Photoacoustic tomography for imaging the prostate: a transurethral illumination probe design and application.

imaging of prostate cancer with photoacoustic tomography is currently limited by the lack of sufficient local fluence for deep tissue penetration and the risk of over-irradiation near the laser-tissue contact surface. We propose the design of a transurethral illumination probe that addresses those limitations. A high energy of 50 mJ/pulse is coupled into a 1000-µm-core diameter multimode fiber.

Determination of effective treatment duration of interferential current therapy using electromyography.

[Purpose] This study used electromyography to measure the effective treatment duration of interferential current therapy for muscle fatigue. [Subjects and Methods] Fifteen healthy adult men volunteered to participate in the study (age: 24.2 ± 1.

Evaluation of wavelength-dependent hair growth effects on low-level laser therapy: an experimental animal study.

In this study, we aimed to investigate the wavelength-dependent effects of hair growth on the shaven backs of Sprague-Dawley rats using laser diodes with wavelengths of 632, 670, 785, and 830 nm. Each wavelength was selected by choosing four peak wavelengths from an action spectrum in the range 580 to 860 nm. The laser treatment was performed on alternating days over a 2-week period.

A comparison of temperature profile depending on skin types for laser hair removal therapy.

Although numerous lasers with different wavelengths are available for laser hair removal, their use in individuals with dark-pigmented skin remains a challenge. The present study aims to develop a numerical heat diffusion model considering skin types over various wavelengths. This numerical mode uses Pennes approximation to represent heat from metabolism, blood perfusion and an external heating source.

Development of the theragnostic optical system for a high-intensity laser therapy (HILT).

Recently, high-intensity laser therapy (HILT) has been introduced for muscle disorders, but its efficacy has not been confirmed due to the absence of quantitative assessments and treatment feedback data in real-time. In this clinical study, a theragnostic optical system comprised of a high-intensity laser and a non-invasive optical monitoring system was developed to assess spasticity. To avoid interference between the two different light sources, the therapeutic wavelength for HILT was selected at 808 nm, one of the isosbestic points.

Effects of electro-acupuncture therapy on post-stroke depression in patients with different degrees of motor function impairments: a pilot study.

[Purpose] The present study examined whether electro-acupuncture therapy reduces post-stroke depression (PSD) and whether motor function impairments interact with the effects of the therapy. [Subjects] Twenty-eight PSD patients were assessed and assigned to either a good or poor motor function group depending on their motor grade. [Methods] The Beck Depression Inventory (BDI), Hamilton Depression Rating Scale (HDRS) and Manual Muscle Test (MMT) were administered at the screening and initial phases of the study, and at the 4th, 8th, 12th and 16th week of the daily electro-acupuncture treatment.

Ablation efficiency and relative thermal confinement measurements using wavelengths 1,064, 1,320, and 1,444 nm for laser-assisted lipolysis.

Laser-assisted lipolysis is routinely used for contouring the body and the neck while modifications of the technique have recently been advocated for facial contouring. In this study, wavelength-dependence measurements of laser lipolysis effect were performed using different lasers at 1,064, 1,320, and 1,444 nm wavelengths that are currently used clinically. Fresh porcine skin with fatty tissue was used for the experiments with radiant exposure of 5-8 W with the same parameters (beam diameter = 600 μm, peak power = 200 mJ, and pulse rate = 40 Hz) for 1,064, 1,320 and 1,444 nm laser wavelengths.

Evaluation of photothermal effects in cartilage using FT-IR spectroscopy.

Photothermal effects after laser irradiation of cartilage are investigated using an infrared focal plane array (IR-FPA) camera and a Fourier transform infrared (FT-IR) spectrometer. The IR-FPA camera records radiometric temperature profile, while the local laser heating is applied to the sample; whereas the FT-IR spectrometer analyzes absorption peaks of cartilage constituents. As the major effect of photothermal heating in cartilage is water evaporation, spectral changes because of dehydration between control and laser-irradiated cartilage are recorded by FT-IR spectrometer measurements.

A comparison of mass removal, thermal injury, and crater morphology of cortical bone ablation using wavelengths 2.79, 2.9, 6.1, and 6.45 microm.

Background And Objective: Previous investigations have reported evidence of wavelength dependence on cortical bone ablation. This study used mid-infrared laser wavelengths generated by a free electron laser (FEL) and mass removal measurements to further examine the ablation efficiency of a wavelength (2.79 microm) not previously reported and three wavelengths (2.

Mid-IR laser ablation of articular and fibro-cartilage: a wavelength dependence study of thermal injury and crater morphology.

Background And Objective: The aim of this study was to evaluate areas of collateral thermal injury and crater morphology for evidence of wavelength-dependent effects on the ablation of articular cartilage and fibro-cartilage (meniscus) using selected mid-IR wavelengths produced by a free electron laser.

Study Design/materials And Methods: Two types of cartilage, articular cartilage and fibro-cartilage were used in the study. The wavelengths (lambda) evaluated were 2.

Depth-resolved phase retardation measurements for laser-assisted non-ablative cartilage reshaping.

Since polarization-sensitive optical coherence tomography (PS-OCT) is emerging as a new technique for determining phase retardation in biological materials, we measured phase retardation changes in cartilage during local laser heating for application to laser-assisted cartilage reshaping. Thermally-induced changes in phase retardation of nasal septal cartilage following Nd:YAG laser irradiation were investigated using a PS-OCT system. A PS-OCT system and infrared imaging radiometer were used to record, respectively, depth-resolved images of the Stokes parameters of light backscattered from ex vivo porcine nasal septal cartilage and radiometric temperature changes following laser irradiation.

Free electron laser ablation of articular and fibro-cartilage at 2.79, 2.9, 6.1, and 6.45 microm: mass removal studies.

Background And Objective: The wavelength and tissue-composition dependence of cartilage ablation was examined using selected mid-infrared laser wavelengths.

Study Design/materials And Methods: The mass removal produced by pulsed laser ablation of articular and fibro-cartilage (meniscus) were measured. The wavelengths examined were 2.

Electrokinetic measurement of cartilage using differential phase optical coherence tomography.

When an electric field is applied to cartilage, current-generated stress gradients are produced and stress deformation occurs. Since differential phase optical coherence tomography (DP-OCT) is sensitive to tiny surface displacement, these tiny displacements are induced electrokinetically in cartilage and the electric-current-induced stress gradients were measured with DP-OCT. The electrokinetic surface displacement of cartilage was characterized by applying sinusoidal voltages with two amplitudes (5 and 10 V) and different frequencies (1.

Imaging tissue response to electrical and photothermal stimulation with nanometer sensitivity.

Background And Objectives: Tissue response to thermal, electrical, or chemical stimuli are important in the health and survival of tissue. We report experimental results to assess tissue response to various stimuli using a low coherence differential phase interferometer.

Study Design/materials And Methods: The optical system utilized to measure tissue response is a novel fiber-based phase sensitive optical low coherence reflectometer (PS-OLCR).