Stojanović Radovan, Đurković Jovan, Vukmirović Mihailo, Babić Blagoje, Miranović Vesna, Škraba Andrej
Faculty of Electrical Engineering, University of Montenegro, 81000 Podgorica, Montenegro.
MECOnet Ltd., 81000 Podgorica, Montenegro.
Sensors (Basel). 2025 Jul 24;25(15):4573. doi: 10.3390/s25154573.
Data over sound (DoS) is an established technique that has experienced a resurgence in recent years, finding applications in areas such as contactless payments, device pairing, authentication, presence detection, toys, and offline data transfer. This study introduces CardiaWhisper, a system that extends the DoS concept to the medical domain by using a medical data-over-sound (MDoS) framework. CardiaWhisper integrates wearable biomedical sensors with home care systems, edge or IoT gateways, and telemedical networks or cloud platforms. Using a transmitter device, vital signs such as ECG (electrocardiogram) signals, PPG (photoplethysmogram) signals, RR (respiratory rate), and ACC (acceleration/movement) are sensed, conditioned, encoded, and acoustically transmitted to a nearby receiver-typically a smartphone, tablet, or other gadget-and can be further relayed to edge and cloud infrastructures. As a case study, this paper presents the real-time transmission and processing of ECG signals. The transmitter integrates an ECG sensing module, an encoder (either a PLL-based FM modulator chip or a microcontroller), and a sound emitter in the form of a standard piezoelectric speaker. The receiver, in the form of a mobile phone, tablet, or desktop computer, captures the acoustic signal via its built-in microphone and executes software routines to decode the data. It then enables a range of control and visualization functions for both local and remote users. Emphasis is placed on describing the system architecture and its key components, as well as the software methodologies used for signal decoding on the receiver side, where several algorithms are implemented using open-source, platform-independent technologies, such as JavaScript, HTML, and CSS. While the main focus is on the transmission of analog data, digital data transmission is also illustrated. The CardiaWhisper system is evaluated across several performance parameters, including functionality, complexity, speed, noise immunity, power consumption, range, and cost-efficiency. Quantitative measurements of the signal-to-noise ratio (SNR) were performed in various realistic indoor scenarios, including different distances, obstacles, and noise environments. Preliminary results are presented, along with a discussion of design challenges, limitations, and feasible applications. Our experience demonstrates that CardiaWhisper provides a low-power, eco-friendly alternative to traditional RF or Bluetooth-based medical wearables in various applications.
通过声音传输数据（DoS）是一种成熟的技术，近年来再度兴起，在非接触式支付、设备配对、认证、存在检测、玩具和离线数据传输等领域得到应用。本研究介绍了CardiaWhisper，这是一个通过使用医学声音数据（MDoS）框架将DoS概念扩展到医学领域的系统。CardiaWhisper将可穿戴生物医学传感器与家庭护理系统、边缘或物联网网关以及远程医疗网络或云平台集成在一起。使用发射设备，诸如心电图（ECG）信号、光电容积脉搏波描记图（PPG）信号、呼吸频率（RR）和加速度/运动（ACC）等生命体征被感测、调节、编码，并通过声音传输到附近的接收器——通常是智能手机、平板电脑或其他小工具——并且可以进一步中继到边缘和云基础设施。作为一个案例研究，本文展示了ECG信号的实时传输和处理。发射机集成了一个ECG传感模块、一个编码器（基于锁相环的调频调制器芯片或微控制器）以及一个标准压电扬声器形式的声音发射器。以手机、平板电脑或台式计算机形式存在的接收器通过其内置麦克风捕获声音信号，并执行软件例程来解码数据。然后，它为本地和远程用户启用一系列控制和可视化功能。重点在于描述系统架构及其关键组件，以及在接收器端用于信号解码的软件方法，其中几种算法是使用开源的、与平台无关的技术（如JavaScript、HTML和CSS）实现的。虽然主要重点是模拟数据的传输，但也展示了数字数据传输。CardiaWhisper系统针对多个性能参数进行了评估，包括功能、复杂性、速度、抗噪声能力、功耗、范围和成本效益。在各种现实的室内场景中进行了信噪比（SNR）的定量测量，包括不同距离、障碍物和噪声环境。展示了初步结果，并讨论了设计挑战、局限性和可行的应用。我们的经验表明，在各种应用中，CardiaWhisper为传统基于射频或蓝牙的医疗可穿戴设备提供了一种低功耗、环保的替代方案。
