The profile specifies the CANopen communication between medical sub-systems (diagnostic devices) and their add-on modules. It covers the general definitions (part 1) and the CANopen interface for injector devices (part 2).

Injectors from different manufacturers implementing this profile may be attached to a diagnostic device via a standardized CANopen interface. Thus, a diagnostic device manufacturer does not need to hold several spare injectors available. The same injector interface implementation may be also used in diverse diagnostic devices of one manufacturer.

The physical device interface complies with IEC 60601-1 for medical electrical equipment. CANopen-related physical layer accords to CiA 301 v. 4.2.0. Bit rate of 250 kbit/s is supported. Four connectors are specified. Five of the connector pins are used for geographical node-ID assignment. Medical diagnostic devices use the node-IDs 1 to 15. Geographical addressing is not mandatory for permanently connected nodes. Here the node-ID setup is done internally by hardware or software. The network installer has to ensure that a node-ID is not used twice. Typically, the medical diagnostic device provides the CANopen NMT (network management) manager capability and the add-on modules provide the NMT server functionality.

The CANopen injector interface (CiA 425-2) specification is used to connect automatic and semi-automatic injectors to the CANopen network allowing operation of third-party products. It covers injectors connected to such medical diagnostic systems as angiography, computer tomography, magneto resonance, ultra sonic, etc. The injector may provide up to eight configurable pistons. Each injector implements a certain compatibility class (0 to 5) showing the diagnostic device’s capability to control the injector. This reaches from injector monitoring (class 0) to real-time adjustment of the injector parameters. The higher class provides the functionality of the lower class. If required, the injector may use the safety-related communication according to EN 50325-5.

The specified state machine (FSA) defines the injector’s application behavior. It is also specified on which events certain FSA transitions and actions are executed. The injector may be operated by local commands (not specified) or via CANopen network by the control word sent from the medical diagnostic device. The injector reports its state in the status word. The FSA is also controlled by detected errors.

The programmable injection protocol is a sequence of configured phases (injection, test bolus, delay and wait) with defined actions. The injection and test bolus phases require configuration of total volume, total flow rate and piston ratio. Optionally, the rise time and pressure limit may be configured. The diagnostic device controls and monitors the phase processing by means of the control word resp. the status word. The injector may support three operation modes (monitor, tracking, and control). The CiA 425-2 further defines the RPDO 1 and TPDOs 1 to 4, the complex data types and the required application objects. Additionally to the mentioned above, the latter include the current and configured values, physical units (specified according to CiA 303-2) and limitations for volume, pressure, and flow rate related to the corresponding phase types. Time-related values, piston attributes, configured language, supported CiA profile version, as well as device (diagnostic device and injector) description are specified within certain objects.