Patients under systemic (ethylenediaminetetraacetic acid) EDTA are at risk of hemorrhage for any accidental trauma even the superficial ones. This research is a trial to use 980 nm wavelength laser light to provide co...Patients under systemic (ethylenediaminetetraacetic acid) EDTA are at risk of hemorrhage for any accidental trauma even the superficial ones. This research is a trial to use 980 nm wavelength laser light to provide coagulation for such patients in a local region without collateral thermal damage. Material and Method: 980 nm Diode laser operating in a continuous mode (CW) was incident on human blood treated with EDTA inDurhamtubes. The used parameters were (2.25, 3, 3.75 and 6.75) W output power for variable exposure times (1, 3, 9 and 27) s. Results: A homogenous clot was performed at 4327.84 J/cm2 deposited energy density with the absence of any thermal stress in the blood. Conclusion: 980 nm laser wavelength provides a local photochemical bond break of the anticoagulant enhancing blood coagulation for medically compromised patients.展开更多
The ablation theory of cornea and biology effect by 193-nm ArF excimer laser axe introduced. The ablation tracks model is put forward to make laser spots scan axound cornea by many steps and many areas to change corne...The ablation theory of cornea and biology effect by 193-nm ArF excimer laser axe introduced. The ablation tracks model is put forward to make laser spots scan axound cornea by many steps and many areas to change cornea curvature. The corneal average ablation curve is calculated by software so as to explain the feasibility of the ablation tracks model. By analyzing the actual ablation shapes of many axbitrary cornea sections, the optimal ablation method for deciding the random position of every laser spot in every ablation track is obtained. Experiments combining the ablation model with the device testify the energy stability of laser spots and the accuracy of rectifying anisometropia.展开更多
We propose a scheme to prepare the Bell states for atomic qubits trapped in separate optical cavities via atom-cavity-laser interaction.The quantum information of each qubit is encoded on the degenerate ground states ...We propose a scheme to prepare the Bell states for atomic qubits trapped in separate optical cavities via atom-cavity-laser interaction.The quantum information of each qubit is encoded on the degenerate ground states of the atom,so the entanglement between them is relatively stable against spontaneous emission.The proposed scheme consists of a Mach-Zehnder interferometer（MZI） with two arms,and each arm contains a cavity with an N-type atom in it.It requires two classical fields and a single-photon source. By controlling the sequence and time of atom-cavity-laser interaction,the deterministic production of the atomic Bell states is shown.We also introduce the generalization of the present scheme to generate the 2N-atom Greenberger-Horne-Zeilinger state.展开更多
Molecules such as water,proteins and lipids that are contained in biological tissue absorb mid-infrared(MR)light,which allows such light to be used in laser surgical treatment.Esters,amides and water exhibit strong ab...Molecules such as water,proteins and lipids that are contained in biological tissue absorb mid-infrared(MR)light,which allows such light to be used in laser surgical treatment.Esters,amides and water exhibit strong absorption bands in the 5-7μm wavelength range,but at present there are no lasers in clinical use that can emit in this range.Therefore,the present study focused on thequantum cascade laser(QCL),which is a new type of semiconductor laser that can emit at MIRwavelengths and has recentiy achieved high output power.A high-power QCL with a peakwavelength of 5.7μm was evaluated for use as a laser scalpel for ablating biological soft tissue.The interaction of the laser beam with chicken breast tissue was compared to a conventional CO_(2) laser,based on surface and cross-sectional images.The QCL was found to have sufficient power to ablate soft tissue,and its coagulation,carbonization and ablation effects were similar to those forthe CO_(2) laser.The QCL also induced comparable photothermal effects because it acted as apseudo-continuous wave laser due to its low peak power.A QCL can therefore be used as an effective laser scalpel,and also offers the possibility of less invasive treatment by targeting specificabsorption bands in t he MIR region.展开更多
In endoscopic submucosal dissection(ESD),the narrow gastrointestinal space can cause difficulty in surgical interventions.Tissue ablation apparatuses with high-power CO_(2) lasers or Nd:YAG lasers have been developed ...In endoscopic submucosal dissection(ESD),the narrow gastrointestinal space can cause difficulty in surgical interventions.Tissue ablation apparatuses with high-power CO_(2) lasers or Nd:YAG lasers have been developed to facilitate endoscopic surgical procedures.We studied the interaction of 808-nm laser light with a porcine stomach tissue,with the aim of developing a therapeutic medical device that can remove lesions at the gastrointestinal wall by irradiating a near-infrared laser light incorporated in an endoscopic system.The perforation depths at the porcine fillet and the stomach tissues linearly increased in the range of 2–8mm in proportion to the laser energy density of 63.7–382 kJ/cm^(2).Despite