Nervous System Activity Research Articles

Emotion Detection using EEG Signal Analysis

Emotion is a subjective experience-based mental state and emotive response to an event. This feeling is fundamental to everyday human behaviour and communication. Emotion is a psychophysiological process that influences a person's behaviour in a certain setting and is crucial to inter-personal communication. A person's voice, facial expressions, muscles, nervous system activity, and endocrine system activity are all influenced by their emotions. The electroencephalogram (EEG) is one technique for identifying emotions. Furthermore, EEG-based emotion identification has applications in a variety of industries, including marketing, gaming, and e-learning, and it has the potential to improve the intelligence of human-computer interfaces. This project records useful information related to various emotional states by using an EEG sensor to monitor brain waves in realtime. This raw data is transmitted to an ESP8266 micro controller by the EEG sensor. The DF Mini Player and the ESP8266 work together flaw-lessly to playback preset audio files that correlate to the identified emotions. As an Internet of Things device, the ESP8266 allows audio playback information and the detected emotional state to be communicated to the cloud or other devices that are connected. This allows for remote monitor-ing and the initiation of activities based on the user's emotions.

Can HRV Biofeedback Training Improve the Mental Resilience of Icelandic Police Officers?

High heart rate variability (HRV) is increasingly recognized as an indicator of a healthy regulatory system, reflecting the dynamic balance between sympathetic (SNS) and parasympathetic (PSNS) nervous system activity. According to the neurovisceral integration model, this balance is managed by the central autonomic network (CAN), comprised of specific brain regions involved in emotional, attentional, and autonomic regulation. HRV thus reflects the performance of the cognitive, affective, and autonomic regulation system. Numerous studies support the relationship between HRV and the CAN, including research on HRV biofeedback training (HRVBF). Studies on the effectiveness of HRVBF for professions such as police officers have shown improvements in self-regulation, decision-making, and performance. However, few studies have specifically explored HRVBF's influence on HRV metrics in police officers, highlighting a need for further research. This study addresses this gap by randomly assigning 27 Icelandic police officers to intervention or wait-list control groups. The intervention group underwent a five-week HRVBF program, including group and individual training sessions. Results showed significant increases in HRV metrics for the intervention group, indicating improved autonomic function and stress resilience. Mental resilience increased significantly as measured by subjective measures of attentional control, mindful awareness, and reduced fatigue. These findings support the efficacy of HRVBF in enhancing HRV and mental resilience for police officers, suggesting its applicability and potential for integration into existing training programs.

The Effects of a Single Vagus Nerve's Neurodynamics on Heart Rate Variability in Chronic Stress: A Randomized Controlled Trial.

The modulation of the autonomic nervous system's activity, particularly increasing its parasympathetic tone, is of significant interest in clinical physiotherapy due to its potential benefits for stress-related conditions and recovery processes. This study evaluated the effectiveness of the addition of neurodynamics in enhancing parasympathetic activation in subjects with chronic stress. A clinical trial randomly assigned participants to a group with neurodynamics (6 bpm breathing protocol + manual therapy + neurodynamic technique) or a group without neurodynamics (6 bpm breathing protocol + manual therapy only). Metrics of heart rate variability (HRV), including the Mean Heart Rate (Mean HR), standard deviation of intervals between consecutive heartbeats (SDNN), Heart Rate Difference (Diff. HR), Root Mean Square of Successive Differences (RMSSD), number of intervals differing by more than 50 ms (NN50), percentage of consecutive NN intervals that differed by more than 50 ms (pNN50), and the high-frequency component measured in standardized units (HF), were assessed before, during, and after the intervention. During the intervention, the group with neurodynamics showed significant changes in all variables except in the pNN50 and HF while the group without neurodynamics only showed improvements in the Mean HR, SDNN, and RMSSD. In the post-intervention phase, the group with neurodynamics maintained an increase in HRV while the group without neurodynamics experienced a decrease, suggesting an increase in sympathetic activity. Vagal nerve neurodynamics appear to represent an effective method for enhancing parasympathetic activation in patients with chronic stress. The results highlight the importance of a more comprehensive analysis of HRV variables in order to obtain a correct picture of the impact of interventions on the complex and multifaceted functioning of the autonomic nervous system.

