Photoplethysmography (PPG) is a non-invasive optical technique that employs variations in light absorption produced by alteration in the blood volume in capillaries at the skin during the cardiac cycle. This study aims to understand factors related to PPG morphology; a hand-elevation, the study has modified blood flow to and from the finger was conducted in the laboratory. It is widely established that the position of the limb relative to the heart has an effect on blood flow in arteries and venous. Peripheral digital pulse wave (DPW) signals were obtained from 15 healthy volunteer participants during hand-elevation, and hand-lowering techniques wherein the right hand was lifted and lowered relative to heart level, while the left hand remained static. The pulse width, time to peak (TTP), the time to the maximum slope (TTMas) were computed from 30sec DPW signals at three positions of the right hand with regard to heart level, i.e. 35 cm above heart level (+35 cm), at the level of the heart (0 cm), and 35 cm below the level of the heart (-35 cm). DPW characteristics were found to alter with hand position. On lowering the hand to -35 cm relative to heart level, DPW width from the middle finger increased by (6%), but lowering the arm decreased the TTP (by 11 %), TTMas (by 18 %). These changes in time-dependent DPW indices may be attributed to changes in hydrostatic pressure and the venoarterial reflex that changes the blood vessels filling from completely filled one at -35 cm due to arterial vasoconstriction and decreased venous return to partially emptied blood vessels due to arterial vasodilatation and increased venous return at +35 cm. It was assumed that these time-dependent morphological DPW indices alterations were controlled by changes in downstream venous resistance rather than arterial or arteriolar, resistance. Keywords: photo plethysmography, hand elevation, vasoconstriction, vasodilation, vascular mechanics
The study addressed the water ecosystems of the marshes of Maysan Governorate as one of the important areas in Iraq in terms of the environmental, economic and tourism aspects. This area was exposed to great environmental changes due to natural and human factors which greatly affected the water ecosystem and made the area susceptible to many problems that affected the biological life of living organisms. The marshes of Maysan Governorate was affected by vital factors and non-vital factors. The marshes of Maysan Governorate was characterized by the UN Organization as one of the most important centers of biodiversity in the world because of the abundance of different and rare living organisms such as birds, fish, and reptiles as well as the e
... Show MoreThis research deals with the topic (the position of women) in the literature literature, and the researcher cites a bouquet of woolen yarn, examples of verses and poems from this fine literature that looks at the woman with respect and appreciation. In their poems.
The research is a comparative search for Arab and Kurdish literature, by selecting six famous poets in the literature, three of them are from Arabic literature, and the other three are from Kurdish literature, and thus the research is divided into two subjects and six demands.
Finally, the researcher tried to set a brick that would be an entry point to find an indicative explanation and a suitable explanation that would break those symbols and signs that caused the exp
The aim of the present study is to provide the adequate knowledge about the role of time management in facilitate the work requirements for employees of the administrative department at the Ministry of Higher Education and Scientific Research. The research depend on studying four important dimensions which are (time planning, time organization, time direction and time observation). In addition to study other five dimensions which are (new procedures, clear procedures, short procedures, the available information and the simplicity of the methods
used).Questionnaire sheets consist of (38 questions) distributed to (170) employees and (146) sheets only were considered in the study. SPSS program was used
... Show MoreThe research aims to know the impact of science, technology, engineering, and mathematics education on both creative thinking and mathematical achievement. To achieve it, the two researchers followed the quasi-experimental approach with an experimental design for two groups, one experimental and the other a control. The research sample consisted of (32) female students from the fourth scientific grade in Al-Intisar Preparatory School for Girls/ AlRasafa, First Directorate. The sample was chosen intentionally and was divided into two groups: a control group studying by the traditional method, their number (16), and an experimental group that applied the STEM approach, their number also (16). There was parity between the two research groups i
... Show MoreTo achieve excellence in the quality of performance in school sports administration, which has suffered a lot of problems and constraints on the administrative system, supervision and education level as well as the regulatory environment and available resources available and contribute to the provision of some processors and overcome difficulties to participate in the formation of the individual good of itself and society through sports activities. Hence the importance came this study to create a reference to the quality of the performance criteria school sports from the perspective of supervisors (specialists and technicians) in the districts of breeding Baghdad, to be of help to all those involved in school sports and maintaining an excep
... Show MoreThere significant correlation between vehicles Home (carbohydrates, protein, fiber and fat and injury borer stalk corn was for vehicles secondary effect is clear in injury borer stalk corn coumarin clear impact in the survival rate of larvae The more of these compounds in genotype I survival rate of larvae