45 research outputs found
The 2023 wearable photoplethysmography roadmap
Photoplethysmography is a key sensing technology which is used in wearable devices such as smartwatches and fitness trackers. Currently, photoplethysmography sensors are used to monitor physiological parameters including heart rate and heart rhythm, and to track activities like sleep and exercise. Yet, wearable photoplethysmography has potential to provide much more information on health and wellbeing, which could inform clinical decision making. This Roadmap outlines directions for research and development to realise the full potential of wearable photoplethysmography. Experts discuss key topics within the areas of sensor design, signal processing, clinical applications, and research directions. Their perspectives provide valuable guidance to researchers developing wearable photoplethysmography technology
Optical Fiber Interferometric Sensors
The contributions presented in this book series portray the advances of the research in the field of interferometric photonic technology and its novel applications. The wide scope explored by the range of different contributions intends to provide a synopsis of the current research trends and the state of the art in this field, covering recent technological improvements, new production methodologies and emerging applications, for researchers coming from different fields of science and industry. The manuscripts published in the Special issue, and re-printed in this book series, report on topics that range from interferometric sensors for thickness and dynamic displacement measurement, up to pulse wave and spirometry applications
Recent Trends in Computational Research on Diseases
Recent advances in information technology have brought forth a paradigm shift in science, especially in the biology and medical fields. Statistical methodologies based on high-performance computing and big data analysis are now indispensable for the qualitative and quantitative understanding of experimental results. In fact, the last few decades have witnessed drastic improvements in high-throughput experiments in health science, for example, mass spectrometry, DNA microarray, next generation sequencing, etc. Those methods have been providing massive data involving four major branches of omics (genomics, transcriptomics, proteomics, and metabolomics). Information about amino acid sequences, protein structures, and molecular structures are fundamental data for the prediction of bioactivity of chemical compounds when screening drugs. On the other hand, cell imaging, clinical imaging, and personal healthcare devices are also providing important data concerning the human body and disease. In parallel, various methods of mathematical modelling such as machine learning have developed rapidly. All of these types of data can be utilized in computational approaches to understand disease mechanisms, diagnosis, prognosis, drug discovery, drug repositioning, disease biomarkers, driver mutations, copy number variations, disease pathways, and much more. In this Special Issue, we have published 8 excellent papers dedicated to a variety of computational problems in the biomedical field from the genomic level to the whole-person physiological level
Intelligent Biosignal Processing in Wearable and Implantable Sensors
This reprint provides a collection of papers illustrating the state-of-the-art of smart processing of data coming from wearable, implantable or portable sensors. Each paper presents the design, databases used, methodological background, obtained results, and their interpretation for biomedical applications. Revealing examples are brain–machine interfaces for medical rehabilitation, the evaluation of sympathetic nerve activity, a novel automated diagnostic tool based on ECG data to diagnose COVID-19, machine learning-based hypertension risk assessment by means of photoplethysmography and electrocardiography signals, Parkinsonian gait assessment using machine learning tools, thorough analysis of compressive sensing of ECG signals, development of a nanotechnology application for decoding vagus-nerve activity, detection of liver dysfunction using a wearable electronic nose system, prosthetic hand control using surface electromyography, epileptic seizure detection using a CNN, and premature ventricular contraction detection using deep metric learning. Thus, this reprint presents significant clinical applications as well as valuable new research issues, providing current illustrations of this new field of research by addressing the promises, challenges, and hurdles associated with the synergy of biosignal processing and AI through 16 different pertinent studies. Covering a wide range of research and application areas, this book is an excellent resource for researchers, physicians, academics, and PhD or master students working on (bio)signal and image processing, AI, biomaterials, biomechanics, and biotechnology with applications in medicine
XXII International Conference on Mechanics in Medicine and Biology - Abstracts Book
This book contain the abstracts presented the XXII ICMMB, held in Bologna in September 2022. The abstracts are divided following the sessions scheduled during the conference
Infrared Thermography for the Assessment of Lumbar Sympathetic Blocks in Patients with Complex Regional Pain Syndrome
[ES] El síndrome de dolor regional complejo (SDRC) es un trastorno de dolor crónico debilitante que suele afectar a una extremidad, y se caracteriza por su compleja e incomprendida fisiopatología subyacente, lo que supone un reto para su diagnóstico y tratamiento. Para evitar el deterioro de la calidad de vida de los pacientes, la consecución de un diagnóstico y tratamiento tempranos marca un punto de inflexión. Entre los diferentes tratamientos, los bloqueos simpáticos lumbares (BSLs) tienen como objetivo aliviar el dolor y reducir algunos signos simpáticos de la afección. Este procedimiento intervencionista se lleva a cabo inyectando anestesia local alrededor de los ganglios simpáticos y, hasta ahora, se realiza frecuentemente bajo el control de diferentes técnicas de imagen, como los ultrasonidos o la fluoroscopia. Dado que la termografía infrarroja (TIR) ha demostrado ser una herramienta eficaz para evaluar la temperatura de la piel, y teniendo en cuenta el efecto vasodilatador que presentan los anestésicos locales inyectados, se ha considerado el uso de la IRT para la evaluación de los BSLs.
