Filtry
wszystkich: 1692
-
Katalog
- Publikacje 1271 wyników po odfiltrowaniu
- Czasopisma 60 wyników po odfiltrowaniu
- Konferencje 1 wyników po odfiltrowaniu
- Osoby 29 wyników po odfiltrowaniu
- Wynalazki 1 wyników po odfiltrowaniu
- Projekty 4 wyników po odfiltrowaniu
- Kursy Online 101 wyników po odfiltrowaniu
- Wydarzenia 3 wyników po odfiltrowaniu
- Dane Badawcze 222 wyników po odfiltrowaniu
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: subarachnoid space width
-
Human subarachnoid space width oscillations in the resting state
PublikacjaAbnormal cerebrospinal fluid (CSF) pulsatility has been implicated in patients suffering from various diseases, including multiple sclerosis and hypertension. CSF pulsatility results in subarachnoid space (SAS) width changes, which can be measured with near-infrared transillumination backscattering sounding (NIR-T/BSS). The aim of this study was to combine NIR-T/BSS and wavelet analysis methods to characterise the dynamics of the...
-
Modeling of subarachnoid space width change caused by blood circulation in brain vessels
PublikacjaThe subarachnoid space is an anatomic space, lying in the central nervous system, between the arachnoid membrane and the pia mater. It is filled with cerebrospinal fluid, which protects and nourishes the brain. The pathological disorder of the subarachnoid space (i.e. increase or decrease of its width) a ects the nervous system. Therefore, it is important to diagnose the width changes of the subarachnoid space. One way to support...
-
Impact of slow breathing on the blood pressure and subarachnoid space width oscillations in humans
PublikacjaThe aim of the study was to assess cardiac and respiratory blood pressure (BP) and subarachnoid space (SAS) width oscillations during the resting state for slow and fast breathing and breathing against inspiratory resistance. Experiments were performed on a group of 20 healthy volunteers (8 males and 12 females; age 25.3 ± 7.9 years; BMI = 22.1 ± 3.2 kg/m2). BP and heart rate (HR) were measured using continuous finger-pulse photoplethysmography....
-
Modelling of subarachnoid space width changes in apnoea resulting as a function of blood flow parameters
PublikacjaDuring apnoea, the pial artery is subjected to two opposite physiological processes: vasoconstriction due to elevated blood pressure and vasorelaxation driven by rising pH in the brain parenchyma. We hypothesized that the pial artery response to apnoea may vary, depending on which process dominate. Apnoea experiments were performed in a group of 19 healthy, non-smoking volunteers (9 men and 10 women). The following parameters...
-
Coupling between Blood Pressure and Subarachnoid Space Width Oscillations during Slow Breathing
PublikacjaThe precise mechanisms connecting the cardiovascular system and the cerebrospinal fluid (CSF) are not well understood in detail. This paper investigates the couplings between the cardiac and respiratory components, as extracted from blood pressure (BP) signals and oscillations of the subarachnoid space width (SAS), collected during slow ventilation and ventilation against inspiration resistance. The experiment was performed on...
-
Acute hypoxia diminishes the relationship between blood pressure and subarachnoid space width oscillations at the human cardiac frequency
PublikacjaAcute hypoxia exerts strong effects on the cardiovascular system. Heart-generated pulsatile cerebrospinal fluid motion is recognised as a key factor ensuring brain homeostasis. We aimed to assess changes in heart-generated coupling between blood pressure and subarachnoid space width oscillations during hypoxic exposure.
-
Increased inspiratory resistance affects the dynamic relationship between blood pressure changes and subarachnoid space width oscillations
PublikacjaBackground and objective Respiration is known to affect cerebrospinal fluid (CSF) movement. We hypothesised that increased inspiratory resistance would affect the dynamic relationship between blood pressure (BP) changes and subarachnoid space width (SAS) oscillations. Methods Experiments were performed in a group of 20 healthy volunteers undergoing controlled intermittent Mueller Manoeuvres (the key characteristic of the procedure...
-
Technical foundations for noninvasive assessment of changes in the width of the subarachnoid space with near-infrared transillumination-backscattering sounding (NIR-TBSS)
PublikacjaPraca opisuje metodę transiluminacji w bliskiej podczerwieni umożliwiającą nieinwazyjne monitorowanie zmian szerokości przestrzeni podpajęczynówkowej oraz amplitudy tętnienia naczyń powierzchniowych mózgu.
-
Influence of Acute Jugular Vein Compression on the Cerebral Blood Flow Velocity, Pial Artery Pulsation and Width of Subarachnoid Space in Humans
PublikacjaCelem pracy jest zaprezentowanie wyników badań dotyczących oceny wpływu silnego obustronnego zwężenia żył szyjnych na amplitudę pulsacji i zmiany szerokości przestrzeni podpajęczynówkowej, prędkość przepływu mózgowego krwi, obwodowe ciśnienie krwi oraz możliwe relacje między wymienionymi parametrami.
-
Pial artery and subarachnoid width response to apnoea in normal humans
PublikacjaBackground: Little is known about intracranial pressure (ICP)-cerebral haemodynamic interplay during repetitive apnoea. A recently developed method based on near-infrared transillumination/backscattering sounding (NIR-T/BSS) noninvasively measures changes in pial artery pulsation (cc-TQ) as well as subarachnoid width (sas-TQ) in humans. Method: We tested the complex response of the pial artery and subarachnoid width to apnoea...
