# Conductive Textiles for Signal Sensing and Technical Applications
## 5 Application of Conductive Textiles
### As Electronic Textiles (E-Textiles) for Bio-Sensing and Health Care  
People have been investigating the medical applications of electricity in clothing, such as cosets and belts, as early as the 1850s [[PERSON]]. The first wearable computer was imagined in 1955 by [PERSON] to predict roulette, terminating in a cooperative endeavor of M.I.T. with [PERSON] in 1960-1961 [290]. E-textiles, in which electronic functions are integrated more closely within the textile, evolved from wearable computing in the early 1990s. A \"Wearable Motherboard\" (smart [PERSON]) was developed to monitor the vital signs of humans in an unobtrusive manner, which opened up a new border in healthcare and telemedicine [291]. Scientists conducted additional research on wearable textiles to measure blood pressure, blood oxygen saturation, EEG, EOG, periodic leg movement, core body temperature, and skin temperature in the 2000s [292; 293; 294; 295; 296]. A spirometry, a simple test used to help diagnose and monitor certain lung conditions by measuring how much air people can breathe out in one forced breath by pinching noses with a clip and holding a mouthpiece in their mouth, is an uncomfortable condition for the users. An e-textile-based wearable spirometer, Spiro Vest, was demonstrated to gain more comfort than estimated lung behavior from torso-girth movements [297]. E-textiles-based stretch sensors were installed as elbow supports to maintain an ideal setting, and a knitted shirt was used to simulate a daily use setting to prevent caregiver injury in health and medical science [[PERSON]]. Based on built-in graphene-clad conductive textiles, elastic bands, and lithium batteries for power, a fully wearable smart medical garment comfortably worn around the wrists or neck was reported for ECG monitoring [299]. Sleeping disorders are a major health danger issue in high-paced modern society. A smart bedsheet using a triboelectric nanogenerator (TENG) with pressure sensitivity, large scalability, and washability for real-time and self-powered sleep behavior monitoring was reported [300]. Waterproof fiber-based strain sensors with a high gauge factor and outstanding stability are necessary for smart textiles, wearable devices, and biomedical electronics. To monitor various human motions (e.g., phonation, pulse, finger bending, and walking), this kind of strain sensor was invented and designed through a combination of PU yarn, multi-layer graphene nanosheets (GNSs)/thin gold film (Au)/GNSs, and a PDMS wrapping layer [301]. Recently, a textile magneto-elastic generator (MEG) was invented that could work as a self-powered sensor for continuous respiratory monitoring with heavy perspiration without any encapsulation [302]. Smart fabric sensors (SFS) are produced by modifying a fabric extrinsically or intrinsically for the sensor properties of SFSs. This can be done in various ways, such as the e-textiles fabrication method, via connectors or electrodes or textile circuitry and elements, encapsulation techniques, and coating. SFS sensors can be categorized as pressure and force sensors, fabric strain sensors, optical fabric sensors, fabric sensors for detecting chemicals and gases, and some parameters such as temperature- and humidity-sensitive fabrics [303]. Sensor development, fabric-based ECG signals, skin-electrode interface improvement, sensing shirts, and belts for sleep measurement were investigated. Different parameters, including movement, posture, and temperature, were reviewed and compared to the innovations in the textile field [304]. Figure 8 shows the construction of an ECG detecting smart garment as an example. The ECG sensor patches (5) were placed inside the undershift (\"1. 2.\" outside and inside faces for men or the bra strap \"3. 4.\" for women). (6) Cross-sectional view of the textile electrode (hitoe(r)). The cloth of polyester nanofiber (8) was coated by electroconductive polymer PEDOT-PSS (7, blue circles), and its surface was directly placed on the skin (9).