CAN interfaces in medical applications

The history of CAN and CANopen in medical technology started many years ago. In 1992 Philips Medical Systems developed a software protocol for use in its patient tables and x-ray systems. This first approach served as the basis for the so called CAL protocol, which evolved into today‘s CANopen protocol. CANopen is today a well-established and secure communication standard, which is used for many medical devices.

The background

Modern medical devices consist of a multitude of modules, which are connected to one another. By using a standardized bus system such as CANopen, individual system components – such as X-ray generators, patient tables or injectors – can be independently developed and modularly connected.  This saves development costs, enables universal and scalable use of the components in a wide range of systems and also considerably reduces the number of cables.

A decisive advantage of CANopen as communication protocol is the availability of profiles for a large number of medical devices. As a result of which, interoperability of the components can be easily ensured for different manufacturers. Furthermore, the CAN and CANopen technology has already been approved by TÜV Deutschland and the FDA in the USA for use in medical systems.

The solution

To enable a computer to control medical tasks, the computer must be able to communicate with the CAN/CANopen modules in use. The CAN interfaces from HMS meet the electrical requirements according to IEC60601-1 and enable the connection of PC-based applications to CAN-based networks. In addition, HMS offers several CANopen driver packages for Windows. For example, by using the Ixxat CAN interfaces together with the Ixxat CANopen Master API, medical devices can be controlled via a PC. Also, medical data can be imported for further evaluation.

The CiA 425 application profile allows easy connection of injectors for contrast media to control computers for CT systems. The control computer with the Ixxat CANopen Master API detects the connected devices and their position in the network, and can automatically configure and control the entire system. In this context, it is particularly interesting that the CT system is frequently supplemented with components – e.g. Injectors – from third parties (3rd party vendors) without impairing the reliable functioning of the overall system.

There are many other applications. Various well-known providers in the field of medical technology and laboratory automation rely on the proven quality of CAN/CANopen products from HMS:

• Dialysis machines
  Pumps in dialysis machines are controlled by means of a PC equipped with CAN interfaces.
  
• Laboratory automation
  Communication in and between conveyor belts, robots, centrifuges, pipetting systems, etc. is in many cases implemented with CAN and CANopen.
  
• Mammography
  Ixxat CAN interfaces or Ixxat control PCs with Ixxat CANopen software are also used in automatic mammography devices.
  
• Eye surgery
  Ixxat interface cards and software are used in market-leading laser- and ultrasonic devices, which are especially used during cataract removal.
  
• Automated surgery
  Not only individual machines and components in medical technology are networked, but entire operating rooms – from the operating table to the lighting control to the robotic assistance for the surgeon – rely on the experience and quality of Ixxat products from HMS.

Benefits and advantages of the Ixxat PC/CAN interfaces:

• Support for all common PC interface form factor.
• Common driver for easy change of interfaces.
• Complete solutions for hardware and software from one source.
• Powerful drivers for Windows, Linux, INtime, QNX, RTX and VxWorks.
• High quality standards for development and production.
• Long-term availability.