A photoacoustic imaging system

Abstract

The embodiments of the invention provide a photo-acoustic imaging system comprising a detection laser, an excitation laser, a light path system, a water container, a metal film and an imaging processing device. The detection laser is used for generating detection laser and the excitation laser is used for generating excitation laser. The water container holds water for transmitting optical and acoustic waves, wherein the refractive index of the water changes by the action of the optical and acoustic waves. The metal film is used for receiving incoming detection laser, and the detection laser generates surface plasma resonance on an upper surface of the metal film to obtain reflected detection laser. The imaging processing device is used for performing imaging on samples according to the reflected detection laser. The light path system is used for transmission of detection laser among the detection laser, the metal film and the imaging processing device and also used for transmission of excitation laser between the excitation laser and samples. The system has the advantage of high imaging resolution.

Description

technical field [0001] The invention relates to the field of imaging, in particular to a photoacoustic imaging system. Background technique [0002] Photoacoustic imaging technology based on photoacoustic effect is a booming biomedical imaging technology. It organically combines two physical methods of optical excitation and acoustic detection. The generated broadband ultrasonic waves (ie, photoacoustic waves) realize the specific observation of tissue optical absorption characteristics. The early photoacoustic tomography technology had a spatial resolution of 200 μm, and the subsequent dark-field illumination photoacoustic imaging technology not only improved the lateral resolution to 50 μm, but also significantly improved the image quality, and successfully observed subcutaneous (>3.0mm) melanin Three-dimensional structure of tumor and vascular network. The photoacoustic imaging system with optical resolution achieves micron-level lateral resolution, and clearly image...

AI Technical Summary

Problems solved by technology

Restricted by the properties of the piezoelectric material itself, piezoelectric ceramic ultrasonic transducers generally have the disadvantages of narrow detection bandwidth (about 40-60MHz) and low sensitivity (noise equivalent sound pressure: hundreds of Pascals to thousands of Pascals).

The bandwidth of piezoelectric ceramic ultrasonic transducers limits the longitudinal resolution of photoacoustic imaging, which not only affects the accuracy of depth positioning, but also seriously distorts 3D images

At the same time, the limited acoustic detection bandwidth leads to the loss of photoacoustic spectral information, and will cause saturation effects, which cannot accurately reflect the optical absorption properties of substances

The detection sensitivity of piezoelectric ceramic ultrasonic transducers seriously affects the signal-to-noise ratio and reduces the quality of photoacoustic images

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