CiA® 425 series: CANopen application profile for medical diagnostic add-on modules

Figure 1: Network topology example with a permanently installed medical diagnostic device

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 internally done 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) master capability and the add-on modules provide the NMT slave 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 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.

Figure 2: Injector state machine (FSA: finite state automaton)

The specified state machine (FSA) defines 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’s (diagnostic device and injector) description are specified within certain objects.

Title Details
CiA 1301 version 1.0.0Application layer and communication profile
DescriptionThis document specifies the CANopen FD application layer. This includes the data types, encoding rules and object dictionary data objects as well as the CANopen FD communication services and protocols. In addition, this document specifies the CANopen FD network management services and protocols. This document also specifies the CANopen FD communication profile, e.g. the physical layer, the pre-defined communication object identifier connection set, and the content of the EMCY, TIME, and SYNC communication objects.
DSP2.2 MiB2017-09-28Login
CiA 303-2 version 1.5.0Recommendation - Part 2: Representation of SI units and prefixes
DescriptionThis document provides recommendation on how to represent the international system of units and prefixes in CANopen device, interface and application profiles.
public120 KiB2012-04-27Login
CiA 425-1 version 2.1.0CANopen application profile for medical diagnostic add-on modules – Part 1: General definitions
DescriptionThe CANopen application profile for medical diagnostic add-on modules includes several parts: Part 1 describes general definitions. Part 2 defines the profile for injector devices. Devices compliant to these profiles use communication techniques, which conforms to those described in the CANopen application layer and communication profile (CiA 301). In addition, medical devices and sub-systems may use communication techniques, which conform to those described in the CANopen additional application layer functions specification (CiA 302). These specifications should be consulted in parallel to these device profile specifications.
DS243 KiB2011-06-03Login
CiA 425-2 version 2.4.0CANopen application profile for medical diagnostic add-on modules – Part 2: Injector
DescriptionThis profile specifies the CANopen device profile for injector interface units. This profile covers injectors connected to a medical diagnostic system (angiography, computer tomography, and other medical diagnostic devices), which provide CANopen Manager functionality. If a safety-related communication is required, the injector device is compliant to the CANopen framework for safety-related communication (EN 50325-5). The definition of SRDOs (safety-related data objects) is not in the scope of this document. A prerequisite for the conformity to this CANopen device profile is conformity with the CANopen communication profile (CiA 301). Additionally, in the case that the module is programmable it shall conform to the framework for programmable CANopen devices (CiA 302). These specifications should be consulted in parallel to this device profile specification.
DSP795 KiB2017-11-17Login