Non-invasive Monitoring Device Research Articles

Noninvasive Real-Time Glucose Monitoring Is in the Near Future.

Objective: Since the introduction of continuous glucose monitoring (CGM) technology, developers have rigorously researched the feasibility of creating a noninvasive glucose monitoring device. In a recent pilot study, investigators reported a strong correlation between glucose values obtained from novel noninvasive monitoring device (GWave) values to venous and capillary glucose measurements. Research Design and Methods: We investigated whether the level of accuracy observed in the pilot study could be reproduced in a larger cohort, using a smaller third-generation manufacturable device (Gen III GWave) containing a standardized sensor chip that can be mass produced for commercial use. The evaluation assessed concordance with capillary blood glucose, reproducibility between two Gen III devices, and accuracy during insulin-induced hypoglycemia. Results: Assessment of samples from 75 subjects (type 2 diabetes, n = 6; type 1 diabetes, n = 28; nondiabetic pregnant subjects, n = 10; and nondiabetic, n = 31) showed that 97% of values were in Zone A with 3% in Zone B of the Clarke Error Grid, with a mean absolute relative difference of 6.7% from reference blood glucose. Comparison between two independent Gen III GWave devices demonstrated reproducibility between the sensors (R2 = 0.95), with 100% of values within Zone A. In the hypoglycemia assessment, measurements from the Gen III sensor tightly followed the capillary glucose measurements down to 42 mg/dL (2.3 mmol/L), whereas the CGM measurements from two different CGM only converged with the GWave and capillary glucose readings after 90 min of decreasing glucose levels. Conclusion: Our results show promise as potentially the first noninvasive technology. Future studies will focus on larger number of people in all glucose ranges. Real-time noninvasive blood glucose monitoring is possible using GWave technology.

Measuring congestion with a non-invasive monitoring device in heart failure and haemodialysis: CONGEST-HF.

We examined the effectiveness of a novel cardiopulmonary management wearable sensor (worn for less than 5 mins) at measuring congestion and correlated the device findings with established clinical measures of congestion. We enrolled three cohorts of patients: (1) patients with heart failure (HF) receiving intravenous diuretics in hospital; (2) patients established on haemodialysis, and (3) HF patients undergoing right heart catheterization (RHC). The primary outcomes in the respective cohorts were a Spearman correlation between (1) change in weight and change in thoracic impedance (TI) (from enrolment, 24 h after admission to discharge) in patients hospitalized for HF; (2) lung ultrasound B-lines and volume removed during dialysis with device measured TI, and (3) pulmonary capillary wedge pressure (PCWP) and sub-acoustic diastolic, third heart sound (S3) in the patients undergoing RHC. A total of 66 patients were enrolled. In HF patients (n = 25), change in weight was correlated with both change in device TI (Spearman correlation [rsp] = -0.64, p = 0.002) and change in device S3 (rsp = -0.53, p = 0.014). In the haemodialysis cohort (n = 21), B-lines and TI were strongly correlated before (rsp = -0.71, p < 0.001) and after (rsp = -0.77, p < 0.001) dialysis. Volume of fluid removed by dialysis was correlated with change in device TI (rsp = 0.49, p = 0.024). In the RHC cohort (n = 20), PCWP measured at one time point and device S3 were not significantly correlated (rsp = 0.230, p = 0.204). There were no device-related adverse events. A non-invasive device was able to detect changes in congestion in patients with HF receiving decongestion therapy and patients having fluid removed at haemodialysis. The cardiopulmonary management device, which measures multiple parameters, is a potentially useful tool to monitor patients with HF to prevent hospitalizations.

