A non-invasive, concealed electrocardiogram and bioimpedance measurement system for captive primates.

Captive housed non-human primates, specifically great apes such as chimpanzees (Pan troglodytes) are frequently reported to have died from or are diagnosed with potentially fatal heart conditions that require the monitoring of physiological signals such as electrocardiogram (ECG) or respiratory rate. ECG screening must be conducted after applying full anaesthesia, causing potential physical and emotional stress as well as risk for the animal. Here, we present an electronic system that simultaneously measures the ECG and the electrical bioimpedance for the early detection of abnormal cardiovascular activity. Modified gloves whose fingers are equipped with electrodes enable the caregiver to obtain three cardiovascular signals (ECG, pulse rate and respiratory rate) by placing the fingertips on specific parts of the non-human primate without needing any prior physical preparations. Validation (ECG and bioimpedance) was performed both on humans and on captive housed chimpanzees, where all the signals of interest were correctly acquired.

Impact of patent ductus arteriosus on non-invasive assessments of lung fluids in very preterm infants during the transitional period.

This prospective observational study aimed to evaluate whether lung fluids, assessed by lung ultrasonography and transthoracic electrical bioimpedance (TEB), may be influenced by the presence of a haemodynamically significant patent ductus arteriosus (hsPDA) in very preterm infants during the transitional period. Infants < 32 weeks of gestational age (GA) admitted to the neonatal intensive care units of IRCCS AOU Bologna and Niguarda Metropolitan Hospital of Milan (Italy) underwent a daily assessment of a lung ultrasound score (LUS) and of a TEB-derived index of thoracic fluid contents (TFC) during the first 72 h after birth. Echocardiographic scans were simultaneously performed to evaluate the concomitant ductal status (hsPDA vs. restrictive or closed duct). The correlation between LUS, TFC, and the ductal status was tested using generalized estimating equations. Forty-six infants (median GA: 29 [interquartile range, IQR: 27-31] weeks; median birth weight: 1099 [IQR: 880-1406] g) were included. At each daily evaluation, the presence of a hsPDA was associated with significantly higher LUS and TFC compared with a restrictive or closed ductus (p < 0.01 for all comparisons). These results were confirmed significant even after adjustment for GA and for the ongoing modality of respiratory support. Conclusion: Even during the first 72 h of life, the presence of a hsPDA determines a significant increase in pulmonary fluids which can be non-invasively detected and monitored over time using lung ultrasonography and TEB. What is Known: • Lung ultrasonography provides a non-invasive assessment of lung fluids and is widely used in neonatal settings. • In preterm infants, the persistence of a haemodynamically significant patent ductus arteriosus (hsPDA) over the first weeks can negatively affect pulmonary outcomes. What is New: • The presence of aan hsPDA is associated with increased lung fluids since early postnatal phases. • Lung ultrasonography and transthoracic electrical bioimpedance can effectively monitor lung fluid clearance in preterm infants with a hsPDA during the transitional period, with potential clinical implications.

Prediction of respiratory distress severity and bronchopulmonary dysplasia by lung ultrasounds and transthoracic electrical bioimpedance.

