Stimulated Raman scattering(SRS)microscopy has the ability of noninvasive imaging of specific chemical bonds and been increasingly used in biomedicine in recent years.Two pulsed Gaussian beams are used in traditional ...Stimulated Raman scattering(SRS)microscopy has the ability of noninvasive imaging of specific chemical bonds and been increasingly used in biomedicine in recent years.Two pulsed Gaussian beams are used in traditional SRS microscopes,providing with high lateral and axial spatial resolution.Because of the tight focus of the Gaussian beam,such an SRS microscopy is difficult to be used for imaging deep targets in scattering tissues.The SRS microscopy based on Bessel beams can solve the imaging problem to a certain extent.Here,we establish a theoretical model to calculate the SRS signal excited by two Bessel beams by integrating the SRS signal generation theory with the fractal propagation method.The fractal model of refractive index turbulence is employed to generate the scattering tissues where the light transport is modeled by the beam propagation method.We model the scattering tissues containing chemicals,calculate the SRS signals stimulated by two Bessel beams,discuss the influence of the fractal model parameters on signal generation,and compare them with those generated by the Gaussian beams.The results show that,even though the modeling parameters have great influence on SRS signal generation,the Bessel beams-based SRS can generate signals in deeper scattering tissues.展开更多
Phase-contrast microscopy converts the phase shift of light passing through a transparent specimen,e.g.,a biological cell,into brightness variations in an image.This ability to observe structures without destructive f...Phase-contrast microscopy converts the phase shift of light passing through a transparent specimen,e.g.,a biological cell,into brightness variations in an image.This ability to observe structures without destructive fixation or staining has been widely utilized for applications in materials and life sciences.Despite these advantages,phase-contrast microscopy lacks the ability to reveal molecular information.To address this gap,we developed a bond-selective transient phase(BSTP)imaging technique that excites molecular vibrations by infrared light,resulting in a transient change in phase shift that can be detected by a diffraction phase microscope.By developing a time-gated pump-probe camera system,we demonstrate BSTP imaging of live cells at a 50 Hz frame rate with high spectral fidelity,sub-microsecond temporal resolution,and sub-micron spatial resolution.Our approach paves a new way for spectroscopic imaging investigation in biology and materials science.展开更多
Spectroscopic stimulated Raman scattering(SRS)imaging generates chemical maps of intrinsic molecules,with no need for prior knowledge.Despite great advances in instrumentation,the acquisition speed for a spectroscopic...Spectroscopic stimulated Raman scattering(SRS)imaging generates chemical maps of intrinsic molecules,with no need for prior knowledge.Despite great advances in instrumentation,the acquisition speed for a spectroscopic SRS image stack is fundamentally bounded by the pixel integration time.In this work,we report three-dimensional sparsely sampled spectroscopic SRS imaging that measures~20%of pixels throughout the stack.In conjunction with related work in low-rank matrix completion(e.g.,the Netflix Prize),we develop a regularized non-negative matrix factorization algorithm to decompose the sub-sampled image stack into spectral signatures and concentration maps.This design enables an acquisition speed of 0.8 s per image stack,with 50 frames in the spectral domain and 40,000 pixels in the spatial domain,which is faster than the conventional raster laser-scanning scheme by one order of magnitude.Such speed allows real-time metabolic imaging of living fungi suspended in a growth medium while effectively maintaining the spatial and spectral resolutions.This work is expected to promote broad application of matrix completion in spectroscopic laser-scanning imaging.展开更多
Stimulated Raman scattering(SRS)microscopy is a highly sensitive chemical imaging technique.However,the SRS imaging performance hinges on two key factors:the reliance on low-noise but bulky solid-state laser sources a...Stimulated Raman scattering(SRS)microscopy is a highly sensitive chemical imaging technique.However,the SRS imaging performance hinges on two key factors:the reliance on low-noise but bulky solid-state laser sources and stringent sample requirements necessitated by high numerical aperture(NA)optics.Here,we present a fiber laser based stimulated Raman photothermal(SRP)microscope that addresses these limitations.While appreciating the portability and compactness of a noisy source,fiber laser SRP enables a two-order-of-magnitude improvement in signal to noise ratio over fiber laser SRS without balance detection.Furthermore,with the use of low NA,long working distance optics for signal collection,SRP expands the allowed sample space from millimeters to centimeters,which diversifies the sample formats to multiwell plates and thick tissues.The sensitivity and imaging depth are further amplified by using urea for both thermal enhancement and tissue clearance.Together,fiber laser SRP microscopy provides a robust,user-friendly platform for diverse applications.展开更多
