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Neurological disorders, cardiovascular diseases and strokes are leading causes of mortality worldwide. Diagnostics and therapeutics for patients under timely point-of-care can save thousands of lives. However, lack of access to minimally-intrusive monitoring systems makes timely diagnosis difficult and sometimes impossible. Existing ambulatory reco...
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... trocardiogram (ECG) is a simple non-invasive test to observe the vari- ations in biopotentials originating from the heart, through electrode sensors placed on the surface of the skin. The ECG waveform ac- quired from a derived Lead II electrode placement system is shown in Figure 7, which clearly depicts the classical components of the ECG waveform. The waveform characteristics of the ECG include P wave, QRS complex, T and U waves. ...
Citations
... Traditional wet electrodes made of Ag/AgCl and gels may irritate the skin and perform worse after drying. 76,77 The dry electrode made of metal may be uncomfortable, unpleasant, or inconvenient despite its durability. The properties of polymer gels can be tailored by varying the type of polymer used, the degree of cross-linking, and the environmental conditions. ...
Wearable sensors offer a non-invasive, continuous, and personalized approach to monitor various physiological and environmental parameters. Among the various materials used in the fabrication of wearable sensors, polymers have gained significant attention due to their versatile properties, low cost, and ease of integration. We present a comprehensive review of recent advances and challenges in the development of polymer-based wearable sensors. We begin by highlighting the key characteristics of wearable sensors, emphasizing their potential applications and advantages. Subsequently, we delve into the various types of polymers employed for sensor fabrication, such as conductive polymers, elastomers, and hydrogels. The unique properties of each polymer and its suitability for specific sensing applications are discussed in detail. We also address the challenges faced in the development of polymer-based wearable sensors and describes the mechanism of action in these kinds of wearable sensor-capable smart polymer systems. Contact lens-based, textile-based, patch-based, and tattoo-like designs are taken into consideration. Additionally, we paper discuss the performance of polymer-based sensors in real-world scenarios, highlighting their accuracy, sensitivity, and reliability when applied to healthcare monitoring, motion tracking, and environmental sensing. In conclusion, we provide valuable insights into the current state of polymer-based wearable sensors, their fabrication techniques, challenges, and potential applications.
... Ionic flux is critical in signaling, conduction, and contractility in various cell and tissue lineages. [7][8][9][10][11] Furthermore, ionic and molecular components of sweat are essential for identifying the effects of body stress. [12][13][14] Recently, wearable sensors have been in demand to monitor sweat, and similar systems can be devised to monitor internal and external body fluids and secretions. ...
... Data from transducers shown on the left, and theoretical data for density and concentration relationship shown on the right from cited research.77,85,86,87 ll OPEN ACCESS10 iScience 26, 106907, June 16, 2023 ...
Sensing the ionic content of a solution at high spatial and temporal resolution andsensitivity is a challenge in nanosensing. This paper describes a comprehensiveinvestigation of the possibility of GHz ultrasound acoustic impedance sensorsto sense the content of an ionic aqueous medium. At the 1.55 GHz ultrasonic fre-quency used in this study, the micron-scale wavelength and the decay lengths inliquid result in a highly localized sense volume with the added potential for hightemporal resolution and sensitivity. The amplitude of the back reflected pulse isrelated to the acoustic impedance of the medium and a function of ionic speciesconcentration of the KCl, NaCl, and CaCl2 solutions used in this study. A concen-tration sensitivity as high as 1 mM and concentration detection range of 0 to 3 M was achieved. These bulk acoustic wave pulse-echo acoustic impedance sensorscan also be used to record dynamic ionic flux.
... Therefore, a method is presented to reduce the number of electrodes needed so that a wearable device that captures ECG can be designed to capture all information needed for an accurate diagnosis without compromising the quality of life for patients and diagnostic utility. We present this method as a complementary technique to wearable ECG monitoring technology that our research group has previously demonstrated using cloth-based Nanosensor technology [24]. Even though the electrode placements in the proposed method span the whole area of the chest, a wearable device in a textile form factor can be designed to capture the necessary leads with the advantage of not requiring adhesives, conductive gels, or skin preparation [25]. ...
Background and objective:
The prevalence of chronic cardiovascular diseases (CVDs) has risen globally, nearly doubling from 1990 to 2019. ECG is a simple, non-invasive measurement that can help identify CVDs at an early and treatable stage. A multi-lead ECG, up to 15 leads in a wearable form factor, is desirable. We seek to derive multiple ECG leads from a select subset of leads so that the number of electrodes can be reduced in line with a patient-friendly wearable device. We further compare personalized derivations to generalized derivations.
Methods:
Long-Short Term Memory (LSTM) networks using Lead II, V2, and V6 as input are trained to obtain generalized models using Bayesian Optimization for hyperparameter tuning for all patients and personalized models for each patient by applying transfer learning to the generalized models. We compare quantitatively using error metrics Root Mean Square Error (RMSE), R2, and Pearson correlation (ρ). We compare qualitatively by matching ECG interpretations of board-certified cardiologists.