This study aims to evaluate whether the assessment of a lung ultrasound score (LUS) by lung ultrasonography and of thoracic fluid contents (TFC) by electrical cardiometry may predict RDS severity and the development of bronchopulmonary dysplasia (BPD) in preterm infants with respiratory distress (RDS). Infants ≤ 34 weeks' gestation admitted with RDS to two neonatal intensive care units were prospectively enrolled in this observational study. A simultaneous evaluation of LUS and TFC was performed during the first 72 h. The predictivity of LUS and TFC towards mechanical ventilation (MV) need after 24 h and BPD development was evaluated using receiver operating characteristic analysis. Sixty-four infants were included. The area under the curve (AUC) for the prediction of MV need was 0.851 (95%CI, 0.776-0.925, p < 0.001) for LUS and 0.793 (95%CI, 0.724-0.862, p < 0.001) for TFC, while an AUC of 0.876 (95%CI, 0.807-0.946, p < 0.001) was obtained for combined LUS and TFC evaluation. LUS and TFC AUC for BPD prediction were 0.769 (95%CI, 0.697-0.842, p < 0.001) and 0.836 (95%CI, 0.778-0.894, p < 0.001), respectively, whereas their combined assessment yielded an AUC of 0.867 (95%CI, 0.814-0.919, p < 0.001). LUS ≥ 11 and TFC ≥ 40 were identified as cut-off values for MV need prediction, whereas LUS ≥ 9 and TFC ≥ 41.4 best predicted BPD development.   Conclusion: A combined evaluation of LUS and TFC by lung ultrasonography and EC during the first 72 h may represent a useful predictive tool towards short- and medium-term pulmonary outcomes in preterm infants with RDS. What is Known: • Lung ultrasonography is largely used in neonatal intensive care and can contribute to RDS diagnosis in preterm infants. • Little is known on the diagnostic and predictive role of TFC, measured by transthoracic electrical bioimpedance, in neonatal RDS. What is New: • Combining lung ultrasonography and TFC evaluation during the first 72 h can improve the prediction of RDS severity and BPD development in preterm infants with RDS and may aid to establish tailored respiratory approaches to improve these outcomes.

Electrical Bioimpedance Analysis for Evaluating the Effect of Pelotherapy on the Human Skin: Methodology and Experiments.

BACKGROUND: Pelotherapy is the traditional procedure of applying curative muds on the skin's surface-shown to have a positive effect on the human body and cure illnesses. The effect of pelotherapy is complex, functioning through several mechanisms, and depends on the skin's functional condition. The current research objective was to develop a methodology and electrodes to assess the passage of the chemical and biologically active compounds of curative mud through human skin by performing electrical bioimpedance (EBI) analysis. METHODS: The methodology included local area mud pack and simultaneous tap water compress application on the forearms with the comparison to the measurements of the dry skin. A custom-designed small-area gold-plated electrode on a rigid printed circuit board, in a tetrapolar configuration, was designed. A pilot study experiment with ten volunteers was performed. RESULTS: Our results indicated the presence of an effect of pelotherapy, manifested by the varying electrical properties of the skin. Distinguishable difference in the measured real part of impedance (R) emerged, showing a very strong correlation between the dry and tap-water-treated skin (r = 0.941), while a poor correlation between the dry and mud-pack-treated skin (r = 0.166) appeared. The findings emerged exclusively in the frequency interval of 10 kHz …1 MHz and only for R. CONCLUSIONS: EBI provides a promising tool for monitoring the variations in the electrical properties of the skin, including the skin barrier. We foresee developing smart devices for promoting the exploitation of spa therapies.

State of the Art of Non-Invasive Technologies for Bladder Monitoring: A Scoping Review.

Bladder monitoring, including urinary incontinence management and bladder urinary volume monitoring, is a vital part of urological care. Urinary incontinence is a common medical condition affecting the quality of life of more than 420 million people worldwide, and bladder urinary volume is an important indicator to evaluate the function and health of the bladder. Previous studies on non-invasive techniques for urinary incontinence management technology, bladder activity and bladder urine volume monitoring have been conducted. This scoping review outlines the prevalence of bladder monitoring with a focus on recent developments in smart incontinence care wearable devices and the latest technologies for non-invasive bladder urine volume monitoring using ultrasound, optical and electrical bioimpedance techniques. The results found are promising and their application will improve the well-being of the population suffering from neurogenic dysfunction of the bladder and the management of urinary incontinence. The latest research advances in bladder urinary volume monitoring and urinary incontinence management have significantly improved existing market products and solutions and will enable the development of more effective future solutions.

Sensor-Location-Specific Joint Acquisition of Peripheral Artery Bioimpedance and Photoplethysmogram for Wearable Applications.