the distinct structural and compositional di®erence,the variation of the perforation depth between the stomach and the fillet was not found at 808-nm wavelength in our measurement.We further studied the laser–tissue interaction by changing the concentration of the methyl blue solution used conventionally as a submucosal fluidic cushion(SFC)in ESD procedures.The temperature of the mucosal layer increased more rapidly at higher concentration of the methyl blue solution,because of enhanced light absorption at the SFC layer.The insertion of the SFC would protect the muscle layer from thermal damage.We confirmed that more effective laser treatment should be enabled by tuning the opto-thermal properties of the SFC.This study can contribute to the optimization of the driving parameters for laser incision techniques as an alternative to conventional surgical interventions.展开更多
Traditional moxibustion therapy can stimulate heat and blood-vessel expansion and advance blood circulation.In the present study,a novel noncontact-type thermal therapeutic system was developed using a near-infrared l...Traditional moxibustion therapy can stimulate heat and blood-vessel expansion and advance blood circulation.In the present study,a novel noncontact-type thermal therapeutic system was developed using a near-infrared laser diode.The device allows direct interaction of infrared laser light with the skin,thereby facilitating a controlled temperature distribution on the skin and the deep tissues below the skin.While using a tissue-mimicking phantom as a substitute for real skin,the most important optical and thermal parameters are the absorption/attenuation coefficient,thermal conductivity,and specic heat.We found that these parameters can be manipulated by varying the agar-gel concentration.Hence,a multilayer tissue-mimicking phantom was fabricated using different agar-gel concentrations.Thermal imaging and thermocouples were used to measure the temperature distribution inside the phantom during laser irradiation.The temperature increased with the increase in the agar-gel concentration and reached a maximum value under the tissue phantom surface.To induce a similar thermal effect of moxibustion therapy,controlled laser-irradiation parameters such as output power,wavelength and pulse width were obtained from further analysis of the temperature distribution.From the known optothermal properties of the patient's skin,the temperature distribution inside the tissue was manipulated by optimizing the laser parameters.This study can contribute to patient-specic thermal therapy in clinics.展开更多
文摘Patients under systemic (ethylenediaminetetraacetic acid) EDTA are at risk of hemorrhage for any accidental trauma even the superficial ones. This research is a trial to use 980 nm wavelength laser light to provide coagulation for such patients in a local region without collateral thermal damage. Material and Method: 980 nm Diode laser operating in a continuous mode (CW) was incident on human blood treated with EDTA inDurhamtubes. The used parameters were (2.25, 3, 3.75 and 6.75) W output power for variable exposure times (1, 3, 9 and 27) s. Results: A homogenous clot was performed at 4327.84 J/cm2 deposited energy density with the absence of any thermal stress in the blood. Conclusion: 980 nm laser wavelength provides a local photochemical bond break of the anticoagulant enhancing blood coagulation for medically compromised patients.
文摘The ablation theory of cornea and biology effect by 193-nm ArF excimer laser axe introduced. The ablation tracks model is put forward to make laser spots scan axound cornea by many steps and many areas to change cornea curvature. The corneal average ablation curve is calculated by software so as to explain the feasibility of the ablation tracks model. By analyzing the actual ablation shapes of many axbitrary cornea sections, the optimal ablation method for deciding the random position of every laser spot in every ablation track is obtained. Experiments combining the ablation model with the device testify the energy stability of laser spots and the accuracy of rectifying anisometropia.
基金supported by the National Natural Science Foundation of China(No.10947135)the Opening Project of the Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control(Hunan Normal University),Ministry of Education of China (No.QSQC0903)+1 种基金the Scientific Research Fund of Hunan Provincial Education Department(No.09C062)the construct program of the key discipline in Hunan Province,and the construct program of the key discipline in Changsha University of Science and Technology.
文摘We propose a scheme to prepare the Bell states for atomic qubits trapped in separate optical cavities via atom-cavity-laser interaction.The quantum information of each qubit is encoded on the degenerate ground states of the atom,so the entanglement between them is relatively stable against spontaneous emission.The proposed scheme consists of a Mach-Zehnder interferometer（MZI） with two arms,and each arm contains a cavity with an N-type atom in it.It requires two classical fields and a single-photon source. By controlling the sequence and time of atom-cavity-laser interaction,the deterministic production of the atomic Bell states is shown.We also introduce the generalization of the present scheme to generate the 2N-atom Greenberger-Horne-Zeilinger state.