Lumpectomy,also called breast-conserving surgery,has become the standard surgical treatment for early-stage breast cancer.However,accurately locating the tumor during a lumpectomy,especially when the lesion is small a...Lumpectomy,also called breast-conserving surgery,has become the standard surgical treatment for early-stage breast cancer.However,accurately locating the tumor during a lumpectomy,especially when the lesion is small and nonpalpable,is a challenge.Such difficulty can lead to either incomplete tumor removal or prolonged surgical time,which result in high re-operation rates(~25%)and increased surgical costs.Here,we report a fiber optoacoustic guide(FOG)with augmented reality(AR)for sub-millimeter tumor localization and intuitive surgical guidance with minimal interference.The FOG is preoperatively implanted in the tumor.Under external pulsed light excitation,the FOG omnidirectionally broadcasts acoustic waves through the optoacoustic effect by a specially designed nano-composite layer at its tip.By capturing the acoustic wave,three ultrasound sensors on the breast skin triangulate the FOG tip’s position with 0.25-mm accuracy.An AR system with a tablet measures the coordinates of the ultrasound sensors and transforms the FOG tip’s position into visual feedback with<1-mm accuracy,thus aiding surgeons in directly visualizing the tumor location and performing fast and accurate tumor removal.We further show the use of a head-mounted display to visualize the same information in the surgeons’first-person view and achieve hands-free guidance.Towards clinical application,a surgeon successfully deployed the FOG to excise a“pseudo tumor”in a female human cadaver.With the high-accuracy tumor localization by FOG and the intuitive surgical guidance by AR,the surgeon performed accurate and fast tumor removal,which will significantly reduce re-operation rates and shorten the surgery time.展开更多
基金This work was supported in part by the National Key R&D Program of China under Grant No.2018YFC0910600the National Natural Science Foundation of China under Grant Nos.81871397,81627807,11727813,91859109+2 种基金the Shaanxi Science Fund for Distinguished Young Scholars under Grant No.2020JC-27the Shaanxi Young Top-notch Talent of"Special Support Program"the Best Funded Projects for the Scientific and Technological Activities for Excellent Overseas Researchers in Shaanxi Province(2017017)..
文摘Stimulated Raman scattering(SRS)microscopy has the ability of noninvasive imaging of specific chemical bonds and been increasingly used in biomedicine in recent years.Two pulsed Gaussian beams are used in traditional SRS microscopes,providing with high lateral and axial spatial resolution.Because of the tight focus of the Gaussian beam,such an SRS microscopy is difficult to be used for imaging deep targets in scattering tissues.The SRS microscopy based on Bessel beams can solve the imaging problem to a certain extent.Here,we establish a theoretical model to calculate the SRS signal excited by two Bessel beams by integrating the SRS signal generation theory with the fractal propagation method.The fractal model of refractive index turbulence is employed to generate the scattering tissues where the light transport is modeled by the beam propagation method.We model the scattering tissues containing chemicals,calculate the SRS signals stimulated by two Bessel beams,discuss the influence of the fractal model parameters on signal generation,and compare them with those generated by the Gaussian beams.The results show that,even though the modeling parameters have great influence on SRS signal generation,the Bessel beams-based SRS can generate signals in deeper scattering tissues.
基金supported by an R01 Grant GM126049 to J.X.C.the National Science Foundation grant CBET-0939511 STC(to G.P.).
文摘Phase-contrast microscopy converts the phase shift of light passing through a transparent specimen,e.g.,a biological cell,into brightness variations in an image.This ability to observe structures without destructive fixation or staining has been widely utilized for applications in materials and life sciences.Despite these advantages,phase-contrast microscopy lacks the ability to reveal molecular information.To address this gap,we developed a bond-selective transient phase(BSTP)imaging technique that excites molecular vibrations by infrared light,resulting in a transient change in phase shift that can be detected by a diffraction phase microscope.By developing a time-gated pump-probe camera system,we demonstrate BSTP imaging of live cells at a 50 Hz frame rate with high spectral fidelity,sub-microsecond temporal resolution,and sub-micron spatial resolution.Our approach paves a new way for spectroscopic imaging investigation in biology and materials science.