El objetivo de esta tesis es, estudiar la capacidad de la TIR como una técnica complementaria para la evaluación de la eficacia en la ejecución de los BSLs. Para cumplir este objetivo, se han realizado tres estudios implementando la TIR en pacientes diagnosticados de SDRC de miembros inferiores sometidos a BSLs.
El primer estudio se centra en la viabilidad de la TIR como herramienta complementaria para la evaluación de la eficacia ejecución de los BSLs. Cuando se realizan los BSLs, la colocación correcta de la aguja es crítica para llevar realizar el procedimiento técnicamente correcto y, en consecuencia, para lograr los resultados clínicos deseados. Para verificar la posición de la aguja, tradicionalmente se han utilizado técnicas de imagen, sin embargo, los BSLs bajo control fluoroscópico no siempre aseguran su exacta ejecución. Por este motivo, se han aprovechado las alteraciones térmicas inducidas por los anestésicos locales y se han evaluado mediante la TIR. Así, cuando en las imágenes infrarrojas se observaron cambios térmicos en la planta del pie afectado tras la inyección de lidocaína, se consideró que el BSL era exitoso.
El segundo estudio trata del análisis cuantitativo de los datos térmicos recogidos en el entorno clínico a partir de diferentes parámetros basados en las temperaturas extraídas de ambos pies. Según los resultados, para predecir adecuadamente los BSLs exitosos, se deberían analizar las temperaturas de las plantas de los pies durante los primeros cuatro minutos tras la inyección del anestésico local. Así, la aplicación de la TIR en el entorno clínico podría ser de gran ayuda para evaluar la eficacia de ejecución de los BSLs mediante la evaluación de las temperaturas de los pies en tiempo real.
Por último, el tercer estudio aborda el análisis cuantitativo mediante la implementación de herramientas de machine learning (ML) para evaluar su capacidad de clasificar automáticamente los BSLs. En este estudio se han utilizado una serie de características térmicas extraídas de las imágenes infrarrojas para evaluar cuatro algoritmos de ML para tres momentos diferentes después del instante de referencia (inyección de lidocaína). Los resultados indican que los cuatro modelos evaluados presentan buenos rendimientos para clasificar automáticamente los BSLs entre exitosos y fallidos. Por lo tanto, la combinación de parámetros térmicos junto con de clasificación ML muestra ser eficaz para la clasificación automática de los procedimientos de BSLs.
En conclusión, el uso de la TIR como técnica complementaria en la práctica clínica diaria para la evaluación de los BSLs ha demostrado ser totalmente eficaz. Dado que es un método objetivo y relativamente sencillo de implementar, puede permitir que los médicos especialistas en dolor identifiquen los bloqueos realizados fallidos y, en consecuencia, puedan revertir esta situación.[CA] La síndrome de dolor regional complex (SDRC) és un trastorn de dolor crònic debilitant que sol afectar una extremitat, i es caracteritza per la seua complexa i incompresa fisiopatologia subjacent, la qual cosa suposa un repte per al seu diagnòstic i tractament. Per a evitar la deterioració de la qualitat de vida dels pacients, la consecució d'un diagnòstic i tractament primerencs marca un punt d'inflexió. Entre els diferents tractaments , els bloquejos simpàtics lumbars (BSLs) tenen com a objectiu alleujar el dolor i reduir alguns signes simpàtics de l'afecció. Aquest procediment intervencionista es duu a terme injectant anestèsia local al voltant dels ganglis simpàtics i, fins ara, es realitza freqüentment sota el control de diferents tècniques d'imatge, com els ultrasons o la fluoroscopia. Atés que la termografia infraroja (TIR) ha demostrat ser una eina eficaç per a avaluar la temperatura de la pell, i tenint en compte l'efecte vasodilatador que presenten els anestèsics locals injectats, s'ha considerat l'ús de la TIR per a l'avaluació dels BSLs.