Abstract PO1-07-05: Preliminary Evaluation in Breast Cancer of PointCheck: a Noninvasive AI-Based Neutropenia Monitoring Device

Abstract Background Febrile neutropenia (FN) is a common complication that can arise in breast cancer patients receiving myelosuppressive chemotherapy and increases the risk of fatal infections. Despite better preventive strategies there are between 140,000 to 200,000 FN-related hospitalizations yearly. Quick detection and awareness of grade III neutropenia (Absolute Neutrophil Count [ANC] &amp;lt; 1,000/µL) or greater can be critical to managing FN and treatment scheduling and dosing in patients with breast cancer. The current gold standard for neutropenia detection is a peripheral blood collection that requires patients to come into the clinic. PointCheck™ is a novel, noninvasive technology that can monitor for grade III neutropenia or greater and enable prompt detection in the home by acquiring microscopy videos of superficial capillaries through the nailfold skin and analyzing those videos with computer vision AI algorithms. To evaluate the usability, diagnostic performance, and preliminary clinical utility of PointCheck™ on FN detection we conducted a multi-center observational usability and diagnostic study. Methods The present study included an overall cohort of 175 diverse cancer patients, with 70 breast cancer patients. The primary endpoint was to achieve a score over 80.8 on a standardized System Usability Scale (SUS). Secondary endpoint was achievement of diagnostic performance with an area under the curve (AUC) above 0.80. We also performed an exploratory analysis on the device's clinical utility. Eligible participants were introduced to the device, watched a tutorial video and were given a user manual. They used the device autonomously under the supervision of the clinical team. Usability data was collected using the SUS, the scoring system that has a scale between 0-100. PointCheck™ measurements were analyzed using AI algorithms and compared to same-day Complete Blood Counts (CBCs) collected within 90 minutes of the measurement to assess accuracy in classifying patients as grade III neutropenic or greater (&amp;lt; 1,000/µL), or non-grade III neutropenic (≥1,000/µL). In the exploratory clinical utility analysis, clinicians provided narrative insights by completing a Likert survey assessing how PointCheck™ would support or impact their clinical decisions. Results 81.4% of breast cancer patients scored above 80.8 on the SUS scale across all sites, with a mean SUS score of 87.7 (SD=13.2). Furthermore, the AI-based PointCheck™ classifier accurately discriminated neutropenia patients with an AUC = 0.90 in the overall cohort. In the exploratory analysis, a majority of clinicians (65.2%) agreed that the device could have helped better evaluate their patients (Table 1). Whereas almost 3 out of 4 clinicians (72.4%), described that the use of PointCheck™ could have avoided preparing a chemotherapy infusion if the patient was not ready due to grade III neutropenia or greater. Conclusions The present study showed that there is a high perception of usability of PointCheck™, indicating an above average user experience and falling within the top 10% of systems. Furthermore, we found that PointCheck™ can accurately detect grade III neutropenia or greater in a large cohort of patients including breast cancer patients. Application of PointCheck™ to clinical practice as a monitoring system can contribute to the early detection of FN and antineoplastic therapy management. Table 1: Clinical Utility Survey Results Citation Format: Juan Garcia-Mosquera, Manuel Alva, Toshiaki Iwase, Ganimete Lamaj, Pablo Tolosa, Rodrigo Sánchez-Bayona, José Pelaez-Escobar, Alberto Pablo-Trinidad, Ryan Benasutti, Aurélien Bourquard, Ian Butterworth, Alvaro Sánchez-Ferro, Carlos Castro-González, José Manuel Pérez-García, Alejandro Martínez-Bueno, Eva Ciruelos, Azadeh Nasrazadani. Preliminary Evaluation in Breast Cancer of PointCheck: a Noninvasive AI-Based Neutropenia Monitoring Device [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-07-05.

Surface-adaptive interfaces: Bioresorbable ultrasound biomedical devices for noninvasive monitoring and imaging of deep-tissue homeostasis

Surface-adaptive interfaces: Bioresorbable ultrasound biomedical devices for noninvasive monitoring and imaging of deep-tissue homeostasis

Agreement between three noninvasive temperature monitoring devices during spinal anaesthesia for caesarean delivery: a prospective observational study.

