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PloS One 2023A mechanical device inspired by the rapid rotational motion of the pistol shrimp plunger has been developed to experimentally study the contraction/expansion dynamics of...
A mechanical device inspired by the rapid rotational motion of the pistol shrimp plunger has been developed to experimentally study the contraction/expansion dynamics of a gas bubble inside a confined liquid volume and in the vicinity of solid surfaces. The apparatus consists of a limb with a V-shaped end, which fits into a socket forming a cylindrical compression chamber. Air bubbles of different sizes and in different positions inside the chamber were seeded to study their shape evolution in liquids when subjected to pressure pulses induced by the limb closure. By changing the standoff and curvature parameters, as well as the closing power of the limb it was possible to control the dynamical behavior of the cavity. Four stages describing the dynamic behavior of the bubble were found: 1) A slight expansion-contraction stage accompanied by very weak volumetric oscillations. 2) First compression stage. The formation of gas and liquid micro-jets is observed when the vertical symmetry axis of the bubble is initially located outside of the chamber symmetry axis, on the other hand, when there is a coincidence between these axes, the bubble only contracts exhibiting non-spherical shapes, alternating between oblate and prolate spheroidal structures. 3) An expansion stage where the cavity reaches the walls of the chamber exhibiting irregular shapes on its surface. 4) Second compression stage. This process begins when the limb rebounds and stops sealing the chamber allowing a jet of liquid to enter from the fluid medium outside, inducing a very violent collapse accompanied by the emission of light. The proposed technique represents a novel alternative to study the dynamic evolution of bubbles near and on solid boundaries of various geometries. Other attractive features of the apparatus are its low manufacturing cost, simple design and compact size which makes it easily portable.
PubMed: 38096256
DOI: 10.1371/journal.pone.0293839 -
Micromachines Mar 2024Machining special microstructures on the surface of silicon nitride ceramics helps improve their service performance. However, the high brittleness and low fracture...
Machining special microstructures on the surface of silicon nitride ceramics helps improve their service performance. However, the high brittleness and low fracture toughness of silicon nitride ceramics make it extremely difficult to machine microstructures on their surface. In this study, a femtosecond laser is used to machine parallel grooved microstructures on the surface of silicon nitride ceramics. The effects of the laser polarization angle, laser single pulse energy, scanning line spacing, and laser scan numbers on the surface morphology and geometric characteristics of grooved microstructures are researched. It is found that a greater angle between the direction of the scanning path and laser polarization is helpful to obtain a smoother surface. As the single pulse energy increases, debris and irregular surface structures will emerge. Increasing the laser scan line spacing leads to clearer and more defined parallel grooved microstructures. The groove depth increases with the increase in the scan numbers. However, when a certain number of scans is reached, the depth will not increase further. This study serves as a valuable research foundation for the femtosecond laser processing of silicon nitride ceramic materials.
PubMed: 38542641
DOI: 10.3390/mi15030394 -
Sensors (Basel, Switzerland) Nov 2023Smartwatches equipped with automatic atrial fibrillation (AF) detection through electrocardiogram (ECG) recording are increasingly prevalent. We have recently reported...
Smartwatches equipped with automatic atrial fibrillation (AF) detection through electrocardiogram (ECG) recording are increasingly prevalent. We have recently reported the limitations of the Apple Watch (AW) in correctly diagnosing AF. In this study, we aim to apply a data science approach to a large dataset of smartwatch ECGs in order to deliver an improved algorithm. We included 723 patients (579 patients for algorithm development and 144 patients for validation) who underwent ECG recording with an AW and a 12-lead ECG (21% had AF and 24% had no ECG abnormalities). Similar to the existing algorithm, we first screened for AF by detecting irregularities in ventricular intervals. However, as opposed to the existing algorithm, we included all ECGs (not applying quality or heart rate exclusion criteria) but we excluded ECGs in which we identified regular patterns within the irregular rhythms by screening for interval clusters. This "irregularly irregular" approach resulted in a significant improvement in accuracy compared to the existing AW algorithm (sensitivity of 90% versus 83%, specificity of 92% versus 79%, < 0.01). Identifying regularity within irregular rhythms is an accurate yet inclusive method to detect AF using a smartwatch ECG.