Results:
ECG interpretations from personalized models, when corrected for an intra-observer variance, were identical to the original ECGs, whereas generalized models led to errors. Mean performance values for generalized and personalized models were (RMSE-74.31 µV, R2-72.05, ρ-0.88) and (RMSE-26.27 µV, R2-96.38, ρ-0.98), respectively.
Conclusions:
Diagnostic accuracy based on derived ECG is the most critical validation of ECG derivation methods. Personalized transformation should be sought to derive ECGs. Performing a personalized calibration step to wearable ECG systems and LSTM networks could yield ambulatory 15-lead ECGs with accuracy comparable to clinical ECGs.
... The ATMEGA 328 is functionally identical to other ICs in terms of pin compatibility and features a 32kB flash memory, additional SRAM and EEPROM, pin change interrupts, and timers [12] [13]. Some of the features of ATMEGA 328 are: 28-pin AVR microcontroller with 32 Kbytes of Flash program memory, 1 Kbytes of EEPROM data memory, 2 Kbytes of SRAM data memory, 23 I/O pins, two 8-bit timers, an A/D converter, six channels of PWM, an embedded USART, and an external oscillator with a 20 MHz operating frequency are among the features of the ATMEGA 328 [14] [15]. ...
This manuscript addresses the design and implementation of a portable PC-based ECG device. Three electrodes are often employed for ECG recording, with two of them being connected to the patient's chest via the ECG amplifiers' differential inputs. Therefore, every stage of the design takes into account factors like low cost, low power consumption, portability, and simplicity of usage. In this system, the ATMEL Company's ATMEGA 328 low-power microcontroller is investigated for signal processing and delivering digital format to a PC through a serial connection, where it is then displayed utilizing LabVIEWTM SP1 software ( The released version in Feb. 2022). A portable tool that can capture, amplify, filter, and analyze biological signals is this one ECG. The intended device's target beneficiary was the intensive care unit.
... fabric, thread, or yarn) are an important element in the realization of smart textiles. It can act as an interconnect between components to transfer signals or power such as health monitoring sensors(Rai et al., 2014) and solar cells. Meanwhile, it can also be used in applications of electromagnetic interference (EMI) shielding, resistive fiber sensors, and wearable antennas, because of its own features. ...
In latest revolutionary achievement in functional textile is Nano engineering and
Nano technology. The potential consideration of this technology cause to
develop new material and products to fulfill the end uses. As per end users,
uniqueness of materials and their characteristics that will extended to
economically with huge potential, and also attracting the new ventures and
researchers. In globally, the research interest has been provoked on nano
engineered materials and textiles. They moved into develop the tool to enhance
the performance and feature of the textile product. There also some
contradictory issues on the environment and human health. With massive
researches that reveals, the developed products with their commercial reality and
viable production. The impact of nanotechnology on textiles shows only the
way to uplift the product features to suit the application of multi functionality.
The products such as nano fibres, nano coatings, nano finishing and composites
are giving promising potentiality in textile revolution as anti bacterial textiles,
self cleaning fabrics, Absorbency and wicking controlled textiles, Fire proof
textiles, conductive fabrics and Ultra violet radiation without affecting the
features and properties of fibres. The properties of fibres and Nano material can
be used to manufacture the fabric with good chemical resistance, antimicrobial
and bacterial, water repellency etc., The method of nanotechnology overcomes
the conventional method of processing with their limitations and also the
material properties. The effect of toxicity of nanoparticles on consumer products
also a point to be understand. This chapter focuses on the development and
potential applications of nanotechnology in developing multifunctional textiles
such as Sensing textiles, drug release application of textiles, Photonic
technologies, Electronics in textiles, graphene yarns, graphene coated textiles
and nanofinishing of textile substrates.
... Brooklyn, NY) combined with demographics data (age, gender, height, and weight) which is added as a predictor so that the confounding effects encountered by pulse wave-based techniques could be potentially mitigated. SimpleSense is a non-invasive, wearable, and portable medical device that uses cloth-based nanosensor technology 13 (Fig. 1). The garment was designed with an emphasis on ease of wearing and takes between 20 and 30 s for most subjects to put on. ...
Targeted maintenance of blood pressure for hypertensive patients requires accurate monitoring of blood pressure at home. Use of multiparametric vital signs ECG, heart sounds, and thoracic impedance for blood pressure estimation at home has not been reported previously. In an observational multi-site study, 120 subjects (female (N = 61, 52%)) between 18 and 83 years of age were recruited with the following stratification (Normal (20%), prehypertensive (37%), stage 1(26%), and stage 2 (18%). From these subjects, 1686 measurements of blood pressure from a sphygmomanometer were associated with simultaneously acquired signals from the SimpleSense device. An ensemble of tree-based models was trained with inputs as metrics derived from the multiparametric and patient demographics data. A test Mean Absolute Difference (MAD) of ± 6.38 mm of Hg and ± 5.10 mm of Hg were obtained for systolic and diastolic blood pressures (SBP; DBP), respectively. Comparatively, the MAD for wrist-worn blood pressure cuff OMRON BP6350 (GUDID—10073796266353) was ± 8.92 mm of Hg and ± 6.86 mm of Hg, respectively. Machine learning models trained to use multiparametric data can monitor SBP and DBP without the need for calibration, and with accuracy levels comparable to at-home cuff-based blood pressure monitors.
