Self-Aligning Magnetic Connectors Provide Optimal Power and Data Solutions for Medical Applications

By Guadalupe Chalas | April 28, 2020

Magnetic connectors designed to self-align, self-locate, handle a high number of mating cycles, and safely unmate can provide optimal solutions for power and data transmission.

Technological advancements in healthcare have led to an increased demand for electronic devices for inpatient and outpatient medical care. These devices are used for a wide range of applications, including diagnostics, life support, long-term care, mobility aid, hospital room entertainment, and prosthetics. They are used by doctors, nurses, medical technicians, caregivers, and patients. Medical equipment often features some degree of portability to allow for easy transport between different rooms or facilities, and some equipment can even be implanted into, worn, or carried around by the patient.

Medical devices increasingly need to transmit data. Data demands span simple communications, such as conveying a battery’s state of charge, to more complex tasks, such as transferring data from the patient into a diagnostics machine (e.g., an electrocardiogram). Reliable power and data connections play an important role in these operations and components should be selected for design-in with ease of patient and operator usability, safety, reliability, and hazardous medical environments in mind.

magnetic connectors

Often, the equipment used for inpatient diagnostics is both battery-powered and portable. This enables equipment to be moved from one room and patient to another. Similarly, medical beds not only need to be rolled between different spaces, but also feature controls that allow medical personnel and caregivers to adjust the bed height or position.

Wearable outpatient portable medical-assist devices and implantable devices, such as oxygen concentrators, ventricular aid devices (VADs), and prosthetics, attach to or are integrated within the patient. These devices utilize portable power delivered via smart battery. Powered solutions for patients with limited mobility, such as wheelchairs, scooters, and lifts, are also widely available and use portable power to provide patients with increased mobility.

Since reliable power and data connections play such a critical role in medical devices, design engineers should give due consideration to both the repetitive mating cycles these devices are frequently subjected to and the patients and medical professionals who will be handling them. Due to the vastly different experience, skill, and comfort levels that patients and medical professionals have with medical devices, magnetic connectors designed to self-align, self-locate, handle a high number of mating cycles, and safely unmate even when unintended forces are applied can provide optimal solutions for power and data transmission, or even a combination of both.

Magnetic Connectors 

Magnetic connectors self-align and self-locate with respect to their mating half to provide effortless, zero-mating-force connections. They also provide enough retention force for the connectors to remain mated until due force is applied to override the magnetic retention force specified for a given interface, whether intentional or accidental (e.g., cable snags), and are designed to safely disconnect and prevent equipment damage. Magnetic connectors with standard interfaces, including USB, Micro USB, and RJ45, are widely available in the market. Customized solutions for more challenging medical applications, such as hybrid power and fiber optic magnetic connectors for high-definition hospital room displays, are also available.

magnetic connectors from Rosenberger

Rosenberger offers a wide range of standard and custom magnetic connector products in a variety of different shapes and sizes. Medical market solutions include (clockwise from top right) MagneticUSB Micro-B Standard USB 2.0 connectors, RoDI® Rosenberger Diagnostic Interface Products, MagneticUSB 2.0 Mini-B/Micro-B Type-B connectors, and MultiMag 6 connectors.

Compared to magnetic connectors, conventional pin and socket connectors with latches or twist locks have a much greater risk of interface damage and subsequent equipment malfunctions when their cables are subjected to unintentional pull forces. Interface damage typically requires connector replacement, which costs both time and money. Moreover, in cases where the pulling action is caused by someone tripping over the equipment cord, a conventional connector with enough retention force could remain connected and cause a fall, whereas a magnetic interface would safely disconnect to prevent damage to the equipment or harm to the individual.

The self-aligning features on these types of connectors, combined with the attraction force of the magnets, requires zero mating force for engagement. These connectors mate without any user effort and remain mated without the assistance of external forces or mechanical latching features. Once mated, magnetic connectors achieve a steady contact pressure that supports the high-reliability transmission of data, power, or both data and power simultaneously. To ensure that these connectors stay mated throughout their intended use, they are subjected to shock and vibration testing with a profile that simulates a standard medical environment. Magnetic connectors are also designed for durability — with single connector pairs routinely specified for anywhere between 2,500 and 10,000 mating cycles — and made to withstand the many hazards common to medical environments, including chemical exposure and sterilization processes.