L'objectiu d'aquesta tesi és, estudiar la capacitat de la TIR com una tècnica complementària per a l'avaluació de l'eficàcia en l'execució dels BSLs. Per a complir aquest objectiu, s'han realitzat tres estudis implementant la TIR en pacients diagnosticats de SDRC de membres inferiors sotmesos a BSLs.
El primer estudi avalua la viabilitat de la TIR com a eina complementària per a l'analisi de l'eficàcia en l'execució dels BSLs. Quan es realitzen els BSLs, la col·locació correcta de l'agulla és crítica per a dur a terme el procediment tècnicament correcte i, en conseqüència, per a aconseguir els resultats clínics desitjats. Per a verificar la posició de l'agulla, tradicionalment s'han utilitzat tècniques d'imatge, no obstant això, els BSLs baix control fluoroscòpic no sempre asseguren la seua exacta execució. Per aquest motiu, s'han aprofitat les alteracions tèrmiques induïdes pels anestèsics locals i s'han avaluat mitjançant la TIR. Així, quan en les imatges infraroges es van observar canvis tèrmics en la planta del peu afectat després de la injecció de lidocaIna, es va considerar que el BSL era exitós.
El segon estudi tracta de l'anàlisi quantitativa de les dades tèrmiques recollides en l'entorn clínic a partir de diferents paràmetres basats en les temperatures extretes d'ambdós peus. Segons els resultats, per a predir adequadament l'execució exitosa d'un BSL, s'haurien d'analitzar les temperatures de les plantes dels peus durant els primers quatre minuts després de la injecció de l'anestèsic local. Així, l'implementació de la TIR en l'entorn clínic podria ser de gran ajuda per a avaluar l'eficàcia d'execució dels BSLs mitjançant l'avaluació de les temperatures dels peus en temps real.
El tercer estudi aborda l'anàlisi quantitativa mitjançant la implementació d'eines machine learning (ML) per a avaluar la seua capacitat de classificar automàticament els BSLs. En aquest estudi s'han utilitzat una sèrie de característiques tèrmiques extretes de les imatges infraroges per a avaluar quatre algorismes de ML per a tres moments diferents després de l'instant de referència (injecció de lidocaïna). Els resultats indiquen que els quatre models avaluats presenten bons rendiments per a classificar automàticament els BSLs en exitosos i fallits. Per tant, la combinació de paràmetres tèrmics juntament amb models de classificació ML mostra ser eficaç per a la classificació automàtica dels procediments de BSLs.
En conclusió, l'ús de la TIR com a tècnica complementària en la pràctica clínica diària per a l'avaluació dels BSLs ha demostrat ser totalment eficaç. Atés que és un mètode objectiu i relativament senzill d'implementar, pot ajudar els metges especialistes en dolor a identificar els bloquejos realitzats fallits i, en conseqüència, puguen revertir aquesta situació.[EN] Complex regional pain syndrome (CRPS) is a debilitating chronic pain condition that usually affects one limb, and it is characterized by its misunderstood underlying pathophysiology, resulting in both challenging diagnosis and treatment. To avoid the patients' impairment quality of life, the achievement of both an early diagnosis and treatment marks a turning point. Among the different treatment approaches, lumbar sympathetic blocks (LSBs) are addressed to alleviate the pain and reduce some sympathetic signs of the condition. This interventional procedure is performed by injecting local anaesthetic around the sympathetic ganglia and, until now, it has been performed under different imaging techniques, including the ultrasound or the fluoroscopy approaches. Since infrared thermography (IRT) has proven to be a powerful tool to evaluate skin temperatures and taking into account the vasodilatory effects of the local anaesthetics injected in the LSB, the use of IRT has been considered for the LSBs assessment.
Therefore, the purpose of this thesis is to evaluate the capability of IRT as a complementary assessment technique for the LSBs procedures performance. To fulfil this aim, three studies have been conducted implementing the IRT in patients diagnosed with lower limbs CRPS undergoing LSBs.
The first study focuses on the feasibility of IRT as a complementary assessment tool for LSBs performance, that is, for the confirmation of the proper needle position. When LSBs are performed, the correct needle placement is critical to carry out the procedure technically correct and, consequently, to achieve the desired clinical outcomes. To verify the needle placement position, imaging techniques have traditionally been used, however, LSBs under radioscopic guidance do not always ensure an exact performance. For this reason, the thermal alterations induced by the local anaesthetics, have been exploited and assessed by means of IRT. Thus, the LSB procedure was considered successfully performed when thermal changes within the affected plantar foot were observed in the infrared images after the lidocaine injection.
