Wearable Medical Devices: High-Level System Design Considerations and Tradeoffs

A wristwatch-style wearable dielectric resonator antenna (DRA) is proposed for the 2.45-GHz ISM band and sub-6 GHz 5G NR bands around 2.5 GHz, such as the commercial band for China Mobile Communications Corporation. The antenna is designed for applications on forearms and ankles. Practical concerns, including the aligning method, platform size, specific absorption rate, and user effects are investigated. Coplanar feeding structure is applied for alignment and isolation. Analysis of the watchband-like substrate is highlighted to avoid performance degradation. Given that platform configurations are not discretionary in actual devices, parasitic loading is introduced to attain desirable substrate effects and suppress unwanted ones. The user-device interplay is studied in light of actual application scenarios. The specific absorption rate is calculated through multilayer biological tissue models. Meanwhile, radiation variation caused by users is estimated based on human phantom models and measurements. INDEX TERMS Dielectric resonator antennas (DRAs), specific absorption rate (SAR), substrate effects, user effects, wearable antennas.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Wristwatch-Style Wearable Dielectric Resonator Antennas for Applications on Limps

Pan

Wang

et al. 2020

“…At present, smart clothing has begun to be applied in various fields, such as sports equipment, health equipment, and game equipment. Wearable technology is a new application that has emerged in recent years [1]. It can be widely used in clinical fields such as clinical monitoring, family health care, sleep analysis, emergency care, and special population monitoring [2].…”

Section: Introductionmentioning

confidence: 99%

Negative Electrode Material Properties and Motion Safety of Wearable Medical Devices

Zhang

Ren

2020

As health care has gradually become a hot research topic, the use of wearable medical devices to detect human exercise status and health indicators has become a focus of research. In this paper, lithium titanate materials with high safety and good structural stability were taken as the main research objects, and lithium titanate films with amorphous structure were studied. The film exhibited good electrochemical performance in the potential region of 0∼3 V, and the reversible capacity at 0.1 C was 283 mAh g-1, and only 3% of the capacity was lost after 100 charge and discharge. At a magnification of 5 C, the reversible capacity of the lithium titanate thin film reached 160 mAh g-1, and the loss rate after 100 charge and discharge was less than 7%. Based on EEMD (Ensemble Empirical Mode Decomposition), the intermuscular coherence was analyzed, and the characteristics of myoelectric signals were analyzed from different levels, and the muscle safety characteristics during exercise were estimated. Based on the test data analysis, the correlation between the average instantaneous frequency of sEMG (surface Electromyographic) and the intermuscular coupling characteristics during exercise is analyzed to provide a comprehensive evaluation method for muscle safety analysis. Finally, testing and analyzing the actual data to estimate the effectiveness of muscle safety provides a reference standard for the designation of exercise plans and the measurement of exercise volume. INDEX TERMS Wearable medical devices, negative electrode film, electrochemical performance, muscle exercise safety analysis, myoelectric signal.

“…Conformal antennas are preferable in electronic devices for vehicles, aircrafts, missiles, and wearable or implantable systems [10], [11]. These antennas are applied directly on the nonplanar surface of devices.…”

Section: Introductionmentioning

confidence: 99%

Estimation and Utilization of Ground Effects on Conformal Dielectric Resonator Antennas

Pan

Wang

et al. 2019

Ground effects on arc-shaped conformal dielectric resonator antennas (DRAs) working in the TE z 11δ mode are investigated and utilized to attain various radiation performances. Manipulation of directivity patterns are achieved with the help of the three-dimensional curved metal ground. The backlobe, beamwidth, broadside gain, backscattering, and cross-polarization level of the antenna are all readily controllable. The geometric theory of diffraction is applied to provide an intuitional explanation for the radiation changes. Detailed analysis is then conducted from the perspective of ground current. It is found that the current distribution is affected by configurations of both the arc DRA and ground plane. Based on this, analytical methods are developed to calculate the ground effects exclusively for conformal arc-shaped DRAs. Next, the design theory of arc DRAs with curved ground is proposed. To demonstrate it, two conformal DRAs owning directional and wide beams, respectively, are designed as paradigms. At last, a prototype is fabricated and measured for validation. INDEX TERMS Conformal antennas, dielectric resonator antennas (DRAs), ground effects, radiation patterns.