Hypothermia during obstetric spinal anaesthesia is a common and important problem, yet temperature monitoring is often not performed due to the lack of a suitable, cost-effective monitor. This study aimed to compare a noninvasive core temperature monitor with two readily available peripheral temperature monitors during obstetric spinal anaesthesia. We undertook a prospective observational study including elective and emergency caesarean deliveries, to determine the agreement between affordable reusable surface temperature monitors (Welch Allyn SureTemp® Plus oral thermometer and the Braun 3-in-1 No Touch infrared thermometer) and the Dräger T-core© (using dual-sensor heat flux technology), in detecting thermoregulatory changes during obstetric spinal anaesthesia. Predetermined clinically relevant limits of agreement (LOA) were set at ± 0.5°C. We included 166 patients in our analysis. Hypothermia (heat flux temperature < 36°C) occurred in 67% (95% CI 49 to 78%). There was poor agreement between devices. In the Bland-Altman analysis, LOA for the heat flux monitor vs. oral thermometer were 1.8°C (CI 1.7 to 2.0°C; bias 0.5°C), for heat flux monitor vs. infrared thermometer LOA were 2.3°C (CI 2.1 to 2.4°C; bias 0.4°C) and for infrared vs. oral thermometer, LOA were 2.0°C (CI 1.9 to 2.2°C; bias 0.1°C). Error grid analysis highlighted a large amount of clinical disagreement between methods. While monitoring of core temperature during obstetric spinal anaesthesia is clinically important, agreement between monitors was below clinically acceptable limits. Future research with gold-standard temperature monitors and exploration of causes of sensor divergence is needed.

A Wearable Electrochemical Biosensor Utilizing Functionalized Ti3C2Tx MXene for the Real-Time Monitoring of Uric Acid Metabolite.

Wearable, noninvasive sensors enable the continuous monitoring of metabolites in sweat and provide clinical information related to an individual's health and disease states. Uric acid (UA) is a key indicator highly associated with gout, hyperuricaemia, hypertension, kidney disease, and Lesch-Nyhan syndrome. However, the detection of UA levels typically relies on invasive blood tests. Therefore, developing a wearable device for noninvasive monitoring of UA concentrations in sweat could facilitate real-time personalized disease prevention. Here, we introduce 1,3,6,8-pyrene tetrasulfonic acid sodium salt (PyTS) as a bifunctional molecule functionalized with Ti3C2Tx via π-π conjugation to design nonenzymatic wearable sensors for sensitive and selective detection of UA concentration in human sweat. PyTS@Ti3C2Tx provides many oxidation-reduction active groups to enhance the electrocatalytic ability of the UA oxidation reaction. The PyTS@Ti3C2Tx-based electrochemical sensor demonstrates highly sensitive detection of UA in the concentration range of 5 μM-100 μM, exhibiting a lower detection limit of 0.48 μM compared to the uricase-based sensor (0.84 μM). In volunteers, the PyTS@Ti3C2Tx-based wearable sensor is integrated with flexible microfluidic sweat sampling and wireless electronics to enable real-time monitoring of UA levels during aerobic exercise. Simultaneously, it allows for comparison of blood UA levels via a commercial UA analyzer. Herein, this study provides a promising electrocatalyst strategy for nonenzymatic electrochemical UA sensor, enabling noninvasive real-time monitoring of UA levels in human sweat and personalized disease prevention.

Behavioral Disorders of Spatial Cognition in Patients with Mild Cognitive Impairment due to Alzheimer's Disease: Preliminary Findings from the BDSC-MCI Project.

(1) Background: Spatial cognition (SC) is one of the earliest cognitive domains to be impaired in the course of Alzheimer's disease (AD), resulting in spatial disorientation and becoming lost even in familiar surroundings as later dementia symptoms. To date, few studies have identified initial alterations of spatial navigation (SN) in the premorbid AD phase by real-world paradigms, and none have adopted an innovative technological apparatus to better detect gait alterations as well as physiological aspects correlated to spatial disorientation (SD). The present study aimed at exploring initial SN defects in patients with prodromal AD via a naturalistic task by using a sensory garment. (2) Methods: 20 community-dwelling patients with Mild Cognitive Impairment (MCI) due to AD and 20 age/education controls were assessed on their sequential egocentric and allocentric navigation abilities by using a modified version of the Detour Navigation Test (DNT-mv). (3) Results: When compared to controls, patients with MCI due to AD exhibited higher wrong turns (WT) and moments of hesitation (MsH) in the DNT-mv, reflecting difficulties both in sequential egocentric and allocentric navigation, depending on hippocampal deterioration. Moreover, they reported more complaints about their SN competencies and lower long-term visuospatial memory abilities than controls. Remarkably, WTs and MsH manifested in the allocentric naturalistic task of the DNT-mv were associated with autonomic nervous system alteration pertaining to cardiac functioning in the whole sample. (4) Conclusions: Naturalistic navigation tests of hippocampal function using a continuous non-invasive monitoring device can provide early markers of spatial disorientation in patients with MCI due to AD. Future studies should develop cognitive remediation techniques able to enhance SC residual abilities in patients at high risk of conversion into dementia and ecological paradigms to be replicated on a large scale.

