Methods for measuring times-of-flight of ultrasound echo signals

A method for measuring a time-of-flight of an ultrasound echo signal, comprising:

• S1:
• capturing an echo signal, including:
• acquiring the echo signal transmitted by an ultrasonic transducer in a receive mode based on a preset acquisition parameter, wherein the preset acquisition parameter includes a preset frequency and a preset intensity of an ultrasonic wave;
• adjusting an emission parameter in response to a signal-to-noise ratio of the echo signal being lower than a second threshold, including:
• reducing a vibration frequency of the ultrasonic transducer by a preset frequency adjustment amount to lower a frequency of an ultrasonic signal emitted by the ultrasonic transducer;
• and re-controlling the ultrasonic transducer in a transmit mode to emit the ultrasonic signal based on the adjusted emission parameter until the signal-to-noise ratio of the echo signal is higher than the second threshold;
• S2:
• obtaining a reconstructed echo signal by performing and reconstruction on the echo signal using an empirical wavelet transform;
• S3:
• obtaining a preset reference echo signal, normalizing the preset reference echo signal to obtain a preset reference echo peak value, normalizing the reconstructed echo signal to obtain a reconstructed echo peak value, and determining an echo characteristic peak of the reconstructed echo signal using a preset characteristic peak positioning algorithm, wherein the operation S3 includes:
• S31:
• obtaining the preset reference echo signal;
• S32:
• normalizing the preset reference echo, and obtaining the preset reference echo peak value and the reconstructed echo peak value;
• S33:
• obtaining a first echo peak value, a second echo peak value, and a third echo peak value of preset three consecutive cycles of the preset reference echo signal, and obtaining echo peak values of any three consecutive cycles of the reconstructed echo signal;
• S34:
• performing cosine distance calculations between the echo peak values of the preset three consecutive cycles of the preset reference echo signal and the echo peak values of the any three consecutive cycles of the reconstructed echo signal;
• S35:
• determining cosine distances between echo peak values of remaining three consecutive cycles of the reconstructed echo signal and the echo peak values of the preset three consecutive cycles of the preset reference echo signal, sorting the cosine distances by numerical magnitude, and identifying a portion of the reconstructed echo signal corresponding to three consecutive cycles corresponding to a maximum value of the cosine distances;
• and
• S36:
• obtaining a position of a preset echo characteristic peak of the preset reference echo signal in S33, and obtaining a position of an echo characteristic peak of the reconstructed echo signal corresponding to the maximum value of the cosine distances based on the position of the preset echo characteristic peak;
• S4:
• obtaining high-frequency sampling points corresponding to the preset reference echo signal in S3, mapping the high-frequency sampling points to a preset region corresponding to the echo characteristic peak, obtaining a data sequence corresponding to the preset region, and obtaining an echo characteristic point corresponding to the data sequence by performing calculations on the data sequence using a preset interpolation algorithm, wherein the operation S4 includes:
• S41:
• obtaining the high-frequency sampling points corresponding to the preset reference echo signal in S3;
• S42:
• mapping the high-frequency sampling points to the preset region corresponding to the echo characteristic peak, and obtaining the data sequence corresponding to the preset region;
• S43:
• obtaining a preset zero position of the data sequence corresponding to the preset region in S42;
• and
• S44:
• obtaining the echo characteristic point corresponding to the data sequence by performing calculations on a position before the preset zero position and a position after the preset zero position using the preset interpolation algorithm;
• and
• S5:
• measuring the time-of-flight of the echo signal based on the echo characteristic point using a preset measurement algorithm.