Whoever introduced hospital computers on wheels and workstations on wheels as COWs and WOWs had a comic streak, but choosing among these powered carts is anything but a laugh. Proliferating by the day and increasingly sophisticated, WOWs, the progeny of COWs, present a wide range of ergonomic issues that require careful evaluation. Cornell University’s Human Factors and Ergonomics Research Group have designed a tool for the purpose, the Cornell Healthcare Computer Cart Ergonomic Checklist.
Professor Alan Hedge, Ph.D., CPE, director of the Cornell team, predicts a surge in demand for WOWs, which explains why the ergonomics questions have become pressing enough for a checklist. He foresees that “the demand for these kinds of products is going to increase very dramatically as hospitals computerize more and more and more.”
The professor estimates some 50,000 of the powered carts were sold last year in the United States, and predicts the number will increase dramatically, in part because the carts only have a life of three to five years. “They are used 24 hours, seven days a week,” he explained in a recent interview with The Ergonomics Report®. “They are wheeled around … bashed into. [And] stuff gets spilled on them. There’s a finite life span to them.”
The increase in computerization he foresees anticipates President Barak Obama’s mission to reform the national healthcare system. The projected reforms begin with requiring doctors and healthcare facilities to plug into a national network for sharing electronic medical records (EMRs).
Professor Hedge recapped the evolution of COWS and WOWS to explain the need for the Cornell checklist. First came automation and computerization in hospitals, he said, then the desire to bring both “down to the level of every patient. In other words, as you have taken your readings of blood pressure, or heart rate or whatever it is, or administered a drug, that information is fed into an electronic medical record system that then keeps track of what’s happening to that individual patient.
The barcode underpins the process. “The nurse wears a barcode," he explained, "and will scan that barcode, scan the patient’s barcode, scan the barcode of the medication they’ve just administered. … Then the system will automatically record all of that and automatically keep track of the patient’s record.”
A computer is central to this kind of automation, but the design of older hospitals can’t always accommodate a computer in every room, according to the professor. “In those kinds of facilities, there was a desire to create a mobile cart that could move the computer from room to room.” He pointed out that the arrangement, optimally one computer for every six rooms, presents cost benefits over the one-per-room model.
In the early days, by that I mean about four years ago, he said, “these were like shopping carts … for wheeling around desktop computers.” Plugs and network connections were often insufficient in the rooms, creating the need for carts with their own power source. The newer carts have a battery unit, “and that battery can power, say, a laptop computer or a desktop-compliant computer for the whole shift. … And if you have a wireless network, you can be connected as you go from patient to patient to patient.”
According to the professor, the COW developed into what is now called a WOW because the unit is no longer just a computer, but a work station. “Now you can actually have a bigger screen, and you can do everything you would normally do at a desk,” but the whole unit is mobile.
The power source remained an issue. In some of the earlier carts, he noted, you had no way of knowing how much power was left in the battery. “So a nurse would arrive on the shift, collect the cart and wheel it into the room. You’d turn things on, and half way through entering data, the thing would die because it didn’t have enough power. And then what tended to happen was nurses would take that cart and just push it into the corridor somewhere and forget to plug it in. So when the next shift came along, there would be no way of figuring out which cart had plenty of power and which cart had very little power.”
Designs these days, the professor said, give the user information about the amount of power stored in the battery, and also audible and visual warnings when the battery is starting to run low. “You can then go and connect it to a power source and recharge [it] in time for the next shift – and those power management systems are getting increasingly sophisticated.”
Interacting with the Cart
“All of the ergonomic issues have started to become much, much, much more important,” Professor Hedge noted. The nurse’s job now involves interacting with the unit as well as pushing it around. “You are entering data into it. You are reading the screen, etc, so the ergonomic design is how you deliver the technology to the nurse.” He said the ability to sit or stand to use the computer becomes important, as well as the ability to easily raise the keyboard, mouse and screen to the right level.
The ergonomic picture must also take in anthropometrics. The range of sizes of the nurses “has really pushed the envelope in the design of these products,” he explained, adding that the average height of a nurse in California is 5 feet 2 inches. It’s much smaller than the average height of a nurse on the east coast, because many nurses in the state came from Asian countries. A cart has to be able to accommodate those people as well as Midwesterners. Traditionally people from Minnesota, in particular, “are very tall because they are from Swedish stock.”
And you have to be able to accommodate the changing abilities of a person as they age. “Once you hit your forties, your vision starts to change. And your ability to read things off the screen starts to change.” He pointed out that the average age of a nurse across the United States is now 43, and is mid fifties in many east coast hospitals.
Introducing the Checklist
Cornell’s ergonomic checklist doesn’t list features. Instead, it lists the factors that will affect the ease of use, safety and effectiveness of a cart. The 35 questions can be used to evaluate a single cart or to compare multiple cart designs. And all dimensions are based on the latest anthropometric data for United States adults.
It is organized into five sections: Cart Maneuvering; Worksurfaces/Data input; Screen/Document Reading; Storage/Accessories/Power; and Hygiene. Each section has a number of items with a binary response (Yes/No) about whether the cart satisfies the item or not. If an item is not relevant it can be omitted and the scoring can be adjusted accordingly. If all items are relevant then the total number of ‘YES’ values can be tallied at the end of each of the five sections and an overall total score summed at the end of the whole checklist. The maximum score possible is ‘35’ and the higher the score the better the ergonomic design of the cart.
Filling a Need
Until some two years ago, the professor explained, a hospital’s information technology people made the purchasing decisions. “These days, that is changing. More and more, ergonomists are getting involved in those decisions because of the human factor issues that you are dealing with here.” He explained that he has been traveling around the country during his sabbatical leave from the university, “giving talks on what’s going to happen in hospitals as a result of the information technology initiative that the President Obama administration is bringing to bear on the healthcare system.”
As part of that, he said, it became very clear to me that the ergonomists out there didn’t have any tools to help them make some sensible decisions about the computer carts that are available from the standpoint of ergonomics, rather than: ‘here’s a list of product features.’ Anybody can put those lists together, but it’s really what are those important ergonomic considerations and what role can an ergonomist in a hospital play in helping make wise choices about the products the nurses are going to use. So that really is the origin and genesis of the checklist that we created here.”
Professor Alan Hedge; Cornell Healthcare Computer Cart Ergonomic Checklist http://ergo.human.cornell.edu/Pub/AHquest/CUCompCartEval.pdf
This article originally appeared in The Ergonomics Report™ on 2009-04-01.