The symptomatic degenerative meniscus continues to be a source of discomfort for a significant number of patients. With vascular penetration of less than onethird of the adult meniscus, healing potential in the settin...The symptomatic degenerative meniscus continues to be a source of discomfort for a significant number of patients. With vascular penetration of less than onethird of the adult meniscus, healing potential in the setting of chronic degeneration remains low. Continued hoop and shear stresses upon the degenerative meniscus results in gross failure, often in the form of complex tears in the posterior horn and midbody. Patient history and physical examination are critical to determine the true source of pain, particularly with the significant incidence of simultaneous articular pathology. Joint line tenderness, a positive Mc Murray test, and mechanical catching or locking can be highly suggestive of a meniscal source of knee pain and dysfunction. Radiographs and magnetic resonance imaging are frequently utilized to examine for osteoarthritis and to verify the presence of meniscal tears, in addition to ruling out other sources of pain. Non-operative therapy focused on nonsteroidal anti-inflammatory drugs and physical therapy may be able to provide pain relief as well as improve mechanical function of the knee joint. For patients re-fractory to conservative therapy, arthroscopic partial meniscectomy can provide short-term gains regarding pain relief, especially when combined with an effective, regular physiotherapy program. Patients with clear mechanical symptoms and meniscal pathology may benefit from arthroscopic partial meniscectomy, but surgery is not a guaranteed success, especially with concomitant articular pathology. Ultimately, the long-term outcomes of either treatment arm provide similar results for most patients. Further study is needed regarding the short and long-term outcomes regarding conservative and surgical therapy, with a particular focus on the economic impact of treatment as well.展开更多
Ultrasound-guided biopsy procedure for prostate cancer diagnosis,which is the current gold standard,involves quasi-random sampling of prostate tissue without any functional guidance.In this study,we discuss the possib...Ultrasound-guided biopsy procedure for prostate cancer diagnosis,which is the current gold standard,involves quasi-random sampling of prostate tissue without any functional guidance.In this study,we discuss the possibility to augment the detection of prostate cancer using a dual-modality optical approach,which can be coupled with the current needle biopsy setup.Two techniques are light reflectance spectroscopy(LRS)that uses a broadband light source and a CCD array spectrometer,and auto-fluorescence lifetime measurement(AFLM)that uses a custom-designed,time-correlated single photon counting(TCSPC)system.Both LRS and AFLM were employed sequentially in this study to measure cancer tissue along with control tissue on a rat prostate tumor model.At an excitation wavelength of 447 nm,we investigated auto-fluorescence decay curves at the emission wavelengths of 532,562,632 and 684 nm for in vivo and ex vivo AFLM.These results show that auto-fluorescence lifetimes at all measured emission wavelengths differ between control and cancerous tissues with 100% specificity and sensitivity.Moreover,absolute values of hemoglobin derivatives and scattering coe±cient were quantified using in vivo LRS.This part of study also demonstrates that light scattering and absorption are significantly different between the control and cancerous tissue.Overall,the study demonstrates that both LRS and AFLM may provide several intrinsic biomarkers for in vivo detection of prostate cancer.展开更多
Digital holographic microscopy is a single-shot technique for quantitative phase imaging of samples,yielding thickness profiles of phase objects.It provides sample features based on their morphology,leading to their c...Digital holographic microscopy is a single-shot technique for quantitative phase imaging of samples,yielding thickness profiles of phase objects.It provides sample features based on their morphology,leading to their classification and identification.However,observing samples,especially cells,in fluids using holographic microscopes is difficult without immobilizing the object.Optical tweezers can be used for sample immobilization in fluids.The present manuscript provides an overview of our ongoing work on the development of a compact,low-cost microscopy system for digital holographic imaging of optically trapped samples.Integration of digital holographic microscopy system with tweezers is realized by using the optical pickup unit extracted from DVD burners to trap microsamples,which are then holographically imaged using a highly compact self-referencing interferometer along with a low-cost,in-house developed quadrant photodiode,providing morphological and spectral information of trapped particles.The developed integrated module was tested using polystyrene microspheres as well as human erythrocytes.The investigated system offers a multitude of sample features,including physical and mechanical parameters and corner frequency information of the sample.These features were used for sample classification.The proposed technique has vast potential in opening up new avenues for low-cost,digital holographic imaging and analysis of immobilized samples in fluids and their classification.展开更多