Psychosomatics: Communication of the Central Nervous System through Connection to Tissues, Organs, and Cells.

This study aimed to scrutinize existing evidence concerning the link between somatic symptoms and nervous system activity. The goal was to pinpoint areas for effective therapeutic interventions. Psychosomatic disorders, an often overlooked field of medicine, bears significance given the multitude of patients experiencing somatic symptoms due to specific emotions and experiences. The literature was explored using the methods of comparative analysis, synthesis and graphical representation. The study introduced pathological neural networks localized in brain regions such as the prefrontal cortex and hippocampus, leading to maladaptive behaviors and heightened negative focus. Activation of the sympathetic nervous system and the hypothalamus-pituitary-adrenal axis, alongside increased cortisol levels, induces chronic distress, inflammation, and disruptions in neurotransmitter metabolism. The gut microbiota significantly influences psychosomatic reactions. Patients with psychosomatic disorders require complex treatment with cognitive-behavioural therapy and hypnosis methods. Within the framework of pathological neural networks, the MindChat technique has yielded effectiveness with the purpose of "dehypnotization" and destruction of aberrant cognitive and emotional patterns. However, it should be noted that this technique requires further empirical support.

The role of gut microbiota metabolites in the regeneration and protection of nervous tissue: a narrative review

The gut microbiota modulates various physiological functions in the human body, including digestion, immune regulation, gut barrier maintenance, and even nervous system activity. The bidirectional communication between gut microbes and the brain, known as the microbiota–gut–brain axis, is crucial for balanced metabolism. Recent studies have indicated that gut microbiota metabolites, such as short-chain fatty acids, indole derivatives, neurotransmitters, and other bioactive compounds, can positively impact neurogenesis, myelination, and axonal regeneration, suggesting their potential in therapeutic strategies for neuroprotection and neuroregeneration. Despite the growing number of studies on gut microbiota metabolites, understanding their role in neuroprotective mechanisms remains limited. This article reviews the classification, production, functions and therapeutic potential of the most well-known gut microbiota metabolites, as well as their impact on neurogenesis, synaptogenesis, energy metabolism, immune modulation, and blood–brain barrier integrity, which will provide a foundation for the study of gut microbiota metabolites in the field of biomedical engineering.

Evaluation of the responsiveness pattern to caffeine through a smart data-driven ECG non-linear multi-band analysis

This study aimed to explore more efficient ways of administering caffeine to the body by investigating the impact of caffeine on the modulation of the nervous system's activity through the analysis of electrocardiographic signals (ECG). An ECG non-linear multi-band analysis using Discrete Wavelet Transform (DWT) was employed to extract various features from healthy individuals exposed to different caffeine consumption methods: expresso coffee (EC), decaffeinated coffee (ED), Caffeine Oral Films (OF_caffeine), and placebo OF (OF_placebo). Non-linear feature distributions representing every ECG minute time series have been selected by PCA with different variance percentages to serve as inputs for 23 machine learning models in a leave-one-out cross-validation process for analyzing the behavior differences between ED/EC and OF_placebo/OF_caffeine groups, respectively, over time. The study generated 50-point accuracy curves per model, representing the discrimination power between groups throughout the 50 min. The best model accuracies for ED/EC varied between 30 and 70 %, (using the decision tree classifier) and OF_placebo/OF_caffeine ranged from 62 to 84 % (using Fine Gaussian). Notably, caffeine delivery through OFs demonstrated effective capacity compared to its placebo counterpart, as evidenced by significant differences in accuracy curves between OF_placebo/OF_caffeine. Caffeine delivery via OFs also exhibited rapid dissolution efficiency and controlled release rate over time, distinguishing it from EC. The study supports the potential of caffeine delivery through Caffeine OFs as a superior technology compared to traditional methods by means of ECG analysis. It highlights the efficiency of OFs in controlling the release of caffeine and underscores their promise for future caffeine delivery systems.