BACKGROUND: Cardiovascular diseases (CVDs), being the culprit for one-third of deaths globally, constitute a challenge for biomedical instrumentation development, especially for early disease detection. Pulsating arterial blood flow, providing access to cardiac-related parameters, involves the whole body. Unobtrusive and continuous acquisition of electrical bioimpedance (EBI) and photoplethysmography (PPG) constitute important techniques for monitoring the peripheral arteries, requiring novel approaches and clever means. METHODS: In this work, five peripheral arteries were selected for EBI and PPG signal acquisition. The acquisition sites were evaluated based on the signal morphological parameters. A small-data-based deep learning model, which increases the data by dividing them into cardiac periods, was proposed to evaluate the continuity of the signals. RESULTS: The highest sensitivity of EBI was gained for the carotid artery (0.86%), three times higher than that for the next best, the posterior tibial artery (0.27%). The excitation signal parameters affect the measured EBI, confirming the suitability of classical 100 kHz frequency (average probability of 52.35%). The continuity evaluation of the EBI signals confirmed the advantage of the carotid artery (59.4%), while the posterior tibial artery (49.26%) surpasses the radial artery (48.17%). The PPG signal, conversely, commends the location of the posterior tibial artery (97.87%). CONCLUSIONS: The peripheral arteries are highly suitable for non-invasive EBI and PPG signal acquisition. The posterior tibial artery constitutes a candidate for the joint acquisition of EBI and PPG signals in sensor-fusion-based wearable devices-an important finding of this research.

Parasitic Effects on Electrical Bioimpedance Systems: Critical Review.

Parasitic capacitance represents the main error source in measurement systems based on electrical impedance spectroscopy. The capacitive nature of electrodes' impedance in tetrapolar configuration can give origin to phase errors when electrodes are coupled to parasitic capacitances. Nevertheless, reactive charges in tissue excitation systems are susceptible to instability. Based on such a scenario, mitigating capacitive effects associated with the electrode is a requirement in order to reduce errors in the measurement system. A literature review about the main compensation techniques for parasitic capacitance was carried out. The selected studies were categorized into three groups: (i) compensation in electronic instrumentation; (ii) compensation in measurement processing, and (iii) compensation by negative impedance converters. The three analyzed methods emerged as effective against fixed capacitance. No method seemed capable of mitigating the effects of electrodes' capacitance, that changes in the frequency spectrum. The analysis has revealed the need for a method to compensate varying capacitances, since electrodes' impedance is unknown.

[Evaluation of nutritional status in patients with systemic sclerosis]. / Ocena stanu odzywienia chorych na twardzine ukladowa.

Systemic sclerosis (SSc) is a multi-organ disease with significant mortality. Diagnosis of malnutrition is sometimes difficult, and gastrointestinal disorders in patients with SSc may play a significant role in deteriorating nutritional status. Many factors can contribute to the development of eating disorders in this group of patients, including mood disorders, depression, anxiety - may reduce appetite, ulceration and skin changes, may cause difficulties in preparing and eating meals. AIM: The aim of the study was to assess the nutritional status of patients with SSc. MATERIALS AND METHODS: The study included 32 patients with diagnosed SSc, mean age 52.9±15.9 years. Anthropometric measurements were performed in all SSc patients and body composition was assessed using electrical bioimpedance (BIA). The hand grip strength range was measured using a dynamometer. RESULTS: Obesity was diagnosed in one patient (3.1%) with SSc. Most patients with SSc, as many as 19 (59.4%), had normal body weight based on BMI. 10 (31.5%) SSc patients were overweight. 2 (6.3%) patients with SSc were diagnosed with malnutrition based on BMI. In the group of patients with SSc, 2 people had deficiencies in lean body mass calculated on the basis of the Fat Free Mass Index (FFMI), while on the basis of the BMI analysis their body mass was normal. In 26 patients with SSc, the content of lean mass assessed on the basis of the FFMI index was normal, while one of these persons had a BMI below the norm and on this basis was diagnosed with malnutrition. CONCLUSIONS: Nutritional disorders are common in patients with SSc. The most common disturbance in nutritional status in SSc patients was overweight, which was present in 31,5 of patients.

Activity Recognition Using Wearable Physiological Measurements: Selection of Features from a Comprehensive Literature Study.