The second study deals with the quantitative analysis of the thermal data collected in the clinical setting through the evaluation of different temperature-based parameters extracted from both feet. According to the results, the proper LSB success prediction could be achieved in the first four minutes after the block through the evaluation of the feet skin temperatures. Therefore, the implementation of IRT in the clinical setting might be of great help in assessing the LSBs performance by evaluating the plantar feet temperatures in real time.
Finally, the third study addresses the quantitative analysis by implementing machine learning (ML) tools to assess their capability to automatically classify LSBs. In this study, a set of thermal features retrieved from the infrared images have been used to evaluate four ML algorithms for three different moments after the baseline time (lidocaine injection). The results indicate that all four models evaluated present good performance metrics to automatically classify LSBs into successful and failed. Therefore, combining infrared features with ML classification models shows to be effective for the LSBs procedures automatic classification.
In conclusion, the use of IRT as a complementary technique in daily clinical practice for LSBs assessment has been evidenced entirely effective. Since IRT is an objective method and it is not very demanding to perform, it is of great help for pain physicians to identify failed procedures, and consequently, it allow them to reverse this situation.Cañada Soriano, M. (2022). Infrared Thermography for the Assessment of Lumbar Sympathetic Blocks in Patients with Complex Regional Pain Syndrome [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/181699TESI
Characterization and processing of novel neck photoplethysmography signals for cardiorespiratory monitoring
Epilepsy is a neurological disorder causing serious brain seizures that severely affect the patients' quality of life. Sudden unexpected death in epilepsy (SUDEP), for which no evident decease reason is found after post-mortem examination, is a common cause of mortality. The mechanisms leading to SUDEP are uncertain, but, centrally mediated apneic respiratory dysfunction, inducing dangerous hypoxemia, plays a key role. Continuous physiological monitoring appears as the only reliable solution for SUDEP prevention. However, current seizure-detection systems do not show enough sensitivity and present a high number of intolerable false alarms. A wearable system capable of measuring several physiological signals from the same body location, could efficiently overcome these limitations. In this framework, a neck wearable apnea detection device (WADD), sensing airflow through tracheal sounds, was designed. Despite the promising performance, it is still necessary to integrate an oximeter sensor into the system, to measure oxygen saturation in blood (SpO2) from neck photoplethysmography (PPG) signals, and hence, support the apnea detection decision.
The neck is a novel PPG measurement site that has not yet been thoroughly explored, due to numerous challenges. This research work aims to characterize neck PPG signals, in order to fully exploit this alternative pulse oximetry location, for precise cardiorespiratory biomarkers monitoring.
In this thesis, neck PPG signals were recorded, for the first time in literature, in a series of experiments under different artifacts and respiratory conditions. Morphological and spectral characteristics were analyzed in order to identify potential singularities of the signals. The most common neck PPG artifacts critically corrupting the signal quality, and other breathing states of interest, were thoroughly characterized in terms of the most discriminative features. An algorithm was further developed to differentiate artifacts from clean PPG signals. Both, the proposed characterization and classification model can be useful tools for researchers to denoise neck PPG signals and exploit them in a variety of clinical contexts. In addition to that, it was demonstrated that the neck also offered the possibility, unlike other body parts, to extract the Jugular Venous Pulse (JVP) non-invasively.
Overall, the thesis showed how the neck could be an optimum location for multi-modal monitoring in the context of diseases affecting respiration, since it not only allows the sensing of airflow related signals, but also, the breathing frequency component of the PPG appeared more prominent than in the standard finger location. In this context, this property enabled the extraction of relevant features to develop a promising algorithm for apnea detection in near-real time.
