Medical and demographic trends drive need for sterilizable battery pack technology

Robin Tichy, medical marketing manager at Micro Power, a designer and manufacturer of battery packs, points out a significant mash-up of technology and market trends in medicine.  First is a change in the demographics of surgeons: An increasing number are women who tend to be, on average, smaller and lighter than male surgeons. In addition, surgery itself is becoming more common, so hospitals are trying to schedule their operating rooms most efficiently, moving patients through faster, and contributing to fatigue for all surgeons, regardless of sex.

In order to spare surgeons and make them more efficient, surgical instruments are more likely to need power than in the past, when the only instruments needing power were in orthopedic surgeries. Now instruments that open, close, and sever, which used to depend more on a sharp edge and a strong arm, need to be powered.

Power cords in a sterile environment are problematic.  Battery power is the best solution, but how do you quickly and repeatedly sterilize a battery pack? Until recently, hospital equipment was sterilized in high-pressure steam autoclaves, a technology that doesn’t currently work well with battery packs. Here’s where another demographic trend comes in: An aging population is making endoscopes one of the most common surgical instruments, but their plastic lenses don’t go well with high-temperature methods of sterilization. This in turn has driven the availability of low-temperature methods of sterilization, with the most common being vaporized hydrogen peroxide.

However, even as vaporized hydrogen peroxide sterilizing equipment becomes common in hospitals, there are still challenges to be met for battery packs. First, the process entails pulling a vacuum on the chamber and then backfilling it with the vaporized hydrogen peroxide, which can present a sealing issue for the battery pack. Second, hydrogen peroxide is highly corrosive, so the pack’s battery management electronics need to be well-sealed, and the pack’s contacts need to be chosen carefully.

Tichy lists these features as important for sterilizable battery packs:

·         Utilizes rechargeable lithium ion cells

·         Supports up to 14.4 V

·         Support up to 80 Amps continuous power delivery

·         Accepts charge in less than one hour

·         Fuel gauge provides 99 % accuracy

·         Failsafe when accidentally sterilized in autoclave (There’s always a risk that the pack will be accidentally placed in a traditional steam autoclave. “Fail-safe” means that although it won’t work anymore, it won’t harm anyone either.)

Micro Power claims it is the first battery pack manufacturer to offer lithium-ion battery packs designed to perform after sterilization with hydrogen peroxide gas.