CiA® 412: CANopen profiles for medical devices

Collimator coordinate system, whereby the individual coordinates are as seen from a front view

The CiA 412 profiles specify the CANopen interface for automatic X-ray collimators (part 2) as well as for dose measurement systems (part 6). Profiles for X-ray generators (part 3), patient tables (part 4), and X-ray stands (part 5) are also under development. Using standardized CANopen interfaces, device manufacturers may supply diverse markets with medical devices implementing the same electronic interface according to CiA 412 and can simply vary the appropriate application software. A system designer may choose between CANopen devices from different manufacturers implementing the same profile-compliant functionality. For development, analysis, and maintenance of the devices, off-the-shelf CANopen tools can be used.

A collimator (see CiA 412-2) has three basic functions for which the profile specifies the appropriate configuration, application, and diagnostic parameters. The main function limits (or collimates) the X-ray beam (e.g. rectangular collimation) issued by an X-ray emitting source (X-ray tube) to a defined (receptor) format. Filters may be applied to influence spectral characteristics of the X-ray beam. The visual simulation of the X-ray beam is the third specified functionality. Some automatic X-ray collimators support local control functionality. The defined collimator functionality coordinates (X, Y, s, ω, D) may be controlled either in position or velocity mode. Devices compliant to this profile are required to support the emergency message (see CiA 301). The defined device errors are sorted in warnings, recoverable errors, and non-recoverable errors.

The introduced collimator device FSA (finite state automaton) specifies the application behavior as well as the corresponding state transitions of the collimators. As a collimator is usable with local control even when the CAN network does not work properly, the communication FSA (CANopen NMT server FSA, see CiA 301) and the collimator FSA are very loosely coupled. Also defined is a coordinate FSA applicable for the symmetric rectangular collimation sets, the quadrangle collimation sets, the circular collimation sets, as well as the spatial filter sets. The third specified FSA (homogeneous filter FSA) has the same states as the coordinate FSA with a different definition for some states. In addition, the X-ray visualization FSA is defined. Further, the profile provides some use case scenarios e.g. coordinate motion between the defined limits, changes of the SID (source image distance) value, etc. The CiA 412-2 pre-defines one RPDO containing the collimator command and the target x-y-position value as well as one TPDO providing the collimator state and the actual x-y-position value.

The CANopen dose measurement system (see CiA 412-6) measures the X-ray dose and the dose area product. In addition, the dose area product rate, dose rate, RD (reference distance) entrance/skin dose, RD entrance/skin dose rate, MD (measured distance) entrance/skin dose, MD entrance/skin dose rate, irradiation time, chamber temperature, as well as the air pressure values are measured. The actual measured values (called field values) are converted to values with a real physical dimension (called process values). The profile specifies all required objects to fulfill this conversation and to represent the mentioned values in a standardized manner. Additionally, CiA 412-6 introduces an FSA for the dose measurement systems. The profile defines one RPDO and two TPDOs respectively transferring the controlword (RPDO1) and the statusword (TPDO1) as well as the current process value (TPDO2).

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CiA 301 version 4.2.0CANopen application layer and communication profile
DescriptionThis specification specifies the CANopen application layer. This includes the data types, encoding rules and object dictionary objects as well as the CANopen communication services and protocols. In addition, this specification specifies the CANopen network management services and protocols. This specification specifies the CANopen communication profile, e.g. the physical layer, the predefined communication object identifier connection set, and the content of the Emergency, Timestamp, and Sync communication objects.
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PAS3.0 MiB2011-02-21Login
CiA 412-1 version 1.0.0CANopen profiles for medical devices - Part 1: General definitions
DescriptionThe CANopen profiles for medical devices includes several parts: Part 1 describes general definitions, Part 2 defines the profile for automatic X-ray collimators, Part 3 defines the profile for X-ray generators, Part 4 defines the profile for patient tables, Part 5 defines the profile for X-ray stands. Devices compliant to these profiles use communication techniques, which conforms to those described in the CANopen communication profile (CiA Draft Standard DS-301, /2/). In addition, medical devices and sub-systems may use communication techniques, which conform to those described in the framework for programmable CANopen Devices (CiA Draft Standard Proposal DSP-302). These specifications should be consulted in parallel to these device profile specifications.
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PAS167 KiB2005-12-31Login
CiA 412-2 version 1.0.0CANopen profiles for medical devices - Part 2: Automatic x-ray collimator
DescriptionThis document represents the CANopen device profile for generic X-ray collimators, and as such describes the generic subset of collimator functionality. A prerequisite for the conformity to this CANopen device profile is conformity with the CANopen communication profile (CiA Draft Standard DS 301). Additionally, in the case that the module is programmable it must conform to the Framework for programmable CANopen devices (CiA Draft Standard Proposal DSP 302). These specifications should be consulted in parallel to this device profile specification.
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PAS1.3 MiB2005-12-31Login
CiA 412-6 version 1.1.0CANopen profiles for medical devices - Part 6: Dose measurement system
DescriptionThis specification defines the CANopen device profile for dose measurement systems. A prerequisite for the conformity to this CANopen device profile is conformity with the CANopen communication profile. Additionally, in the case that the module is programmable conformance to the framework for programmable CANopen devices is required. It is recommended to consulted these specifications in parallel to this device profile specification.
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PAS2.0 MiB2008-08-27Login