فهرست مطالب

فصلنامه لیزر در پزشکی
سال پنجم شماره 3 (پیاپی 29، پاییز 1387)

تاریخ انتشار: 1387/08/11
تعداد عناوین: 10

فارسی
English

انتخاب همه

The Analytical Investigation of Temperature Distribution in Enamel under Er:YAG Laser Radiation

Paeviz Elahi, Bita Farsi, Mohammad Godarzi Shirazi Page 2

In this paper, the temperature distribution in enamel under Er:YAG laser radiation have been investigated analytically. For this reason after simulating the enamel with a cubic block and finding the heat power density due to laser radiation, the heat conduction equation with boundary conditions have been solved analytically. By inserting the thermal coefficients of enamel into the obtained equations, the thermal behavior of enamel have been studied.
Keywords: Temperature distribution, enamel, Er: YAG laser

Abstract View Paper Original: Persian
Make of Treatment Diode Laser with 670 nm and 5mw Output

Jafar Rahmani Kahnamoei, Ali Navid Koshki Page 3

Laser is one of the wonderful phenomenon that in the recent years draw researchers and wise's attention. Nowadays laser is used in different expense, for example co2 laser to operations is used which they are in the sort of the high level or strong lasers. A laser is made in this project is one type from LOW LEVEL LASER or LLL. LLL is called lasers that output power's are between 1-1000 milli watts. In the base on researches and consideration by researchers this kind of lasers have a lot of medicinal effects that we can refer to decrease of pain and inflammation, increase rate of ulcers amendment, cure autoimmune disease like arthrit romatoeid, easing backache and osteoarthrit. This laser is cased the normalize of inside and outside small origin pressure, normalize ATP, decrease of prostaglandins's superficies, increase of macrophages activity, mitose increase, increase of fibroblate's activity, improvement of histologic microsirculation. Is cased to decrease of swelling and inflammation, easing pain, increase of making origin, expediting amendment histologic, increase of security level and histologic prolifration.Nowadays very used from diode laser because it is small and easy to use. But its controlize circuits and drive have especial senses. Invented laser in this project have 5 mw power, 670 nm Wavelength and Duty cycle about 0.1 – 50 %.
Keywords: Diode laser, 5 Mili watt, 670 Nanometer

Abstract View Paper Original: Persian
Study of Fibroblast Cells Behavior on the Acrylic Acid Co2 Pulsed Laser Grafted Silicone Elastomer for Tissue Engineering Application

Hamid Keshvari, Hamid Mirzadeh, Parvin Mansuri, Alireza Zare Shahneh Page 4

In this study Silicone as a base material was selected and poly (acrylic acid) grafted on it using a CO2 pulsed-laser. The effect of laser parameters on weight decreases of silicone sheets were determind by weighing of samples before and after irradiation. In addition the effect of laser pulse density on the samples surfaces were investigated by characterization with Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR), Scanning Electron Microscopy (SEM), water drop contact angle and water surface uptake measurements.Then, L929 fibroblast cells were cultured on the samples in order to determine cell adhesion, spreading and proliferation. Results obtained from in vitro experiments after 12 and 72 hours showed considerable cell adhesion, spreading and proliferation on, silicone surfaces whereas poly (acrylic acid) grafted silicone surfaces showed poor adhesion spreading, and proliferation on basis of the amount of grafted poly (acrylic acid).These results show that the modified surfaces control cell adhesion, spreading and proliferation, while they can be used for immobliziation of proteins and polysaccharides for tissue engineering.
Keywords: cell culture, laser grafting, graft polymerization, acrylic acid, silicone

Abstract View Paper Original: Persian
Evaluation of Reflection Optical Imaging Characteristics Using Fluorescence with Near Infrared Wavelength at Different Depths of Tissue Equivalent Phantom

Hamed Shoghi, Marjaneh Hejazi, Mohammad Ali Oghabian, Reza Massoudi, Hanieh Mohammadreza, Afshan Shirkavand Page 5

Introduction

Fluorescence reflectance imaging (FRI) is applied for detecting the presence of fluorescence sources within biological tissue. The main limitation of conventional FRI systems is a low imaging depth because biological tissues absorb light at visible wavelength. More recent development in FRI imaging is using near infra-red wavelength enabling the reconstruction of deep seated fluorescent sources. The goal of this study was to determine FRI image characterization in the near infra-red wavelength region.

Materials And Methods

The image characterization was based on deriving depth dependent point spread function of a RFI system. The FRI system was implemented using Diode laser 5mW at 630 nm, telescopic lenses, mirrors, a long pass filter and a sensitive CCD camera. A 2-mm-diameter hollow sphere containing quantum dot (QD) or Indocyanine green (ICG) was placed at the bottom of a phantom with tissue-like optical parameters (with). FRI images were recorded for varying thickness d of the phantom on top of the fluorescent spheres. The acquired images were deconvolved with original image for extracting the depth dependent PSF, with the width defined as full width at half maximum (FWHM) on the basis of Gaussian fitting. The PSF was validated theoretically using a solution of the diffusion equation with a point source in an infinite homogeneous medium. Additionally variation of PSF FWHM was also evaluated by changing the fluorescent concentration, source radius and magnification. Finally resolving power of FRI system was measured according to Rayleigh criterion.

