Historically, surgical tools and instruments have not been designed to provide surgeons with feedback at the tool-tissue interface. Yet investigators are increasingly finding that this information may improve surgical outcomes in cardiac surgery, abdominal surgery, and neurosurgery. In the field of otolaryngology, there are several distinct advantages to quantifying forces applied during operative laryngoscopy: understanding tissue dynamics in the airway, predicting peri- and post-operative complications, enhancing deformation modeling, and aiding in the creation of surgical tools that exert less force. Previous efforts have been limited by static equilibrium assumptions, testing on cadaver models, and measurement of overall forces rather than force distribution. To our knowledge, ours is the first study that proposes an integrated data acquisition system for detecting intraoperative forces (and pressures) based on piezoresistive sensors in both cadavers and live patients.
Sixteen piezoresistive sensors were interfaced to a Karl-Storz operating laryngoscope, and all measurement devices were connected to an Arduino MEGA and integrated into a MATLAB graphical user interface. 3-D printed models of a laryngoscope cover and sensor base were affixed to the laryngoscope surface, and sensor calibration and validation was performed within one hour of each procedure with 1–2.5% error across all sensors. The sensor apparatus was used to collect peak force, mean force, and pressure distribution data from three cadaver trials; forces measured during three live head-and-neck operative cases were on the same order of magnitude as values reported in the literature. This custom and low-cost (i.e., less than $500) data acquisition system is a promising tool to inform surgeons during trans-oral surgery and has potential applications for detecting retraction forces in other surgical sub-specialties.