基金supported by a Keck Foundation Science and Engineering Grant and NIH R01GM118471 grant to JXC。
文摘Spectroscopic stimulated Raman scattering(SRS)imaging generates chemical maps of intrinsic molecules,with no need for prior knowledge.Despite great advances in instrumentation,the acquisition speed for a spectroscopic SRS image stack is fundamentally bounded by the pixel integration time.In this work,we report three-dimensional sparsely sampled spectroscopic SRS imaging that measures~20%of pixels throughout the stack.In conjunction with related work in low-rank matrix completion(e.g.,the Netflix Prize),we develop a regularized non-negative matrix factorization algorithm to decompose the sub-sampled image stack into spectral signatures and concentration maps.This design enables an acquisition speed of 0.8 s per image stack,with 50 frames in the spectral domain and 40,000 pixels in the spatial domain,which is faster than the conventional raster laser-scanning scheme by one order of magnitude.Such speed allows real-time metabolic imaging of living fungi suspended in a growth medium while effectively maintaining the spatial and spectral resolutions.This work is expected to promote broad application of matrix completion in spectroscopic laser-scanning imaging.
基金supported by NIH grants R35GM136223, R01EB032391, R01EB035429 to JXC.
文摘Stimulated Raman scattering(SRS)microscopy is a highly sensitive chemical imaging technique.However,the SRS imaging performance hinges on two key factors:the reliance on low-noise but bulky solid-state laser sources and stringent sample requirements necessitated by high numerical aperture(NA)optics.Here,we present a fiber laser based stimulated Raman photothermal(SRP)microscope that addresses these limitations.While appreciating the portability and compactness of a noisy source,fiber laser SRP enables a two-order-of-magnitude improvement in signal to noise ratio over fiber laser SRS without balance detection.Furthermore,with the use of low NA,long working distance optics for signal collection,SRP expands the allowed sample space from millimeters to centimeters,which diversifies the sample formats to multiwell plates and thick tissues.The sensitivity and imaging depth are further amplified by using urea for both thermal enhancement and tissue clearance.Together,fiber laser SRP microscopy provides a robust,user-friendly platform for diverse applications.
基金supported by Walther Cancer FoundationNIH grant CA192645 to J.-X.C.NSF SBIR phase I grant 108852 to Vibronix,Inc.
文摘Lumpectomy,also called breast-conserving surgery,has become the standard surgical treatment for early-stage breast cancer.However,accurately locating the tumor during a lumpectomy,especially when the lesion is small and nonpalpable,is a challenge.Such difficulty can lead to either incomplete tumor removal or prolonged surgical time,which result in high re-operation rates(~25%)and increased surgical costs.Here,we report a fiber optoacoustic guide(FOG)with augmented reality(AR)for sub-millimeter tumor localization and intuitive surgical guidance with minimal interference.The FOG is preoperatively implanted in the tumor.Under external pulsed light excitation,the FOG omnidirectionally broadcasts acoustic waves through the optoacoustic effect by a specially designed nano-composite layer at its tip.By capturing the acoustic wave,three ultrasound sensors on the breast skin triangulate the FOG tip’s position with 0.25-mm accuracy.An AR system with a tablet measures the coordinates of the ultrasound sensors and transforms the FOG tip’s position into visual feedback with<1-mm accuracy,thus aiding surgeons in directly visualizing the tumor location and performing fast and accurate tumor removal.We further show the use of a head-mounted display to visualize the same information in the surgeons’first-person view and achieve hands-free guidance.Towards clinical application,a surgeon successfully deployed the FOG to excise a“pseudo tumor”in a female human cadaver.With the high-accuracy tumor localization by FOG and the intuitive surgical guidance by AR,the surgeon performed accurate and fast tumor removal,which will significantly reduce re-operation rates and shorten the surgery time.
