Research On Cell Photoacoustic Signal Detection Technology Based On Acoustic Metamaterials

Photoacoustic detection technology has been developed rapidly in the past few decades,and the imaging resolution,imaging sensitivity and imaging speed have been significantly improved.Photoacoustic microscopy imaging technology is of great significance for cell detection,and can be used to diagnose diseases caused by changes in cell size,shape,and structure.Acoustic metamaterials are an artificial periodic structure with a scale between macro and micro,which can produce strange physical phenomena that traditional materials cannot.Based on the sound field control characteristics of artificial acoustic metamaterials,a variety of new acoustic functional devices can be obtained through the design of material parameters and structures.The essence of photoacoustic signal is acoustic signal.The introduction of acoustic metamaterials into photoacoustic detection,which is applied in all aspects of the transmission,reception and processing of acoustic signal,has important theoretical significance and engineering value for photoacoustic detection technology.Experiments and finite element simulations have proved that the photoacoustic power spectrum of a single red blood cell has good sensitivity to the morphological characteristics of the cell.However,there is still room for further development in the simultaneous detection of multi-cell photoacoustic signals.In order to realize the simultaneous detection of multi-cell photoacoustic signals,this article mainly carried out three aspects of work.First,the law of mutual influence between cell photoacoustic signals was analyzed,and the appropriate distance between cells was found;secondly,a Y-shaped acoustic waveguide was designed.Structural model,which can realize the directional transmission of multi-channel high-frequency acoustic signals and precise linear interference,and then realize the transmission and comparison of cell photoacoustic signals;finally,according to the characteristics of red blood cell photoacoustic signals,it is constructed to improve the resolution of red blood cell photoacoustic imaging High-speed acoustic hyperlens.At the same time,the acoustic lens also realizes the isolation of single-cell photoacoustic signals,which provides a basis for simultaneous detection of multi-cell photoacoustic signals.The main content of the paper includes:1.Based on the principle of acoustic interference,two red blood cell models at different distances are established on the basis of the single cell model.By comparing the similarity of the photoacoustic signal of the interfered red blood cell with the photoacoustic signal of a single red blood cell at different distances,the mutual influence law of the photoacoustic signal between cells is analyzed.The results show that when the distance between two red blood cells is 26.6 ?m,the signal of the interfered red blood cell has the highest similarity with the signal of the undisturbed single red blood cell.It also shows that by adjusting the distance between the two cells,the detection points of the cells can be obtained with less disturbed photoacoustic signals.2.In order to realize the transmission and comparison of multiple high-frequency acoustic signals,a Y-shaped acoustic waveguide based on acoustic metamaterials is designed,and the acoustic transmission effect of the acoustic waveguide is analyzed.The results show that a single Y-shaped model can realize the transmission and comparison of two high-frequency acoustic signals.When multiple Y-shaped models are cascaded,the transmission and comparison of multiple high-frequency acoustic signals can still be realized.In order to prove the effect of the model on the transmission and comparison of acoustic signals,an acoustic logic operation experiment was carried out.The results show that the model can realize multi-channel signal transmission and precise linear interference.3.Aiming at the characteristics of the red blood cell photoacoustic signal,an acoustic hyperlens based on the rotating body structure of the acoustic metamaterial was constructed,and the transmission of the cell photoacoustic signal with and without the lens was compared,and the lens to a single red blood cell was further analyzed.The enhancement effect of photoacoustic signal.Experiments have proved that the lens can not only realize the transmission of the evanescent wave component in the cell photoacoustic signal,improve the imaging resolution,but also realize the isolation between the cell photoacoustic signals.