In modern automobile factories, and even at your local car mechanic’s, you will find digital torque wrenches that help technicians make sure that nuts and bolts are tightened just right. Compared to dumb wrenches the devices are expensive, but the auto industry has embraced the cost in return for high quality results.
In modern operating rooms, you will find orthopedic surgeons driving screws into bones and tightening bolts on implants with devices that are now considered archaic by the very mechanic that may be under the knife. A team of engineers from Fraunhofer Institute for Manufacturing Engineering and Automation IPA and Weber Instrumente GmbH developed a special handle that can accept various surgical instruments and provide real-time feedback on the torsion of the instrument. The system will activate an internal light that lets the surgeon know when preset pressure level has been reached, helping avoid over-tightening. Moreover, the device is sterilizable and wirelessly rechargeable, making it actually useful in the operating room.
The necessary power is supplied and stored via an inductive charging process or a coil system. “One coil is located inside the hand grip; the other is in a little table. The surgeon merely has to put the handle on the table, and the battery is charged,” explains Giers.
All of the electronics – including the sensors, assessment and LED – are installed in the handle. This means there is no split or seam that would enable germs to penetrate and proliferate. Another special feature: The instrument handle can be sterilized at 134 degrees Celsius. Since the electronics are switched off in the sterilization process, it can withstand the high temperatures undamaged. “Previously, surgical instruments had no electronics inside – the heat would have rendered them inoperative,” explains Giers.
The researchers furthermore intend to enhance the approximately nine-centimeter handle with a wireless interface, so that the sensor data can be transmitted to a PC, thus allowing the surgical process to be documented.