This section discusses the main features of the @HealthCloud application and presents implementation details. The prevalent functionality of the application is to provide medical experts and patients with a mobile user interface for managing healthcare information. The latter interprets into storing, querying and retrieving medical images, patient health records and patient-related medical data (e.g., biosignals). The data may reside at a distributed Cloud Storage facility, initially uploaded/stored by medical personnel through a Hospital Information System (HIS). In order to be interoperable with a variety of Cloud Computing infrastructures, the communication and data exchange has to be performed through non-proprietary, open and interoperable communication standards. @HealthCloud utilizing Web Services connectivity and Android OS supports the following functionality:
Seamless connection to Cloud Computing storage: The main application allows users to retrieve, modify and upload medical content (medical images, patient health records and biosignals) utilizing Web Services and the REST API [17]. The content resides remotely into the distributed storage elements but access is presented to the user as the resources are located locally in the device (see Figure 1e). Patient Health Record Management: Information regarding patient’s status, related biosignals and image content can be displayed and managed through the application’s interface (see Figure 1a).
Image viewing support: The DICOM [18] medical image protocol is supported, while the JPEG2000 standard has been implemented to support lossy and lossless compression, progressing coding and Region of Interest (ROI) coding. The progressive coding allows the user to decode large image files at different resolution levels optimizing this way network resources and allowing image acquisition even in cases network availability is limited (see examples in Figure 1c and Figure 1d). The code for performing wavelet decoding on mobile devices in [10] has been modified to support the JPEG2000 standard on the Android platform. Image annotation is also supported, using the multi-touch functions of the Android OS.
Proper user authentication and data encryption: User is authenticated at the Cloud Computing Service with SHA1 [19] hashing for message authentication and SSL [20] for encrypted data communication.