Activity and emotion recognition based on physiological signal processing in health care applications is a relevant research field, with promising future and relevant applications, such as health at work or preventive care. This paper carries out a deep analysis of features proposed to extract information from the electrocardiogram, thoracic electrical bioimpedance, and electrodermal activity signals. The activities analyzed are: neutral, emotional, mental and physical. A total number of 533 features are tested for activity recognition, performing a comprehensive study taking into consideration the prediction accuracy, feature calculation, window length, and type of classifier. Feature selection to know the most relevant features from the complete set is implemented using a genetic algorithm, with a different number of features. This study has allowed us to determine the best number of features to obtain a good error probability avoiding over-fitting, and the best subset of features among those proposed in the literature. The lowest error probability that is obtained is 22.2%, with 40 features, a least squares error classifier, and 40 seconds window length.

[The role of electrical bioimpedance in the evaluation of the hydration status of patients with liver cirrhosis]. / Rola bioimpedancji elektrycznej w ocenie stanu nawodnienia chorych na marskosc watroby.

Patients with liver cirrhosis are a group particularly exposed to the development of water and electrolyte disturbances, having a significant impact on the course of the disease and the quality of life. Precise and rapid assessment of the hydration status of patients often determines the further course of the disease, the success of treatment and the time of hospitalization. For this reason, it is important to maintain the water and electrolyte balance in a state of equilibrium. So far, no one optimized diagnostic tool has been found to assess the hydration status of the organism, which would become a gold standard. Despite some limitations, it should be noted that the electrical bioimpedance (BIA) method makes it possible to assess the total body water volume, extracellular space, intracellular space, as well as the content of sodium ions, which affects the flow of fluids between these spaces. It is an excellent non-invasive tool in diagnosing hydration status of patients with liver cirrhosis, kidney failure and cardiovascular diseases.

Electrical Cardiometry: A Reliable Solution to Cardiac Output Estimation in Children With Structural Heart Disease.

OBJECTIVE: Comparison of cardiac output (CO) obtained using electric cardiometry (EC) and pulmonary artery catheterization (PAC) in pediatric patients with congenital structural heart disease. DESIGN: Prospective, observational study. SETTING: A tertiary hospital. PARTICIPANTS: The study comprised 50 patients scheduled to undergo cardiac catheterization. INTERVENTIONS: CO data triplets were obtained simultaneously from the cardiometry device ICON (Osypka Medical, Berlin, Germany) and PAC at the following predefined time points-(1) T1: 5 minutes after arterial and venous cannulation and (2) T2: 5 minutes postprocedure; the average of the 3 readings was calculated. Reliability analysis and Bland-Altman analysis were performed to determine the limits of agreement, mean bias, and accuracy of the CO measured with EC. MEASUREMENTS AND MAIN RESULTS: The measured EC-cardiac index 4.22 (3.84-4.60) L/min/m2 and PAC-cardiac index 4.26 (3.67-4.67) L/min/m2 were statistically insignificant (p value>0.05) at T1. Bland-Altman analysis revealed a mean bias of 0.0051 L/min/m2 and precision limits of±0.4927 L/min/m2. The intraclass correlation coefficient was 0.789 and Cronbach's alpha was 0.652, indicating good reproducibility and internal consistency between the two techniques. Postcatheterization analysis also revealed strong agreement and reliability between the two techniques. CONCLUSIONS: This study demonstrated that cardiac indices measured in children with a variety of structural heart diseases using EC reliably represent absolute values obtained using PAC. EC technology is simple and easy to use and offers noninvasive beat-to-beat tracking of CO and other hemodynamic parameters in children with structurally abnormal hearts.

Sensitivity study of a locally developed six electrode focused impedance method.

