[The compression and storage of enhanced external counterpulsation waveform based on DICOM standard].

The development of external counterpulsation (ECP) local area network system and extensible markup language (XML)-based remote ECP medical information system conformable to digital imaging and communications in medicine (DICOM) standard has been improving the digital interchangeablity and sharability of ECP data. However, the therapy process of ECP is a continuous and longtime supervision which builds a mass of waveform data. In order to reduce the storage space and improve the transmission efficiency, the waveform data with the normative format of ECP data files have to be compressed. In this article, we introduced the compression arithmetic of template matching and improved quick fitting of linear approximation distance thresholding (LADT) in combimation with the characters of enhanced external counterpulsation (EECP) waveform signal. The DICOM standard is used as the storage and transmission standard to make our system compatible with hospital information system. According to the rules of transfer syntaxes, we defined private transfer syntax for one-dimensional compressed waveform data and stored EECP data into a DICOM file. Testing result indicates that the compressed and normative data can be correctly transmitted and displayed between EECP workstations in our EECP laboratory.

The semantic extension and storage of EECP Hemodynamic Waveforms based on DICOM Standard.

Digital imaging and communications in medicine (DICOM) Standard has a detailed description on the Information Object Definition (IOD) of all kinds of medical images and waveforms. With the development and application of DICOM, all medical imaging and waveform devices will support the standard. This article describes the method and implementation on how to encapsulate the EECP Hemodynamic Waveforms data acquired from EECP device, integrating patient information, EECP physiological parameters, and diagnosis and treat information into DICOM Hemodynamic Waveform file. We define Private Data Elements to encode and represent EECP parameters which haven't been registered as Standard Data Elements. This is the semantic extension of DICOM applied in EECP. The paper introduces following parts in detail: the structure of DICOM waveform file, Data Element, Nesting of Data Sets, the Waveform IOD Modules and the specification of Private Data Element. Then the method and process of our program are analyzed in depth. According to object-oriented methodology, firstly, Data Element, Nesting of Data Sets and waveform IOD with their corresponding operations and services are respectively abstracted into classes. Then the waveforms data and other attributes are assigned to the corresponding Data Members of the waveform class. Finally, they are stored into a DICOM waveform file by invoking related functions.