In this paper, we reported a numerical solution of laser induced thermal effect in the bio-tissue. The model of photothermal effect and classical Pennes bio-heat transfer equation were introduced. Finite element metho...In this paper, we reported a numerical solution of laser induced thermal effect in the bio-tissue. The model of photothermal effect and classical Pennes bio-heat transfer equation were introduced. Finite element method (FEM), which was realized by Matlab software, was used to calculate the temperature distribution. He-Ne laser (633 nm) was used to simulate the physical therapy in in vivo skin tissue. Under the cylinder coordinates, the three-dimension(3-D) geometry of tissue was reduced to two-dimension(2-D) computation. The results contained the radial, axial and temperature 3-D color plot. Combining the time animation display was possible. By changing the laser and tissue parameters we can get different results. This will be the initial and indispensable work of the non-destructive evaluation of the laser induced injury.展开更多
Water breakdown studies by Nd-YAG laser pulses of duration 100 fs, 30 ps and 6 ns at wavelength 1064 nm are pre- formed to investigate the physical mechanisms which couple the laser energy into the medium. Calculation...Water breakdown studies by Nd-YAG laser pulses of duration 100 fs, 30 ps and 6 ns at wavelength 1064 nm are pre- formed to investigate the physical mechanisms which couple the laser energy into the medium. Calculations are carried out applying a modified kinetic model of water breakdown previously developed by Kennedy (1995) to investigate the correlation between threshold intensity of breakdown and laser pulse length. The modifications considered the introduction of diffusion and recombination loss processes which might take place under the experimental conditions applied in these calculations. The validity of the model is tested by comparing the calculated threshold intensities and the experimentally measured ones where good agreement is shown. The study of the time evolution of the electron density clarifies the correlation between the pulse length and dominant ionization mechanism. The analysis of the spatial distribution of the electron density along the radial and axial distances of the focal spot showed that the size of the formed plasma increases with the increase of the pulse length. On the other hand, studies of self-focusing effect illustrated that under the investigated experimental conditions the effect of this process has an effective contribution only at laser pulses of the order of femtosecond scale when the laser beam is focused by a lens of a focal length ≥8.0 cm. This result in turns assures that using femtosecond pulses in ophthalmic microsurgery could be a safe tool from the retinal damage.展开更多
The effects of combined use of earthworm extract（912）and HpD-laser on the produc-tion of reactive oxygen and the biosynthesis of DNA in S<sub>180</sub> tumor cells were studied throughchemiluminescence m...The effects of combined use of earthworm extract（912）and HpD-laser on the produc-tion of reactive oxygen and the biosynthesis of DNA in S<sub>180</sub> tumor cells were studied throughchemiluminescence measurement and[<sup>3</sup>H]-TdR incorporation assay.The results showed that as com-pared with the control,the intensity of chemiluminescence emitted by tumor cells treatedsimultaneously with 912 and HpD-laser was enhanced more than ten-folds,while that treated with912 or HpD-laser alone was increased only 2～4 folds.The[<sup>3</sup>H]-TdR incorporation into tumorcells of the former group was inhibited upto 74.1%,and that of the latter groups decreased onlyby 42.2% and 40.0%,respectively.In accordance with these biochemical changes,the ultrastructuraldamage of tumor cells of the former,combinedly treated group appeared to be the most serious.This suggests an additive effect of 912 with HpD-laser on tumor cells.In addition,if free radicalscavengers,such as catalase and superoxide dismutase,were added to the reaction systembefore chemiluminescence assay,the luminescent enhancement effect mentioned above was dramaticallyalleviated,implying the presence of O<sub>2</sub><sup> </sup>and H<sub>2</sub>O<sub>2</sub> in the system.Therefore,as to the toxic effecton tumor cells,912 and HpD-laser are not only additive in efficiency,but also similar in theunderlying mechanism of action.展开更多
