1. Data collection: data generated by patients and healthcare organizations are collected through a variety of sensors, devices, and other means.

2. Data storage: the collected data are classified, organized, and stored in the cloud or local servers.

3. Data analysis: use artificial intelligence, big data and other technical means to analyze and mine the data stored in the database to extract valuable information.

4. Decision support: provide support and advice for clinical decision-making based on the analysis results.

Therefore, "lack of security" is not a characteristic of smart healthcare application layer system architecture. On the contrary, as it involves sensitive personal health information, security must be fully considered in the design and implementation, and relevant protection measures must be strengthened.