Topics: Humans; Atrial Fibrillation; Electrocardiography; Heart Rate; Algorithms
PubMed: 38005669
DOI: 10.3390/s23229283 -
Reviews on Environmental Health Jun 2024The fifth generation, 5G, for wireless communication is currently deployed in Sweden since 2019/2020, as well as in many other countries. We have previously published... (Review)
Review
The fifth generation, 5G, for wireless communication is currently deployed in Sweden since 2019/2020, as well as in many other countries. We have previously published seven case reports that include a total of 16 persons aged between 4 and 83 years that developed the microwave syndrome within short time after being exposed to 5G base stations close to their dwellings. In all cases high radiofrequency (RF) radiation from 4G/5G was measured with a broadband meter. RF radiation reached >2,500,000 to >3,180,000 μW/m in peak maximum value in three of the studies. In total 41 different health issues were assessed for each person graded 0 (no complaint) to 10 (worst symptoms). Most prevalent and severe were sleeping difficultly (insomnia, waking night time, early wake-up), headache, fatique, irritability, concentration problems, loss of immediate memory, emotional distress, depression tendency, anxiety/panic, dysesthesia (unusual touched based sensations), burning and lancinating skin, cardiovascular symptoms (transitory high or irregular pulse), dyspnea, and pain in muscles and joints. Balance disorder and tinnitus were less prevalent. All these symptoms are included in the microwave syndrome. In most cases the symptoms declined and disappeared within a short time period after the studied persons had moved to a place with no 5G. These case histories are classical examples of provocation studies. They reinforce the urgency to inhibit the deployment of 5G until more safety studies have been performed.
PubMed: 38889394
DOI: 10.1515/reveh-2024-0017 -
Scars, Burns & Healing 2023Hypertrophic scarring is a common and debilitating consequence of burn scars. While there is limited evidence for current treatment options, laser therapy has been shown...
INTRODUCTION
Hypertrophic scarring is a common and debilitating consequence of burn scars. While there is limited evidence for current treatment options, laser therapy has been shown to be effective, low risk and minimally invasive. This study assesses the use of carbon dioxide lasers and intense pulsed light devices in the treatment of hypertrophic burn scars.
METHODS
In this case series, patients were recruited from a hypertrophic burn scar waitlist and completed a Patient and Observer Scar Assessment Scale prior to and six weeks after laser therapy. The Nordlys (intense pulsed light) and CORE (carbon dioxide) systems from Candela Medical were used, with a range of settings used depending on the assessment of the burn scar. The differences between scores were calculated for the total Patient and Observer Scar Assessment Scale score, pain, itch, colour, stiffness, thickness, irregularity and the overall opinion of the scar. Statistical analysis was completed using a paired, two-tailed student T test.
RESULTS
A total of 31 patients were recruited for this trial with a range of scar locations, surface areas and mechanism of burn injury. The calculated difference in mean showed a significant reduction for the overall Patient and Observer Scar Assessment Scale score (1.93, p < 0.0001), pain (1.39, p = 0.0002), itch (1.84, p = 0.0002), colour (1.97, p < 0.0001), stiffness (2.47, p < 0.0001), thickness (2.1, p < 0.0001), irregularity (1.89, p < 0.0001) and overall opinion (1.58, p = 0.0003).
CONCLUSION
Current management options for hypertrophic scarring have limited evidence. Laser therapy presents a minimally invasive procedure that can be completed under topical anaesthetic and has shown to be effective following a single treatment of combined carbon dioxide laser and intense pulsed light device therapy.
LAY SUMMARY
Many people will suffer a burn injury throughout their life and up to almost 3 out of 4 people with burn injuries will suffer from hypertrophic scars (a thickened, red and itchy scar). These scars cause distress both due to their appearance and their reduction of function, particularly over a joint or muscle. Laser therapy, in which different wave lengths of light (pulsed light) or gas (carbon dioxide) target the scar, has been found to be effective and have minimal side effects in the management of hypertrophic scars. While individual lasers have been assessed and found to be effective and low risk, the combined use of multiple lasers on the same scar has not been extensively studied. We studied the effectiveness of both light and gas laser therapies on hypertrophic scars. Patients with hypertrophic scars completed a questionnaire that focused on their perspective of their scar (pain, itch, stiffness, thickness, irregularity, overall opinion) prior to the treatment. The patients then underwent laser therapy (with local anaesthetic gel) with either pulsed light and/or carbon dioxide (gas) laser. The type of laser used was decided by the clinician performing the therapy depending on scar location and thickness. Patients then re-completed the subjective survey six weeks following the laser therapy, and the results compared. We learnt that laser therapy (both light, gas and a combination of both) are effective (and low risk) in reducing the subjective burden of the scar for the patient.
PubMed: 38022893
DOI: 10.1177/20595131231202103 -
IEEE Journal of Translational... 2024Methamphetamine use disorder (MUD) is an illness associated with severe health consequences. Virtual reality (VR) is used to induce the drug-cue reactivity and...