... Wearable electronic devices have attracted significant attention in recent decades [1][2][3][4][5][6][7][8][9][10]. In various types of wearable devices such as smartwatches, fitness trackers, smart clothing, and wearable medical devices [11][12][13], wearable technology has been extensively applied. Wearable electronic devices are required to be lightweight, flexible, breathable, durable, washable, and economically meet practical and esthetic needs, with maximum freedom of movement and maximum comfort. ...
Among the various wearable electronic devices, textile-based piezo sensors have emerged as the most attractive sensors for practical application. In this study, a conductive nonwoven fabric is fabricated to develop a textile-based piezo sensor. This high-performance fabric is fabricated by depositing multiwalled carbon nanotubes (MWCNTs) on cellulose nonwoven composites with carbon fibers (CNwCa) through a spray process to assign conductivity, followed by electrospinning thermoplastic polyurethane (TPU) on the MWCNT-coated CNwCa to improve surface durability. Each component is optimized through experiments to control the electrical and physical characteristics of the conductive nonwoven fabric. The static and dynamic piezoresistive properties of the fabricated MWCNT composite conductive nonwoven are measured using a source meter and the fabricated sensor driving circuitry. In addition, a prototype bag with a touch sensor is developed using the fabricated conductive nonwoven fabric and its touchpad function is demonstrated using an Android application. The operation as a mode-switchable touch sensor was experimentally verified by inserting the sensor into a bag so that it can be used without direct manipulation on a mobile device. The findings of this study suggest that the developed flexible textile-based conductive nonwoven fabric can be effectively used in wearable devices with piezoresistive sensors.
... Oxygen sensing, biomechanical sensing Polyurethane, polypyrrole-coated lycra/polyester fabric (Mosinger et al., 2010;Rai et al., 2014) 8. ...
The nanotechnology field holds a lot of promise for commercial multifunctional applications in mod-ern textiles. Due to its unique features, nanotechnology’s application in textiles has grown fast. Nanomaterials may be synthesized in a variety of methods, including physical, chemical, and biological methods, and they are simply incorporated into fabric. Its application can improve the properties and value of textile processes and products at a lower cost. Textiles may become multifunctional thanks to nanotechnology, which allows for the creation of materials with unique features such as antibacterial, anti-odor, flame retardant, UV protection, water repellent, and wrinkle resistance. The current study compares the recent progress of various nanoparticle synthesis methodologies and nanotechnology applications in the textile industry, with a special focus on improving key textile properties for multi-functional fabric manufacture.
... Cardiovascular diseases are the leading cause of death worldwide, and the importance of monitoring cardiovascular activities is selfevident [1][2][3][4]. Prompt diagnosis and treatment could save thousands of lives [5][6][7]. The emergence of cardiovascular electronic devices has improved the diagnostic level of patients with cardiovascular diseases, reduced mortality and morbidity, and enhanced the quality of human life, such as the electrocardiogram (ECG) and pulse oximeters [8][9][10][11]. ...
Monitoring cardiovascular activities plays a critical role in predicting and preventing cardiovascular diseases. Flexible and biosafe sensors that can provide complementary information about cardiovascular activity beyond the traditional electrocardiogram (ECG) are in great demand. Here, a novel eco-friendly in-situ gap-generation method by vaporizing soaked distilled water is developed to fabricate a no-spacer triboelectric nanogenerator (NSTENG). This NSTENG reveals more uniform stress/strain distributions and undergoes larger displacement compared with the traditional TENG with spacer under the same pressure; and it obliterates the obstruction on detection of subtle movements near spacer. The unique fabrication method also guarantees biological safety and avoids air contamination in vivo. The established wireless mobile system based on the NSTENG can precisely detect the full pulse waveforms and display them on the phone screen in real time. By mounting onto the rat's heart, it can monitor normal heart motion and the measured heart rate has an accuracy of up to 99.73%. Moreover, the NSTENG can monitor abnormal heart motion and detect subtle heart movements that fail to be captured by the ECG. This work provides a new strategy that promotes the innovation of biosafe and new-structure TENGs, and offers new insights into developing wearable and implantable sensors.
... Layer stack and circuit model of the electrode-body interface for different electrode types. Inspired from[32,34,39,44,50,[52][53][54][55][56][57][58]. ...
Several on-body sensing and communication applications use electrodes in contact with the human body. Body–electrode interfaces in these cases act as a transducer, converting ionic current in the body to electronic current in the sensing and communication circuits and vice versa. An ideal body–electrode interface should have the characteristics of an electrical short, i.e., the transfer of ionic currents and electronic currents across the interface should happen without any hindrance. However, practical body–electrode interfaces often have definite impedances and potentials that hinder the free flow of currents, affecting the application’s performance. Minimizing the impact of body–electrode interfaces on the application’s performance requires one to understand the physics of such interfaces, how it distorts the signals passing through it, and how the interface-induced signal degradations affect the applications. Our work deals with reviewing these elements in the context of biopotential sensing and human body communication.
