The importance of UPS for medical equipment

Power Control
28 Sep 2018

As the medical industry becomes increasingly reliant on technology, there is a greater emphasis on the need for a dependable and consistent power supply. Healthcare facilities not only rely on such power for the everyday running of the infrastructure but also for their diagnostic and monitoring equipment, medical imaging equipment and life support.

Unfortunately, the detrimental effect a loss of electricity to medical equipment can have on a hospital is often overlooked. A loss of power could cause delays in patient recovery, diagnosis treatment and care and can cause the hospital costly delays and downtime.


As there isn’t always the immediate risk to human safety the obvious requirement of a power protection solution for MRI, X-Ray, CT and Ultrasound imaging equipment may be easy to dismiss.

However, in the event of a power failure, there is a danger of the imaging hardware (that can cost upwards of £1million) being damaged causing disruptions and delays to patients and staff. If a power failure should occur during a medical imaging procedure, the recorded data may be lost which could affect the diagnosis and/or treatment of a patient. Furthermore, the imaging computer systems can be corrupted. The hardware and software will need to be reset delaying, and in many cases cancelling procedures.

Further problems of a power outage may occur before a scan if a patient needs to be injected with a radionuclide, radioactive or other tracers. If during the scan power is lost then these tracers cannot be re-injected for a long time. This delays diagnosis and causes problems for the patient’s welfare. The patient could be delayed for weeks.

A UPS (Uninterruptible Power Supply) ensures the loss of power will not result in a loss of productivity and will provide a cost efficient, reliable backup power source. In most cases, a standard UPS used for commercial and IT systems will not be suitable due to the dynamic load characteristics and voltage regulation requirements of most medical imaging equipment. The following special considerations are required for sizing a UPS.


Line impedance

Many medical imaging scanners require an electrical supply with a very low impedance so as to provide a clear image. If the impedance is not within the requirement specified by the imaging manufacture then image could be distorted effecting an accurate diagnosis.

The electrical installation should be designed and installed in a way that provides a low impedance level hence the UPS has to be of special low impedance design meet the requirements.

Inrush currents

UPS products that are suited for data process applications might not work well for diagnostic imaging systems such as MRI, CT, or X-ray.

Medical scanners and imaging equipment demand high inrush currents (pulses) that can be 3-4 times higher than the nominal load. During this time frame, the voltage has to stay within 6% of the nominal line voltage value. While the electrical installations don’t always have to be updated for inrush currents, UPS systems need to be oversized correctly to cope. Otherwise, the UPS will not provide critical backup and could fail prematurely.

The UPS batteries don’t necessarily need to be sized for the inrush currents from imaging equipment. However special consideration is needed for the design of the batteries and DC installation to cope with the demands.


As a result of the increased reliance on electrical power, the regulations have become more stringent including specific guidelines outlining the integration of backup power supplies.

A UPS would ensure a healthcare facilities compliance with regulations highlighted in IEC bulletin 60364-7-710 that power should be resumed for life support equipment within a maximum of 0.5 seconds in all medical locations intended for purposes of diagnosis, treatment, monitoring and care of the patient and where isolated power is installed.

UPS systems for supporting imaging equipment must be compliant with HTM regulations. As well a medical power, the HTM covers UPS design, battery design, and installation and isolation requirements.

Other regulations to consider:

  • BS7671 (British Standard)
  • BS6290-4 (British Standard)
  • IEC90601 (International Electrotechnical Commission)

Identifying the correct UPS system for critical care units requires careful planning and an expertise. With over 25 years of experience in providing comprehensive back up power solutions within the healthcare market, you can rest assured that Power Control will provide the complete support a medical facility requires.