Non-contact miniature photoacoustic imaging head and imaging device thereof

Abstract

The invention provides a non-contact miniature photoacoustic imaging head, which comprises an optical fiber and a lens, and the optical fiber and the lens are coaxially aligned. The invention further provides a non-contact photoacoustic imaging device which comprises the non-contact miniature photoacoustic imaging head, an excitation light source, a detection light source, a beam splitter, a photoelectric detector, a beam expanding and shaping module, a wavelength division multiplexer, an optical fiber circulator and an acquisition card. In non-contact photoacoustic microscopic imaging based on photoacoustic remote sensing, miniaturization of an imaging head, construction simplification and use convenience of an imaging system and simplification of the imaging system in multi-mode imaging development are realized.

Description

technical field [0001] The present application relates to the field of photoacoustic imaging, in particular to a non-contact miniature photoacoustic imaging head and an imaging device thereof. Background technique [0002] Photoacoustic imaging technology has gradually become a powerful tool in the field of biomedicine. In this technique, a pulsed laser with a pulse width of nanoseconds is usually used as excitation light to irradiate the sample. When the photon energy of the laser is absorbed by the sample, the photon energy will be converted into heat, which will generate instantaneous thermal expansion inside the sample. This thermal expansion will cause a pressure change inside the sample, and propagate to the outside of the sample in the form of sound waves, which will be detected by the ultrasonic probe placed around the sample, and the resulting signal is the so-called photoacoustic signal. Since the ultrasonic wave is severely attenuated in the air, if you want to ...

AI Technical Summary

Problems solved by technology

[0003] (1) For the photoacoustic imaging of cerebral blood vessels or capillaries in burnt skin, which have strict hygiene requirements, the contact detection method may cause pollution problems

[0004] (2) When imaging blood vessels in the eye, such as the retina, the use of these ultrasonic coupling agents will cause discomfort to the patient, and even lead to the risk of blindness in severe cases

However, when the sample size is too large and the weight is heavy, for example, when performing photoacoustic remote sensing microscopic imaging on certain parts of humans or other large animals, ordinary electronically controlled displacement platforms cannot meet the requirements

At the same time, when moving a large-volume or heavy-weight sample, it is easy to shake the sample. For a photoacoustic remote sensing microscopic imaging device with a resolution of micron, it will cause the image obtained by scanning to become blurred, or even the scan cannot be completed.

[0009] (2) The photoacoustic remote sensing microscopic imaging device based on free space light is relatively large, which makes it difficult to use in some scenarios, such as photoacoustic scanning inside the oral cavity and inside the digestive tract

[0010] (3) The system construction based on free space light is more complicated

In the photoacoustic remote sensing imaging device based on free space light, multiple optical components need to be used, and it is difficult to ensure the confocality of excitation light and probe light

In addition, when combined with other optical methods, such as fluorescence imaging or optical coherence tomography, the entire imaging device will be particularly complicated, which greatly increases the difficulty of building the optical system, which is not conducive to photoacoustic remote sensing imaging. Further development of micro-imaging technology

[0011] (4) The stability of the optical imaging device based on free space light is not high

However, its imaging head is still based on free-space light, including components such as dichroic mirrors and scanning mirrors, and many of the above-mentioned shortcomings still exist

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