These findings could be of great importance for SUDEP prevention, facilitating the investigation of the mechanisms and risk factors associated to it, and ultimately reduce epilepsy mortality.Open Acces
Impact of arterial stiffness on white matter microstructure in the elderly
La rigidité artérielle fait référence à la perte d'élasticité principalement dans les grandes artères telles que l'aorte et les carotides. On sait que la rigidité artérielle chroniquement élevée contribue à des modifications vasculaires cérébrales telles que des lésions parenchymateuses de la substance blanche cérébrale via une modification du flux sanguin cérébral. En particulier, parmi les structures perfusées par les artérioles fournies par les artères cérébrales antérieure et moyenne, le corps calleux, la capsule interne, la corona radiata et le faisceau longitudinal supérieur sont les plus vulnérables à l’hypoperfusion. Des études antérieures ont montré que l'augmentation de la rigidité artérielle évaluée par la vitesse de l'onde de pouls carotide-fémorale (cfPWV) est associée à une diminution de l'anisotropie fractionnelle (FA) et à une augmentation de la diffusivité radiale (RD). On a émis l'hypothèse que les altérations au niveau des régions vulnérables de la substance blanche (par exemple, le corps calleux, la capsule interne) seraient probablement liées à la démyélinisation axonale. Cependant, bien que la RD a auparavant été corrélée avec la démyélinisation axonale, l'imagerie de diffusion est principalement aveugle à la myéline. En revanche, l'imagerie par transfert de magnétisation (MT) est une métrique adaptée pour estimer la fraction volumique de myéline. De plus, malgré leur sensibilité à l'organisation des fibres axonales, les métriques de tenseur de diffusion (DTI) telles que les FA et RD manquent de spécificité pour la microstructure tissulaire individuelle. Des modèles microstructuraux plus avancés tels que l’imagerie dispersion et de l'orientation des neurites (NODDI) fournissent des outils pour disséquer les changements microstructuraux derrière les mesures DTI.
Dans l'article 1, nous avons utilisé les métriques de DTI et basé sur le MT pour examiner de plus près l'interaction entre la rigidité artérielle et la microstructure de la substance blanche chez les personnes âgées de plus de 65 ans. Nous avons constaté que la mesure de référence absolue de la rigidité artérielle, la mesure de la vitesse de l'onde de pouls entre l’artère fémorale et carotidienne (cfPWV) était associée à l'organisation axonale des fibres telle que reflétée par FA et RD plutôt qu'à la démyélinisation dans les régions de la substance blanche qui ont été précédemment désignées comme vulnérables à rigidité artérielle. Dans notre deuxième article, nous avons utilisé le modèle NODDI pour approfondir la relation entre le cfPWV et l'organisation axonale. Nos résultats ont montré que la cfPWV est positivement associée à la diffusion extracellulaire de l'eau (ISOVF), ce qui signifie que la rigidité artérielle peut entraîner une dispersion axonale, diminuant la contrainte de directionnalité de l'eau le long des axones. En outre, nous avons constaté que la rigidité artérielle est associée à une augmentation de la densité des fibres dans le corps calleux tel que mesuré par l’ICVF, ce qui pourrait suggérer que les personnes à risque plus élevé de déclin cognitif présentent des mécanismes compensatoires précoces avant l'apparition de signes cliniques de déclin cognitif.
Compte tenu de la forte interaction entre la rigidité artérielle et le déclin à la fois de la structure du cerveau et des fonctions cérébrales, on peut envisager un avenir meilleur où la rigidité artérielle sera mesurée dans la pratique clinique de routine afin d'identifier les personnes à risque plus élevé d’altérations de la substance blanche et de déclin cognitif. Ces personnes pourraient bénéficier de programmes multi-interventionnels visant à préserver la structure et la fonction cérébrale. Un seuil de rigidité artérielle est donc nécessaire pour identifier ces individus. L'article 3 présente la première estimation d'une valeur seuil de cfPWV à laquelle la rigidité artérielle affecte la microstructure de la substance blanche chez les personnes âgées. Nos résultats suggèrent que le seuil actuel de 10 m / s de cfPWV adopté par la Société européenne d'hypertension n'est peut-être pas le seuil optimal pour diviser les individus en groupes à risque neurovasculaire élevé et faible. Au lieu de cela, nos résultats suggèrent que le seuil de cfPWV est plus susceptible d’être autour de 8,5 m / s. Bien que le cfPWV offre une excellente valeur pronostique chez les adultes, il reste malheureusement principalement utilisé dans la recherche en raison du besoin d'experts formés pour cette mesure. À l'inverse, la mesure de l'indice de rigidité artérielle (ASI) à l'aide de la pléthysmographie suscite un intérêt croissant ces dernières années en raison de son approche simple à utiliser. Dans l'article 4, nous avons étudié la relation entre l'ASI et la pression pulsée (PP) qui est une mesure indirecte de la rigidité artérielle, avec la FA et les lésions de la substance blanche chez les participants du UK Biobank. Nous avons constaté que la PP prédit mieux l'intégrité de la substance blanche que l'ASI chez les participants de moins de 75 ans. Cette constatation implique que l'ASI de la pléthysmographie ne semble pas être une mesure fiable de la rigidité artérielle chez les personnes âgées.
