Study Of Photoacoustic Signal Image Enhancement Based On Non-negative Constrained Pulse Decomposition

Photoacoustic imaging is an imaging technique which uses photoacoustic signals generated by objects due to photoacoustic effects to reconstruct images.Due to the combination of the advantages of optical and acoustic imaging,photoacoustic imaging technology takes into account the characteristics of high imaging depth and high resolution,and the non-invasive detection method has good biological safety,making it widely used in the field of biomedicine.Photoacoustic tomography and photoacoustic microscopy are two typical imaging methods.The photoacoustic microscope system can perform high-resolution imaging of microvessels of biological tissues,and its resolution can reach the micron or submicron level,and has the potential to detect microvascular-related pathological problems.The current problem is that the weak photoacoustic signal from deep tissues leads to a low signal-to-noise ratio(SNR).In this paper,the signal processing method is used to improve the quality of the image,and after processing by algorithms,the laser used by the photoacoustic imaging system can be reduced and the amount of radiation can make the detection sufficiently safe in an environment with low radiation energy.Therefore,it is important to reduce the noise of the image under low SNR conditions.It can increase the imaging depth,reduce the laser dosage,improve the performance of the photoacoustic imaging system,and increase the safety of the photoacoustic imaging application scenarios.In this paper,a non-negative constrained pulse decomposition algorithm is proposed,which theoretically proves that the method has a significant effect on the improvement of the SNR;then the OR-PAM and AR-PAM systems are respectively tested by the phantoms and live animals.Finally,the Hessian matrix multi-scale fusion of blood vessel enhancement method is combined to extract complete microvessel structure information,and quantitative evaluation of the effect of pulse decomposition algorithm to enhance the photoacoustic image.When the center frequency of the pulse basis function is consistent with the frequency of the system,the algorithm achieves the best noise reduction effect,which improves the image contrast from 2.68 to 3.89.