No skin off your back: the sampling and extraction of sebum for metabolomics.

INTRODUCTION: Sebum-based metabolomics (a subset of "sebomics") is a developing field that involves the sampling, identification, and quantification of metabolites found in human sebum. Sebum is a lipid-rich oily substance secreted by the sebaceous glands onto the skin surface for skin homeostasis, lubrication, thermoregulation, and environmental protection. Interest in sebomics has grown over the last decade due to its potential for rapid analysis following non-invasive sampling for a range of clinical and environmental applications. OBJECTIVES: To provide an overview of various sebum sampling techniques with their associated challenges. To evaluate applications of sebum for clinical research, drug monitoring, and human biomonitoring. To provide a commentary of the opportunities of using sebum as a diagnostic biofluid in the future. METHODS: Bibliometric analyses of selected keywords regarding skin surface analysis using the Scopus search engine from 1960 to 2022 was performed on 12th January 2023. The published literature was compartmentalised based on what the work contributed to in the following areas: the understanding about sebum, its composition, the analytical technologies used, or the purpose of use of sebum. The findings were summarised in this review. RESULTS: Historically, about 15 methods of sampling have been used for sebum collection. The sample preparation approaches vary depending on the analytes of interest and are summarised. The use of sebum is not limited to just skin diseases or drug monitoring but also demonstrated for other systemic disease. Most of the work carried out for untargeted analysis of metabolites associated with sebum has been in the recent two decades. CONCLUSION: Sebum has a huge potential beyond skin research and understanding how one's physiological state affects or reflects on the skin metabolome via the sebaceous glands itself or by interactions with sebaceous secretion, will open doors for simpler biomonitoring. Sebum acts as a sink to environmental metabolites and has applications awaiting to be explored, such as biosecurity, cross-border migration, localised exposure to harmful substances, and high-throughput population screening. These applications will be possible with rapid advances in volatile headspace and lipidomics method development as well as the ability of the metabolomics community to annotate unknown species better. A key issue with skin surface analysis that remains unsolved is attributing the source of the metabolites found on the skin surface before meaningful biological interpretation.

[Distinctive tabard: A solution to avoid work interruptions in the blood transfusion?] / Gilet distinctif : une solution pour éviter les interruptions de tâche dans le domaine transfusionnel ?

AIM: In the blood transfusion, the interruption of work (IW) can lead to serious incidents and/or adverse effects. The aim of our work is to evaluate the wearing of a distinctive tabard in the IW. METHODS: Several voluntary departments from 5 establishments of health in the Center-Val de Loire region have participated in this work from October to December 2017. The survey was given to nurses (identified by the first three letters of the first name) before and after wearing the tabard (for 2 months) for all transfusions realized in their respective department. We matched the survey by nurse and by department. The Student t test was conducted to evaluate the contribution of the tabard during IW. RESULTS: One hundred and one survey (31 in surgery, 70 in medicine) were collected before wearing and 91 (27 in surgery, 64 in medicine) after wearing the tabard. Before wearing the tabard, the number of nurse having or not IW was the same. After wearing the tabard, 42% had an IW and 58% didn't had IW (P=0.43; χ2). Sixty-four surveys were matched (27 exclusions : different IDEs) according to IW before and after wearing the tabard. The wearing of the tabard allows a statistically significant decrease IW (z=2.61, P=0.009, student test). CONCLUSION: Wearing the tabard during blood transfusions is statistically significant means of reducing IW. It's probably a first solution to increase the security of the act, to which must be added other means (poster, phone management, poster and information campaign). It's easier to eliminate IW than to manage.

Effect of compression stockings on cutaneous microcirculation: Evaluation based on measurements of the skin thermal conductivity.

OBJECTIVE: To study of the microcirculatory effects of elastic compression stockings. MATERIALS AND METHODS: In phlebology, laser Doppler techniques (flux or imaging) are widely used to investigate cutaneous microcirculation. It is a method used to explore microcirculation by detecting blood flow in skin capillaries. Flux and imaging instruments evaluate, non-invasively in real-time, the perfusion of cutaneous micro vessels. Such tools, well known by the vascular community, are not really suitable to our protocol which requires evaluation through the elastic compression stockings fabric. Therefore, we involve another instrument, called the Hematron (developed by Insa-Lyon, Biomedical Sensor Group, Nanotechnologies Institute of Lyon), to investigate the relationship between skin microcirculatory activities and external compression provided by elastic compression stockings. The Hematron measurement principle is based on the monitoring of the skin's thermal conductivity. This clinical study examined a group of 30 female subjects, aged 42 years ±2 years, who suffer from minor symptoms of chronic venous disease, classified as C0s, and C1s (CEAP). RESULTS: The resulting figures show, subsequent to the pressure exerted by elastic compression stockings, an improvement of microcirculatory activities observed in 83% of the subjects, and a decreased effect was detected in the remaining 17%. Among the total population, the global average increase of the skin's microcirculatory activities is evaluated at 7.63% ± 1.80% (p < 0.0001). CONCLUSION: The results from this study show that the pressure effects of elastic compression stockings has a direct influence on the skin's microcirculation within this female sample group having minor chronic venous insufficiency signs. Further investigations are required for a deeper understanding of the elastic compression stockings effects on the microcirculatory activity in venous diseases at other stages of pathology.

