# Flexible Wearable Heart Rate Monitoring System and Low-Power Design: A Review
## 6 Design of the Flexible Wearable Heart Rate Signals Transmission and Output Module  
After the heart rate signals are computed, they need to be stably and efficiently transmitted and output to terminal devices such as mobile phones and medical monitoring platforms through the heart rate signal transmission and output module for real-time viewing and further analysis. This process not only involves hardware-level selection and design--for example, wired transmission methods can adopt USB interface transmission, serial port transmission, etc., while wireless transmission can use modules such as Bluetooth Low Energy (BLE), Wi-Fi, and Zigbee and so on to ensure the stability and low-power characteristics of data transmission--but also relies on algorithm-level support, including \begin{table}
\begin{tabular}{p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt}} \hline \hline
**Reference** & **Innovation** & **Practicality** &
\begin{tabular}{c} **Power Optimization** \\ **Method** \\ \end{tabular} & **Power Consumption** & **Power Comparison** \\ \hline
[45] & \begin{tabular}{c} A BioAIP processor for heart rate calculation is proposed. \\ \end{tabular} & \
\begin{tabular}{c} Suitable for various \\ wearable health monitoring scenarios. \\ \end{tabular} & Hardware & 46.8 \(\mu\)W &
\begin{tabular}{c} Its energy consumption is at the lowest level among \\ similar systems. \\ \end{tabular} \\ \hline
[67] & \begin{tabular}{c} The ternary neural network \\ processor for ECG signal \\ computation is proposed for the first time. \\ \end{tabular} & \
\begin{tabular}{c} Suitable for early warning \\ of cardiac arrhythmias. \\ \end{tabular} & Hardware & 746 \(\mu\)W & 746 \(\mu\)W &
\begin{tabular}{c} A power consumption \\ reduction of more than \\ 71.6\% compared to \\ traditional heart rate \\ calculation is achieved. \\ \end{tabular} \\ \hline
[111] & \begin{tabular}{c} A low-power statistical FFT \\ signal analysis method. \\ \end{tabular} & \
\begin{tabular}{c} Suitable for heart rate calculation. \\ \end{tabular} & Algorithm & 2.4 mW &
\begin{tabular}{c} Compared with the \\ traditional FT signal \\ analysis algorithm, the \\ power consumption can be \\ reduced by more than 40\%. \\ \end{tabular} \\ \hline
[117] & \begin{tabular}{c} A lightweight TCN model \\ for heart rate calculation is \\ proposed. \\ \end{tabular} & \
\begin{tabular}{c} Suitable for wearable \\ arrhythmia detection \\ scenarios. \\ \end{tabular} & Algorithm & 1.8 mW &
\begin{tabular}{c} Compared with \\ microcontroller solutions, it \\ reduces power \\ consumption from the \\ microowatt level. \\ \end{tabular} \\ \hline
[119] & \begin{tabular}{c} A customized PPG heart rate estimation hardware \\ has been developed. \\ \end{tabular} & \begin{tabular}{c} Suitable for high-precision \\ long-term heart rate \\ calculation and monitoring. \\ \end{tabular} & \
\begin{tabular}{c} Hardware-Algorithm \\ co-design \\ \end{tabular} & 34.7 \(\mu\)W &
\begin{tabular}{c} Compared with similar \\ solutions, the Figure of \\ Merit is improved by 3.48 \\ times. \\ \end{tabular} \\ \hline
[109] & \begin{tabular}{c} A low-power ECG \\ coprocessor based on DNN \\ is proposed. \\ \end{tabular} & \begin{tabular}{c} Suitable for real-time \\ monitoring scenarios in \\ wearable devices. \\ \end{tabular} & \
\begin{tabular}{c} Hardware-Algorithm \\ co-design \\ \end{tabular} & 8.75 \(\mu\)W &
\begin{tabular}{c} Compared with \\ solutions, the Figure of \\ Merit is improved by 3.48 \\ times. \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Key references comparison of innovations, practicality, power consumption optimization methods, power consumption and power consumption comparison with other similar work of regarding heart rate signal computation module in flexible Wearable Heart Rate Monitoring System. data simplification through reliable compression algorithms, data integrity protection via verification algorithms, and power consumption reduction by optimizing data transmission protocols.