Background:Knee osteoarthritis(OA)is a major cause of disability among the older adults.Few treatments are safe and effective.Moxibustion is commonly used in treating knee OA in Chinese medicine(CM).CO2 Laser moxibust...Background:Knee osteoarthritis(OA)is a major cause of disability among the older adults.Few treatments are safe and effective.Moxibustion is commonly used in treating knee OA in Chinese medicine(CM).CO2 Laser moxibustion device is a substitute for traditional moxibustion,which mimics the effects of traditional moxibustion.More data are needed to support its application in knee OA.Objective:The trial aims to assess the effect and safety of CO2 laser moxibustion in patients with knee osteoarthritis compared with a sham control.Methods:This is a protocol for a multicenter,randomized,double-blind,placebo-controlled trial.A total of 392 participants were recruited and assigned to the CO2 laser moxibustion group and sham laser moxibustion group with a 1:1 ratio at 6 outpatient clinics in Shanghai,China.Participants in both groups received treatment at the affected knee(s)at the acupuncture point Dubi(ST 35)and an Ashi point.There were 3 sessions per week for 4 weeks,and an additional 20-week follow-up.Primary outcomes were changes in the Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC)pain scores at week 4.Secondary outcomes were WOMAC function score,stiffness score and overall score,VAS pain,Short-Form heath survey(SF-36),and patients’global assessment.The serum levels of cytokines involved in progress of knee OA were explored.Safety was assessed during the whole trial.Masking effectiveness was assessed by both participants and treatment providers.Discussion:CO2 laser moxibustion device,designed as a substitute for CM moxibustion,is easy to use and control with no choking smoke and smell,and is a plausible method for double-blind research.This study would provide rigorous evidence for the effect and safety of CO2 laser moxibustion in treating knee OA.展开更多
Biophotonics and laser medicine are very dynamic and continuously increasing fields ecologically as well as economically. Direct communication with medical doctors is necessary to identify specific requests and unmet ...Biophotonics and laser medicine are very dynamic and continuously increasing fields ecologically as well as economically. Direct communication with medical doctors is necessary to identify specific requests and unmet needs. Information on innovative, new or renewed techniques is necessary to design medical devices for introduction into clinical application and finally to become established after positive clinical trials as well as medical approval. The long-term endurance in developing light based innovative clinical concepts and devices are described based on the Munich experience. Fluorescence technologies for laboratory medicine to improve non- invasive diagnosis or for online monitoring are described according with new approaches in improving photody- namic therapeutic aspects related to immunology. Regard- ing clinically related thermal laser applications, the introduction of new laser wavelengths and laser parameters showed potential in the treatment of varicose veins as well as in lithotripsy. Such directly linked research and development are possible when researchers and medical doctors perform their daily work in immediate vicinity, thus have the possibility to share their ideas in meetings by day.展开更多
Photobiomodulation(PBM)is a non-invasive therapeutic modality with demonstrated effects in many fields related to regenerative medicine.In the field of orthopedics,in particular,PBM at various wavelengths has demonstr...Photobiomodulation(PBM)is a non-invasive therapeutic modality with demonstrated effects in many fields related to regenerative medicine.In the field of orthopedics,in particular,PBM at various wavelengths has demonstrated the capacity to trigger multiple biological effects associated with protective mechanisms in musculoskeletal tissues.The articles cited in this review show that devices operating close to or within the near infrared range at low intensities can provoke responses which favor the shift in the predominant catabolic microenvironment typically seen in degenerative joint diseases,especially osteoarthritis(OA).These responses include proliferation,differentiation and expression of proteins associated with stable cell cycles.Additionally,PBM can also modulate oxidative stress,inflammation and pain by exerting regulatory effects on immune cells and blocking the transmission of pain through sensory neuron fibers,without adverse events.Collectively,these effects are essential in order to control the progression of OA,which is in part attributed to exacerbated inflammation and degradative enzymatic reactions which gradually contribute to the destruction of joint tissues.PBM may offer medical experts ease of application,financial viability,efficacy and lack of serious adverse events.Therefore,it may prove to be a suitable ally in the management of mild to moderate degrees of OA.This review explores and discusses the principal biological mechanisms of PBM and how the produced effects may contribute to the amelioration of osteoarthritic progression.Literature was reviewed using PubMed and Google Scholar in order to find studies describing the mechanisms of PBM.The investigation included a combination of nomenclature such as:“photobiomodulation”,“phototherapy”,“laser therapy”,“PBM”,“osteoarthritis”,low level light therapy”,“inflammation”and“cartilage”.We considered only articles written in English,with access to the full text.展开更多
基金This work was supported by Tianjin Natural Science Foundation under Grant No. 023602611.
