A Flexible Multiring Concentric Electrode for Non-Invasive Identification of Intestinal Slow Waves

Abstract

Developing new types of optimized electrodes for specific biomedical applications can substantially improve the quality of the sensed signals. Concentric ring electrodes have been shown to provide enhanced spatial resolution to that of conventional disc electrodes. A sensor with different electrode sizes and configurations (monopolar, bipolar, etc.) that provides simultaneous records would be very helpful for studying the best signal-sensing arrangement. A 5-pole electrode with an inner disc and four concentric rings of different sizes was developed and tested on surface intestinal myoelectrical recordings from healthy humans. For good adaptation to a curved body surface, the electrode was screen-printed onto a flexible polyester substrate. To facilitate clinical use, it is self-adhesive, incorporates a single connector and can perform dry or wet (with gel) recordings. The results show it to be a versatile electrode that can evaluate the optimal configuration for the identification of the intestinal slow wave and reject undesired interference. A bipolar concentric record with an outer ring diameter of 30 mm, a foam-free adhesive material, and electrolytic gel gave the best results.

Evaluation of Swallowing Related Muscle Activity by Means of Concentric Ring Electrodes

“…CREs were first used in electrocardiography to acquire high spatial resolution surface ECG signals [ 20 ]. They were later developed in different configurations [ 21 ], dimensions and materials (from rigid substrates [ 22 ] to flexible or textile ones [ 23 ]) to pick up a wide range of bioelectric signals such as electroencephalographic [ 22 , 24 ], electrohysterographic [ 25 , 26 ], electroenterographic [ 27 , 28 ] and diaphragmatic sEMG [ 29 ], and others from the skeletal muscles [ 30 ]. The masseter EMG has been recorded by CRE in clinical sleep bruxism (SB) diagnosis in the muscles involved in the swallowing process [ 31 ].…”

Evaluation of Bipolar, Tripolar, and Quadripolar Laplacian Estimates of Electrocardiogram via Concentric Ring Electrodes

“…It has been shown that tripolar CREs provide more accurate estimates of surface Laplacian compared to quasi-bipolar and bipolar CREs while also offering better spatial resolution [19,20]. CREs were first implemented on rigid substrates [20,21,22] and subsequently on flexible substrates such as polyester films [23,24,25] polydimethylsiloxane [26], or textiles [27]. This study builds on a series of studies aiming to improve the accuracy of Laplacian estimation using CREs by optimizing the number of concentric rings [28] and inter-ring distances (distances between the consecutive rings) [29,30].…”

Textile Concentric Ring Electrodes: Influence of Position and Electrode Size on Cardiac Activity Monitoring

“…Other configurations of electrode layouts and shapes are needed for better spatial resolution. To deal with this issue, modified electrode designs based on concentric ring electrodes (CREs) have been applied to several bioelectric signal recording and analysis, such as electrocardiographic (ECG) [11][12][13][14][15], electroenterographic (EEnG) [16], and electrohysterographic (EHG) signals [17]. The concentric ring design is a physical approximation to the Laplacian filter, which is the second spatial derivative of the measured potentials and essentially assigns more weight to changes in bioelectric dipoles under measurement points, to enable better differentiation between concurrent, closely spaced dipole sources [14].…”

“…So far, CREs have been built on rigid substrates [12,20,21] or flexible substrates such as polyester films [14,16,17] or polydimethylsiloxane (PDMS) elastomer [22]. We recently produced a CRE on a textile that can potentially benefit from the combination of long-term recording with high spatial resolution [23].…”