Liquid lens-based dynamic focusing photoacoustic proctoscope imaging device and method

Abstract

The invention discloses a liquid lens-based dynamic focusing photoacoustic proctoscope imaging device. The device comprises a sleeve, a laser annular scanning system, a dynamic focusing system, a laser alignment system and a signal acquisition and image reconstruction system, wherein the laser annular scanning system, the dynamic focusing system and the laser alignment system which are sequentially connected through a light path are arranged in the sleeve; the sleeve is respectively connected with the signal acquisition and image reconstruction system; and high and uniform image resolution and contrast ratio in a certain range are realized, and the detection sensitivity is improved. The invention also discloses an imaging method by using the dynamic focusing photoacoustic proctoscope imaging device. The liquid lens technology is applied to the field of photoacoustic imaging, a focus drift phenomenon during annular scanning of the photoacoustic proctoscope is corrected, dynamic focusing and imaging of the photoacoustic proctoscope is realized, and high image resolution and high contrast ratio are guaranteed. The device can be widely applied to the fields of industrial inspection and medical imaging.

Description

technical field [0001] The invention belongs to the technical field of photoacoustic microscopic imaging, and in particular relates to a photoacoustic proctoscope imaging device and an imaging method based on dynamic focusing of a liquid lens. Background technique [0002] Photoacoustic imaging technology refers to that the light-absorbing medium irradiated by short-pulse light (pulse width < microseconds) rapidly heats up and expands after absorbing light energy. Since the irradiation time is much shorter than the heat conduction time inside the irradiated medium, instantaneous thermal expansion results. Ultrasonic signals (called photoacoustic signals) are stimulated. The ultrasonic sensor is used to receive the photoacoustic signal stimulated by the medium, and the image is reconstructed through a certain calculation algorithm, which can invert the distribution of light absorption inside the tissue. functional imaging techniques. Photoacoustic endoscopic imaging tech...

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Problems solved by technology

Since the penetration depth of ultrasound in tissues is greater than that of light in tissues, photoacoustic endoscopic imaging can detect deeper biological tissues than optical endoscopic imaging; but due to the eccentricity of the endoscope cavity or To detect the non-circular symmetry of the sample itself, the focus of the laser beam with a fixed focal length cannot be irradiated on the tissue, which will cause uneven distribution of resolution, that is, the resolution of the tissue is the highest at the focus, and the resolution is low in front or behind the focus; at the same time, due to The eccentricity of the endoscope cavity or the asymmetry of the sample causes the uneven distribution of light energy density irradiated by the tissue, so the signal-to-noise ratio at different positions of the photoacoustic endoscopic imaging is also inconsistent, thus affecting the photoacoustic endoscopic technology. The actual application effect

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