Localised impedance monitoring device for the remote clinical assessment of home-based dialysis patients.

BioImpedance Spectroscopy (BIS) has been clinically used to determine the hydrational status of patients undergoing haemodialysis (HD). In the present project we are developing a calf-localised, integrated impedimetric device to periodically and conveniently measure and transmit information on the hydrational status of home-based patients to a remote clinic. Surprisingly, we have found that simple postural changes before or during measurement lead to significant fluid shifts in the lower leg that are as important and as long lasting as the effects of haemodialysis. These must be taken into account if potentially hazardous errors are not to be made in assessing a patient's hydrational status.

A portable heat flux sensor.

Nowadays monitoring physiological signals in real situations is essential to get the best diagnosis on patients. In this study we focus on the heat flux generated by the human body. We are developing a portable heat flux sensor using specific thermal materials.

Wearable sensor systems: the challenges.

Given the soaring costs associated with the treatment of ever more prevalent chronic disease, it is widely agreed that a revolution is required in health care provision. It is often thought that the necessary technology already exists for the home-based monitoring of such patients and that it is other factors which are holding back the more widespread clinical uptake of these new tools. The authors suggest that the necessary sensor-related technologies are often not as advanced as may first appear; certainly they are generally not adequate for the robust, long-term monitoring of patients under real-life conditions. An additional problem is the evident efforts to apply a given sensor and related technology platform to any and all monitoring scenarios without sufficient consideration of patient needs and the clinical requirements. The authors review the key sensing platforms and suggest the applications for which they are best suited.

Thermal parameters measurement on fire fighter: improvement of the monitoring system.

Real time monitoring of the thermal parameters on firefighter when operating is one of the ProeTEX project goals. The newly developed equipments in the framework of this project, integrate one temperature sensor and one heat flux sensor in the rescuer's outer garment. The environment in which firefighters operate is dangerous and the thermal risks can occur everywhere. Consequently the heat flux is so not necessarily symmetrical. To improve the thermally at risk situation detection, a modified platinum sensors array was integrated in the jacket in order to monitor simultaneously heat flux and temperature surrounding the rescuer. The sensors were placed in the most exposed area (shoulders and chest) to monitor thermal parameter in different directions. The heat flux is calculated from the temperature difference. This sensors array enables the detection of temperature increases and heat flux even when the heat source is localized on one side.

Thermal parameters measurement on fire fighter during intense fire exposition.

To improve rescuer safety, coordination and efficiency, the European program ProeTEX aims at developing new equipment for the intervention staff. This equipment is based on micro and nanotechnologies and consisted of smart textile integrated sensor to monitor physiological parameters, environment of the rescuer but also acquisition module and communication module. Thermal parameters are of primer interest. Internal temperature, external temperature and heat flux are relevant parameters to prevent heat stroke in fire fighter when exposed to intense fire. These parameters are recorded during fire exposition and highlight, on one hand, that the outer garment of fire fighters' equipment insulates the fire fighter from the external environment, and on the other hand, that the thermal monitoring is relevant.

An integrated platform to assess driver's physiological and functional states.

Physiological signals like Heart Rate, Respiration and Skin Resistance are relevant indicators to evaluate driver's mental state. Therefore, most methods based on physiological signals measurements have been improved on driving simulators or in experimental laboratories under carefully controlled conditions and rigorous protocols. To study driver's behavior in actual conditions, we have developed an in-vehicle system which could record contextual driving information, drivers' actions and physiological signals related to them. Recordings from the driver and the vehicle may give valuable information for a close estimation of driver's functional state, its evolution across time and thus a better understanding of driver's behavior. This system provides specific patterns related to the driver's functional state, according to the driving context. This paper is aimed to present the design and implementation of this system, well adapted to ergonomics.

MAPI: active interface pressure sensor integrated into a seat.

The purpose of MAPI project is to propose a method for interface pressure measurement. This method must be exact, easy to build, low cost, and must take into consideration viscoelastic characteristics of the skin and of human morphology. The main areas of the project is related to ergonomics of seating surfaces and prevention of pressure ulcers. An additional stage was performed by developing an electro-pneumatic interface pressure sensor directly integrated into a seat. The sensor is easy to use and presents acceptable characteristics. The average error is 2.58%, and the standard deviation is 1.66 mmHg. Spatial resolution is 3 cm. This first prototype will be improved, with better spatial resolution, and used for different pressure ulcer study and prevention tests.

