The control system may be configured to acquire first image data generated by the ultrasonic sensor array corresponding to at least one first reflected ultrasonic wave received by at least a portion of the ultrasonic sensor array from a target object during a first acquisition time window. The control system may be configured to acquire second image data generated by the ultrasonic sensor array corresponding to at least one second reflected ultrasonic wave received by at least a portion of the ultrasonic sensor array from the target object during a second acquisition time window that is longer than the first acquisition time window. The control system may further be configured to initiate an authentication process based on the first image data and the second image data.

Abstract: A subdermal imaging system which may determine whether a person's body is in contact with a display, and perform a subdermal imaging process to determine subdermal characteristics by a photoacoustic imaging process. Ultrasonic emissions emitted from the photoacoustic process may be received with an ultrasonic receiver array. The subdermal imaging system may adjust the wavelength and/or intensity of the photoacoustic process in order to image desired subdermal features.

Abstract: The described techniques support a sensing scheme for electromagnetic excitation in ultrasonic imaging sensors. A biological tissue may be sensed and imaged using an electromagnetic excitation process to generate ultrasonic waves, such as, within the tissue. A component of a device may generate one or more pulses of electromagnetic waves, which may encounter and enter the biological tissue. In some examples, the component may be a display interface or may be different from a display interface of the device. The electromagnetic waves may excite the biological tissue and generate ultrasonic waves via expansion and contraction of the tissue upon heating. The ultrasonic waves may propagate within the biological tissue and may be sensed by an ultrasonic receiver array. The sensed ultrasonic waves may be converted to pixel image data of a biometric image and may be used for biometric authentication.

Abstract: The described techniques support a sensing scheme for electromagnetic excitation in ultrasonic imaging sensors. A biological tissue may be sensed and imaged using an electromagnetic excitation process to generate ultrasonic waves, such as, within the tissue. A component of a device may generate one or more pulses of electromagnetic waves, which may encounter and enter the biological tissue. The electromagnetic waves may excite the biological tissue and generate ultrasonic waves via expansion and contraction of the tissue upon heating. The ultrasonic waves may propagate within the biological tissue and may be sensed by an ultrasonic receiver array. The ultrasonic waves may be converted to pixel image data of a biometric image and may be used for biometric authentication. This process may be repeated to reconstruct an image of the finger at multiple plane slices of the finger.

Abstract: An apparatus may include an ultrasonic sensor system and a control system. The control system may be configured to distinguish, according to image data acquired via an ultrasonic sensor system, the pyroelectric effect caused by an actual human finger from the pyroelectric effect caused by a sleeve-type spoof or a “fake finger” spoof. Some such examples involve obtaining multiple frames of ultrasonic image data of a target object on or near a platen of an ultrasonic sensor system via the ultrasonic sensor system and determining at least one target object pyroelectric indication based, at least in part, on the multiple frames of ultrasonic image data.

Abstract: An apparatus may include an ultrasonic sensor system and a control system. The control system may be configured to distinguish, according to image data acquired via an ultrasonic sensor system, the pyroelectric effect caused by an actual human finger from the pyroelectric effect caused by a sleeve-type spoof or a “fake finger” spoof. Some such examples involve obtaining multiple frames of ultrasonic image data of a target object on or near a platen of an ultrasonic sensor system via the ultrasonic sensor system and determining at least one target object pyroelectric indication based, at least in part, on the multiple frames of ultrasonic image data.

Abstract: Techniques for authenticating a biometric input are disclosed. An example of a biometric authentication system is configured to receive a biometric input, perform a first authentication process on the biometric input with an application processor, such that the first authentication process generates one or more authentication parameters, provide the one or more authentication parameters to a secure processor, perform a second authentication process on the biometric input on the secure processor, such that the second authentication process utilizes the one or more authentication parameters, and output an authentication score based on the second authentication process.

Abstract: An ultrasonic reflex imaging device and a method are described. A device according to the invention may include a platen, a generator, and a receiver positioned between the platen and the generator. A backer may be positioned so that the insonification device is between the receiver array and the backer. The backer may be configured to absorb or delay energy that originated from the generator. The generator produces an energy pulse, which travels through the receiver and the platen to reach a biological object. Part of the energy pulse is reflected from the biological object. The reflected energy pulse travels through the platen to the detector. The detector converts the reflect energy pulse to electric signals, which are then interpreted to create an image of the biological object.

Abstract: A subdermal imaging system which may determine whether a person's body is in contact with a display, and perform a subdermal imaging process to determine subdermal characteristics by a photoacoustic imaging process. Ultrasonic emissions emitted from the photoacoustic process may be received with an ultrasonic receiver array. The subdermal imaging system may adjust the wavelength and/or intensity of the photoacoustic process in order to image desired subdermal features.

Abstract: Systems and methods for multi-spectral ultrasonic imaging are disclosed. In one embodiment, a finger is scanned at a plurality of ultrasonic scan frequencies. Each scan frequency provides an image information set describing a plurality of pixels of the finger including a signal-strength indicating an amount of energy reflected from a surface of a platen on which a finger is provided. For each of the pixels, the pixel output value corresponding to each of the scan frequencies is combined to produce a combined pixel out put value for each pixel. Systems and methods for improving the data capture of multi-spectral ultrasonic imaging are also disclosed.

Abstract: An object having an outer surface (e.g. a friction-ridge surface of a finger) and internal parts (e.g. tissue layer, papillae, blood vessels, fat, muscle, nail and bone) is scanned by a system having a transmitter, receiver and computer. One such system has a substantially planar piezoelectric transmit-layer, an ultrasonic receiver array having a plurality of receivers, and a platen. The transmit layer is caused to produce an ultrasound plane-wave traveling toward the object residing on the platen. Using the ultrasonic receiver, ultrasonic energy that has been reflected from the object is detected. The detected ultrasonic energy is analyzed to provide an analysis result, and the analysis result is compared to a template. A determination is made as to whether the analysis result and the template are similar, and the object is declared to be alive if the analysis result is determined to be similar to the template.

Abstract: Methods and systems of determining whether an object is alive, and therefore part of a live individual, are described. An object having an outer surface (e.g. a friction-ridge surface of a finger) and internal parts (e.g. tissue layer, papillae, blood vessels, fat, muscle, nail and bone) is scanned by a system having a transmitter, receiver and computer. One such system has a substantially planar piezoelectric transmit-layer, an ultrasonic receiver array having a plurality of receivers, and a platen. The transmit layer is caused to produce an ultrasound plane-wave traveling toward the object residing on the platen. Using the ultrasonic receiver, ultrasonic energy that has been reflected from the object is detected. The detected ultrasonic energy is analyzed to provide an analysis result, and the analysis result is compared to a template.