## 1 Introduction  
Surface Acoustic Wave Sensors (SAWSs) have attained widespread utilization in the sensor technology arena owing to their advantages such as cost-effectiveness, compact dimensions, durability, high sensitivity, easy integration, high compatibility, and wireless and passive operation [1]. Depending on the detection method, SAWS can measure various physical quantities, including temperature, humidity, chemical concentration, and biological signals. With the wireless and passive characteristics of SAWSs, these devices can adapt to complex and even hazardous or toxic detection scenarios [2]. As the core of the human body, the heart requires precise detection and sensing of its parameters to evaluate overall health. The detection of heart conditions requires sensing multiple parameters, which necessitates the assistance of sensors or AI. Advanced medical devices integrate various sensing platforms and AI algorithms for health monitoring or disease prediction [3, 4, 5]. Conventional cardiac parameters, such as temperature and heart rate, are relatively easy to obtain. The magnetic field generated by the heart, known as the cardiac magnetic field, is difficult to measure yet contains unique information about the heart's condition. Measuring the cardiac magnetic field requires magnetic field sensors. There are many types of temperature sensors, but research on temperature sensors specifically for the heart is still limited. One commonly used clinical method for temperature measurement is Infrared Thermography (IRT) [6, 7]. This method is non-contact and provides real-time imaging. However, infrared cameras are expensive and entail high costs. Another proposed method for cardiac temperature measurement is VelocimetricUltrasound (VUS), which features a simple sensor structure and exhibits low measurement error [8]. However, the size of the device makes it more suitable for measuring the overall temperature of a single object rather than two-dimensional temperature distribution. MP-SAWS is compact, easily integrable, and cost-effective. It can be arranged in arrays to measure the temperature distribution of the heart. Due to the rapid response to temperature changes, SAWS can provide real-time measurement of heart temperature [9]. Heart rate detection is a common component in medical diagnostics. There are numerous methods for detecting the heart rate, most of which are fast, accurate, and cost-effective. Recent trends in heart rate detection research focus on integrating these sensors into wearable devices, not just for medical purposes but also for dynamic monitoring during physical activity. For example, hand-worn sensors are based on piezoresistive sensing, and in-ear sensors are based on Photoplethysmography (PPG) [10; 11]. There are also non-wearable sensors that detect heart rate during movement, such as those integrated into vehicle seats using ultrasonic or electrocardiogram (ECG) technologies to monitor the driver's condition [12; 13]. A heart rate sensor based on SAW technology represents a novel concept; its miniaturization makes it suitable for integration into wearable devices to detect both static and dynamic heart rate signals. Magnetic field sensors are currently extensively used in electronic information [14], biomedical [15; 16], industrial production [17], monitoring and detection[18; 19; 20], and other fields. These types of magnetic field sensors now include surface plasmon resonance (SPR) sensors [21; 22; 23], fiber optic sensors [24; 25; 26], magnetoresistance sensors [27], magnetoelectric sensors [28], photonic crystal sensors [29], and more. Human body magnetic field detection is a branch of medical diagnostics that enables health assessment and monitoring of certain diseases. One characteristic of the human magnetic field is its weak signal, which makes it susceptible to interference. Currently, research on biological magnetic fields is primarily limited to laboratory settings.