The Focused Impedance Method (FIM) is a new technique of electrical bioimpedance measurements in the human body. The idea originated in Bangladesh and provides an opportunity for localized measurement of bioimpedance down to reasonable depths from the body surface using skin surface electrodes. This has potential applications for physiological studies of targeted organs in the body and in detecting or diagnosing diseases and disorders. FIM is based on the age-old Tetra-Polar Impedance Measurement (TPIM) but provides a few significant improvements. Technology must be developed indigenously to obtain long-term benefits, particularly in Low and Medium Income countries (LMIC). This paper presents an experimental sensitivity study of the six-electrode version of the Focused Impedance method (FIM-6) with the circuit and phantom indigenously designed in Nepal. The work involved sensitivity studies of both FIM-6 and TPIM with the necessary circuit blocks developed through experimental validation. The sensitivity studies were performed on a simple 2D phantom with different electrode arrangements for FIM-6 and linear TPIM. A cylindrical object was placed at different positions for this study. The FIM-6 gave a high sensitivity in the central part, which remained almost constant within a small region that may be termed as the focused region. On the other hand, TPIM results fell off sharply away from the central point, making it unsuitable for practical measurements on target organs. Besides, there were areas with large negative sensitivities in TPIM, which were much smaller in FIM. The results obtained through this work clearly show the improvement offered by FIM over TPIM.

Standardized phase angle: relationship with functionality, muscle mass and postoperative outcomes in surgical cancer patients.

To evaluate the association of standardized phase angle (SPA) with nutritional status, functional parameters, and postoperative outcomes in surgical cancer patients. This prospective study includes 59 cancer patients from Pelotas (Brazil) admitted for elective cancer surgery. We obtained the phase angle through Bioelectrical Impedance Analysis (BIA) and standardized it according to the population's reference values. We estimated the muscle mass using BIA for later calculation of the Skeletal Muscle Index (SMI) and performed handgrip strength (HGS) and gait speed (GS) tests. We used the Patient-Generated Subjective Global Assessment (PG-SGA) to assess the nutritional status. Postoperative complications and duration of hospital stay were evaluated as the outcomes. The prevalence of malnutrition in the sample was 28.8%, according to ASG-PPP. SPA was statistically lower in patients with malnutrition, with lower HGS and reduced GS. For postoperative outcomes, patients with severe complications and those with prolonged hospitalization also had lower SPA values. The greater the number of functional alterations in patients, the lower the SPA value, mainly when associated with reduced muscle mass assessed by BIA, suggesting that muscle mass reduction plays an important role in the association between functional alterations and phase angle in patients with cancer. According to the parameters used in this study, low SPA value was associated with impaired nutritional and functional status and negative outcomes in the analyzed sample.

Electrical bioimpedance analysis and comparison in biological tissues through crystalloid solutions implementation.

Electrical bioimpedance is a non-invasive and radiation-free technique that was proposed to be used in different clinical areas, however, its practical use is limited due to its low capacity to discriminate between tissues. In order to overcome this limitation, our research group proposes to incorporate the contrast media into the electrical bioimpedance procedure. The main objective of the present study was to assess the crystalloid solutions as a possible contrast media to discriminate between different tissue types in the bioimpedance technique. Two medical-grade crystalloid solutions (Hartmann and NaCl 0.9%) were injected into three biological ex vivo models: kidney, liver, and brain. BIOPAC system was used to acquire bioimpedance data before and after the injections. The data was adjusted to the Debye electrical model. The analysis of measured values showed substantial bioimpedance disparities in tissues subjected to isotonic solutions. The NaCl solution exhibited more pronounced changes in electrical parameters compared to the Hartmann solution. Similarly, NaCl solution displayed superior discriminatory capabilities among tissues, with variations of 465%, 157%, and 206%. Distinct spectral modifications were identified, with tissues demonstrating unique responses at each frequency of analysis relative to untreated tissue. Variations in bandwidth alterations were discernible among tissues, providing clear distinctions. In conclusion, the research showed that the crystalloid solution exhibited greater sensitivity and superior tissue contrast at specific frequencies. This study's findings underscore the feasibility of implementing crystalloid solutions to enhance tissue discrimination, similar to the effects of contrast agents.

Phase angle and impedance ratio as meta-inflammation biomarkers after a colon cleansing protocol in a group of overweight young women.