Results

The evaluation showed that at the depth of 2- 5mm, the depth of ICG and quantum dot was overestimated 9% and 11% respectively. By increasing ICG concentration, error in depth reconstruction were decreased. But the error was increased by increasing the quatum dot concentration. The FRI system can clearly resolved point sources with 4mm apart seated maximum at 3 mm depth.

Conclusion

The results suggested that the developed FRI system can be used in small animal imaging for imaging superficial tumors.

Keywords: fluorescence reflectance imaging (FRI), point spread function (PSF), resolving power, depth, phantom

Abstract View Paper Original: Persian
Optical Elastography: From Theory to Clinical Applications

Maryam Mehdizadeh Dastjerdi, Ali Mahloojifar Page 6

In-vivo evaluating and quantifying the mechanical properties of tissues, particularly the elastic properties of soft tissues, which have been of increasing interest for many medical applications for the past two decades, by utilizing conventional measurement methods are difficult. Elastography is a promising imaging modality for in-vivo tissue characterization. It was proposed to be utilized for breast cancer detection on the basis of tissue hardness being indicative of the presence of a tumor as the practice of palpation examination would indicate. The new imaging technique "Optical Elastography" has the potential as a clinical tool for in-vivo assessing the stiffness of biological tissues. In this paper, we briefly discuss the results of almost a-decade investigations in the field of optical elastography. We present the basic principles and limitations that are involved in the production of elastograms of biological tissues. We conclude the paper with the review of potential applications of this technique for medical diagnosis. We also discuss some fields in which much progress has yet to be made in order for optical elastography to become a viable clinical tool. The usefulness of this technology and the new information it provides suggest that it might soon be available as a commercial system.
Keywords: optical elastography, mechanical properties, elasticity, soft tissue, medical applications

Abstract View Paper Original: Persian
Nd:YAG Laser Hair Removal: Treatment Session and Total Energy Effects on Hair Reduction

Mirhadi Azizjalali, Mina Mamizadeh, Seyed Mehdi Tabaie, Gilamreza Esmaeili Djavid Page 7

Background And Objectives
Traditional hair-removal techniques have included shaving, waxing, chemical depilation, and electrolysis. All of these methods result in temporary hair removal. Laser hair removal (LHR) is a widely used treatment for unwanted hair. In this study, we evaluated the efficacy of number of treatment sessions and total energy on hair reduction.
Materials And Methods
in this prospective study, 71 women referred to dermatologic clinic of Rasol Akaram Hospital during 2007-2008, were enrolled. The women was treated by 1064 nm Nd:YAG laser. Patients’ responses (hair reduction rate) were evaluated by two blinded dermatologist according to visual analogue scale (VAS).
Results
Patients’ mean age was 27.8±5.7 years old. Minimum and maximum treatment sessions were 2 and 16, respectively. Mean of hair reduction was %85.5±%9.7. There was a significant correlation between hair reduction and number of sessions (r=0.471, p<0.001).
Conclusions
the study showed that Nd:YAG laser is a safe method with acceptable response rate for hair removal.
Keywords: Laser hair removal, Nd:YAG, number of session, dose

Abstract Original: Persian
Low Level Laser Therapy in Treatment of Diabetic Foot Ulcers: Double Blind Controlled Clinical Trial

Leila Ataie, Fashtami, Gholamreza E. Djavid, Ahmad Kaviani, Bagher Larijani, Laleh Razavi, Maliheh Salami, Mohsen Fateh, Seyed Mostafa Fatemi, Seyed Mohammad Javad Mortazavi Page 12

Background And Objectives
Diabetic foot problem due to angiopathy and neuropaty account for 50% of all nontraumatic amputations and constitute a significant economic burden to society. Low level laser irradiation (LLLI) has been shown to induce wound healing in conditions of reduced microcirculation. We investigated the influence of LLLI on wound healing by measure the lesion.
Materials And Methods
Sixteen patients with grade I-III diabetic foot for at least three months before this study were included in this double blind randomized clinical trial. Patients received placebo (n= 6) or laser irradiation (n= 10) (GaAlAs/ BTL 685 nm, fluence: 5 J/cm2) over the lesions. Reduction in lesion area was measured and compared between laser and placebo groups.
Results
There were no statistical significant differences in baseline characteristics patients and lesions between laser and placebo groups. Reduction average of lesion areas in laser group was 93.2% vs. with 32.9% in placebo group. Healing rate in laser group was 70% in comparison to placebo group (33.3%) during 16 weeks follow-up (p= 0.072).
Conclusion
The data from this first randomized double- blind placebo- controlled clinical trial demonstrates an increase in healing of diabetic foot lesions.
Keywords: Diabeti0 foot ulcer, double blind clinical trial, low level laser irradiation, GaAlAs, wound area

Abstract View Paper Original: Persian

علمی مصوب

فصلنامه لیزر در پزشکی

Lasers in Medicine

فصلنامه پزشکی

آخرین شماره | آرشیو

ISSN: 1735-3319

صاحب امتیاز:

جهاد دانشگاهی

مدیر مسئول:

دکتر حسین بختو

سردبیر:

دکتر پروین منصوری

تلفن نشریه: ۰۲۱-۶۶۴۹۲۵۷۲

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فهرست مطالب

فصلنامه لیزر در پزشکی سال پنجم شماره 3 (پیاپی 29، پاییز 1387)

فصلنامه لیزر در پزشکی

Lasers in Medicine

فصلنامه لیزر در پزشکی
سال پنجم شماره 3 (پیاپی 29، پاییز 1387)