On the receiving side, the data decompression and the watermark extraction can then be finished. In summary, we make the following contributions: we integrate electrocardiogram digital watermark encryption and a compression algorithm based on an orthogonal wavelet domain, which has never been researched before.This study is organized as follows: in Section 2, we introduce background knowledge and related research. In Section 3, we introduce the architecture and the basic algorithm of the proposed method, including the digital watermark, wavelet transform and compression formulas. In Section 4, we introduce the evaluation method. This is mainly a comparison of the watermarked and compressed object before and after, as well as comparison of the correlation peaks. Some conclusions are drawn in Section 5.

2.?Background and Related Work2.1. ECG Algorithm ReviewThere are currently no ECG studies which include research on both watermarks and compression. However, there are some studies looking at compression or watermarking individually, so based on existing research, we surveyed watermarking and compression as two separate aspects.At present, from the watermark point of view, research on the protection of ECG information is still in its infancy, although there are some research studies, shown in Figure 1, related to the watermarking of ECG signals, and with the use of wavelet transform based digital watermarking encryption technology [5]. Therefore, research in this field has great potential for the researcher. The existing research may be divided several categories.Figure 1.

Related works.The first application is the digital watermark technology used in medical images. This application proposes a novel blind watermarking method, by embedding GSK-3 a secret key into the medical image of ECG signals. The second is a sensor network-based ECG monitoring system. ECG signals are watermarked with patient biomedical information to confirm patient/ECG linkage integrity [6]. The third application is wavelet transform-based ECG digital watermarking technology. In ECG signals, the energy is concentrated in QRS complex waves [7], so the selection of wavelet coefficients for concealment should avoid causing the QRS complex waves to distort obviously. The last application is ECG transmission in a wireless network.

This paper proposes the use of digital watermarking to ensure the safe transmission of ECG signals in a wireless network [8]. A low frequency chirp signal is used to embed the watermark, which is a 15-bit digital code assigned to the patient. The characteristic of the proposed watermarking scheme is that the embedded watermark can be fully removed by the receiver due to the blind recovery feature of the watermark [9]. Dey et al. [10] proposed a novel session based blind watermarking method with a secret key by embedding a binary watermark image into the ECG signal.