To meet the cleaning requirements set forth by various medical standards, magnetic connectors offer various degrees of protection against hazards, including the water ingress and corrosion that can be result from exposure to chemical agents. The magnetic connector solutions designed into powered wheelchairs and scooters, for instance, are fully sealed to prevent water ingress and have been tested for corrosion with saltwater spray to ensure their reliability regardless of weather conditions. Magnetic caps are also widely available to help protect the contacts when the connectors are not in use.

MultiMag15 magnetic connectors from Rosenberger

MultiMag 15 connectors from Rosenberger provide optimal solutions for low-power applications, including medical bed accessories and medical device displays. They self-align and self-locate for user-friendly, zero-force mating, have a magnetic interface with break-off functionality, and are rated at 12V and 4.5A.

Connectors with a magnetic locking mechanism provide many benefits when used in hospital care, in-home care, and portable medical device applications, especially in powered devices that are constantly moved from one place to another and those in which potentially unskilled end-users must plug and unplug the device. Suitable for applications that require power, signal, and data transfer, magnetic connectors are also especially beneficial for users unable to mate and unmate conventional pin and socket connectors with latches or twist locks due to limited mobility, dexterity, or strength. In addition, magnetic interfaces support quicker mating with increased certainty and reliably withstand repetitive mating and un-mating cycles common to medical applications, including diagnostic devices with interchangeable leads and applications where sudden patient movements can result in accidental disconnection from the medical device.

Market Applications 

Magnetic connectors employed in mobile medical equipment are frequently used to establish connections between a power supply and rechargeable lithium-ion batteries. These batteries not only need a power connection, but also require a few additional low-speed data contacts to support the transmission of information about the battery’s state of charge and its temperature. These same types of connector can also be used for charging ventricular assist devices, which are partially implanted within patients and require periodic charging. In these applications, the standard cable harness is replaced with biocompatible cable designed to be non-irritating to human skin.

Magnetic connectors are also ideal for use in scooters and powered wheelchairs with rechargeable batteries. One of the main advantages of magnetic connections in this application area is the breakaway functionality, as it allows users to simply drive away from the charging station while the connector is mated without causing any damage to the charging port or the charging cable. Another is the self-aligned, self-locating, zero-force mating mechanism, which allows many limited-mobility users who are unable to mate standard wheelchair charging connectors on their own to both establish and terminate connections and charge their device.

magnetic RoPD connectors from Rosenberger

Magnetic RoPD® Rosenberger Power Data Connectors have a robust, waterproof design, are rated for up to 60V, 40A, and 2,500 mating cycles, and are ideally suited for electric charging applications in wheelchairs and scooters.

Patient monitoring devices used to document vital signs and biomarkers can also benefit from magnetic connectors. Since these devices remain attached to patients for prolonged periods of time, magnetic connectors can ensure that connections are safely broken if acute tensile force is applied due to a patient’s sudden movements. Additional medical applications that can benefit from magnetic break-away connectors include nurse calling systems, hospital infotainment systems, and medical beds.

More Opportunities for Magnetic Connectors Ahead

Magnetic connectors offer robust, user-friendly alternatives to standard pin and socket connectors while providing all of the same functional capabilities common to traditional connectors. They are widely available in power, data, and hybrid power and data configurations to address the demanding needs of medical market applications. Self-aligning magnetic connectors not only allow for effortless connections but can also improve procedural and testing efficiencies. They are robust enough to meet the challenging demands of medical environments, ranging from high numbers of mating cycles to sterilization processes. 

Visit Rosenberger online.

Like this article? Check out our other harsh environment, high-reliability, power, and Connector Basics articles, our Medical Market Page, and our 2020 and 2019 Article Archives.

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