scholarly journals Dye-free retinal angiography using blood-oxygenation modulation

2018 ◽  
Author(s):  
Lewis E MacKenzie ◽  
Tushar R Choudhary ◽  
Javier Fernandez Ramos ◽  
Nigel Benjamin ◽  
Christian Delles ◽  
...  

Fluorescence angiography (FA) is widely used for studying and diagnosing abnormalities in the retinal blood circulation, but has associated risks of nausea, skin irritation, and even death. We describe a new non-invasive angiography technique: Blood Oxygenation Modulation Angiography, in which multispectral imaging of a transient perturbation in blood-oxygen saturation, yields angiography sequences similar to FA, including key features such as sequential filling of choroidal and retinal-vessels, which underpin assessment of circulation health. This is the first non-invasive angiography technique capable of visualizing these circulation features.

2017 ◽  
Vol 17 (07) ◽  
pp. 1740005 ◽  
Author(s):  
SHREYA BHAT ◽  
MUHAMMAD ADAM ◽  
YUKI HAGIWARA ◽  
EDDIE Y. K. NG

Early investigation on blood circulation by Hertzman (1937) leads to the observation of vital body signs such as respiration rate, heart rate (HR), blood oxygenation and vascular assessment using photoplethysmographic (PPG) device. PPG is a noninvasive, painless optical technique used to monitor the pulsations linked to alteration in the blood volume. The PPG waveform is a summation of pulsatile and nonpulsatile components and contains useful information about the physiological systems. With the breakthrough in technology and development of powerful analytical tools, PPG devices are constantly being used in advanced medical equipments such as smart-watches and smart-wristbands for HR monitoring, pulse oximeters for measuring respiratory rate and noncontact PPG device for blood oxygen saturation measurement. This paper presents description on PPG and its characteristic waveform and working principle. It also includes brief explanation on nonlinear analysis of PPG signals and salient applications of PPG followed by its advantages and limitations.


2015 ◽  
Vol 77 (7) ◽  
Author(s):  
Sheena P. Philimon ◽  
Audrey K. C. Huong ◽  
Xavier T. I. Ngu

This paper presents the use of Extended Modified Lambert Beer (EMLB) model for quantification of transcutaneous blood oxygen saturation (StO2) via a noninvasive approach. Continuous wave (CW) reflectance spectroscopy system is employed for measurement of intensity reflected from left index finger of an Asian nonsmoking volunteer at resting condition. Multispectral images captured in the wavelength range of 520 − 600 nm at an interval of 10 nm are mathematically analyzed and fitted using the developed fitting algorithm to give the best estimation of StO2. The result from this preliminary study revealed a mean StO2 value of 75 ± 5% for the participating individual, which value agreed considerably well with that presented in previous works. This work concluded that the developed spectroscopy system and quantification technique can potentially be used as an alternative means to clinical assessment of wound healing progress


Vestnik ◽  
2021 ◽  
pp. 225-230
Author(s):  
З.Б. Есимсиитова ◽  
Н.Т. Аблайханова ◽  
Ж.М. Базарбаева ◽  
Г.А. Естемирова ◽  
З. Бекен ◽  
...  

Одним из перспективных направлений в развитии фармакологии будущего является поиск новых методов обновления механизмов саморегуляции организма, расширения его функциональных возможностей. Применение лекарственных трав в качестве немедикаментозного средства коррекции повышения его функциональных возможностей при нарушении физиологических функций организма человека приобретает все большее распространение. В статье показано, что лекарственный композит, изготовленный из растительного и животного сырья, обладает низкой дозой расширения дыхательных путей, повышая насыщение крови кислородом, повышая тонус и сопротивление периферических сосудов, способствуя централизации кровообращения, а при регулярном вдыхании запаха больших доз ладана существует высокая вероятность нарушения функций дыхательной, сердечно-сосудистой и нервной систем. Выявлено, что в условиях острой интоксикации под воздействием ароматических веществ в организме животных происходят изменения различного характера. Поэтому травяные ароматические вещества можно рассматривать как универсальные профилактические вещества, обладающие рядом преимуществ перед другими профилактическими средствами. One of the promising directions in the development of future pharmacology is the search for new methods of updating the mechanisms of self-regulation of the body, expanding its functional capabilities. The use of medicinal herbs as a non-drug means of correcting the increase of its functional capabilities in violation of the physiological functions of the human body is becoming more and more widespread. The article shows that a medicinal composite made from plant and animal raw materials has a low dose of expansion of the airways, increasing blood oxygen saturation, increasing the tone and resistance of peripheral vessels, contributing to the centralization of blood circulation, and with regular inhalation of the smell of high doses of incense, there is a high probability of a violation of sides of the respiratory, cardiovascular and nervous systems. It was revealed that under conditions of acute intoxication under the influence of aromatic substances in the body of animals there are changes of a different nature. Therefore, herbal aromatic substances can be considered as universal prophylactic substances that have a number of advantages over other prophylactic agents.


2014 ◽  
Vol 622 ◽  
pp. 45-50 ◽  
Author(s):  
R. Premkumar ◽  
Chokkalingam Arun ◽  
Ramakrishnan Sai Divya

Obstructive sleep apnea (OSA) is the most common type of sleep apnea and is caused by obstruction of the upper airway. Its distinctive feature is occurrence of repetitive pauses in breathing during sleep, due to intermittent relaxing and blocking of the patients airway by the throat muscles. Continuous such actions might narrow down the throat or may completely block it. These actions cause more difference in breathing sounds and are usually associated with a reduction in blood oxygen saturation. The breathing sounds of the patients with and without obstructive sleep apnea were recorded using a non-invasive, low-cost sensor during wakefulness in supine (lying) position and Continuous wavelet 1-D analysis was performed on those signals.


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