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Polymer Nanocomposites-Based Wearable Smart Sensors
Published in Anandhan Srinivasan, Selvakumar Murugesan, Arunjunai Raj Mahendran, Progress in Polymer Research for Biomedical, Energy and Specialty Applications, 2023
Mohammed Khalifa, C. Shamitha, Sawan Shetty, Anandhan Srinivasan
Moreover, this flexible sensor was connected to the wrist to monitor the real-time radial artery pulse. The pulse signals before and after exercises were measured. Obviously, the pulse signal frequency increased after exercise (see Figure 12.9e). Moghadam, Hasanzadeh, and Simchi (2020) have developed PVDF/microporous zirconium-based metal–organic framework (MOF)-based piezoelectric self-powered wearable sensors for arterial pulse monitoring. The nanocomposite sensing material was fabricated using electrospinning technique. The arterial pulse monitoring was carried out by attaching the sensor to the wrist of a 32-year-old male before and after exercise (Figure 12.9f and g). They were able to distinguish the signals associated with the pulse waveform. The signals consisted of four systolic waves and one diastolic wave, as shown in Figure 12.9h.
Urinary system
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
Some patients with end-stage renal failure require haemodialysis. Ideally this is achieved by the surgical creation of an arteriovenous fistula, typically in the patient’s non-dominant arm. Common sites of fistulae include connection of the radial artery with the cephalic vein at the wrist, or the brachial artery with the cephalic vein or basilic vein at the elbow. As the vein receives high pressure blood directly from the artery, it arterialises (‘matures’), enlarging and becoming thicker walled. Flow though the fistula may be clinically noticeable as a palpable ‘thrill’ (a buzz). This large vein provides easier long term access for the large gauge dialysis needles and allows continuous high volumes of blood flow necessary for efficient dialysis. However, over time stenoses may develop, often around the site of the anastomosis or the needling sites; this can cause reduced blood flow, and if untreated can lead to suboptimal dialysis and/or thrombosis of the fistula. Stenoses may be treated by angioplasty, while thrombosis, if diagnosed early enough, may be treated with thrombolysis, mechanical or aspiration thrombectomy or ‘trawling’ the thrombus with an angioplasty balloon. Alternative access for haemodialysis may be provided via a tunnelled central venous catheter. In difficult cases this can be inserted under radiographic control.
Blood Pressure Measurement
Published in John G. Webster, Halit Eren, Measurement, Instrumentation, and Sensors Handbook, 2017
Shyam Rithalia, Mark Sun, Roger Jones
Indirect measurement is often called noninvasive measurement because the body is not entered in the process. The upper arm, containing the brachial artery, is the most common site for indirect measurement because of its closeness to the heart and convenience of measurement, although many other sites may have been used, such as forearm or radial artery and finger. Distal sites such as the wrist, although convenient to use, may give much higher SP than brachial or central sites as a result of the phenomena of impedance mismatch and reflective waves [3]. An occlusive cuff is normally placed over the upper arm and is inflated to a pressure greater than the systolic blood pressure. The cuff is then gradually deflated, while a detector system simultaneously employed determines the point at which the blood flow is restored to the limb. The detector system does not need to be a sophisticated electronic device. It may be as simple as manual palpation of the radial pulse. The most commonly used indirect methods are auscultation and oscillometry, each is described later.
Elevated shear rate-induced by exercise increases eNOS ser1177 but not PECAM-1 Tyr713 phosphorylation in human conduit artery endothelial cells
Published in European Journal of Sport Science, 2023
Andrea Tryfonos, Debar Rasoul, Daniel Sadler, James Shelley, Joseph Mills, Daniel J. Green, Ellen A. Dawson, Matthew Cocks
A detailed description of the transradial catheterisation and EC collection process used in this study has been described previously (Tryfonos et al., 2020b). Briefly, an 18–20-gauge catheter (0.9–1.2 mm diameter, 8–10 cm length) (leadercath, Vygon, UK) was inserted into the radial artery of the right arm, under local anaesthesia (2–4 ml Marcain Polyamp steripack 0.5%, Aspen), by a cardiologist. Two separate flexible J-shaped guide wires (paediatric J-wires, 0.46 mm, 40 cm length, Vygon, UK) were advanced 3–4 cm beyond the tip of the catheter and run back and forth to collect ECs from the inside of the artery (Colombo et al., 2002; Feng, Stern, & Pile-Spellman, 1999), before (Pre-) and immediately after the (Post-) intervention (within 2–3 min of the end of exercise). The distal portion of each J-shaped guide wire was transferred to ice-cold dissociation buffer (within 10 s of procedure) and taken immediately to the laboratory for processing (see below), where samples were maintained on ice until fixation (duration between sampling and fixation was approx. 10 min), as previous work suggests cold conditions can improve preservation of phosphoproteins by slowing down enzymatic activity (Gündisch et al., 2015; Wang et al., 2015). Catheters were removed following the post-intervention EC collection.
Cardiopulmonary signal acquisition from different regions using video imaging analysis
Published in Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization, 2019
Ali Al-Naji, Javaan Chahl, Sang-Heon Lee
The cardiopulmonary signal was extracted from five regions where an arterial pulse can be revealed at a distance of approximately 0.5 m from the digital camera. The first region is a pulse in the wrist resulting from the radial artery. The second region is a pulse in the neck resulting from the carotid artery. The third region is a pulse in the arm resulting from the brachial artery. The fourth region is a pulse in the forehead resulting from the temporal artery. The last region is a pulse in the foot resulting from the dorsalis pedis artery. To extract the cardiopulmonary signal from the video data at the selected ROIs, two different analysis methods were proposed to detect arterial pulse motion, including intensity-based method and frame subtraction-based method.
The modified Allen test and a novel objective screening algorithm for hand collateral circulation using differential photoplethysmography for preoperative assessment: a pilot study
Published in Journal of Medical Engineering & Technology, 2020
Radial and femoral arteries are used for HC and PCI, and radial artery and saphenous vein are used for CABG. Recently, the usage of the radial artery has been increasing due to its fewer complications, cost-effectiveness, zero/less bedtime requirement and high preference from patients [8–10]. Also, the radial artery provides a suitable length and inner-diameter for harvesting.