Equip yourself with the data needed to embrace the digital evolution of medical equipment.
Wiping down user interfaces, like this computerized sonography system’s keyboard, can help keep them in operational condition for greater periods of time.
The world we live in is dominated by information technology. Everything from cars to microwaves to telephones has become computerized. Our demand for information—more, better, and faster—has driven technology to provide it at real-time speeds. It is no surprise, then, that vital patient care data is managed, from admit to discharge, by computerized medical equipment.
Medical equipment manufacturers have been producing computerized equipment for decades. Biomeds have been servicing it for just as long. Today’s medical equipment looks more like a personal computer than ever. To service this equipment, it is essential to know a few computer basics.
Computerized equipment contains two key components: hardware and software. If either one of these components fails, the system will not work.
Hardware is the guts of the system; the parts that we can physically touch and see. This includes circuit boards, microprocessors, hard drives, power supplies, keyboards, and mice. It also may include networking devices such as hubs, switches, routers, and access points. Not all systems contain all of these components, but most contain at least one; so it is important to talk about those most commonly found in our medical equipment.
Power supplies provide all of the voltage and current to keep the system running. They take incoming power from a battery or AC outlet and convert it to the power levels required to run the system. Simple equipment, like electronic thermometers, may use a single low voltage to power the system. More complex equipment, like patient-monitoring systems, use multiple voltages for different parts of the system. Regardless of the voltages used, if the power supply isn’t working properly you’ve got problems.
Good, clean incoming power is key to keeping power-supply components healthy. Voltage spikes and drops can wear out capacitors and cause transistors to switch off at inappropriate times. Power surges and bad batteries can cause these problems, and some systems are much more sensitive than others. Power supplies can compensate to some degree, but they can only do so much for so long. For instance, low batteries can cause inaccurate readings on electronic scales. I have also seen dirty AC power ruin motherboards in ultrasound machines. Checking incoming power as needed, and checking and/or changing batteries, can help eliminate many of these problems. A backup power source and/or power conditioner may be helpful, but choose wisely, for not all of them are created equally, and many must be maintained or they will harm rather than help the system.
The motherboard’s job is basically to pass signals throughout the system. After the power supply, the motherboard is typically the next in line on the power pathway, providing a conduit for power and data to travel throughout the system. Motherboards in computerized medical equipment are almost as diverse as the patients in a hospital. They may have just a few data lines and components for signal filtration and signal pass, or they may contain all of the hardware and software needed to run the system. Most motherboards contain the system microprocessor, which will be discussed later.
To understand the motherboard, you must have a good understanding of the architecture of the rest of the system you are dealing with. So let’s move on down the road.
Obviously, not all computerized medical equipment contains hard drives. For instance, it is highly unlikely that you will find one in a noninvasive blood pressure machine. But hard drives are an important component of almost any system that stores data. They are also (arguably) the highest-fail internal item in the system.
The hard drive can be thought of as the permanent memory of the system. It is where files, programs, and operating systems are stored. The hard drive consists of both mechanical and electronic components that work together to store and retrieve data.
If you could look inside a hard drive, you would see that it looks somewhat like a layered record player. The disks inside the drive spin at thousands of RPMs while read/write heads sweep quickly across their surfaces, creating and reading magnetic marks that bring software to life. With literally billions of bytes of data per drive, this process must be precisely controlled to prevent error. This task is given to the controller board, which is typically mounted to the bottom of the drive. It is the traffic cop of data flow to and from the hard drive, and it controls the motor and head actuator systems accordingly. Power for the drive comes directly from the power supply to this board.
Though hard drives have mechanical parts, not very much can be done to keep them from failing. Yes, they do have filters; no, they cannot be removed and cleaned. The best defense against hard-drive failure is backups, backups, backups! In the world of patient care, where systems run 24×7 and data sometimes must be kept indefinitely, this is especially important.
Nearly every piece of computerized medical equipment contains at least one microprocessor. You could say that a processor is what makes a piece of equipment computerized. The microprocessor was invented in the 1970s, and guess what? The PC was invented in the 1980s. So, the processor is the heart of computerized equipment.
At its core, the processor is just a whole lot of transistors (which we all know and love) that switch on and off millions of times per second. The microprocessor receives requests from software to utilize system resources, and then it carries those requests out; it is like the computer’s engine. One of the processor’s most common functions is to move data in and out of memory as needed by in-use programs.
