Smart bioimpedance-controlled craniotomy: Concept and first experiments

Abstract

Craniotomy is part of many neurosurgical interventions to create surgical access to intracranial structures. The procedure conventionally bears a high risk of unintended dural tears or damage of the soft tissue underneath the bone. A new synergistically controlled instrument has recently been introduced to address this problem by combining a soft tissue preserving saw with an automatic cutting depth control. Many approaches are known to obtain the information required on the local bone thickness. However, they suffer from unsatisfactory robustness against disturbances occurring during surgery and many approaches require additional intra- or preoperative steps in the workflow. This article presents first concepts for real-time cutting depth control based on in-process bioimpedance measurements. Furthermore, sensor integration into a synergistic surgical device incorporating a bidirectional oscillating saw is demonstrated and evaluated in first feasibility tests on a fresh bovine bone specimen. Results of bipolar measurements show that the transition of different layers of bicortical bone and bone breakthrough lead to characteristic impedance patterns that can be used for process control.

A Miniaturized Ultrasonic Micro-Hole Perforator for Minimally Invasive Craniotomy

“…However, as brain is protected by skull, a high strength bio-composite material with micro-porosities, this natural barrier needs to be penetrated for the insertion of micro-tools for minimally invasive neural intervention. Perforation of skull bone is conventionally achieved by material-removal techniques such as drilling/grinding [5,6]. Due to the high strength of skull bone (Young's modulus of 22-45 GPa [7]), a micro drill bit would easily fracture under a large thrust force, making it difficult to safely generate a micro-hole on skull by drilling.…”

“…Due to the high strength of skull bone (Young's modulus of 22-45 GPa [7]), a micro drill bit would easily fracture under a large thrust force, making it difficult to safely generate a micro-hole on skull by drilling. Meanwhile, as bone tissue is removed by rotating cutting edges in the conventional drilling craniotomy, rotating cutting edges would pose a great thread to soft tissue such as dura or even brain tissue at the end of skull perforation [5].…”

Let’s Smarten Up: Smart Devices and the Internet of Things, an Untapped Resource for Innovation in Craniofacial Surgery

“…The diversity of tools used by craniofacial surgeons intraoperatively provides a fertile ground for the development of smart devices. For example, bioimpedance equipped saws stand to improve safety during craniotomy and smart cannulas aim to reduce life-threatening embolic complications during fat grafting 3,4. Perioperatively, IoT devices can augment both treatment and monitoring.…”

“…For example, bioimpedance equipped saws stand to improve safety during craniotomy and smart cannulas aim to reduce lifethreatening embolic complications during fat grafting. 3,4 Perioperatively, IoT devices can augment both treatment and monitoring. In treatment, continuous distraction devices, with adaptive force and vector, have shown promise in mandibular reconstruction.…”