Emerging Paradigms in Fetal Heart Rate Monitoring: Evaluating the Efficacy and Application of Innovative Textile-Based Wearables

Figures

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  Figure 1. (a) Non-invasive fHR measurement. (b) Invasive fHR measurement, reproduced from [19] under terms of the Creative Commons Attribution License.

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  Figure 2. Wearable fetal ECG monitoring system from abdominal ECG recording. (a) Electrode placement. (b) Postures of the subject. (c) Monitoring system. (d) Hardware prototype. Reprinted from [30] under terms of the Creative Commons Attribution License.

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  Figure 3. Sample recordings of ECG which includes the P wave, QRS complex, and T wave; these help clinicians assess the timing and magnitude of electrical impulses that coordinate the heartbeat and PCG signals where the first heart sound (S1) corresponds to the closure of the mitral and tricuspid valves at the start of systole, while the second heart sound (S2) corresponds to the closure of the aortic and pulmonary valves at the end of systole additional sounds, such as S3 and S4, which can indicate pathological conditions. Reprinted from [38] under terms of the Creative Commons Attribution License.

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  Figure 4. Basic schematic diagram of non-invasive PCG-based interferometric sensors and adaptive system for fHR monitoring. Reprinted from [38] under terms of the Creative Commons Attribution License.

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  Figure 5. Different commercially available FHR monitoring systems (a) STAN monitors from Neoventa Medical, Goteborg, Sweden. (b) Monica AN24 Monitor from Monica Healthcare, Nottingham, UK. (c) MindChild Medical from North Andover, MA. (d) Novii, GE Healthcare, Cambridge, UK.

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  Figure 6. (a) Experimental setup and environment. (b) Illustration showing the proof-of-concept setup with three sensor nodes Reprinted from [88] with permission, Copyright © 2024 Elsevier B.V.

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  Figure 7. Schematics of (a) U.S. Patent US4781200A and (b) US Patent US20170150926A1. Reproduced from [106,107] under the Creative Commons Attribution License.

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  Figure 8. A textile-based sensor. (a) Placement of electrodes using elastic belts on the mother’s belly. (b) Four textile electrodes. (c) Schematic configuration of the electrodes and the related bipolar leads, which are identified by arrows. The design is symmetric concerning the navel. Reproduced from [99] under terms of the Creative Commons Attribution License.

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  Figure 9. Stretchable fHR monitoring device. (a) Schematic of the relative position of the electrodes on the mother’s abdomen and the fabrication of the sensors on the bodysuit; (b) a functional diagram of the Telefetalcare System. Reproduced from [104] under terms of the Creative Commons Attribution License.