Evaluation and patient experience of wireless noninvasive fetal heart rate monitoring devices.

In clinical practice, fetal heart rate monitoring is performed intermittently using Doppler ultrasound, typically for 30 minutes. In case of a non-reassuring heart rate pattern, monitoring is usually prolonged. Noninvasive fetal electrocardiography may be more suitable for prolonged monitoring due to improved patient comfort and signal quality. This study evaluates the performance and patient experience of four noninvasive electrocardiography devices to assess candidate devices for prolonged noninvasive fetal heart rate monitoring. Non-critically sick women with a singleton pregnancy from 24 weeks of gestation were eligible for inclusion. Fetal heart rate monitoring was performed during standard care with a Doppler ultrasound device (Philips Avalon-FM30) alone or with this Doppler ultrasound device simultaneously with one of four noninvasive electrocardiography devices (Nemo Fetal Monitoring System, Philips Avalon-Beltless, Demcon Dipha-16 and Dräger Infinity-M300). Performance was evaluated by: success rate, positive percent agreement, bias, 95% limits of agreement, regression line, root mean square error and visual agreement using FIGO guidelines. Patient experience was captured using a self-made questionnaire. A total of 10 women were included per device. For fetal heart rate, Nemo performed best (success rate: 99.4%, positive percent agreement: 94.2%, root mean square error 5.1 BPM, bias: 0.5 BPM, 95% limits of agreement: -9.7 - 10.7 BPM, regression line: y = -0.1x + 11.1) and the cardiotocography tracings obtained simultaneously by Nemo and Avalon-FM30 received the same FIGO classification. Comparable results were found with the Avalon-Beltless from 36 weeks of gestation, whereas the Dipha-16 and Infinity-M300 performed significantly worse. The Avalon-Beltless, Nemo and Infinity-M300 closely matched the performance of the Avalon-FM30 for maternal heart rate, whereas the performance of the Dipha-16 deviated more. Patient experience scores were higher for the noninvasive electrocardiography devices. Both Nemo and Avalon-Beltless are suitable devices for (prolonged) noninvasive fetal heart rate monitoring, taking their intended use into account. But outside its intended use limit of 36 weeks' gestation, the Avalon-Beltless performs less well, comparable to the Dipha-16 and Infinity-M300, making them currently unsuitable for (prolonged) noninvasive fetal heart rate monitoring. Noninvasive electrocardiography devices appear to be preferred due to greater comfort and mobility.

Photoplethysmography for Assessing Microcirculation in Hypertensive Patients After Taking Antihypertensive Drugs: A Review.

High blood pressure (BP) is a common disease and is associated with many chronic diseases. Measuring BP is essential for the treatment and management of many diseases, and therefore there is a growing need for a non-invasive, sleeveless and continuous BP monitoring device. With the development of technology, pulse waveform analysis using photoplethysmography (PPG) has become more feasible for evaluating BP. This study aimed to evaluate the changes of vascular elasticity and blood volume over time by using the characteristic parameters extracted by PPG. We reviewed the latest progress and literature on the observation of capillary network characteristics in hypertensive and non-hypertensive patients by PPG, the influence of different drugs on microcirculation characteristics in hypertensive patients with PPG, and further explored the key relationship between microcirculation and hypertension. We found that the PPG waveform produced by the fingertips of hypertensive patients is very different from that of healthy people, and the PPG waveform changes significantly during diastolic period after antihypertensive treatment. With the rapid development of medical technology, people can get more intuitive microcirculation image data, which provides beneficial help for the comprehensive understanding of hypertension.

