Eric Gustafson

It is an interesting paradox—medical technology has been advancing at a rapid rate over the last 15 to 20 years, yet the protocols and procedures for maintaining medical devices remain relatively unchanged. Opportunities to increase efficiencies and improve overall reliability are getting missed. One area where I have witnessed this firsthand is in battery maintenance. I have been visiting many hospital biomeds recently with the specific goal of gaining insight into their battery maintenance programs as well as generating new ideas on how to help biomeds improve efficiencies.

On a recent trip to a hospital’s clinical engineering department I was impressed to learn about the thorough, well-defined procedures it was implementing to ensure its battery-operated devices work as expected. Frequent user checks and semi-annual or annual preventive maintenance checks were executed and recorded meticulously. This hospital’s biomed group has an enviable reliability rating and should be commended. However, there is also a significant cost associated with this, in both out-of-pocket expenses to replace batteries and the amount of effort expended by the biomedical and clinical staff to ensure proper device operability. Is all this effort and associated cost truly necessary, or is it overkill? Are hospitals today expending too many valuable resources and dollars on battery maintenance that could be better utilized and reallocated elsewhere? With recent advances in battery chemistries and technologies, there are apt to be alternative ways to manage hospital battery inventories more efficiently.

The battery “interval replacement” practice common to many facilities, where batteries are replaced on a fixed interval such as every 24 months, is one area to be examined. While earlier chemistries yielded a battery life of no more than 2 years, today’s newer, more robust chemistries, such as lithium Ion (Li-ion), have extended battery life due to the following factors:

  • Li-ion chemistry provides more capacity per unit volume. For example, a Li-ion cell can contain >40% capacity of an equally sized sealed lead acid battery;
  • Newer chemistries have a longer rated useful life than their predecessors; and
  • Newer technology devices consume less power than their analog predecessors.

Taking these factors into account, if you are using a 2-year replacement cycle, you could be discarding batteries with one or more years remaining of useful life. Multiply that times a 7- to 10-year device life expectancy. Then multiply that against the number of total devices per hospital along with the added cost of the newer batteries. It is easy to see a significant amount of money being spent unnecessarily. While this makes a compelling argument, how can a facility optimize maintenance and replacement without adding the risk of the device failing during use without employing the time-replacement method?

With emerging technology, tools are being created to help technical staff execute a performance-based maintenance and replacement program. For example, battery management software, such as the ZOLL SurePower, allows the user to view battery details such as remaining runtime and overall battery capacity loss. This software also provides tools to let the user select battery pass/fail criteria and run reports for total battery fleet management. Such tools allow biomeds to define a pass/fail threshold for their devices, and shift away from the “one size fits all” time-replacement practice.

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In another facility I reviewed, the interval replacement method was perceived as too costly. Batteries were being replaced on an 18-month schedule, so every 18 months it would incur an expense to replace a large volume of batteries. By implementing new performance measurement tools, they developed a creative, performance-based maintenance and replacement procedure that has helped them reduce cost and staff time. For example, by realizing its defibrillators in the ED and ICU/CCU units had much higher demands than those used in medical surgical areas (med surg) on crash carts, the facility was able to define different capacity thresholds for each unit, such as 75% total capacity minimum for ICU and 60% capacity minimum for med surg. As a result, it implemented a process where all new batteries are installed in the highest-demand units. When these batteries fall below their defined threshold, they are relocated to lower acuity areas. The oldest batteries are then removed from the less demanding environments and taken out of service. By doing this, not only did the facility lower overall battery expenses because overall battery life increased, but it was also able to stagger the purchase cycle so it is more predictable and tolerable. The final, unforeseen benefit is that the new practice improved nurse and nurse management satisfaction and resulted in a greater appreciation for the work performed by the biomed staff.

In citing these two examples, it is becoming evident that new chemistries and technology are providing biomeds with the ability to manage and replace batteries in a much more efficient and economic way, all while maintaining, or even improving, reliability.

Eric Gustafson, a product manager for professional defibrillators at ZOLL Medical Corp, Chelmsford, Mass, and a former biomedical engineer, has been active in the medical device industry for the past 17 years. For more information, contact .

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