Effects of Exposure to Electromagnetic Fields (EMFs) on Biological Systems

Electromagnetic Field (EMF) is a natural phenomenon; however, anthropogenic activities have significantly shifted its equilibrium, leading to potential deleterious effects on biological systems. As technology becomes more integrated into daily life, the increased use of electronic devices has contributed to a rise in man-made EMF exposure. This exposure can affect biological systems on physiological and molecular levels, raising concerns about its potential effects on animal development, reproductive systems, and overall ecosystem health. The review explores the physiological effects of exposure to static, extremely low-frequency (ELF), and radiofrequency (RF) fields, analyzing how EMF impacts oxidative stress, reproductive physiology, cardiovascular function, brain and nervous system activity, and DNA/RNA integrity. It also acknowledges the emerging concern of EMF in aquatic environments, where underwater power supplies and extensive underwater cable networks are sources of EMF exposure that may affect marine and freshwater species. The potential effects on marine life include disruptions to migratory patterns, altered reproductive cycles, and changes in aquatic biodiversity. The review acknowledges that research on EMF has improved over time, but significant gaps and information remain. It emphasizes the need for immediate attention to address the challenges and opportunities in this field.

In vitro and in silico investigation of FDA-approved drugs to be repurposed against Alzheimer's disease.

Alzheimer's disease (AD), one of the main causes of dementia, is a neurodegenerative disorder. Cholinesterase inhibitors are used in the treatment of AD, but prolonged use of these drugs can lead to serious side effects. Drug repurposing is an approach that aims to reveal the effectiveness of drugs in different diseases beyond their clinical uses. In this work, we investigated in vitro and in silico inhibitory effects of 11 different drugs on cholinesterases. The results showed that trimebutine, theophylline, and levamisole had the highest acetylcholinesterase inhibitory actions among the tested drugs, and these drugs inhibited by 68.70 ± 0.46, 53.25 ± 3.40, and 44.03 ± 1.20%, respectively at 1000 µM. In addition, these drugs are bound to acetylcholinesterase via competitive manner. Molecular modeling predicted good fitness in acetylcholinesterase active site for these drugs and possible central nervous systemaction for trimebutine. All of these results demonstrated that trimebutine was determined to be the drug with the highest potential for use in AD.

Molecular adaptations underlying high-frequency hearing in the brain of CF bats species

BackgroundThe majority of bat species have developed remarkable echolocation ability, especially for the laryngeally echolocating bats along with high-frequency hearing. Adaptive evolution has been widely detected for the cochleae in the laryngeally echolocating bats, however, limited understanding for the brain which is the central to echolocation signal processing in the auditory perception system, the laryngeally echolocating bats brain may also undergo adaptive changes.ResultIn order to uncover the molecular adaptations related with high-frequency hearing in the brain of laryngeally echolocating bats, the genes expressed in the brain of Rhinolophus ferrumequinum (CF bat) and Myotis pilosus (FM bat) were both detected and also compared. A total of 346,891 genes were detected and the signal transduction mechanisms were annotated by the most abundant genes, followed by the transcription. In hence, there were 3,088 DEGs were found between the two bat brains, with 1,426 highly expressed in the brain of R. ferrumequinum, which were significantly enriched in the neuron and neurodevelopmental processes. Moreover, we found a key candidate hearing gene, ADCY1, playing an important role in the R. ferrumequinum brain and undergoing adaptive evolution in CF bats.ConclusionsOur study provides a new insight to the molecular bases of high-frequency hearing in two laryngeally echolocating bats brain and revealed different nervous system activities during auditory perception in the brain of CF bats.