Methamphetamine use disorder (MUD) is an illness associated with severe health consequences. Virtual reality (VR) is used to induce the drug-cue reactivity and significant EEG and ECG abnormalities were found in MUD patients. However, whether a link exists between EEG and ECG abnormalities in patients with MUD during exposure to drug cues remains unknown. This is important from the therapeutic viewpoint because different treatment strategies may be applied when EEG abnormalities and ECG irregularities are complications of MUD. We designed a VR system with drug cues and EEG and ECG were recorded during VR exposure. Sixteen patients with MUD and sixteen healthy subjects were recruited. Statistical tests and Pearson correlation were employed to analyze the EEG and ECG. The results showed that, during VR induction, the patients with MUD but not healthy controls showed significant [Formula: see text] and [Formula: see text] power increases when the stimulus materials were most intense. This finding indicated that the stimuli are indiscriminate to healthy controls but meaningful to patients with MUD. Five heart rate variability (HRV) indexes significantly differed between patients and controls, suggesting abnormalities in the reaction of patient's autonomic nervous system. Importantly, significant relations between EEG and HRV indexes changes were only identified in the controls, but not in MUD patients, signifying a disruption of brain-heart relations in patients. Our findings of stimulus-specific EEG changes and the impaired brain-heart relations in patients with MUD shed light on the understanding of drug-cue reactivity and may be used to design diagnostic and/or therapeutic strategies for MUD.
Topics: Humans; Methamphetamine; Cues; Brain; Heart Rate; Virtual Reality
PubMed: 38059128
DOI: 10.1109/JTEHM.2022.3206333 -
Sensors (Basel, Switzerland) Aug 2023At present, a medium-level microcontroller is capable of performing edge computing and can handle the computation of neural network kernel functions. This makes it...
At present, a medium-level microcontroller is capable of performing edge computing and can handle the computation of neural network kernel functions. This makes it possible to implement a complete end-to-end solution incorporating signal acquisition, digital signal processing, and machine learning for the classification of cardiac arrhythmias on a small wearable device. In this work, we describe the design and implementation of several classifiers for atrial fibrillation detection on a general-purpose ARM Cortex-M4 microcontroller. We used the CMSIS-DSP library, which supports Naïve Bayes and Support Vector Machine classifiers, with different kernel functions. We also developed Python scripts to automatically transfer the Python model (trained in Scikit-learn) to the C environment. To train and evaluate the models, we used part of the data from the PhysioNet/Computing in Cardiology Challenge 2020 and performed simple classification of atrial fibrillation based on heart-rate irregularity. The performance of the classifiers was tested on a general-purpose ARM Cortex-M4 microcontroller (STM32WB55RG). Our study reveals that among the tested classifiers, the SVM classifier with RBF kernel function achieves the highest accuracy of 96.9%, sensitivity of 98.4%, and specificity of 95.8%. The execution time of this classifier was 720 μs per recording. We also discuss the advantages of moving computing tasks to edge devices, including increased power efficiency of the system, improved patient data privacy and security, and reduced overall system operation costs. In addition, we highlight a problem with false-positive detection and unclear significance of device-detected atrial fibrillation.
Topics: Humans; Atrial Fibrillation; Bayes Theorem; Algorithms; Heart Rate; Neural Networks, Computer
PubMed: 37687975
DOI: 10.3390/s23177521 -
Heliyon Mar 2024Heart failure is a cardiovascular disease in which heart fails to pump sufficient blood required by the body. Significant signs of worsening heart failure include...
Heart failure is a cardiovascular disease in which heart fails to pump sufficient blood required by the body. Significant signs of worsening heart failure include decreased thoracic impedance, increased heart rate, irregular electrocardiogram (ECG), and lack of motion activity of the patient. Heart failure can be better managed if monitored continuously and in real-time. The existing solutions for continuous monitoring of these parameters are invasive and hence are not only expensive but can also cause serious health risks. This paper discusses the development of a telehealth system that consists of an Internet of Things including a wearable device connected to a cloud-based database and a mobile application using Wi-Fi. The wearable device is a noninvasive monitor that consists of different sensors embedded with a microcontroller and can be a potential solution for better management of heart failure. It continuously monitors the above-mentioned parameters and sends data to the mobile application using a cloud-based system. The mobile application has separate portals for patients and doctors where doctor can monitor a specific patient enrolled under his profile. The performance of the developed device is validated in 10 healthy individuals.
PubMed: 38439888
DOI: 10.1016/j.heliyon.2024.e26841 -
Journal of the American Medical... Oct 2023Improved health among older women remains elusive and may be linked to limited knowledge of and interventions targeted to population subgroups. Use of structured...
Using Omaha System data to explore relationships between client outcomes, phenotypes, and targeted home intervention approaches: an exemplar examining practice effectiveness for older women with circulation problems.
BACKGROUND
Improved health among older women remains elusive and may be linked to limited knowledge of and interventions targeted to population subgroups. Use of structured community nurse home visit data exploring relationships between client outcomes, phenotypes, and targeted intervention approaches may reveal new understandings of practice effectiveness.
