Balancing connectivity priorities in mobile medical equipment

Connectivity is at the core of the devices transforming healthcare, yet interconnects are often an afterthought. Selecting the right connectors in the initial design process supports better overall performance and functionality.

Medtech designers face some of the toughest design challenges in the electronics industry. Portable medical devices must be compact and lightweight enough to be moved easily, while tolerating the vibration, shock, and impact of frequent transport. Because these products operate within a larger network of connected devices and systems, electromagnetic interference (EMI) and interoperability should also be considered early on in the design process.

In addition to the usual design considerations like size, torque, pin count, and locking mechanism, connectors used in medical devices must withstand moisture, dust, chemicals, and high temperatures. They must be easy to use and durable enough to last thousands of mating cycles, all while meeting the industry’s stringent regulations.

Maximizing wireless connectivity

Portable medical devices have to move data from the point of care – whether that’s a hospital room, ambulance, or patient’s home – to a cloud or an internal server where it can be securely accessed by healthcare providers. Bluetooth, cellular, and Wi-Fi are currently the most commonly used wireless technologies for this purpose. Determining which is best suited to an application depends on how and where a device will be used, amount of data to be sent, and connection frequency, among other factors.

Bluetooth is widely deployed in healthcare applications due to its ease of use and low power consumption. Drawbacks include low-speed data transmission at limited range. New Wi-Fi 6/6E technologies offer stable, higher-speed, large-capacity communication. However, Wi-Fi in general struggles to maintain stable connections while devices move between indoor and outdoor locations.

Cellular networks offer more widespread coverage, reliability, and seamless interoperability with existing IT infrastructure. Disadvantages include cost, higher power consumption, and security concerns. Maximizing device connectivity is a combination of choosing the right electronic components, including interconnects, and the most suitable wireless technology for the application’s requirements.

The need for high-speed, high-quality data transmission

While some medical equipment requires straightforward device-to-device communication, portable diagnostic equipment must transmit detailed, accurate, and high-resolution data at very high speeds. Factors like crosstalk, distortion, and noise can degrade signal quality and cause unacceptable delays or errors, impacting patient care in real-time. Components like high-frequency printed circuit boards (PCBs) are uniquely designed to maximize signal integrity. Fully shielded connectors also ensure signal integrity and allow for connectors to be placed near the on-board antennas used for wireless connectivity.

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Here’s how interconnects apply to portable ultrasound probe assemblies

Interconnects for ultrasound equipment must deliver reliable high-speed connectivity to enable detailed high-quality images in a variety of challenging conditions. A single ultrasound probe assembly requires many coaxial wires that send signals from the individual transducers to the signal processors, making flexible components a requirement.

These systems typically use fine-gauge micro-coaxial cable ranging from 36-42 AWG to reduce equipment weight and size, and support cable flexibility. The impedance-controlled micro-coaxial wires and EMI-shielded connectors transmit signals to and from the transducer on the ultrasound probe. Their signal lines are shielded to prevent EMI and crosstalk. This enables the highest signal quality of the probe data to the signal processors to ensure the transmission of clean images.

Connector solutions include direct termination of the cable to paddle cards and board-to-board connectors, or direct termination to other connector types. Paddle cards are small PCBs designed for direct wire termination, but often have a board-to-board connector on the other side of the card, allowing the paddle card to make the connection between the wires and the connector.

Other connector types can terminate the wires directly, without the PCB paddle card. Many micro-coaxial cable connectors, for instance, have a modular construction that not only supports direct termination, but also allows the probe assemblies to be made in pieces and then assembled, which can positively impact production efficiency, especially in the case of repairs and rework.

Internal connectors can include multiple low pin-count connectors, but a high pin-count connector is required for the plug end of high-signal-count ultrasound probe assemblies. The challenge of high pin-count connectors is increased insertion force. Operators need to be able to exchange one probe assembly quickly and easily for another, depending on the imaging task they’re performing. This issue can be addressed by designing high pin-count connectors that require lower insertion force, making these systems easier to use and reconfigure.

How I-PEX helps OEMs successfully build portable medical devices

I-PEX offers some of the world’s most advanced, high-quality, high-speed, very small connectors. Their ultra-precision manufacturing process has been perfected over the past 60 years, and their connectors have a proven track record in medical device applications. To learn more about I-PEX’s interconnect solutions, visit www.l-PEX.com.