基金supported by JSPS KAKENHI Grant Number 24241209.
文摘Molecules such as water,proteins and lipids that are contained in biological tissue absorb mid-infrared(MR)light,which allows such light to be used in laser surgical treatment.Esters,amides and water exhibit strong absorption bands in the 5-7μm wavelength range,but at present there are no lasers in clinical use that can emit in this range.Therefore,the present study focused on thequantum cascade laser(QCL),which is a new type of semiconductor laser that can emit at MIRwavelengths and has recentiy achieved high output power.A high-power QCL with a peakwavelength of 5.7μm was evaluated for use as a laser scalpel for ablating biological soft tissue.The interaction of the laser beam with chicken breast tissue was compared to a conventional CO_(2) laser,based on surface and cross-sectional images.The QCL was found to have sufficient power to ablate soft tissue,and its coagulation,carbonization and ablation effects were similar to those forthe CO_(2) laser.The QCL also induced comparable photothermal effects because it acted as apseudo-continuous wave laser due to its low peak power.A QCL can therefore be used as an effective laser scalpel,and also offers the possibility of less invasive treatment by targeting specificabsorption bands in t he MIR region.
基金This study was supported by grants from the Industrial Core Technology Development Program (10047904)the Industrial Strategic Technology Development Program (10049743) of the Korea Evaluation Institute of Industrial Technology(KEIT)the Human Resources Development Program (20134010200580)of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)funded by the Ministry of Trade,Industry and Energy,Republic of Korea.
文摘In endoscopic submucosal dissection(ESD),the narrow gastrointestinal space can cause difficulty in surgical interventions.Tissue ablation apparatuses with high-power CO_(2) lasers or Nd:YAG lasers have been developed to facilitate endoscopic surgical procedures.We studied the interaction of 808-nm laser light with a porcine stomach tissue,with the aim of developing a therapeutic medical device that can remove lesions at the gastrointestinal wall by irradiating a near-infrared laser light incorporated in an endoscopic system.The perforation depths at the porcine fillet and the stomach tissues linearly increased in the range of 2–8mm in proportion to the laser energy density of 63.7–382 kJ/cm^(2).Despite the distinct structural and compositional di®erence,the variation of the perforation depth between the stomach and the fillet was not found at 808-nm wavelength in our measurement.We further studied the laser–tissue interaction by changing the concentration of the methyl blue solution used conventionally as a submucosal fluidic cushion(SFC)in ESD procedures.The temperature of the mucosal layer increased more rapidly at higher concentration of the methyl blue solution,because of enhanced light absorption at the SFC layer.The insertion of the SFC would protect the muscle layer from thermal damage.We confirmed that more effective laser treatment should be enabled by tuning the opto-thermal properties of the SFC.This study can contribute to the optimization of the driving parameters for laser incision techniques as an alternative to conventional surgical interventions.
基金the National Research Foundation sponsored by the Ministry of Science,ICT and Future Planning(NRF-2016R1A2B4012095)the Ministry of Education(NRF-2016R1D1A1A09917195),Republic of Korea.
文摘Traditional moxibustion therapy can stimulate heat and blood-vessel expansion and advance blood circulation.In the present study,a novel noncontact-type thermal therapeutic system was developed using a near-infrared laser diode.The device allows direct interaction of infrared laser light with the skin,thereby facilitating a controlled temperature distribution on the skin and the deep tissues below the skin.While using a tissue-mimicking phantom as a substitute for real skin,the most important optical and thermal parameters are the absorption/attenuation coefficient,thermal conductivity,and specic heat.We found that these parameters can be manipulated by varying the agar-gel concentration.Hence,a multilayer tissue-mimicking phantom was fabricated using different agar-gel concentrations.Thermal imaging and thermocouples were used to measure the temperature distribution inside the phantom during laser irradiation.The temperature increased with the increase in the agar-gel concentration and reached a maximum value under the tissue phantom surface.To induce a similar thermal effect of moxibustion therapy,controlled laser-irradiation parameters such as output power,wavelength and pulse width were obtained from further analysis of the temperature distribution.From the known optothermal properties of the patient's skin,the temperature distribution inside the tissue was manipulated by optimizing the laser parameters.This study can contribute to patient-specic thermal therapy in clinics.
