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CN-121994348-A - Flexible monitoring sensor for actively sounding fish and signal analysis method

CN121994348ACN 121994348 ACN121994348 ACN 121994348ACN-121994348-A

Abstract

The invention discloses a flexible monitoring sensor for actively sounding fishes and a signal analysis method, and relates to the technical field of aquaculture. The sensitive layer is made of PDMS and graphene composite material, and the surface of the sensitive layer is provided with a micro pyramid structure array which is regularly arranged. The sensor is attached to the body surface of the fish sounding part, generates deformation in response to body surface sound vibration in a preset frequency range through the micro pyramid structure, and converts the sound vibration into a resistance change signal between the interdigital electrodes by utilizing the piezoresistive effect of the composite material. According to the invention, through the design of the PDMS-graphene composite material and the surface micro pyramid structure, the high-fidelity and direct capturing of body surface vibration signals generated by active sounding of individual fishes are realized, and the problems of group sound mixing and weak signal relevance in the traditional method are effectively avoided.

Inventors

  • WANG LINLIN
  • LI PEIYU
  • MA XINLI
  • CAI WEIMING

Assignees

  • 浙大宁波理工学院

Dates

Publication Date
20260508
Application Date
20260122

Claims (10)

  1. 1. A flexible monitoring sensor for actively sounding fish, comprising: A flexible substrate (1); an interdigital electrode (2) disposed on the flexible substrate; and a piezoresistive sensitive layer (3) overlying the interdigital electrode; The piezoresistive sensitive layer (3) is formed by a composite material of polydimethylsiloxane (31) and graphene (32), and the surface of the piezoresistive sensitive layer (3) is provided with a micro pyramid structure (33) array which is regularly arranged; The flexible monitoring sensor is attached to the surface of the sounding part of the active sounding fish, the micro pyramid structure (33) array on the surface of the piezoresistive sensitive layer (3) responds to the acoustic vibration in the preset frequency range of the sounding part surface to generate deformation, and the acoustic vibration is converted into a resistance change signal between the interdigital electrodes (2) through the piezoresistive effect of the piezoresistive sensitive layer (3).
  2. 2. A flexible monitoring sensor for actively sounding fish as set forth in claim 1, characterized in that the flexible substrate (1) is a polyethylene terephthalate film.
  3. 3. A flexible monitoring sensor for actively sounding fish as set forth in claim 1, characterized in that the interdigital electrode (2) is a chromium/gold electrode.
  4. 4. The flexible monitoring sensor for actively sounding fish according to claim 1, wherein the preset frequency range is a vibration frequency band of a body surface when the sounding part of the actively sounding fish sounds.
  5. 5. A flexible monitoring sensor for actively sounding fish as set forth in claim 1, further comprising a signal processing module electrically connected with the interdigital electrode (2) for collecting the resistance change signal.
  6. 6. The flexible monitoring sensor for actively sounding fish of claim 5 further comprising a waterproof encapsulation layer encasing the flexible substrate (1), interdigital electrodes (2), piezoresistive sensitive layers (3) and signal processing modules.
  7. 7. A signal analysis method applied to the flexible monitoring sensor for actively sounding fish as set forth in any one of claims 1 to 6, comprising the steps of: s1, acquiring a resistance change signal converted by a flexible monitoring sensor; S2, carrying out self-adaptive baseline estimation on the resistance change signal through a median filter, and subtracting a baseline estimation value from the resistance change signal; s3, performing short-time Fourier transform on the signal subjected to baseline correction to generate a corresponding time-frequency spectrogram; s4, calculating a sound pressure level based on the amplitude value of the time-frequency spectrogram, and synthesizing a multi-channel characteristic image containing time, frequency and sound pressure level information; s5, inputting the multichannel characteristic images into a pre-trained lightweight convolutional neural network model to obtain classification results of physiological states corresponding to the active sounding behaviors of the fishes.
  8. 8. The signal analysis method of flexible monitoring sensor for actively sounding fish according to claim 7, wherein in the step S2, the window size of the median filter is determined according to the data length of the resistance change signal, and the window size is set to be an odd number not greater than 201.
  9. 9. The signal analysis method of a flexible monitoring sensor for actively sounding fish as set forth in claim 7, wherein in the step S4, the sound pressure level is calculated by the following formula: in the formula, For the sound pressure level of the sound, Is the magnitude value of the short-time fourier transform, To prevent a small constant for taking the log of zeros, Is an offset coefficient.
  10. 10. The method according to claim 7, wherein in the step S5, the classification result corresponds to a stress state or an active behavior state of the actively sounding fish, the stress state includes at least one of capturing, cooling, heating, and hypoxia, and the active behavior state includes at least one of ingestion and coupling.

