Electrical characterization of conductive textile materials and its evaluation as electrodes for venous occlusion plethysmography

Abstract

The ambulatory monitoring of biosignals involves the use of sensors, electrodes, actuators, processing tools and wireless communication modules. When a garment includes these elements with the purpose of recording vital signs and responding to specific situations it is call a 'Smart Wearable System'. Over the last years several authors have suggested that conductive textile material (e-textiles) could perform as electrode for these systems. This work aims at implementing an electrical characterization of e-textiles and an evaluation of their ability to act as textile electrodes for lower extremity venous occlusion plethysmography (LEVOP). The e-textile electrical characterization is carried out using two experimental set-ups (in vitro evaluation). Besides, LEVOP records are obtained from healthy volunteers (in vivo evaluation). Standard Ag/AgCl electrodes are used for comparison in all tests. Results shown that the proposed e-textiles are suitable for LEVOP recording and a good agreement between evaluations (in vivo and in vitro) is found.

E-textiles in Clinical Rehabilitation: A Scoping Review

“…Textile-based bioimpedance measures have focused on body composition [24,37] and segmental volume estimation [23,44]. Hannikainen et al [24] proposed a total body water estimate using textile electrodes (material not disclosed), each connected by conductive yarn to a metallic snap fastener.…”

“…The authors qualitatively ascertained a maximum difference of 50 mL in tidal volume estimates between the two methods. Turning to the lower extremity, Goy et al [23] systematically investigated the utility of five different conductive textile materials (formed into 2 cm × 21 cm surface electrodes) for impedance-based estimation of blood volume changes, both in vitro (agar-agar synthetic skin) and in 5 healthy volunteers. Compared to standard Ag/AgCl electrodes, Goy et al obtained the strongest signal via two-way stretch knit fabric made of silver coated nylon/elastomer thread (76% nylon, 24% elastic fibre; 100% Ag coating) and deemed textile electrodes as suitable for lower extremity venous occlusion plethysomography.…”

The E-Textile for Biomedical Applications: A Systematic Review of Literature

“…Finally, in recent years, to the authors’ best knowledge, the last diagnostic solution in the field of cardiology, by means of e-textiles, was oriented to record lower extremity venous occlusion plethysmography (LEVOP). To this aim, Goy et al [ 40 ] developed and fabricated a custom-made battery powered plethysmograph, connected on the one side to an oscilloscope, and on the other side on a set of different e-textile electrodes. The authors conducted LEVOP recordings on 5 HC demonstrating all the three set of the proposed e-textiles materials can be used for LEVOP recordings, showing additionally a statistical in-depth analysis related to the recorded signals from the different materials.…”

Fabrication and application of flexible graphene silk composite film electrodes decorated with spiky Pt nanospheres

“…[23][24][25] Conductive textiles are another exible material used for ambulatory monitoring of biosignals. 26,27 Conductive textiles can be made with pure metal threads such as silver and stainless steel bres, 27 or produced with insulated bres including cotton, polyester, and nylon, coated with electrically conductive elements, like carbon, aluminium, copper, gold, or silver. [28][29][30][31][32] Electronic conductive coating of bres leads to the development of smart clothing in daily life with electrodes, sensors, and circuits directly embedded in the clothes.…”