文摘In this paper, we reported a numerical solution of laser induced thermal effect in the bio-tissue. The model of photothermal effect and classical Pennes bio-heat transfer equation were introduced. Finite element method (FEM), which was realized by Matlab software, was used to calculate the temperature distribution. He-Ne laser (633 nm) was used to simulate the physical therapy in in vivo skin tissue. Under the cylinder coordinates, the three-dimension(3-D) geometry of tissue was reduced to two-dimension(2-D) computation. The results contained the radial, axial and temperature 3-D color plot. Combining the time animation display was possible. By changing the laser and tissue parameters we can get different results. This will be the initial and indispensable work of the non-destructive evaluation of the laser induced injury.
文摘Water breakdown studies by Nd-YAG laser pulses of duration 100 fs, 30 ps and 6 ns at wavelength 1064 nm are pre- formed to investigate the physical mechanisms which couple the laser energy into the medium. Calculations are carried out applying a modified kinetic model of water breakdown previously developed by Kennedy (1995) to investigate the correlation between threshold intensity of breakdown and laser pulse length. The modifications considered the introduction of diffusion and recombination loss processes which might take place under the experimental conditions applied in these calculations. The validity of the model is tested by comparing the calculated threshold intensities and the experimentally measured ones where good agreement is shown. The study of the time evolution of the electron density clarifies the correlation between the pulse length and dominant ionization mechanism. The analysis of the spatial distribution of the electron density along the radial and axial distances of the focal spot showed that the size of the formed plasma increases with the increase of the pulse length. On the other hand, studies of self-focusing effect illustrated that under the investigated experimental conditions the effect of this process has an effective contribution only at laser pulses of the order of femtosecond scale when the laser beam is focused by a lens of a focal length ≥8.0 cm. This result in turns assures that using femtosecond pulses in ophthalmic microsurgery could be a safe tool from the retinal damage.
基金Supported by the National Natural Science Foundation of China No.3860835
文摘The effects of combined use of earthworm extract（912）and HpD-laser on the produc-tion of reactive oxygen and the biosynthesis of DNA in S<sub>180</sub> tumor cells were studied throughchemiluminescence measurement and[<sup>3</sup>H]-TdR incorporation assay.The results showed that as com-pared with the control,the intensity of chemiluminescence emitted by tumor cells treatedsimultaneously with 912 and HpD-laser was enhanced more than ten-folds,while that treated with912 or HpD-laser alone was increased only 2～4 folds.The[<sup>3</sup>H]-TdR incorporation into tumorcells of the former group was inhibited upto 74.1%,and that of the latter groups decreased onlyby 42.2% and 40.0%,respectively.In accordance with these biochemical changes,the ultrastructuraldamage of tumor cells of the former,combinedly treated group appeared to be the most serious.This suggests an additive effect of 912 with HpD-laser on tumor cells.In addition,if free radicalscavengers,such as catalase and superoxide dismutase,were added to the reaction systembefore chemiluminescence assay,the luminescent enhancement effect mentioned above was dramaticallyalleviated,implying the presence of O<sub>2</sub><sup> </sup>and H<sub>2</sub>O<sub>2</sub> in the system.Therefore,as to the toxic effecton tumor cells,912 and HpD-laser are not only additive in efficiency,but also similar in theunderlying mechanism of action.