The Relationship Between Sodium Consumption Patterns, Stress Levels, and Physical Activity with Hypertension of Elderly Participants at UPTD Puskesmas Rantau Tijang, Pugung District, Tanggamus Regency in 2022

A person with hypertension has a rise in blood pressure above the healthy range of <120/<80. The amount of sodium that the body retains can impact blood prduction. Via the sympathetic nervous system's activation, which causes blood pressure to rise intermittently, stress causes hypertension. A sufficient amount of regular exercise significantly lowers blood pressure in hypertensive individuals. Elderly people frequently experience health issues. Many of these illnesses are non-communicable diseases like high blood pressure. The Province of Lampung has a 31,9% prevalence of hypertension. According to data on hypertension in the Tanggamus district, 120,276 persons have the condition. The research objective was to determine the correlation between sodium consumption patterns, stress levels, and physical activity with hypertension in prolanis participants at the Rantau Tijang Public Health Center, Tanggamus Regency in 2022. This study used quantitative research using a cross-sectional research design. The population in this study were 63 people using the total sampling technique. Bivariate analysis in this study uses the Gamma test. The results showed a significant correlation between the level of stress and physical activity and hypertension with a p-value of 0,001 and 0,003 and no significant correlation between sodium consumption and hypertension with a p-value of 0,746.

Gross Motor Skills in Early Grade Students: A Bibliometric Study

Gross motor skills refer to fundamental motor skills such as running, walking, crawling, jumping and catching. This domain requires adequate coordination of muscular, skeletal and nervous system activity. The objective was to perform a bibliometric analysis of the literature indexed in Scopus on gross motor skills in students of the initial level, between 2003 and 2023. Methodologically, it was a quantitative bibliometric study. The scientific production indicators were generated from 498 documents selected from Scopus using keywords in English ("gossip", "motor", "skills", "childhood"). From 2016 to 2022, published papers increased (66.1%), indicating a growing interest in the subject of study. The United States is the country with the most scientific production (21.3%; n=157), and the University of Wollongong in Australia, has the most publications (n=21). The International Journal of Environmental Research and Public Health published 24 papers, while the most cited was Developmental Medicine and Child Neurology with 707 citations, with author Goodway, J.D. (n=10 papers) being the most cited (n=682). From the studies analyzed, it is concluded that the early stages of a child's life are vital for the growth of gross motor skills, which in turn fosters the acquisition of knowledge, independence and confidence. Consequently, early learners can benefit from physical activity, as it helps them refine their motor skills by giving them the opportunity to work on balance, control and coordination.

Physiology and emotions: Within individual associations during caregiver-adolescent conflict.

Concordance between physiological and emotional responses is central to models of emotion and has been shown to correspond to effective responses and well-being in adults. A deeper understanding of physiological-emotional concordance during ecologically relevant scenarios is essential to then determine if these associations predict mental health problems or can serve as a helpful biomarker of risk or resilience in adults and youth. The present study assessed the minute-to-minute associations between sympathetic (i.e., skin conductance level [SCL]) and parasympathetic (i.e., respiratory sinus arrhythmia [RSA]) nervous system activity and self-reported emotions, assessed via video-mediated recall procedures, during a parent-adolescent conflict discussion task. Associations between emotion ratings and physiological activity were assessed in adolescents (N = 97; ages 10-15) and their adult caregivers (N = 97). Utilizing a multilevel modeling approach, findings demonstrated a significant positive association between SCL and emotion ratings for youth, suggesting that increased engagement and alertness contributed to more positive emotion. RSA was unrelated to emotion ratings. The presence of significant variability in associations indicated the presence of potential moderators. This could include clinically relevant processes (e.g., emotion regulation, relationship quality, and mental health). Future research should continue to build on findings to determine if, when, and for whom, physiological-emotional concordance occurs, and whether the degree of concordance predicts risk for mental and physical health problems.