Analysis of Non-Invasive Devices and Techniques Involved in Continuous Monitoring of Interstitial Glucose of Patients with Type 1 Diabetes

Abstract: There are 422 million diabetes patients worldwide according to 2023 census of WHO, and around 100 million cases in India. 8.4 million type 1 diabetes cases were recorded as of 2021. By 2040, it is projected that the number of people living with Type 1 Diabetes will reach 13.5–17.4 million. The surge in diabetes cases has created the critical need for regular glucose monitoring to effectively manage this prevalent health issue. Currently, glucose levels are predominantly measured invasively by pricking the finger for a blood sample and involves invasive methods, such as fingertip pricks, which can be uncomfortable and inconvenient, particularly for paediatric patients. This method utilizes blood glucose monitoring devices, which measure sugar levels in a small blood sample placed on a disposable test strip and have a certain degree of inaccuracy. Patients do not test as often as they should because of the pain and hassle of finger pricks and many do not achieve optimal glycaemic control. However, the shift toward non-invasive continuous glucose monitoring is becoming increasingly imperative and a promising alternative. With current biotechnological advances, many techniques offer a non-invasive, continuous means of monitoring glucose levels and have garnered significant attention in recent years. The objective is to consolidate and summarize recent advancements in non-invasive continuous glucose monitoring, emphasizing integration into wearable platforms for seamless and real-time monitoring. Furthermore, paediatric patients with Type 1 Diabetes face elevated risks of severe hypoglycaemic and hyperglycaemic events due to challenges in glycaemic control. Frequently, monitoring blood glucose is crucial to mitigate these risks and achieve optimal glycaemic management. The objective of ongoing research is to validate AI-based algorithms utilizing ECG signals collected through non-invasive devices to detect glycaemic events. These advancements, once commercially available, have the potential to revolutionize glucose monitoring, offering a convenient, efficient, and less intrusive approach, particularly benefiting paediatric patients and improving overall healthcare management. Despite substantial research and development, challenges persist, including standardizing sweat collection methods, addressing sample degradation, accounting for variations in sweat composition among individuals, optimizing diverse detection methods, improving glucose detection sensitivity, and ensuring overall commercial viability. Overcoming these challenges is paramount to bridge the gap between research and market availability, paving the way for a technological revolution in glucose monitoring. In this study, we compared potential non-invasive glucose monitoring devices and techniques to evaluate the most accurate, pain-free, fast, and cost-friendly device. Upon examination and survey, we have theorized the drawbacks persisting in the existing devices and hypothesized techniques. Looking forward this study has a broader application in not only understanding the limitations and creating more accurate devices but also in continuous glucose monitoring for diabetic patient care.

Electro-Structured Cu Distorted Nanopyramids for Superior Sweat Glucose Sensing

There is a rising global demand for non-invasive glucose monitoring devices, due to an increase in diabetes and its associated health problems. Nanostructures, including needles, fibers, and rods, have drawn considerable attention due to their unique structural-based physical and chemical features in non-enzymatic electrochemical sensing. Copper is a potential candidate for applied research because of its higher electrical conductivity, low cost, and strong reactivity. To create 3-D nano copper structures, researchers have investigated chemical, electrochemical, and hydrothermal techniques. The electrochemical method can better control the formation reaction for these structures. The electrochemical process has better control over the formation reaction for these structures.Distinctive and self-supported copper nanopyramids were electrochemically created on a copper substrate within a few seconds by electrochemical deposition in a one pot synthesis. The SEM image of the constructed nano copper pyramids are shown in figure 1a. The built nano pyramids have a length of ~200 nm. The generated nanostructures display excellent catalytic activity for non-enzymatic glucose sensing. The created nonenzymatic sensor was tested for glucose detection in synthetic sweat and it displayed a linear response in the range of 20 µM- 2000 µM, making it appropriate for practical applications. The chrono amperometry for glucose sensing was performed at 0.5V for 60s. Figure 1b shows the calibration plot for glucose sensing. Linear response for the glucose was observed in the range from 20µM – 2000µM. The device showed a very low interference for uric acid and ascorbic acid. The device is stable upto 60 days, highly reproducible and can be reused upto 5 times. The correlation coefficient was 0.9857 for the linear equation I(μA) = (9.52*10-3) *C (in µM) + 5.065 and a sensitivity of 1.17 nA/(μM-cm2) was observed Figure 1