基金Supported by National Natural Science Foundation of China(81320108028)National Basic Research Program of China(2015CB554505)Key Program of the State Administration of Traditional Chinese Medicine of China(ZYSNXD-CC-ZDXK-07)。
文摘Background:Knee osteoarthritis(OA)is a major cause of disability among the older adults.Few treatments are safe and effective.Moxibustion is commonly used in treating knee OA in Chinese medicine(CM).CO2 Laser moxibustion device is a substitute for traditional moxibustion,which mimics the effects of traditional moxibustion.More data are needed to support its application in knee OA.Objective:The trial aims to assess the effect and safety of CO2 laser moxibustion in patients with knee osteoarthritis compared with a sham control.Methods:This is a protocol for a multicenter,randomized,double-blind,placebo-controlled trial.A total of 392 participants were recruited and assigned to the CO2 laser moxibustion group and sham laser moxibustion group with a 1:1 ratio at 6 outpatient clinics in Shanghai,China.Participants in both groups received treatment at the affected knee(s)at the acupuncture point Dubi(ST 35)and an Ashi point.There were 3 sessions per week for 4 weeks,and an additional 20-week follow-up.Primary outcomes were changes in the Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC)pain scores at week 4.Secondary outcomes were WOMAC function score,stiffness score and overall score,VAS pain,Short-Form heath survey(SF-36),and patients’global assessment.The serum levels of cytokines involved in progress of knee OA were explored.Safety was assessed during the whole trial.Masking effectiveness was assessed by both participants and treatment providers.Discussion:CO2 laser moxibustion device,designed as a substitute for CM moxibustion,is easy to use and control with no choking smoke and smell,and is a plausible method for double-blind research.This study would provide rigorous evidence for the effect and safety of CO2 laser moxibustion in treating knee OA.
文摘Biophotonics and laser medicine are very dynamic and continuously increasing fields ecologically as well as economically. Direct communication with medical doctors is necessary to identify specific requests and unmet needs. Information on innovative, new or renewed techniques is necessary to design medical devices for introduction into clinical application and finally to become established after positive clinical trials as well as medical approval. The long-term endurance in developing light based innovative clinical concepts and devices are described based on the Munich experience. Fluorescence technologies for laboratory medicine to improve non- invasive diagnosis or for online monitoring are described according with new approaches in improving photody- namic therapeutic aspects related to immunology. Regard- ing clinically related thermal laser applications, the introduction of new laser wavelengths and laser parameters showed potential in the treatment of varicose veins as well as in lithotripsy. Such directly linked research and development are possible when researchers and medical doctors perform their daily work in immediate vicinity, thus have the possibility to share their ideas in meetings by day.
文摘Photobiomodulation(PBM)is a non-invasive therapeutic modality with demonstrated effects in many fields related to regenerative medicine.In the field of orthopedics,in particular,PBM at various wavelengths has demonstrated the capacity to trigger multiple biological effects associated with protective mechanisms in musculoskeletal tissues.The articles cited in this review show that devices operating close to or within the near infrared range at low intensities can provoke responses which favor the shift in the predominant catabolic microenvironment typically seen in degenerative joint diseases,especially osteoarthritis(OA).These responses include proliferation,differentiation and expression of proteins associated with stable cell cycles.Additionally,PBM can also modulate oxidative stress,inflammation and pain by exerting regulatory effects on immune cells and blocking the transmission of pain through sensory neuron fibers,without adverse events.Collectively,these effects are essential in order to control the progression of OA,which is in part attributed to exacerbated inflammation and degradative enzymatic reactions which gradually contribute to the destruction of joint tissues.PBM may offer medical experts ease of application,financial viability,efficacy and lack of serious adverse events.Therefore,it may prove to be a suitable ally in the management of mild to moderate degrees of OA.This review explores and discusses the principal biological mechanisms of PBM and how the produced effects may contribute to the amelioration of osteoarthritic progression.Literature was reviewed using PubMed and Google Scholar in order to find studies describing the mechanisms of PBM.The investigation included a combination of nomenclature such as:“photobiomodulation”,“phototherapy”,“laser therapy”,“PBM”,“osteoarthritis”,low level light therapy”,“inflammation”and“cartilage”.We considered only articles written in English,with access to the full text.