A bimembrane neuron for computational neuroscience

A biological neuron has endomembrane and extracellular membrane, and its capacitive effect can be described in an equiavlent neural circuit composed of two capacitors. In this paper, a smooth nonlinear resistor with cubic term for the current-voltage (i-v) is introduced into a nonlinear circuit connected with two capacitors and one inductor. The characteristic of field energy is analyzed and unknown parameters are identified with adaptive law. Furthermore, a magnetic flux-controlled memristor (MFCM) is connected to this circuit to estimate its memristive effect on dynamics and energy flow. After scale transformation, the two kinds of nonlinear circuits are replaced by equivalent neuron models, which can present similar spiking, bursting patterns as those presented in biological neurons. Energy function is obtained in theoretical way for discerning the relation between mode selection and energy level. Noisy disturbance is applied to induce coherence resonance, and the involvement of memristive current can induce coherence resonance with lower noise intensity. The results confirmed that energy flow can be controlled to regulate the electric activities in neurons, and higher energy level is obtained in periodic patterns of neuron under coherence resonance. This neural circuit and the memristive model are more suitable for identifying the neural activities in nervous system composed of biological neurons.

The neuroscience of cancer.

The nervous system regulates tissue stem and precursor populations throughout life. Parallel to roles in development, the nervous system is emerging as a critical regulator of cancer, from oncogenesis to malignant growth and metastatic spread. Various preclinical models in a range of malignancies have demonstrated that nervous system activity can control cancer initiation and powerfully influence cancer progression and metastasis. Just as the nervous system can regulate cancer progression, cancer also remodels and hijacks nervous system structure and function. Interactions between the nervous system and cancer occur both in the local tumour microenvironment and systemically. Neurons and glial cells communicate directly with malignant cells in the tumour microenvironment through paracrine factors and, in some cases, through neuron-to-cancer cell synapses. Additionally, indirect interactions occur at a distance through circulating signals and through influences on immune cell trafficking and function. Such cross-talk among the nervous system, immune system and cancer-both systemically and in the local tumour microenvironment-regulates pro-tumour inflammation and anti-cancer immunity. Elucidating the neuroscience of cancer, which calls for interdisciplinary collaboration among the fields of neuroscience, developmental biology, immunology and cancer biology, may advance effective therapies for many of the most difficult to treat malignancies.

Myricetin improves pathological changes in 3×Tg-AD mice by regulating the mitochondria-NLRP3 inflammasome-microglia channel by targeting P38 MAPK signaling pathway

BackgroundAlzheimer's disease (AD) represents the common neurodegenerative disease featured by the manifestations of cognitive impairment and memory loss. AD could be alleviated with medication and improving quality of life. Clinical treatment of AD is mainly aimed at improving the cognitive function of patients. Donepezil, memantine and galantamine are commonly used drug. But they could only relieve AD, not cure it. Therefore, new treatment strategies focusing on AD pathogenesis are of great significance and value. Myricetin (Myr) is a natural flavonoid extracted from Myrica rubra. And it shows different bioactivities, such as anti-inflammation, antioxidation as well as central nervous system (CNS) activities. Nonetheless, its associated mechanism in treating AD remains unknown. PurposeHere we focused on investigating Myr's effect on treating AD and exploring if its protection on the nervous system activity was associated with specifically inhibiting P38 MAPK signaling pathway while regulating mitochondria-NLRP3 inflammasome-microglia. Study design and methodsThis work utilized triple transgenic mice (3 × Tg-AD) as AD models and Aβ25–35 was used to induce BV2 cells to build an in vitro AD model. Behavioristics, pathology and related inflammatory factors were examined. Molecular mechanisms are investigated by western-blot, immunofluorescence staining, CETSA, molecular docking, network pharmacology. ResultsAccording to our findings, Myr could remarkably improve memory loss, spatial learning ability, Aβ plaque deposition, neuronal and synaptic damage in 3 × Tg-AD mice through specifically inhibiting P38 MAPK pathway activation while restraining microglial hyperactivation. Furthermore, Myr promoted the transformation of microglial phenotype, restored the mitochondrial fission-fusion balance, facilitated mitochondrial biogenesis, and restrained NLRP3 inflammasome activation and neuroinflammation. For the in-vitro experiments, P38 agonist dehydrocorydaline (DHC) was utilized to confirm the key regulatory role of P38 MAPK signaling pathway on the mitochondria-NLRP3 inflammasome-microglia channel. ConclusionsOur results revealed the therapeutic efficacy of Myr in experimental AD, and implied that the associated mechanism is possibly associated with inhibiting tmitochondrial dysfunction, activating NLRP3 inflammasome, and neuroinflammation which was mediated by P38 MAPK pathway. Myr is the drug candidate in AD therapy via targeting P38 MAPK pathway.