Development of Non- Invasive Cholesterol Monitoring System Using TCRT5000 Sensor with Android Compatibilty

High cholesterol levels cause several diseases, such as atherosclerosis (narrowing of the arteries), coronary heart disease, high blood pressure, obesity, thyroid disorders, diabetes mellitus, liver disease, and kidney disease. Generally, such checking is carried out invasively in clinical laboratories or hospitals. The checking can be done individually at a lower cost by using non invasive cholesterol measuring devices. This study aims to design and implement an android-based non-invasive cholesterol monitoring device using the TCRT5000 sensor. The tool developed was tested to measure cholesterol levels in 15 respondents aged 20-30 years. The research procedure consisted of several stages, starting with the design stage of the tool, which was carried out by assembling the components; the second stage was the tool coefficient of determination test, the third stage was the accuracy test, and the last stage was the data transfer speed test. The average accuracy of the tool is 83.18%, and the avarage of delay is 8.8 ms. This tool has considerable potential to be used in a telemedicine system that can be accessed remotely regularly to determine the estimated value of cholesterol levels in the blood.

Use of remote patient monitoring kits to reduce hospitalization and mortality rates for patients with heart failure.

Patients with heart failure (HF) are at an increased risk of volume overload, which can lead to hospital admission. Use of noninvasive remote patient monitoring (RPM) devices utilizing biometric sensors and weighing scales to track vital signs and body weight has uncertain benefits. At the Baptist Health Louisville (BHLOU) HF Clinic, high-risk patients were given RPM kits. The purpose of this study was to determine whether RPM led to reductions in HF hospitalizations and mortality. This single-center, retrospective chart review evaluated adult patients presenting to the BHLOU HF Clinic after a recent hospitalization for HF or need for intravenous diuretics within the past 60 days. The study evaluated patients before and after implementation of RPM kits. The primary endpoints were differences in the rates of 30-day HF hospitalization and 30-day mortality. Secondary endpoints included differences in the number of interventions in 90 days, the 90-day rate of HF hospitalization, and the 90-day rate of mortality. The final analysis included 58 patients in the preimplementation group and 34 patients in the postimplementation group. The rate of 30-day HF hospitalization was 10.3% in the preimplementation group and 0% in the postimplementation group. The rate of 30-day mortality was 3.4% in the preimplementation group and 0% in the postimplementation group. For the secondary endpoints, the number of interventions in 90 days was 3 vs 4, the 90-day rate of HF hospitalization was 22.4% vs 11.8%, and the rate of 90-day mortality was 6.9% vs 5.9% in the preimplementation vs postimplementation group, respectively. Implementation of RPM in patients with acutely decompensated HF led to numerically lower 30-day and 90-day rates of HF hospitalization.

Agreement of continuous non-invasive arterial blood pressure monitoring (CNAP) and pulmonary artery catheter thermodilution method in estimating the hemodynamic parameters of post CABG patients

