Sponsored by Innovatus Imaging
By Ted Lucidi, CBET
This month, we are going to take a tangent and discuss a common problem associated with ultrasound scanners: infrequent and inadequate preventive maintenance (PM). You may be asking, “Innovatus Imaging repairs ultrasound probes and MRI coils, why are they discussing systems?” The answer: An ultrasound probe provides an image only as good as the system to which it is connected. Full-size ultrasound systems – such as the GE E-series, Siemens S-series and Philips Epiq – employ massive power supplies when compared to their portable, battery-powered counterparts. The high-power requirements are needed for the high voltage pulsers and other functional systems in the front-end processor.
Challenge 1: Heat Generation
The challenge with large power supplies and any electronic-heavy design is heat generation. The enemy of any type of electronic component is heat generation. Increased heat leads to increased current draw and increased current draw leads to increased heat generation. It can be a never-ending circle until broken, either by design or by component failure and, as I’ll explain, sometimes both. Obviously to address heat generation, device manufacturers implement significant cooling systems in full-size scanners. Typically, the power supply itself has its own cooling system, separate from the overall scanner and E-box. Challenge solved: A series of cooling fans constantly draw cool air into the scanner.
Challenge 2: Dust and Lint
Our next challenge is in the form of dust and lint. Health care facilities are full of linen and other dust-generating materials. Drawing unfiltered air into any type of electronics is failure waiting to happen. Over time, the tiny dust particles in unfiltered air collect on each electronic component, thus reducing its ability to efficiently radiate heat. This can easily be seen in office computers with the large amounts of dust built up in the processor’s cooling fan, heatsinks and on the motherboard. Challenge solved: OEMs design most full-size scanners with one or more air filters.
Challenge 3: Infrequent and inadequate preventive maintenance
Most can relate to having to replace the air filter in our home’s HVAC system every so often. How often is the filter cleaned on an ultrasound scanner and upon whom does the responsibility fall? Reading through several user manuals, the responsibility is set upon the end-user and the interval ranges from every week to as needed. In my 30 years in the HTM industry, I’ve only encountered a select few end-users who cleaned the filters on their scanners. The activity typically only occurs as part of a PM performed by a service engineer. The second part of this challenge is that a PM on an ultrasound scanner may only occur every 12 months.
Once an air filter becomes clogged, fans tend to draw-in cool air from the path of least resistance. One pathway that offers minimal resistance is the location of the probe connector ports. Eventually dust will build up on and in the connector ports compromising the quality of a probe’s connection. On some scanners, the ports are highly visible and dust build-up can be easily visualized and addressed. On scanners such as the GE E-Series and Siemens S-series, the connector ports are hidden behind mechanically keyed doors. To further complicate the issue, the probes compatible on these scanners have pin-less connectors which interface to micro-pins (only about 1-2 millimeters in height) within the scanner’s ports. Over time, without proper filter cleaning, a blanket of dust can build-up on the micro-pins. Poor quality probe-to-scanner connections can result in highly intermittent, extremely diverse and very non-specific problems. Overall, poor image quality, image dropout, noise artifacts and no-ID problems are just a few of the issues that are possible.
Comprehensive Solution:
As an in-house service engineer, I established a comprehensive PM program for the ultrasound systems in the facility that significantly minimized system downtime. One part of that program involved cleaning the air filters on many of the full-sized scanners every two-weeks. I recognized that the end-users would not perform the task, not perform it adequately or not as frequently as needed. As part of the six-month PM, the connector ports were thoroughly cleaned. On the pin-less scanners, the port’s doors were opened, and a soft-bristled brush was used to aid in dust removal. As part of the annual PM, the scanner was opened, and each circuit board was cleaned of dust and re-seated. Any connection within the scanner was also re-seated.
For those that maintain their ultrasound systems via service contract or T&M, either with the OEM or a third-party, it may be prudent to engage with department managers and stress the need of frequent filter cleaning. I would go as far as recommending purchasing a vacuum for each department and demonstrating the task. The cost of a small vacuum is much less than a single service call and not as costly as downtime.
When troubleshooting performance and image quality complaints, a good rule of thumb is to start with a known good, clean system. Since that can be challenging in the clinical environment, take a next-best approach. 1) Have the sonographer disconnect/reconnect the probe using the same scanner port and see if the problem reappears. 2) Disconnect/reconnect the probe to the scanner using a different port and see if the problem reappears. 3) Test the probe on a different scanner. 4) Assess the cleanliness of the probe’s pin-bank as well as the connector port on each scanner, and 5) implement some of the best-practices mentioned above. A cool, clean system is a healthy, reliable system.
Ted Lucidi, CBET, is a clinical marketing and commercialization specialist at Innovatus Imaging. He may be reached at ted.lucidi@innovatusimaging.com.