The Relationship between Sleep Duration and Metabolic Syndrome Severity Scores in Emerging Adults.

Research suggests sleep duration can influence metabolic systems including glucose homeostasis, blood pressure, hormone regulation, nervous system activity, and total energy expenditure (TEE), all of which are related to cardiometabolic disease risk, even in young adults. The purpose of this study was to examine the relationship between sleep duration and metabolic syndrome severity scores (MSSS) in a sample of emerging adults (18-24 y/o). Data were collected between 2012 and 2021 from the College Health and Nutrition Assessment Survey, an ongoing, cross-sectional study conducted at a midsized northeastern university. Anthropometric, biochemical, and clinical measures were obtained following an overnight fast and used to assess the prevalence of metabolic syndrome (MetS). MetS severity scores (MSSS) were calculated using race- and sex-specific formulas. Sleep duration was calculated from the difference in self-reported bedtime and wake time acquired through an online survey. ANCOVA was used to examine the relationship between sleep duration and MetS severity score while adjusting for covariates (age, sex, BMI, physical activity level, smoking status, alcohol consumption, and academic major). In the final sample (n = 3816), MetS (≥3 criteria) was present in 3.3% of students, while 15.4% of students presented with ≥2 MetS criteria. Mean MSSS was -0.65 ± 0.56, and the reported sleep duration was 8.2 ± 1.3 h/day. MSSS was higher among low sleepers (<7 h/day) and long sleepers (>9 h/day) compared to the reference sleepers (7-8 h/day) (-0.61 ± 0.02 and -0.63 ± 0.01 vs. -0.7 ± 0.02, respectively, p < 0.01). Our findings suggest short (<7 h/day) and long (>9 h/day) sleep durations raise the risk of MetS in a sample of emerging adults. Further research is needed to elucidate the impact of improving sleep habits on future disease risk.

Skin-Interfaced Superhydrophobic Insensible Sweat Sensors for Evaluating Body Thermoregulation and Skin Barrier Functions.

Monitoring sweat rate is vital for estimating sweat loss and accurately measuring biomarkers of interest. Although various optical or electrical sensors have been developed to monitor the sensible sweat rate, the quantification of the insensible sweat rate that is directly related to body thermoregulation and skin barrier functions still remains a challenge. This work introduces a superhydrophobic sweat sensor based on a polyacrylate sodium/MXene composite sandwiched between two superhydrophobic textile layers to continuously measure sweat vapor from insensible sweat with high sensitivity and rapid response. The superhydrophobic textile on a holey thin substrate with reduced stiffness and excellent breathability allows the permeation of sweat vapor, while preventing the sensor from being affected by the external water droplets and internal sensible sweat. Integrating the insensible sweat sensor with a flexible wireless communication and powering module further yields a standalone sensing system to continuously monitor insensible sweat rates at different body locations for diverse application scenarios. Proof-of-concept demonstrations on human subjects showcase the feasibility to continuously evaluate the body's thermoregulation and skin barrier functions for the assessment of thermal comfort, disease conditions, and nervous system activity. The results presented in this work also provide a low-cost device platform to detect other health-relevant biomarkers in the sweat (vapor) as the next-generation sweat sensor for smart healthcare and personalized medicine.