MATERIALS AND METHODS
Omaha System data of 2363 women 65 years and older with circulation problems receiving at least 2 community nurse home visits were accessed. Previously identified phenotypes (Poor circulation; Irregular heart rate; and Limited symptoms), 7 intervention approaches (High-Surveillance; High-Teaching/Guidance/Counseling; Balanced-All; Balanced-Surveillance-Teaching/Guidance/Counseling; Low-Teaching/Guidance/Counseling-Balanced Other; Low-Surveillance-Mostly-Teaching/Guidance/Couseling-TreatmentProcedure-CaseManagement; and Mostly-TreatementProcedure+CaseManagement), and client knowledge, behavior, and status outcomes were used. Client-linked intervention approach counts, proportional use per phenotypes, and associations with client outcome scores were descriptively analyzed. Associations between intervention approach proportional use by phenotype and outcome scores were analyzed using parallel coordinate graph methodology for intervention approach effectiveness.
RESULTS
Percent use of intervention approach differed significantly by phenotype. The 2 most widely employed intervention approaches were characterized by either a high use of surveillance interventions or a balanced use of all intervention categories (surveillance, teaching/guidance/counseling, treatment-procedure, case-management). Mean outcome discharge and change scores significantly differed by intervention approach. Proportionally deployed intervention approach patterns by phenotype were associated with outcome small effects improvement.
DISCUSSIONS AND CONCLUSIONS
The Omaha System taxonomy supported the management and exploration of large multidimensional community nursing data of older women with circulation problems. This study offers a new way to examine intervention effectiveness using phenotype- and targeted intervention approach-informed structured data.
Topics: Humans; Female; Aged; Case Management; Vocabulary, Controlled
PubMed: 37335871
DOI: 10.1093/jamia/ocad106 -
Alternative Therapies in Health and... Jan 2024In China, there have been instances of sudden cardiac death among university students, with a significant number of students being at risk of cardiovascular diseases....
BACKGROUND
In China, there have been instances of sudden cardiac death among university students, with a significant number of students being at risk of cardiovascular diseases. This risk is often attributed to sub-health conditions such as weight gain and obesity, which are triggered by sedentary lifestyles, irregular living habits, and unregulated diets. Therefore, it is crucial to enhance the guidance for participation in physical activities, encouraging students to actively reduce their risk of cardiovascular diseases (CVD). Jogging, characterized by its convenience, simplicity, and low-risk participation, has been widely accepted by university students. This study takes the impact of jogging on the cardiovascular function of university students as a starting point. It aims to explore the content of the changing process suitable for the development of cardiovascular function in university students. The ultimate goal is to promote the healthy development of the cardiovascular system function in university students and improve their adherence to physical activities.
METHODS
The study recruited 60 university students with no exercise habits through on-campus poster advertisements. These 60 participants were randomly divided into two groups. The students in the experimental group were required to jog no less than three times a week, with each session lasting at least 30 minutes. The organizers of the experiment would remind the students daily in a WeChat group to complete their weekly exercise plan and persist in jogging, promoting the benefits of this activity. During jogging, the students used the Keep mobile application to record their jogging time and heart rate, which they then uploaded to the WeChat group. Follow-ups were conducted with students who did not complete their exercise plan, providing encouragement and guidance to continue participating in the experiment. The study employed a comparative research approach between the experimental group and the control group.
RESULTS
According to the experimental protocol, after 12 weeks of jogging intervention, the cardiovascular health indicators of both male and female students in the experimental group showed positive changes. Measurements of cardiac function indicators in the experimental group of boys SPTI, DPTI, ED has decreased, SEVR has increased, the relevant indicators compared with the relevant indicators of the control group (P < .05) is significant; in the experimental group of girls, SPTI, DPTI, SEVR indicators decreased, ED increased, and compared with the relevant indicators of the control group (P < .01) has a very significant significance. Changes in vascular indicators in the experimental and control groups after the experiment, SBP, DBP, PP, CAP decreased in the experimental group, and DBP, CAP in the male and female groups were found to be (P < .01), with highly significant changes; while SBP, PP intergroup comparison (P < .05), with significant changes.
CONCLUSION
Jogging is a good aerobic exercise program characterized by convenient ways of carrying out simple methods and low risk of participation. The benefits of jogging are not only reflected physiologically but also psychologically; it can make participants enhance their self-confidence and make their moods more pleasant. It can also improve sleep quality and maintain a good mental state. Long-term jogging habits can effectively improve endothelial function and heart contraction function, reduce blood pressure effectively prevent atherosclerosis and prevent CVD by reducing the incidence of CVD risk factors.
PubMed: 38290441
DOI: No ID Found