Description

Flexible monitoring sensor for actively sounding fish and signal analysis method Technical Field The invention relates to the technical field of aquaculture, in particular to a flexible monitoring sensor for actively sounding fishes and a signal analysis method. Background Along with the development of global aquaculture industry to scale and intensification, the stress sources faced by fishes in the links of cultivation, transportation and the like are more and more complex, and the physiological health and the product quality of the fishes are severely challenged. Under the background, developing a real-time, accurate and non-invasive physiological monitoring technology becomes a key requirement for guaranteeing the health of the cultured animals and improving the production benefit. The specific acoustic signals generated by driving the air bladder side drum muscles of the actively sounding fish represented by large yellow croaker provide a unique biological basis for directly reflecting the physiological and behavioral states of the fish through acoustic means. At present, related technical researches on fish physiological monitoring mainly develop along the following directions, namely a fish wearable flexible sensing technology, such as a strain or impedance sensor based on a liquid metal composite material, can be attached to the surface of a fish to monitor morphological and electrical characteristic changes caused by stress, but capture indirect and derived physiological parameters, are weak in direct association with active behaviors such as ingestion, coupling and the like, and an underwater acoustic detection technology, such as a hydrophone based on graphene and the like, is mainly used for collecting broadband environmental underwater acoustic signals, is difficult to separate and locate specific individual sounding from a group mixed sound field in a dense culture environment, cannot realize individual monitoring, and an optical monitoring method, such as a photoelectric volume wave tracing method, is applied to fish heart rate measurement, has high performance depending on water transmittance, is remarkably reduced in reliability in an actual turbid and changeable culture environment, and is also provided with a flexible device integrated with various sensing functions, is generally universal in design, and is not optimized for capturing and analyzing specific biological signals of fish sounding. In summary, the prior art either fails to directly capture acoustic signals strongly related to active behaviors of fish, or suffers from the disturbance of the culture environment, or cannot distinguish individual sound sources, or lacks an integrated design of real-time analysis from special sensing, so that it is difficult to meet the management requirement of performing continuous, stable and real-time intelligent judgment on the physiological state of individual fish in a practical complex culture scene. Disclosure of Invention In order to better capture acoustic signals of active behaviors of fishes and conduct continuous, stable and real-time intelligent judgment on physiological states of individual fishes, the invention provides a flexible monitoring sensor for actively sounding fishes, which comprises the following components: a flexible substrate; Interdigital electrodes disposed on the flexible substrate; and a piezoresistive sensitive layer overlying the interdigital electrode; The piezoresistance sensitive layer is formed by a composite material of polydimethylsiloxane and graphene, and the surface of the piezoresistance sensitive layer is provided with a micro pyramid structure array which is regularly arranged; The flexible monitoring sensor is attached to the surface of the sounding part of the active sounding fish, the micro pyramid structure array on the surface of the piezoresistive sensitive layer responds to the acoustic vibration in the preset frequency range of the surface of the sounding part to generate deformation, and the acoustic vibration is converted into a resistance change signal between the interdigital electrodes through the piezoresistive effect of the piezoresistive sensitive layer. According to the invention, through the design of the polydimethylsiloxane-graphene composite material and the surface micro pyramid structure, the high-fidelity and direct capturing of the body surface vibration signals generated by active sounding of individual fishes are realized, and the problems of mixed group sound and weak signal relevance in the traditional method are effectively avoided. Further, the flexible substrate is a polyethylene terephthalate film. Further, the interdigital electrode is a chromium/gold electrode. Further, the preset frequency range is a vibration frequency band of the body surface when the sound of the sound generating part of the actively sounding fish is generated. Further, the device also comprises a signal processing module, wherein the signal pro