文摘The symptomatic degenerative meniscus continues to be a source of discomfort for a significant number of patients. With vascular penetration of less than onethird of the adult meniscus, healing potential in the setting of chronic degeneration remains low. Continued hoop and shear stresses upon the degenerative meniscus results in gross failure, often in the form of complex tears in the posterior horn and midbody. Patient history and physical examination are critical to determine the true source of pain, particularly with the significant incidence of simultaneous articular pathology. Joint line tenderness, a positive Mc Murray test, and mechanical catching or locking can be highly suggestive of a meniscal source of knee pain and dysfunction. Radiographs and magnetic resonance imaging are frequently utilized to examine for osteoarthritis and to verify the presence of meniscal tears, in addition to ruling out other sources of pain. Non-operative therapy focused on nonsteroidal anti-inflammatory drugs and physical therapy may be able to provide pain relief as well as improve mechanical function of the knee joint. For patients re-fractory to conservative therapy, arthroscopic partial meniscectomy can provide short-term gains regarding pain relief, especially when combined with an effective, regular physiotherapy program. Patients with clear mechanical symptoms and meniscal pathology may benefit from arthroscopic partial meniscectomy, but surgery is not a guaranteed success, especially with concomitant articular pathology. Ultimately, the long-term outcomes of either treatment arm provide similar results for most patients. Further study is needed regarding the short and long-term outcomes regarding conservative and surgical therapy, with a particular focus on the economic impact of treatment as well.
基金funded in part by Department of Defense(grant#W81XWH-09-1-0406)Texas Ignition Fund.
文摘Ultrasound-guided biopsy procedure for prostate cancer diagnosis,which is the current gold standard,involves quasi-random sampling of prostate tissue without any functional guidance.In this study,we discuss the possibility to augment the detection of prostate cancer using a dual-modality optical approach,which can be coupled with the current needle biopsy setup.Two techniques are light reflectance spectroscopy(LRS)that uses a broadband light source and a CCD array spectrometer,and auto-fluorescence lifetime measurement(AFLM)that uses a custom-designed,time-correlated single photon counting(TCSPC)system.Both LRS and AFLM were employed sequentially in this study to measure cancer tissue along with control tissue on a rat prostate tumor model.At an excitation wavelength of 447 nm,we investigated auto-fluorescence decay curves at the emission wavelengths of 532,562,632 and 684 nm for in vivo and ex vivo AFLM.These results show that auto-fluorescence lifetimes at all measured emission wavelengths differ between control and cancerous tissues with 100% specificity and sensitivity.Moreover,absolute values of hemoglobin derivatives and scattering coe±cient were quantified using in vivo LRS.This part of study also demonstrates that light scattering and absorption are significantly different between the control and cancerous tissue.Overall,the study demonstrates that both LRS and AFLM may provide several intrinsic biomarkers for in vivo detection of prostate cancer.
基金The work was supported by research grants SERB(EMR/20l7/002724),DAE-BRNS(2013/34/11/BRNS/504),DST-FIST and DST-PURSE.AA and VC would like to acknowledge Abdus Salam International center for Theoretical Physics(ICTP),Trieste,Italy for Regular Associate fellowship.
文摘Digital holographic microscopy is a single-shot technique for quantitative phase imaging of samples,yielding thickness profiles of phase objects.It provides sample features based on their morphology,leading to their classification and identification.However,observing samples,especially cells,in fluids using holographic microscopes is difficult without immobilizing the object.Optical tweezers can be used for sample immobilization in fluids.The present manuscript provides an overview of our ongoing work on the development of a compact,low-cost microscopy system for digital holographic imaging of optically trapped samples.Integration of digital holographic microscopy system with tweezers is realized by using the optical pickup unit extracted from DVD burners to trap microsamples,which are then holographically imaged using a highly compact self-referencing interferometer along with a low-cost,in-house developed quadrant photodiode,providing morphological and spectral information of trapped particles.The developed integrated module was tested using polystyrene microspheres as well as human erythrocytes.The investigated system offers a multitude of sample features,including physical and mechanical parameters and corner frequency information of the sample.These features were used for sample classification.The proposed technique has vast potential in opening up new avenues for low-cost,digital holographic imaging and analysis of immobilized samples in fluids and their classification.