-
Subarachnoid Space: New Tricks by an Old Dog
PublikacjaPurpose: The purpose of the study was to: (1) evaluate the subarachnoid space (SAS) width and pial artery pulsation in both hemispheres, and (2) directly compare magnetic resonance imaging (MRI) to near-infrared transillumination/backscattering sounding (NIR-T/BSS) measurements of SAS width changes in healthy volunteers.Methods: The study was performed on three separate groups of volunteers, consisting in total of 62 subjects (33...
-
New aspects in assessment of changes in width of subarachnoid space with near-infrared transillumination/backscattering sounding, part 2: clinical verification in the patient
PublikacjaW pracy przedstawiono porównanie wyników symulacji propagacji promieniowania z zakresu bliskiej podczerwieni z danymi uzyskanymi na drodze pomiarów wykonanych w warunkach klinicznych. Różnice między nimi nie przekraczały 4 dB, co potwierdziło słuszność przyjętych założeń w procesie symulacji. W pomiarach wykorzystano unikatowy zetstaw nadajników i odbiorników promieniowania podczerwonego, pozwalającego prowadzenie pomiarów transmisji...
-
New aspects in assessment of changes in width of subarachnoid space with near-infrared transillumination/backscattering sounding, part 1: Monte Carlo numerical modeling
PublikacjaW pracy wykorzystano zmodyfikowaną metodę Monte Carlo do numerycznego modelowania propagacji promieniowania z zakresu bliskiej podczerwieni w warstwach anatomicznych głowy. Badano efekt zmian szerokości warstwy podpajęczynówkowej pod wpływem tętna na natężenie promieniowania wstecznie rozpraszanego. Przeprowadzone obliczenia pokazały, że możliwe jest monitorowanie zmian tej szerokości na podstawie pomiarów transmisji promieniowania...
-
Spectral analysis of mechanical and respiratory influences on width of subarachnoid space assessed with non-invasive method of near-infrared transillumination/back scattering sounding
PublikacjaW pracy przedstawiono zastosowanie analizy widmowej do badania zmian szerokości przestrzeni podpajęczynówkowej spowodowanych ruchami głowy i wysilonym oddechem w nieinwazyjnej metodzie transiluminacji w bliskiej podczerwieni.
-
Effects of consecutive apneas on pial artery pulsation and subarachnoid width in healthy subjects
PublikacjaHypercapnia is known to dilate the pial artery, disrupt cerebral autoregulation and increase pial artery pulsation. The cerebral blood flow velocity (CBFV) response to hypercapnia is biphasic. Below the threshold for the increase of blood pressure (BP) with carbon dioxide partial pressure (pCO2), the CBFV measurement reflects vascular reactivity to pCO2 alone at a constant BP. Above this threshold, the CBFV measurement provides...
-
Effect of Maximal Breath Hold Apnea on Pial Artery Pulsation and Subarachnoid Width in Human
PublikacjaLittle is known about intracranial pressure (ICP)-cerebral hemodynamic interplay during maximal breath-hold apnea. A recently developed method based on near-infrared transillumination/backscattering sounding (NIR-T/BSS) noninvasively measures changes in pial artery pulsation (cc-TQ) as well as subarachnoid width (sas-TQ) in humans. Changes in sas-TQ correlate with ICP to a considerable extent, whereas cc-TQ reflects the functional...
-
Use of Near Infrared Transillumination/Back Scattering Sounding (NIR-T/BSS) to assess effects of elevated intracranial pressure on width of subarachnoid space and celebrovascular pulsation in animals
PublikacjaW pracy dokonano ocenę zmiany szerokości przestrzeni podpajęczynówkowej i tętnienia naczyń mózgowych w czasie chwilowego zwiększenia ciśnienia śródczaszkowego u królików doświadczalnych. Badania zostały przeprowadzone przy wykorzystaniu metody transiluminacji w bliskiej podczerwieni z rozpraszaniem zwrotnym NIRT-BSS.
-
New method to monitor changes in the subarachnoid width and pial artery pulsation for physiological and clinical research
PublikacjaThere are several medical conditions associated with brain oedema such as traumatic brain injury, intoxication or tumors. Brain edema and related brain parenchyma expansion may lead to compression and subsequent injury of several brain structures. So far, the only method enabling detection and monitoring of the progress a cerebral oedema in a patient, has been monitoring of intracranial pressure (ICP) with a pressure probe inserted...
-
Effect of Maximal Apnoea Easy-Going and Struggle Phases on Subarachnoid Width and Pial Artery Pulsation in Elite Breath-Hold Divers
PublikacjaPurpose: The aim of the study was to assess changes in subarachnoid space width (sas-TQ), the marker of intracranial pressure (ICP), pial artery pulsation (cc-TQ) and cardiac contribution to blood pressure (BP), cerebral blood flow velocity (CBFV) and cc-TQ oscillations throughout the maximal breath hold in elite apnoea divers. Non-invasive assessment of sas-TQ and cc-TQ became possible due to recently developed method based on...
-
Monitoring of subarachnoid space and cerebrovascular pulsation with near-infrared transillumination/back scattering : new aspects of the method
PublikacjaW pracy zaprezentowano nowe aspekty nieinwazyjnej metody NIRT-BS w zastosowaniu do zapisu zmian szerokości przestrzeni podpajęczynówkowej (SAS) jako źródła informacji o amplitudzie tętnienia naczyń na powierzchni mózgu.