Des études futures sont évidemment nécessaires pour valider nos résultats, en particulier notre seuil de cfPWV. Une fois ce seuil validé, nous envisageons un avenir radieux où la mesure du cfPWV sera non seulement utilisée pour aider à sélectionner les personnes qui bénéficieraient le plus d'un programme multi-interventionnel visant à préserver l'intégrité cérébrale, mais pourrait également être utilisée pour surveiller l’effet d’une telle intervention.Arterial stiffness refers to the loss of elasticity mainly in large arteries such as the aorta and carotids. Chronically elevated arterial stiffness contributes to cerebrovascular changes such as cerebral white matter parenchymal damage via an alteration of cerebral blood flow. In particular, among the areas perfused by arterioles supplied by the anterior and middle
cerebral arteries, the corpus callosum, the internal capsule, the corona radiata, and the superior longitudinal fasciculus are more vulnerable to cerebral hypoperfusion. Previous studies have shown that increased arterial stiffness as assessed by carotid-femoral pulse wave velocity (cfPWV) is associated with a decrease in fractional anisotropy (FA) and
increase in radial diffusivity (RD). It was hypothesized that alterations in vulnerable white matter tracts (e.g. corpus callosum, internal capsule) are likely to be related to axonal demyelination. However, while RD was previously correlated with axonal demyelination, diffusion imaging is mostly blind to myelin. In contrast magnetization transfer (MT) imaging is
a tailored metric to estimate myelin volume fraction. Moreover, despite their sensitivity to axon fiber organization, diffusion tensor metrics (DTI) such as FA and RD lack specificity for individual tissue microstructure. More advanced microstructural model such as neurite orientation dispersion and density imaging (NODDI) give tools to disecate the microstructural
changes behind DTI metrics.
In Article 1 we used DTI and MT based metric to look more closely at the interplay between arterial stiffness and white matter microstructure in older adults > 65 years old. We found that the gold standard measure of arterial stiffness, the measure of carotid femoral pulse wave velocity (cfPWV) was associated with axonal fiber organization as reflected by FA and RD rather than demyelination in the white matter regions that have been previously denoted as vulnerable to arterial stiffness. In our second Article, we used the NODDI model to take a further look at the relationship between cfPWV and axonal organization. Our results showed that cfPWV is positively associated with the extracellular water diffusion (ISOVF) which means that arterial stiffness may result in axonal dispersion, lessening the constraint of water directionality along axons. In addition, we found that arterial stiffness is associated with increased fibers density in the corpus callosum as measured by ICVF which could suggest that individuals at higher risk for cognitive decline demonstrate early compensatory
mechanisms before the appearance of clinical signs of cognitive decline.
Considering the strong interplay between arterial stiffness and decline both in brain structure and function, one can envision a bright future where arterial stiffness would be measured in routine clinical practice in order to identify individuals at higher risk for white matter changes and cognitive decline. Such individuals could benefit from multi-interventions programs
aiming to preserve brain structure and function. A cut-off arterial stiffness is thus needed to identify these individuals. Article 3 presents the first estimation of an cfPWV cut-off value at which arterial stiffness impacts the white matter microstructure in older adults. Our results suggested that the current 10 m/s cfPWV cut-off adopted by the European Society of
Hypertension may not be the optimal threshold to split individuals into high and low neurovascular risk groups. Instead, our findings suggest that the cfPWV cut-off is more likely to fall around 8.5 m/s. While cfPWV provides excellent prognostic value in adults, it remains unfortunately mainly used in research due to the need of trained experts. Conversely,
measure of arterial stiffness index (ASI) using plethysmography is getting increased interest in the last few years due to its simple-to-use approach. In article 4, we investigated the relationship between ASI and pulse pressure (PP), an indirect measure of arterial stiffness, with FA and white matter lesions in participants of the UK Biobank. We found that PP better
predicts white matter integrity compared to ASI in participants younger than 75 years old.
This finding implies that ASI from plethysmography may not be a reliable measure of arterial stiffness in older adults.
Future studies are obviously needed to validate our results, in particular our cfPWV cut-off.
Once such cut-off will be validated, the present author envision a bright future where measure of cfPWV will not only be used to help selecting individuals that would most benefit from a multi intervention program aiming to preserve brain integrity, but could also be used to monitor the effect of such intervention