Search results for "Laser"

Noninvasive diagnostic techniques of port wine stain.

2021

Port-wine stain (PWS) is a benign capillary malformation that most commonly occurs in the head and neck. It is present at birth and progresses over time. It is formed by progressive dilatation of post-capillary venules and is associated with hypertrophy and nodularity with increasing age, leading to cosmetic disfigurement and psychological aggravation. It is caused by genetic mosaicism in GNAQ and GNA11 genes. Histopathology is the gold standard for assessment of PWS but it is invasive and may cause scarring. Inadequate characterization of the lesions may predispose to inadequate treatment protocols as well as higher treatment dosages. Clinical evaluation of treatment efficacy is subjective…

Gefäßrekanalisation mit einem elektrischen Thermokauter-Katheter -In-vitro-Erfahrungen mit einem neuen Kathetersystem

1988

Recanalisation of arteriosclerotic occlusions by means of laser angioplasty, Kensey catheter and the "hot tip" catheter is undergoing early, successful clinical trials. The thermo-cautery catheter described in this paper uses the well known technique of cutting with high frequency electric currents in order to achieve vascular recanalisation. Seven attempts were made to recanalise occlusions at post mortem; four were successful, but perforation occurred in three. Histologically we found a narrow rim of carbonisation of tissues surrounded by a zone of homogenisation and a transitional zone.

Laser Doppler Scanning: How Many Measurements are Required to Assess Regional Cerebral Blood Flow?

2000

This study was initiated to determine the optimal number of measuring sites necessary to estimate regional cerebral blood flow (CBF) under pathophysiological conditions.

TRANSFORMATIONS IN TYPE II LEYDIG CELLS IN THE RAT AFTER ANTERIOR PITUITARY IRRADIATION WITH LOW INCIDENT LEVELS OF HeNe LASER ENERGY

1995

Laser in surgical scar clearance : an update review

2021

Scar formation is a consequence of wound healing that developed from damaged tissue either from physical injury or surgical incision. A hypertrophic scar develops due to an abnormal healing response to trauma. It might lead to serious functional and cosmetic disability. There are numerous methods mentioned in the literature to treat such scars but to date, no single method has been known to cure them. In this review, we focused on differences between various types of nonsurgical management of hypertrophic scar focusing on the indication, mechanism of action, and efficacy of the pulsed dye laser (PDL), fractional carbon dioxide laser (fCO2), Er-YAG laser, and intense pulse light (IPL). The l…

Fractional CO2 Laser: the new frontier for the treatment of vulvo-vaginal atrophy symptoms

2014

The vulvo-vaginal atrophy (VVA) is a chronic condition characterized by gradual involution of the mucous membranes and vulvo-vaginal tissues, which is manifested in the climacteric phase. Numerous therapeutic options, hormonal and non-hormonal, have been proposed to alleviate the symptoms related to VVA, but to date none of them is able to guarantee long-term effects. The use of Fractional CO2 Laser technology applied to the vulvo-vaginal area represents an innovative procedure to make a real "regeneration treatment" of the vaginal tissues. In fact, it is possible to spread the laser energy in the various layers of the vaginal wall, reactivating the synthesis of extracellular matrix and col…

2021

Patients with unilateral vocal fold cancer (T1a) have a favorable prognosis. In addition to the oncological results of CO2 transoral laser microsurgery (TOLMS), voice function is among the outcome measures. Previous early glottic cancer studies have reported voice function in patients grouped into combined T stages (Tis, T1, T2) and merged cordectomy types (lesser- vs. larger-extent cordectomies). Some authors have questioned the value of objective vocal parameters. Therefore, the purpose of this exploratory prospective study was to investigate TOLMS-associated oncological and vocal outcomes in 60 T1a patients, applying the ELS protocols for cordectomy classification and voice assessment. P…

Laser illumination designs for snapshot multi-spectral-line imaging

2019

For multi-spectral imaging, both acquisition time of the spectral image set and the spectral bandwidth of each image have to be minimized. Ultimate performance can be achieved if the set of monochromatic (single-wavelength) spectral images is obtained with a single snapshot — a technique provisionally called "snapshot multi-spectral-line imaging" or SMSLI. Using contemporary RGB colour cameras, up to three spectral line images can be extracted from a snapshot image data cube at specific illumination that comprises only three spectral lines, each of them positioned within one of the detection bands (R, G or B) [1]. Techniques able to provide more spectral line images are under development, a…

Microvascular blood flow changes of the abductor pollicis brevis muscle during sustained static exercise

2021

A practical assessment of the general health and microvascular function of the palm muscle, abductor pollicis brevis (APB), is important for the diagnosis of different conditions. In this study, we have developed a protocol and a probe to study microvascular blood flow using near-infrared diffuse correlation spectroscopy (DCS) in APB during and after thumb abduction at 55% of maximum voluntary contraction (MVC). Near-infrared time resolved spectroscopy (TRS) was also used to characterize the baseline optical and hemodynamic properties. Thirteen (n=13) subjects were enrolled and subdivided in low MVC (N=6, MVC<2.3 kg) and high MVC (N=7, MVC≥2.3 kg) groups. After ruling out significant cha…

Variations in acoustical beam properties of intracoronary Doppler catheters.

1993

The limitations of coronary angiography in assessing the functional significance of coronary obstructions is well known. While the critical variable of coronary blood flow cannot be readily measured, intraluminal Doppler sonography offers useful related functional information on blood flow velocity. In order to fully evaluate Doppler signals it is essential to have exact knowledge of the transducer transmission characteristics and of the ultrasound beam topology. In an experimental set-up, the transmitter-receiver characteristics of five commonly used Doppler catheters were investigated. In comparing the beam characteristics we found inhomogeneities in the lateral beam spread. At a penetrat…