Traditionally, opening a patient’s thoracic wall requires fast movement and consistent torque to minimise trauma. This is accomplished with a hand cranked thoracic retractor operated by the surgeon. Utilising this methodology, current loops are typically applied in place of a torque sensor to monitor torque when automating small systems. However, this setup offers poor accuracy and a non-linearity of ± 5–10 per cent.
A new device has the hand crank being replaced with a miniature, high-precision, brushless DC servo motor and gear-head. Alongside the DC servo motor is Futek’s QTA141 micro reaction torque sensor, with an accuracy and non-linearity of ± 0.5 per cent.
By adopting this setup Futek provides the surgeon with a faster and more accurate torque feedback system, which will benefit the patient with less time spent in the operating room, a reduction in potential bone fractures, and a more rapid recovery time.
Using the QTA141, a miniature servo motor, and gear-head with supporting electronics. Futek’s IAA series amplifier sends an amplified signal to the motor controller for closed loop control The drive shaft passes neatly through the sensor, allowing for easy coupling.
The QTA141 provides high accuracy, strain gauge and torque measurement. It has a 1N-m capacity,1.3mV/V output and a safe operational overload up to 150 per cent in a 2.18cm diameter x 0.99cm height package.