Semi-compact photoacoustic devices and systems
An apparatus may include a platen, a light source system and an ultrasonic receiver system. The platen may be configured to separate one or more received arterial ultrasonic waves generated by blood in an artery, by an arterial wall, or by a combination thereof, from one or more other types of received ultrasonic waves. The platen may have an outer surface with an acoustic impedance that is configured to approximate the acoustic impedance of human skin. The outer surface of the platen may be configured to conform to a surface of the human skin. The apparatus may include a noise reduction system. The light source system may include at least one multi-junction laser diode. The apparatus may include a mirror layer residing between the ultrasonic receiver system and the platen.
1 . An apparatus, comprising:
a platen;
a light source system configured for providing light to a target object on an outer surface of the platen; and
an ultrasonic receiver system configured to receive ultrasonic waves generated by the target object, responsive to the light from the light source system provided to the target object, wherein the platen includes a first cone-shaped platen portion configured for transmitting the light from the light source system to the outer surface of the platen along a first axis corresponding with the first platen portion and a second cone-shaped platen portion configured for transmitting the ultrasonic waves generated by the target object along a second axis corresponding with the second platen portion, the first platen portion being connected to the second platen portion, a first surface of first platen portion being proximate the light source system, the first surface of first platen portion being offset from a second surface of the second platen portion proximate the ultrasonic receiver system by an angle between the first axis and the second axis.
2 . The apparatus of claim 1 , wherein the platen is configured to increase an intensity of ultrasonic energy received by at least a portion of the ultrasonic receiver system.
3 . The apparatus of claim 1 , wherein the platen includes an acoustic waveguide.
4 . The apparatus of claim 1 , wherein the platen includes an acoustic lens.
5 . The apparatus of claim 4 , wherein the acoustic lens resides on, or proximate, the outer surface of the platen.
6 . The apparatus of claim 4 , wherein the acoustic lens comprises a spherical lens or a cylindrical lens.
7 . The apparatus of claim 1 , wherein the second platen portion has a cylindrical shape.
8 . The apparatus of claim 1 , wherein at least one surface of the platen comprises an anti-reflective layer.
9 . The apparatus of claim 7 , wherein the ultrasonic receiver system comprises two or more receiver elements adjacent to a region of the platen through which light from the light source is transmitted towards the target object.
10 . The apparatus of claim 1 , wherein the platen, the light source system, or a combination thereof, is configured for transmitting light in the near infrared range.
11 . The apparatus of claim 1 , wherein the apparatus is, or includes, a mobile device and wherein the outer surface of the platen corresponds with, or is proximate, an outer surface of the mobile device.
12 . The apparatus of claim 11 , wherein the mobile device comprises a cellular telephone.
13 . The apparatus of claim 11 , wherein the mobile device comprises a pen or a stylus.
14 . The apparatus of claim 13 , wherein the pen or the stylus includes a force sensor, a motion sensor, a spring, or combinations thereof.
15 . The apparatus of claim 1 , wherein a thickness of the platen, an acoustic velocity of the platen, or a combination thereof, are configured to separate ultrasonic waves generated by blood in an artery from other ultrasonic waves.
16 . The apparatus of claim 1 , wherein the platen provides an acoustic attenuation of the ultrasonic waves in a range from 0.3-3.0 decibels per centimeter per megahertz.
17 . The apparatus of claim 1 , wherein at least an outer surface of the platen has an acoustic impedance that is configured to approximate an acoustic impedance of human skin.
18 . The apparatus of claim 1 , wherein at least an outer surface of the platen is configured to conform to a surface of human skin.
19 . The apparatus of claim 1 , wherein a speed of sound in the platen is in a range from 800-3000 meters per second.
20 . The apparatus of claim 1 , further comprising a control system configured to:
control the light source system to emit light;
receive signals from the ultrasonic receiver system corresponding to the ultrasonic waves generated by the target object;
identify arterial blood signals from the ultrasonic receiver system corresponding to ultrasonic waves generated by blood within an artery of the target object; and
estimate one or more cardiac features based, at least in part, on the arterial blood signals.
21 . The apparatus of claim 1 , further comprising a control system configured to:
control the light source system to emit light;
receive signals from the ultrasonic receiver system corresponding to the ultrasonic waves generated by the target object;
identify one or more arterial wall signals from the ultrasonic receiver system corresponding to ultrasonic waves generated by one or more arterial walls of the target object; and
estimate one or more cardiac features based, at least in part, on the one or more arterial wall signals.
22 . The apparatus of claim 1 , further comprising one or more optical waveguides.
23 . The apparatus of claim 22 , wherein at least a portion of one of the one or more optical waveguides resides in a portion of the platen.
24 . An apparatus, comprising:
a platen;
light source means for providing light to a target object on, or proximate, an outer surface of the platen; and
an ultrasonic receiver system configured to receive ultrasonic waves generated by the target object, responsive to the light from the light source means provided to the target object, wherein the platen includes a first cone-shaped platen portion configured for transmitting the light from the light source system to the outer surface of the platen along a first axis corresponding with the first platen portion and a second cone-shaped platen portion configured for transmitting the ultrasonic waves generated by the target object along a second axis corresponding with the second platen portion.
25 . The apparatus of claim 24 , wherein the platen is configured to increase an intensity of ultrasonic energy received by at least a portion of the ultrasonic receiver system.
26 . The apparatus of claim 24 , wherein the platen includes an acoustic waveguide.
27 . The apparatus of claim 24 , wherein the platen includes an acoustic lens.