A method of controlling a process for the manufacture of a multicomponent sheet material having a desired pre-determined parameter comprising applying an acoustic or an electromagnetic signal to interact with the sheet material whereby the interaction modifies the applied signal, detecting the modified signal, comparing the modified signal or data derived from it with data relating to the pre-determined parameter and modifying at least one step of the process whereby the data relating to the modified signal is modified towards the data relating to the pre-determined parameter.

A subject information acquisition apparatus includes: an acoustic wave detector which detects an acoustic wave which is generated from a subject by irradiating light and outputs a detection signal; an amplifier which amplifies the detection signal which is output from the acoustic wave detector; a gain control unit which changes a gain of the amplifier as time elapses, according to a gain control table, in order to correct a drop in intensity of the acoustic wave caused by attenuation of fluence inside the subject; and a signal processing unit which obtains information inside the subject based on the signal amplified by the amplifier. Measurement under a plurality of measurement conditions, where at least fluence distribution inside the subject or a position of the acoustic wave detector differs, is possible, and the gain control unit changes the gain control table according to the measurement conditions.

Systems and methods are disclosed herein in which multi-level square wave excitation signals are used instead of or in addition to fully-analog excitation signals to drive an array of transceiver elements to create a sound field. Use of multi-level square wave excitation signals produces acceptable transceiver output with reduced complexity, cost, and/or power consumption as compared with use of fully-analog excitation signals. In addition, use of such signals facilitates system implementation using application-specific integrated circuits (ASICs) and is not as restricted in voltage level and speed. At the same time, the benefits and applications of fully-analog excitation signals (e.g., acoustic holography, beam superposition, signal-to-noise ratio (SNR) improvements, suppression of parasitic modes, increased material penetration, potential for coded pulsing algorithms and suppression of side lobes in ultrasonic field) can still be achieved with multi-level square wave excitation signals.

The present technology relates generally to portable acoustic holography systems for therapeutic ultrasound sources, and associated devices and methods. In some embodiments, a method of characterizing an ultrasound source by acoustic holography includes the use of a transducer geometry characteristic, a transducer operation characteristic, and a holography system measurement characteristic. A control computer can be instructed to determine holography measurement parameters. Based on the holography measurement parameters, the method can include scanning a target surface to obtain a hologram. Waveform measurements at a plurality of points on the target surface can be captured. Finally, the method can include processing the measurements to reconstruct at least one characteristic of the ultrasound source.