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Libérez-vous des contraintes de conception des appareils médicaux.

Digital technology is invading more and more in the hospital world. Augmented reality, robotics, computer networks, VPN, Wi-Fi, IP TV, computer carts have already entered medical places. But these are the premises of a revolution.

IoT enters the medical community but watch out for regulations

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The Internet of Things (IoT) revolution is stimulating creativity and opening up possibilities in all sectors of the industry. The medical world is not to be outdone. The development of applications in this area will also increase in the coming years. However, the medical world is highly regulated, particularly with regard to the electrical safety of medical devices.

Beware of electric shock

In general, the use of electrical devices in a medical environment is a risk for patients as well as for operator operators. This risk is mainly linked to the leakage current generated by the power supply systems.

What are MOPP and MOOP.

To frame the design of medical devices, the designers can rely on the IEC 60601-1 standard which follows from the European directive 93/42 / EEC . It defines the limit values ​​not to be exceeded and the latest edition dissociates the means of protection (MOP) according to whether the device will be used by an operator or used in contact with a patient. These two categories are so named:

- The MOOP (Means Of Operator Protection) - Means of protection for operators

- MOPP (Means Of Patient Protection)  - Means of protection for Patients

The table below provides the insulation levels according to the MOP. 

Classes

Champs disruptif

Creepage

Isolation

1 MOOP

1500 V a.c.

2,5 mm

simple

2 MOOP

3000 V a.c.

5 mm

Double (reinforced)

1 MOPP

1500 V a.c.

4 mm

simple

2 MOPP

4000 V a.c.

8 mm

Double (reinforced)

 

An increased requirement for patients

Given the state of health and possible contact with the device, the MOPP is more demanding than the MOOP . In addition, the standard defines several subdivisions of MOPP according to the area and the type of equipment dedicated to the patient.

Part Type B - (Body), devices that are used near patients. (1500 V AC, 2.5 mm, basic insulation, 1 MOPP)

Part Type BF - (Body Floating), devices that come into contact with patients. (3000 V AC, 5 mm, double insulation, 2 MOPP)

Part Type CF - (Cardio Floating), devices that come into contact with patients' hearts. (4000 VAC, 8 mm, double insulation, 2 MOPP)

So, depending on the nature of your design, you can determine the appropriate means of protection.

Difficult to respond to different constraints

The Directive 93/42 / EEC includes many other requirements to which the designer must submit:

  • CEM
  • Risk management
  • Marking
  • Measurement
  • Energies
  • use
  • Materials
  • etc.

These multiple constraints complicate the task of the designer. For example, the combination of EMC and electrical risks causes conflicts in design. As IEC 60601-1 recommends, to eliminate the risk of electric shock, it is necessary to electrically isolate the devices in order to suppress leakage currents to protect patients and operators. But the addition of EMI / RFI protections allowing EMC compliance implies the use of components generating leakage currents, such as in particular EMI / RFI filtering capacitors. Solutions exist, such as ZVS, zero-voltage switching, but they considerably increase the final cost of the product.

The use of transformers in switching power supplies allows excellent yields ('Energy' requirement). But it also generates a source of leakage current. To avoid any risk of electric shock, it is imperative to reduce it. It is therefore advisable to install an additional DC / DC converter in series. It reduces the leakage current and provides an additional means of protection (MOP), but complicates the design and increases the final cost.

Designers, make your job easier!

Whatever the electronic design envisaged, the European directives ErP and CEM and others ... have increased the requirement of the specifications imposed on the designers of electrical equipment. They have thus seriously complicated the production of supply systems, which requires high expertise in this area.

For those who wish to design products adapted to the medical environment, it will be necessary to demonstrate an additional level of expertise by adding the requirements of the standard CEI60601-1 which arise from the  European directive 93/42 / EEC .

In order to free yourself from a complex design and certification tests, manufacturers such as  TRACO POWER , offer you a complete range of converters and power supplies compliant with standard IEC60601-1 and other standards related to the equipment directive. medical.

nicolas.brunet n'a pas encore rempli le champs " à propos de moi" ...
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