Medical Devices and Healthcare IT

Smiths Interconnect Custom Grid Array reduces size, weight, and cost of medical equipment

23 November 2022

Modern medical suites and operating rooms are increasingly being equipped with complex diagnostic and monitoring devices and operating instruments such as magnetic resonance imaging (MRI) machines, x-ray imagers, computed tomography (CT) scanners and electrosurgical/endoscopic tools. This equipment may require numerous cables that provide power, signal, data, video and voice communications. To ensure safe and error-free operation, coaxial cables are often used to provide shielding to reduce electromagnetic interference and extraneous noise to and from nearby equipment.

The growing number of coaxial cables and connectors that are needed in medical suites and operating rooms can take up valuable space, increase equipment weight, and ultimately increase equipment and operating costs. This article discusses how Smiths Interconnect has developed a Custom Grid Array layout which provides reduced size, weight and cost of medical equipment when compared to standard cabled coaxial cable solutions.

Coaxial connectors advantages and disadvantages

Connectors equipped with traditional coaxial contacts consist of an inner or center conductor and an outer conductor arranged to form concentric cylinders. A dielectric material typically separates the inner from the outer conductor. Coaxial connectors present several advantages and disadvantages. First and foremost, they are fairly common, easy to use and flexible, allowing them to be used interchangeably on several pieces of equipment in several different configurations and operating environments. They can also transmit data at high rates and high frequencies, increasing the bandwidth of medical devices. Since the outer conductor improves attenuation and effectively shields the inner or center conductor, coax cables are less susceptible to electromagnetic noise when compared to twisted cables.

The primary disadvantage of connectors equipped with traditional coaxial contacts is that they are bulky and have relatively large connectors. Because of the sheer volume of coaxial connectors needed by equipment in modern medical suites and operating rooms, these facilities may quickly become untenable as new systems and technologies proliferate.

Smiths Interconnect custom grid array

To address the growing need for more compact interconnect solutions in medical suites and operating rooms, Smiths Interconnect, a leading provider of technically differentiated electronic products and components in the medical device industry, has developed their Custom Grid Array connector product shown in figure 1.

Figure 1. Pin grid array (PGA) layout. Source: Smiths InterconnectFigure 1. Pin grid array (PGA) layout. Source: Smiths Interconnect

The Custom Grid Array layout offers the same level of radio frequency (RF) performance and signal integrity as standard coaxial contacts, but at a significantly reduced size, weight and cost. This is accomplished by replacing the traditional pin and socket contacts found in traditional coaxial contacts with spring probes and flat target contacts arranged in a regular grid. Since these contacts can be packaged more efficiently, the Custom Grid Array contacts occupy only about one-half the space of traditional coaxial contacts. Furthermore, the efficient packaging enables use of less contact materials, resulting in a 30% cost reduction.

The Custom Grid Array offers several other advantages. The number of ground pins used can be optimized to improve the performance of the connector for specific frequencies or coil designs. The grid array layout enables multiple configurations that can be used for different purposes or to address different requirements. Furthermore, the spring probe design simplifies the termination of cables by allowing mass solder termination to printed circuit boards. Since medical devices must continually be cleaned and sterilized, the flat target contacts are simpler to clean than coaxial sockets, thereby improving throughput and increasing utilization of medical devices.

These advantages are realized without compromising performance. The spring probe and flat target contacts are qualified to survive a minimum of 100,000 mating cycles. Contact resistance between the probes and flat targets is less than 50 milli-ohms. The RF performance of the Custom Grid Array has been tested from DC to 300 MHz, which found less than 1 dB of insertion loss and less than 20 dB of return loss. Crosstalk ranges from only -35 dB to -50 dB based on the configuration chosen. The Smiths Interconnect Custom Grid Array is therefore poised to offer safe and error-free operation for the current and future generations of medical suites and operating rooms.


Smiths Interconnect is a leading provider of technically differentiated electronic products and components in the medical device industry as well as several other industries. Our products provide exceptional performance whenever a technologically advanced, high-quality solution is required to ensure reliability and safety. Our in-house capabilities encompass the full range of design, development, manufacturing and testing to anticipate market needs, respond quickly and accurately to customers, and provide the most reliable connectivity solutions. Smiths Interconnect has a global presence with 25 sales, research and development, and manufacturing locations located in 12 countries throughout North America, Europe, Asia and North Africa. More information about Smiths Interconnect and their Custom Grid Array medical connectors can be found on their website.

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