Three nervous system-specific expressed genes are potential biomarkers for the diagnosis of sporadic amyotrophic lateral sclerosis through a bioinformatic analysis

BackgroundAmyotrophic lateral sclerosis (ALS) is the most common neurodegenerative disease in adults. However, ALS, especially sporadic ALS (sALS), is difficult to diagnose due to the lack of biomarkers.ResultsWe used the bioinformatics technology to find the potential biomarker and we found that two hundred seventy-four DEGs were identified and enrichment analysis showed DEGs were involved in nervous system activity, like axon_guidance and the neurotrophin_signaling_pathway. Five nervous system-specific expressed hub genes were further validated by three GEO datasets. APP, LRRK2, and PSEN1 might be potential diagnostic and prognostic biomarkers of sALS, and NEAT1-miR-373-3p/miR-302c-3p/miR-372-3p-APP, circ_0000002-miR-302d-3p/miR-373-3p-APP and XIST-miR-9-5p/miR-30e-5p/miR-671-5p might be potential ceRNA regulatory pathways. APP SNP analysis showed subjects harboring the minor G allele of rs463946, minor G allele of rs466433 and minor C allele of rs364048 had an increased risk of sALS development.ConclusionsOur results identified three nervous system-specific expressed hub genes that might be diagnostic and prognostic markers of sALS and APP might be a genetic susceptibility factor contributing to sALS development.

The time has come to stop using the audible pop caused by thrust manipulation as a criterion of success

High velocity, small amplitude thrust manipulation has been shown to beneficial and is indicated to reduce pain, improve joint mobility, and reduce disability. Thrust manipulation of the spine often results in a popping sensation. The exact mechanism responsible for the audible pop remains elusive. Current clinical guidelines indicate that clinicians should use research evidence to guide clinical decision making. The effects and/or benefit of the audible pop during spinal manipulation has been the subject(s) of several previous studies. Such studies evaluated and failed to demonstrate any direct effect of an audible pop’s presence on the subjective reported pain levels, improvement in joint mobility, a change in nervous system activity, and a change in patient perceived disability. Based on current evidence, it seems abundantly clear that the audible pop cannot be used as a criterion (by clinicians and researchers) to determine if the spinal thrust manipulation was successful. Despite the current evidence, the research community continues to ignore this and uses the audible pop as a standard for the success of a spinal thrust manipulation. Additionally, the thrust manipulation will be repeated a second time if no audible pop is obtained or switching to the opposite spinal segment and attempted twice to achieve the audible pop. This potentially results into multiple capsular stretch maneuvers and makes comparison post intervention unreliable. The audible pop is not correlated to therapeutical success; stop using it for that.

Apnea detection from photoplethysmography signal using dicrotic notch

Abstract Photoplethysmography signal (PPG) provides information about the cardiovascular, respiratory, or nervous system activity. Recent studies proposed methods of apnea identification from PPG using amplitude or baseline modulation, or area under the curve. We hypothesized that analysis of the dicrotic notch could improve the sensitivity and specificity of apnea detection. We applied four methods to detect apnea from PPG records experimentally obtained from 10 volunteers, where each volunteer simulated three apneic pauses. We adopted the Area under the PPG and Pulse wave amplitude parameters, and we proposed the Dicrotic notch area parameter. For the methods, we determined the delay in apnea detection and the sensitivity and specificity of apnea detection. The average delay in detecting an apneic pause from the PPG using the Dicrotic notch area was 6.1 s. Combining the parameters of the Area under the PPG with the Dicrotic notch area increased the specificity of apnea detection from 73.8% to 80.0%, although sensitivity decreased from 91.1% to 85.6%. The newly proposed parameter Dicrotic notch area showed its potential for automatic apnea detection.