健身追踪器（或“可穿戴设备”）产品在过去十年间席卷健身行业。根据Precedence Research的数据，2022年全球可穿戴设备市场价值达到1380亿美元；预计到2032年这一价值将接近5000亿美元。无论是专业选手、铁杆健身爱好者，还是休闲慢跑爱好者，都在使用此类设备来监测一系列生命体征，以确保健康并有效地进行日常锻炼。

最近，一家名为Muse Wearables的印度初创企业以一款戒指形产品引爆健身市场，更重新定义了可穿戴设备的形态。这一称为“Ring One”的产品不仅仅代表了一种时尚，更是一款能够监测心率、心率变异性、血压、呼吸频率、体温和血氧水平的临床级追踪器。如果您认为这些功能还不够丰富，仅需简单切换运行模式，Ring One就能变身为一部支持NFC的电子支付设备。

智能戒指通过小型化的产品形式为健康追踪提供了绝佳机会，可用作日常陪伴和时尚配件。 配备 NFC 充电、支付和认证服务，为用户体验带来便利性和功能性。 低功耗蓝牙^® SoC 有助于优化性能、降低功耗和减少 BOM，是高度集成设备的理想选择。 其先进的加密块可在传输前保护敏感数据，而大型内部存储器会在手机不在身边时记录数据。

系统优势：

• 用于电池充电、支付和身份验证应用的共享 NFC 天线
• 降压—升压架构可实现稳定的功率输出，不受电池充电状态的影响
• 先进的加密技术、BLE 5.x 支持和嵌入式闪存，功耗相比同类产品中极低

The Future of Wearable Technology: Revolutionizing Health Monitoring with Smart Rings

Design Challenges

The high-level requirements for a smart ring include form factor, robustness, visual appeal, comfort, and battery runtime. Since the intention is that the ring is worn continuously, it must withstand various environments and conditions just as our hands do. This includes regular hand washing with soap, exposure to acids and other substances when cooking, salt water when swimming in the ocean, hot temperatures when in the sauna, and the list goes on.

At the same time, the ring is worn on the hand and must be comfortable and non-intrusive, avoiding any hindrance or clunky appearance. If the ring must be removed too often to charge, it will become a burden to the user, charging overnight is not an option since it needs to be worn to assess recovery during sleep.

To translate these high-level requirements into design specifications means the physical space for components is extremely limited, the overall thickness is very limited, and encapsulation in waterproof yet skin-compatible material is necessary. The average power consumption needs to be low enough to allow operation for multiple days on a minuscule battery while keeping a high enough measurement frequency for accurate data collection. The connectivity interface must be secure to ensure that only authorized users can access the data. All these features must fit into a circular object with varying radii to accommodate different ring sizes.

System Setup

This is where Renesas' Smart Ring winning combination (see diagram below) helps smart ring designers achieve their targets. The ring's core is designed around the DA14592, a Bluetooth^® Low Energy SoC offering the lowest power consumption and smallest solution footprint in its class. With an ultra-low active current of 34µA/MHz, 2.3mA at 0dBm transmit power, and 1.2mA when receiving, the SoC provides significant processing power with its multi-core processing architecture, which together with Reality AI can implement edge AI applications to optimize the power consumption while maximizing the data analysis. The PTX30W, a single-chip solution for NFC-based charging, integrates an NFC tag, rectifier, Li-ion battery charger, and charging protocol controller all in a WL-CSP of 1.78mm x 1.78mm. Using the NFC-based technology offers the advantage of relatively simple antenna technology based on ultra-thin flexible circuit boards that can reuse the space required by the battery. Combined with the PTX130W NFC Poller on the charger side it allows simple, yet effective wireless charging based on the NFC technology. Combined with the highly integrated yet efficient ISL9120 buck-boost regulator this leaves the designer with as much space as possible to integrate the sensing functionalities.