With that many transistors switching on and off so fast, modern processors tend to generate a lot of heat! It is especially important to keep the system cool to ensure processor reliability. For this reason, placement of computerized medical equipment in a properly ventilated area is very important. But even in a properly ventilated area, accumulation of dust can prevent the system from “breathing” properly. Regular vacuuming and/or dusting of the system is also key to keeping it in tip-top shape. And make sure those fans are running!
Another hardware component commonly found in computerized medical equipment is memory. Memory is simply a storage place for data. This can be temporary or permanent, depending on the system. Some newer PCs use memory to house the operating system and software, so they don’t have a hard drive anymore! Most bedside monitoring equipment has used this architecture for decades (and still does). In systems with a hard drive, though, memory provides faster and easier data access for the processor.
Most of us think of memory as those little rows of chips on memory boards that plug into the motherboard of our computer. In older systems, this is the primary memory. In newer equipment, however, the processor has its own memory called cache, which is used much more often than that other memory. Regardless of where it is located, memory can significantly affect system speed and performance.
The operating software of most systems loads into memory on boot-up; so if you have a memory problem, you probably have a software problem to go with it. I have seen more bad memory than I expected in my career, especially given that it’s just a bunch of microchips. However, memory is typically one of the more reliable parts of the system and is normally upgraded more than it is repaired.
User Interfaces (Mice and Other Critters)
You can’t make a system do what you want if you don’t have a way to interact with it. User interfaces provide us with the means to access the system. These include keyboards, keypads, touch screens, switch panels, mice, and remote controls. I will also include displays (monitors) under this heading because most computerized equipment can still acquire data without a display. Because of their exposure to the elements (such as dust, saline, ultrasound gel, body fluids, large metal objects, and gravity), user interfaces are the highest-fail items on any piece of computerized medical equipment. Therefore, cleaning is especially important to keeping these items running. Regular vacuuming and wipe-downs with appropriate cloth and solution go a long way. It’s something that I do on every ultrasound preventive maintenance, even if the users do not.
Many other circuit boards with many different functions can be used in a piece of computerized medical equipment. They may perform tasks like video processing, pump controlling, valve regulating, network interfacing, scanhead powering, and EKG acquiring. It would be impossible to cover them all in one article. Suffice it to say that they are all controlled by the core components of the system and perform a specific function for that system. They are subject to failure based on their design and use.
Since so many of our patient-monitoring, x-ray, cath lab, and OR systems are networked, it is prudent to include a little information about the hardware that runs these networks. Simply put, a network is a means of sharing data from one piece of equipment to another. Devices like hubs, switches, bridges, and routers all control the flow of information across a network. Each of these has its own software and hardware that helps it accomplish this task.
Networks are connected by physical cabling or wireless technology. As such, they can be subject to physical damage or wireless interference. Proper installation is key to reducing network component failures. Try to install cables out of harm’s way. Give enough length to allow for full range of motion on equipment that is designed to move around while still plugged into the jack at the wall. Test out wireless network components to ensure reliability and compatibility before you commit to an installation.
Most network hardware I run across is very reliable, though less-expensive brands seem more buggy. Much of today’s network hardware works a lot like a small computer, with its own processor, memory, and operating system; so all of the aforementioned maintenance applies here as well.
Finally, we come to something we all have a lot of experience with (good and bad). Software is not what the equipment is, but rather what it does. It is the programs and subroutines that run in the background that give us the text you see on this page, or the EKG waveform you see on the screen of a patient monitor. The software tells the computer what it wants from the hardware so that we get what we want out of it. Without software, the hardware is just a bunch of plastic and metal.
Software problems plague our world, and this is no different in the medical field. Though it takes several years and lots of testing to clear a medical device through the Food and Drug Administration, today’s computerized medical equipment still has many software problems.
It is a good idea to keep a backup of your operating system software and your application software in a safe place. System hardware is fairly easy to replace, but software may be more difficult (and costly)—plus, a software reload is one of the first things that most people will recommend when trying to fix a system that has strange, intermittent problems. Believe it or not, some maintenance can be done to keep software running at its best. Defragmentation of your hard drive and proper deletion of old or bad program data will help programs run more efficiently.
The Best Fix
Based on designs today, we can only expect medical equipment to become more computerized in the future. Overall, the best service solution for computerized medical equipment is education. Knowledge will give you the power to fix these devices. There are many resources on the Internet and in books that will help, including books for A+ certification and Network+ certification. I highly recommend Scott Mueller’s books; they have been an enormous help to me in my career. Experience is also a great teacher, so try building your own PC. Good luck, and good learning! 24×7
Chris Moreau is a field service engineer at UTS Medical, Dallas.