Abstract Background The use of hemodynamic parameters in monitoring patients after coronary artery bypass surgery is an essential element of clinical practice. It helps intensivist and physicians to properly manage patients after surgery where hemodynamic parameters are usually dynamic and complicated. Pulmonary artery guided thermodilution (PACT) has been the gold standard in assessing the adequacy of cardiac output, however, its invasive nature is also associated with more complex procedures and the risk of complications, including infections. With the emergence of new non-invasive hemodynamic monitoring devices such as the CNAP (continuous non-invasive arterial pressure), alternative methods for hemodynamic monitoring is now possible. Compared to invasive methods, it is easier to use with an error-free application, safer, less risk of infection and more cost effective. Purpose To determine the agreement of Continuous non-invasive arterial pressure (CNAP) and pulmonary artery guided thermodilution in monitoring the hemodynamic parameters of patients who underwent coronary artery bypass graft surgery. Methods This is a cross-sectional study conducted at the cardiovascular surgical intensive care unit and included 63 patients with Coronary artery disease who underwent elective coronary artery bypass graft surgery. Cardiac output, Cardiac Index, Stroke volume and Systemic vascular resistance were simultaneously obtained using both the CNAP and PACT. Three consecutive sets of measurements were recorded for each patient with a 3 hour interval; during arrival at the ICU, 3 hours post op, and 6 hours post op. Results The mean difference between PACT-CO and CNAP-CO was -0.81 L/min (SD -1.18 to -0.44) with a 95% limits of agreement of -3.74 to 2.11 L/min on the 0 hour, -0.81L/min (SD -1.22 to -0.41) with a 95% limits of agreement of -1.98 to 1.18 L/min on the 3rd hour, and -0.77L/min (SD -1.08 to -0.46) with a 95% limits of agreement of -3.22 to 1.68 L/min on the 6th hour post op. The results showed a significant difference between the PACT and CNAP. However, a positive correlation was noted between PACT-CO and CNAP-CO, the correlation coefficient on the 0, 3rd and 6th hour were 0.5384, 0.5158, and 0.6265 respectively. Conclusion CNAP derived hemodynamic parameters had a high mean difference compared to the PACT and there was no agreement between the two methods. However, it was able to have a positive correlation with the PACT, making it possible for the CNAP to track the hemodynamic changes during the post operative course.

Abstract 14381: A Novel Non-Invasive Screening Device for Aortic Stenosis

Introduction: Severe AS is a significant health concern in the elderly population, and a large proportion of asymptomatic cases are not receiving appropriate care. Early intervention is associated with a significant reduction in long-term mortality making early diagnosis and intervention crucial. Hypothesis: Recent progress in non-invasive (NI) hemodynamic measurements and AI has prompted the exploration of NI screening tools for AS. The ClearSight® system (Edwards) is a NI monitoring device using a finger cuff for continuous hemodynamic assessment. This study aims to evaluate its accuracy as a severe AS screening tool. Methods: 7,000 consecutive patients referred for TTE were enrolled prospectively, between 12/2020 and 04/2022 and underwent concomitant non-invasive hemodynamic monitoring using the ClearSight ® system. Complete data were obtained on 6,858 patients. The development cohort consisted of 5,334 patients, whereby an AI system was trained to interpret the data obtained from the device with the TTE data serving as the gold standard for diagnosis of severe AS. After the development phase, 1,036 patients were included in the validation cohort, whereby the trained AI system used the data obtained from the device to predict the presence of severe AS. Results: Severe AS was confirmed by TTE in 54 patients. Based on the optimal threshold (ROC curve), the sensitivity for detecting severe AS in patients without other VHD was 87%, with a NPV of 98.1%, and a specificity of 80%. When including all patients, with and without concomitant non-aortic VHD, the sensitivity remained at 87% for the same threshold, with a similarly very high NPV at 98.9%, while the specificity decreased to 70.7%. Conclusions: The ClearSight ® system, a finger-cuff NI hemodynamic monitoring tool, serves as an excellent screening test for the early detection of severe AS, with high sensitivity and specificity, and a very high NPV in a large cohort of patients consecutively referred to a TTE laboratory.

The effect of temperature on permittivity measurements of aqueous solutions of glucose for the development of non-invasive glucose sensors based on electromagnetic waves

This article presents for the first time an empirical study that shows the importance of considering temperature when analyzing the permittivity (dielectric constant) of aqueous glucose solutions of various concentrations. The permittivity is a parameter that is investigated by researchers as a biomarker for non-invasive measurement of glucose without drawing blood. The development of this technology will allow personalized healthcare diagnostics to monitor and prevent diabetes. Since human glucose levels in the blood vary in the range of a few milligrams per decilitre, estimating such small variations of glucose will require a highly accurate and repeatable sensing technology. Electromagnetic (EM) waves, specifically in the microwave and terahertz frequency ranges, have shown promise in detecting changes in the electrical properties of blood plasma as they relate to glucose concentration. However, it's important to note that while this technology shows promise, it is still in the research and development phase. It is shown here that the body temperature can affect the accuracy of the blood glucose measurements. Experiments were conducted with different glucose concentration solutions under various temperatures and the complex permittivity of the glucose was studied across a wide frequency range from 400 MHz to 11 GHz. The rise in thermal energy normally causes dipolar liquids like water to vibrate and rotate disrupting the alignment of the dipoles in response to an electric field thereby reducing its permittivity. Empirical results however show that for aqueous solution of glucose the permittivity increases with rise in temperature from 16 °C to 37 °C. This is attributed to the polar nature of the water and glucose molecules that becomes more pronounced with increased thermal energy. Based on the experimental results an accurate analytical expression is derived that considers the temperature of the aqueous glucose solution. The accuracy of the analytical expression is shown experimentally to be above 99%. The findings from the study should enable the design of accurate non-invasive glucose monitoring devices based on electromagnetic sensing techniques.