New methodology for preventing pressure ulcers using actimetry and autonomous nervous system recording.

Pressure ulcers constitute an important health problem. They affect lots of people with mobility disorder and they are difficult to detect and prevent because the damage begins on the muscle. This paper proposes a new approach to study pressure ulcers. We aim at developing a methodology to analyse the probability for a patient to develop a pressure ulcer, and that can detect risky situation. The idea is to relate the mobility disorder to autonomic nervous system (ANS) trouble. More precisely, the evaluation of the consequence of the discomfort on the ANS (stress induced by discomfort) can be relevant for the early detection of the pressure ulcer. Mobility is evaluated through movement measurement. This evaluation, at the interface between soft living tissues and any support has to consider the specificity of the human environment. Soft living tissues have non-linear mechanical properties making conventional rigid sensors non suitable for interface parameters measurement. A new actimeter system has been designed in order to study movements of the human body whatever its support while seating. The device is based on elementary active cells. The number of pressure cells can be easily adapted to the application. The spatial resolution is about 4 cm(2). In this paper, we compare activity measurement of a seated subject with his autonomic nervous system activity, recorded by E.motion device. It has been developed in order to record six parameters: skin potential, skin resistance, skin temperature, skin blood rate, instantaneous cardiac frequency and instantaneous respiratory frequency. The design, instrumentation, and first results are presented.

Which techniques to improve the early detection and prevention of pressure ulcers?

Pressure ulcers are a serious health problem for people with mobility disorders, like elders in acute care, long-term care, and home care settings. It also concerns paraplegics, tetraplegics or persons with burned injuries. Pressure ulcers result in significant morbidity and mortality. Consequences are a high human suffering, with high cost in terms of treatment. Several risk factors have been identified for the development of pressure ulcers: they are classified into extrinsic and intrinsic factors. Extrinsic factors include interface pressure, shear forces, friction. Intrinsic factors are the nutritional state of the patient, its age, diseases. There is little information about the mechanism of the formation of pressure sores but it is agreed that it is a complex process. The difficulty of the prevention lies in the evaluation of these factors. It is an essential stage to optimize the preventative measures. Actually, no quantifiable parameters exist to predict the formation of a pressure ulcer. This article is aimed to propose new techniques developed for the early detection of pressure ulcers. First, extrinsic parameters as the interface pressure and its consequences on the mobility are investigated. A new actimeter is presented to monitor the movements of the patient. The second part is dedicated to the presentation of a new imaging technique which can help the physician to control tissue elasticity of the patient. The technique is called elastography, it is a 3D strain estimation of soft biological tissues. Finally, the last way of investigation is the combination of extrinsic and intrinsic factors evaluation for a most relevant earlier diagnosis. Before the description of these techniques, it is essential to understand the phenomenology associated to the development of pressure sores. Only in this way, new techniques can be developed.

Interface pressure monitoring for a secured instrumented childbirth.

Complications in forceps deliveries are rare but their consequences might be dramatics. This situation could be avoided if the obstetrician knows the information concerning symmetry of the obstetrical forceps position on the fetal head and the related interface pressure. Indeed, forceps delivery is an emergency gesture which is normally not expected. Our purpose is to determinate relevant parameters for a fast decision-making without any danger for the fetus. We have developed a new interface pressure measurement system in order to study pressure distribution of human body whatever its support (forceps, chair, bed...). This method has been adapted to measure the interface pressure between the fetal head and the forceps. This new system also provides information of forceps position symmetries. The aims of this system are: first, to prevent instrumented delivery accidents. Secondly, to provide a safe training of forceps technique. This paper presents results about experiments performed on phantoms of fetal head. Different forceps positions on phantom have been tested according to the classification of forceps application as per A.C.O.G 1981 (revised in 1991). These experiments have lead to the definition of relevant parameters in order to help the physician to validate the forceps positions before extraction.

A non invasive wearable sensor for the measurement of brain temperature.