Objective. Blood C-reactive protein (CRP) and the electrical bioimpedance spectroscopy (EBIS) variables phase angle (PhA) and impedance ratio (IR) have been proposed as biomarkers of metainflammation in overweight/obesity. CRP involves taking blood samples, while PhA and IR imply a less-than-2-minute-non-invasive procedure. In this study, values for these variables and percent body fat mass (PBFM) were obtained and compared before and immediately after a colon cleansing protocol (CCP), aimed at modulating intestinal microbiota and reducing metainflammation, as dysbiosis and the latter are intrinsically related, as well as along a period of 8 weeks after it.Approach. 20 female volunteers (20.9-24.9 years old) participated: 12 in an overweight group (OG), and 8 in a lean group (LG). TheOGwas divided in two subgroups (n= 6, each): control (CSG) and experimental (ESG). TheESGunderwent a 6-day CCP at week 2, while 5 volunteers in theCSGunderwent it at week 9.Main results.Pre/post-CCP mean values for the variables in theOGwere: PBFM (34.3/31.3%), CRP (3.7/0.6 mg dl-1), PhA (6.9/7.5°) and IR*10 (0.78/0.77). CalculatedR2correlation factors among these variables are all above 0.89. The favourable changes first seen in theESGwere still present 8 weeks after the CCP.Significance.(a) the CCP drastically lowers meta-inflammation, (b) EBIS can be used to measure metainflammation, before and after treatment, (c) for microbiota modulation, CCP could be a good alternative to more drastic procedures like faecal microbiota transplantation; (d) reestablishing eubiosis by CCP could be an effective coadjutant in the treatment of overweight young adult women.

Role of the phase angle in the prognosis of the cirrhotic patient: 15 years of follow-up.

BACKGROUND: In 2019, cirrhosis accounted for 2.4% of global deaths. The projection for 2030 is an increase in this index. In recent years, hospitalization costs have escalated by 36% for compensated cirrhosis and 24% for decompensated cirrhosis. Therefore, it is necessary to identify a tool capable of predicting the mortality of these patients according to their clinical condition and consequently extending their survival time. Different studies have shown that the phase angle (PA) can be a feasible method in clinical practice, with the potential to guide assertive patient management in the therapeutic of chronic liver disease. AIM: To evaluate the prognostic role of PA in cirrhotic patients over a 15-year follow-up period. METHODS: Retrospective cohort study with 129 cirrhotic patients of both sexes over 18 years old. Diagnosis of cirrhosis by liver biopsy. The first year of data collection was 2007, and data regarding outcomes was collected in 2023. Data were gathered from medical records, such as esophageal varices (EV), EV bleeding, ascites, spontaneous bacterial peritonitis (SBP), encephalopathy, laboratory findings and PA. The cut-off value for the PA was 5.4°, a value described in 2012 by Fernandes et al for 129 patients evaluated in this study and the cut-off points for the Brazilian population presented in percentiles (P), as described by Mattiello et al. The mortality was assessed using the PA percentile through Kaplan-Meier curves and multivariate binary logistic regression models. RESULTS: Patients were divided into two groups according to the PA 5.4th (PA > 5.4°, n = 40; PA ≤ 5.4°, n = 89) PA percentile (< P50, n = 56; ≥ P50 n = 73). The percentile classification was more accurate in identifying long-term deaths than the 5.4º PA. Patients with < P50 had a higher number of relevant complications such as ascites, SBP, liver encephalopathy and HCC. PA is strongly correlated with serum albumin (P < 0.001), International Normalized Ratio (P = 0.01), total bilirubin (P = 0.02) and direct bilirubin (P = 0.003). PA is correlated with survival time (P < 0.001) and length of stay (P = 0.02). Logistic regression analysis shows that an increase of 1° in PA enlarges the cirrhotic patient's chance of survival by 17.7%. CONCLUSION: PA is a good predictor of morbidity and mortality for cirrhotic patients. The PA by percentile showed greater sensitivity in predicting mortality compared to the cut-off point of 5.4º.