Beware of buying online noninvasive continuous glucose monitoring devices: danger is just around the corner!

Beware of buying online noninvasive continuous glucose monitoring devices: danger is just around the corner!

Pulse Waveforms Monitoring Using Supercapacitive Sensing

There is a recent boost of interest in wearable, flexible sensors, and devices for non-invasive monitoring of physiological parameters. Among such flexible sensors, considerable research has been appointed towards flexible pressure sensors. These pressure sensors can detect large and small deformations suitable for applications ranging from e-skin to detecting tiny pulse waveforms from the neck and wrist artery. In order to realize a sensor capable of pressure sensing targeting numerous applications, the recent sensors should have high sensitivity with an extended pressure range, fast response time, and a high signal-to-noise ratio. Pulse waveforms are important cardiovascular biomarkers that bear essential information about cardiovascular health. In order to visualize and extract meaningful information from the pulse waveforms, acquiring high-quality pulse waveforms is the prerequisite. However, building highly sensitive pressure sensors is still challenging while maintaining the sensitivity with a broad pressure sensing range. Targeting these issues, this study presents a facile and cost-effective approach to realize a capacitive pressure sensor based on a supercapacitive sensing mechanism. The sensor could achieve high sensitivity of 2.9kPa-1 with a broad and linear range of around 100kPa. Besides, the sensor has a fast response time of 0.2s and negligible hysteresis. The sensor showed no performance degradation after 5000 cycles. In order to show the practicality, the sensor was used to acquire pulse waveforms from wrist and neck arteries under different conditions. The excellent performance of the sensor was observed as the sensor could detect detailed pulse waveforms under all circumstances. The detailed results will be discussed during the presentation.

A fingertip-type magnetic pulse detection device for unusual monitoring conditions

Wearable devices for continuous non-invasive monitoring of physiological signals are crucial for preventive care and management of chronic conditions. However, these devices are either sensitive to skin conditions or require external stimuli, such as light or electrical excitation, to penetrate the skin for pulse detection. This often results in large motion artifacts and unsuitability for certain skin conditions. Here we demonstrate a simple fingertip-type device which can detect clear pulse signals under a range of conditions, including fingers covered by opaque substances such as a plaster or nail polish, or fingers immersed in water. The structure of the device consists of a pair of magnets and a magnetic sensor. Both experimental and numerical results show that the detected pulsation signals correspond directly to the vibrations induced by blood circulation with negligible influence from modulated magnetic signature of blood. Therefore, this device could be used in conditions which are challenging for existing pulse detectors and might also have its application extended to blood pressure measurement.

On the Experimental Investigation of Bone Fracture Recovery Process Using an Ultra-Wideband Planar Monopole Antenna

In this paper, a noninvasive bone fracture monitoring system is developed using a planar monopole antenna. The proposed antenna provides an ultra-wideband response, and its overall size is 18 × 19 × 0.8 mm3. The proposed ultra-wideband monopole (UWM) antenna has a maximum measured gain of 3.77 dBi, and the maximum SAR value for an input power of 18 dBm is less than 1.6 (W/kg) (1 g). A bovine tibia is experimentally tested using a proposed UWM antenna to monitor the fracture recovery process and then further analysed using principle component and linear regression analysis. In addition, a microcontroller with a wireless communication module is developed to monitor the data in an Android application. The proposed system could be a promising approach for developing a portable, noninvasive monitoring device.