Consumers may find that their everyday devices overheat when they’re putting them to their limits, like a laptop overburdened by a video game or a phone heating up after excessive scrolling. However, when it comes to medical devices, overheating can pose a significant safety hazard to patients and operators, making over-temperature protection a must. We’ll cover what over-temperature protection is, why it’s important, and safeguards that medical device manufacturers may implement to prevent overheating. We’ll also address considerations manufacturers may have when choosing a power supply.
What is Over-Temperature Protection?
Over-temperature protection is an important safety feature in medical devices that protects against potential malfunction or damage caused by excessive heat. The internal temperature of the device is monitored and protective measures take appropriate actions when higher than acceptable temperatures are identified. This could include reducing power consumption or shutting off the device entirely to prevent overheating.
Importance of Over-Temperature Protection in Medical Devices
Overheating could lead to several different issues in medical devices. These include:
Reduced Performance
When devices are subjected to high temperatures for long periods, electronic components can degrade and result in delayed response times, inaccurate readings, or complete system failure.
Safety Hazards
An overheated device could burn the operator or the patient. Faulty temperature sensors could also lead to incorrect readings that prevent a safe, reliable treatment for the patient. Overheating can also cause a fire hazard.
Component Damage
Components can also experience physical damage from overheating, including burning, melting, or other damage that leaves the device inoperable.
Regulatory Compliance
Over-temperature protection is a core requirement for compliance with key regulatory standards associated with medical devices, including IEC 60601-1, a standard set of requirements for medical electrical devices.
Requirements for Over-Temperature Protection in Medical Devices
Over-temperature protection measures are necessary to meet regulatory requirements and ensure patient safety. Some approaches medical device manufacturers may implement include:
- Temperature Sensors: These should be placed on the device in strategic areas to monitor the most critical parts prone to overheating.
- Monitoring Circuitry: Temperature readings from the sensors can be read from a dedicated circuit.
- Threshold Settings: Thresholds for appropriate temperatures must be set for the monitors to trigger actions when over-temperature occurs.
- Protective Actions: Devices need to respond to over-temperature conditions with protective measures such as adjusting operating parameters, issuing warnings, shutting down the device, or reducing power consumption.
Types of Over-Temperature Protection in Medical Devices
Hardware or software-based protection can be used in medical devices to offer protection during potential overheating.
Hardware-Based Protection
Thermal fuses or thermal cut-outs can be used to interrupt the power supply. Thermal fuses are of one-time use, whereas cut-outs can be reset once the device reaches an acceptable lower temperature. Thermal circuit breakers open the circuit automatically when a set temperature is exceeded. A positive temperature coefficient (PTC) thermistor can increase resistance as temperature rises, which limits the flow of current.
Software-Based Protection
Medical devices can use microcontroller-based monitoring to monitor temperature sensors and initiate actions when needed. Firmware-based algorithms can also be used to analyze temperature data and implement protection strategies.
Considerations for Medical Device Manufacturers when Choosing a Power Supply
When selecting a power supply for a medical device, manufacturers should consider the over-temperature protection capabilities, including mechanisms for over-temperature shutdown, thermal protection features, and temperature ratings. The power supply should operate within the operating temperature range of the medical device and have built-in features for thermal overload protection. To make getting to market easier, the power supply should also meet relevant safety and EMC standards, including IEC 60601-1.
Best Practices for Implementing Over-Temperature Protection in Medical Devices
Effective implementation of over-temperature protection in medical devices requires a thorough risk assessment, proper design techniques, reliable monitoring components, and rigorous testing to ensure mechanisms will operate as expected during high-temperature conditions.
Over-temperature protection needs to be considered alongside these six other forms of protection:
- Overcurrent protection (OCP)
- Overpower protection (OPP)
- Overvoltage protection (OVP)
- Undervoltage protection (UVP)
- Short-Circuit Protection (SCP)
- Surge and Inrush Protection (SIP)
RAM Technologies offers all 7 forms of protection in our PC-based medical power supplies. Visit our product pages to learn more about our power supplies or contact us with any questions you have about protections and customizations we offer.
RAM Technologies’ power supplies are 60601-1 3.2 certified. When you’re designing your medical device and need help with a PSU, contact us for details.
More Resources:
What the FDA Moving to IEC 60601-1 3.2 Means for Manufacturers
7 Protections to Look For in a Power Supply
Undervoltage Protection (UVP) for Medical Devices