Piezoresistivity modeling of soft tissue electrical-mechanical properties: A validation study.

In general, the electrical property of soft tissues is sensitive to the force applied to their surface. To further study the relationship between the force and the electrical property of soft tissues, this paper attempts to investigate the effect of static and higher-order stresses on electrical properties. Overall, a practical experimental platform is designed to acquire the force information and the electrical property of soft tissues during a contact procedure, which is featured different compression stimuli, such as constant pressing force, constant pressing speed, and step-force compression, etc. Furthermore, the piezoresistive characteristic is innovatively introduced to model the mechanical-electrical properties of soft tissue. Finite Element Modeling (FEM) is adopted to fit the static piezoresistivity of the soft tissue. Finally, experimental studies were performed to demonstrate the effect of stress on the electrical properties and the feasibility of the proposed piezoresistive model to describe soft tissues' mechanical and electrical properties.

Electric Bioimpedance Sensing for the Detection of Head and Neck Squamous Cell Carcinoma.

The early detection of head and neck squamous cell carcinoma (HNSCC) is essential to improve patient prognosis and enable organ and function preservation treatments. The objective of this study is to assess the feasibility of using electrical bioimpedance (EBI) sensing technology to detect HNSCC tissue. A prospective study was carried out analyzing tissue from 46 patients undergoing surgery for HNSCC. The goal was the correct identification of pathologic tissue using a novel needle-based EBI sensing device and AI-based classifiers. Considering the data from the overall patient cohort, the system achieved accuracies between 0.67 and 0.93 when tested on tissues from the mucosa, skin, muscle, lymph node, and cartilage. Furthermore, when considering a patient-specific setting, the accuracy range increased to values between 0.82 and 0.95. This indicates that more reliable results may be achieved when considering a tissue-specific and patient-specific tissue assessment approach. Overall, this study shows that EBI sensing may be a reliable technology to distinguish pathologic from healthy tissue in the head and neck region. This observation supports the continuation of this research on the clinical use of EBI-based devices for early detection and margin assessment of HNSCC.

Electrical bioimpedance measurement and near-infrared spectroscopy in pediatric postoperative neurocritical care: a prospective observational study.

Background: To investigate the clinical significance of the disturbance coefficient (DC) and regional cerebral oxygen saturation (rSO2) as obtained through the use of electrical bioimpedance and near-infrared spectroscopy (NIRS) in pediatric neurocritical care. Participants and methods: We enrolled 45 pediatric patients as the injury group and 70 healthy children as the control group. DC was derived from impedance analysis of 0.1 mA-50 kHz current via temporal electrodes. rSO2 was the percentage of oxyhemoglobin measured from reflected NIR light on the forehead. DC and rSO2 were obtained at 6, 12, 24, 48 and 72 h after surgery for the injury group and during the health screening clinic visit for the control group. We compared DC and rSO2 between the groups, their changes over time within the injury group and their correlation with intracranial pressure (ICP), cerebral perfusion pressure (CPP), Glasgow coma scale (GCS) score, Glasgow outcome scale (GOS) score, and their ability to diagnose postoperative cerebral edema and predict poor prognosis. Results: DC and rSO2 were significantly lower in the injury group than in the control group. In the injury group, ICP increased over the monitoring period, while DC, CPP and rSO2 decreased. DC was negatively correlated with ICP and positively correlated with GCS score and GOS score. Additionally, lower DC values were observed in patients with signs of cerebral edema, with a DC value of 86.5 or below suggesting the presence of brain edema in patients aged 6-16 years. On the other hand, rSO2 was positively correlated with CPP, GCS score, and GOS score, with a value of 64.4% or below indicating a poor prognosis. Decreased CPP is an independent risk factor for decreased rSO2. Conclusion: DC and rSO2 monitoring based on electrical bioimpedance and near-infrared spectroscopy not only reflect the degree of brain edema and oxygenation, but also reflect the severity of the disease and predict the prognosis of the patients. This approach offers a real-time, bedside, and accurate method for assessing brain function and detecting postoperative cerebral edema and poor prognosis.