As the thermoregulation centres are deep in the brain, the cerebral temperature is one of the most important markers of fever, circadian rhythms physical and mental activities. However due to a lack of accessibility, the brain temperature is not easily measured. The axillary, buccal, tympanic and rectal temperatures do not reflect exactly the cerebral temperature. Nevertheless the rectal temperature is used as probably the most reliable indicator of the core body temperature. The brain temperature can be measured using NMR spectroscopy, microwave radiometry, near infrared spectroscopy, ultra-sound thermometry. However none of those methods are amenable to long term ambulatory use outside of the laboratory or of the hospital during normal daily activities, sport, etc. The brain core temperature "BCT" sensor, developed by the Biomedical Microsensors dpt of LPM at INSA-Lyon is a flexible active sensor using "zero-heat-flow" principle. The sensor has been used for experimental measurement: brain temperature during mental activity, and in hospital for the study of circadian rhythms. The results are in agreement with the measurement by the rectal probe. There are 2 versions of this sensor: a non ambulatory for the use in hospitals, and an ambulatory version using teletransmission. We are working for improving the autonomy of the ambulatory version up to several days. This wearable biomedical sensor (WBS) can be used for circadian assessment for chronobiology studies and in medical therapies.

FOR SAFE: instrumented and secured obstetrical forceps.

Operative vaginal deliveries represent a significant amount of vaginal deliveries. Operative delivery involves either forceps either vacuum extraction. Complications are frequent but rarely severe (cutaneaous lesions, facial palsy...). However, it is essential to limit these complications by helping the obstetrician to position his extraction instrument. It is the aim of the FOR SAFE device: provide a new instrumented forceps which performs the interface pressure measurement between the fetal head and the shanks of the forceps. Interface pressure evaluation requires interaction between the living tissue and the sensor, just like a man needs to touch an object with its fingertip to evaluate its compliance. The design of the sensor is "bio inspired". The sensor interacts with the matter, without modifying phenomenon to be measured.

Wrist ambulatory monitoring system and smart glove for real time emotional, sensorial and physiological analysis.

Improvement of the quality and efficiency of the quality of health in medicine, at home and in hospital becomes more and more important Designed to be user-friendly, smart clothes and gloves fit well for such a citizen use and health monitoring. Analysis of the autonomic nervous system using non-invasive sensors provides information for the emotional, sensorial, cognitive and physiological analysis. MARSIAN (modular autonomous recorder system for the measurement of autonomic nervous system) is a wrist ambulatory monitoring and recording system with a smart glove with sensors for the detection of the activity of the autonomic nervous system. It is composed of a "smart tee shirt", a "smart glove", a wrist device and PC which records data. The smart glove is one of the key point of MARSIAN. Complex movements, complex geometry, sensation make smart glove designing a challenge. MARSIAN has a large field of applications and researches (vigilance, behaviour, sensorial analysis, thermal environment for human, cognition science, sport, etc...) in various fields like neurophysiology, affective computing and health monitoring.

New concepts and technologies in home care and ambulatory monitoring.

The world is becoming more and more health conscious. Society, health policy and patients' needs are all changing dramatically. The challenges society is currently facing are related to the increase in the aging population, changes in lifestyle, the need for healthcare cost containment and the need for improvement and monitoring of healthcare quality. The emphasis is put on prevention rather than on treatment. In addition, patients and health consumers are waiting for non-invasive or minimally-invasive diagnosis and treatment methods, for home care, short stays in hospital, enhancement of rehabilitation, information and involvement in their own treatment. Progress in science and technology offers, today, miniaturization, speed, intelligence, sophistication and new materials at lower cost. In this new landscape, microtechnologies, information technologies and telecommunications are key factors. Telemedicine has also evolved. Used initially to exchange patients' files, radiographic data and other information between health providers, today telemedicine contributes to new trends in "hospital extension" through all-day monitoring of vital signs, professional activities, entertainment and home-based activities. The new possibilities for home care and ambulatory monitoring are provided at 4 levels: a) Microsensors. Microtechnologies offer the possibility of small size, but also of intelligent, active devices, working with low energy, wireless and non-invasive or minimally-invasive; b) Wrist devices are particularly user friendly and combine sensors, circuits, supply, display and wireless transmission in a single box, very convenient for common physical activities; c) Health smart clothes make contact with 90 % of the skin and offer many possibilities for the location of sensors. These sensors have to be thin, flexible and compatible with textiles, or made using textile technologies, such as new fibers with specific (mechanical, electrical and optical) properties; d) Health smart homes. The aim of this method is to improve the patient's living conditions and to avoid the cost of long hospitalization. "Exosensors" are used for measurement of the activity and behavior of the patient. The field of applications is very large, e.g. continuous monitoring of elderly populations, professional and military activities, athletes performance and condition, and people with disabilities. This new healthcare approach has to take into account lifestyle for improving prevention. For the patient to be more and more involved in his/her own therapy, new responsibilities and ethics have to be defined. A "societal health education" has to be provided to physicians and to patients to get all the benefits of this new context.

Flysch-type sedimentation in the Alboran Sea, Western Mediterranean.

The Quaternary deposits of the Alboran Sea and associated sediment dispersal patterns, and geographic and tectonic setting of the region, are closely similar to those of some ancient flysch basins preserved in the geological record.