Making robots mill bone more like human surgeons: Using bone density and anatomic information to mill safely and efficiently

Abstract

Surgeons and robots typically use different approaches for bone milling. Surgeons adjust their speed and tool incidence angle constantly, which enables them to efficiently mill porous bone. Surgeons also adjust milling parameters such as speed and depth of cut throughout the procedure based on proximity to sensitive structures like nerves and blood vessels. In this paper we use image-based bone density estimates and segmentations of vital anatomy to make a robot mill more like a surgeon and less like an industrial computer numeric controlled (CNC) milling machine. We produce patient-specific plans optimizing velocity and incidence angles for spherical cutting burrs. These plans are particularly useful in bones of variable density and porosity like the human temporal bone. They result in fast milling in non-critical areas, reducing overall procedure time, and lower forces near vital anatomy. We experimentally demonstrate the algorithm on temporal bone phantoms and show that it reduces mean forces near vital anatomy by 63% and peak forces by 50% in comparison to a CNC-type path, without adding time to the procedure.

A systematic review of robotic surgery: From supervised paradigms to fully autonomous robotic approaches

“…19 Compared to Couldwell et al's approach, this system used features of bone density and porosity during planning to optimise the drilling force and revolutions per minute near vital structures. 18,20 The strategy was shown to reduce mean force near vital structures by 63%, thereby reducing the risk of accidental collisions and reducing the rate of thermal energy transferred to the surrounding structures. 20 The performance was evaluated by drilling the temporal bone funnel for vestibular schwannoma resections on five cadaver heads.…”

“…18,20 The strategy was shown to reduce mean force near vital structures by 63%, thereby reducing the risk of accidental collisions and reducing the rate of thermal energy transferred to the surrounding structures. 20 The performance was evaluated by drilling the temporal bone funnel for vestibular schwannoma resections on five cadaver heads. 19 The time taken to complete the tasks ranged from 32.7 to 57 min for targeted volumes ranging in sizes from 5.03 to 11.67 cm 2 .…”

Outlook and future of inner ear therapy

“…Using preoperative high-resolution computed tomography for surgical planning and intraoperative navigation, the precise trajectory required for cochlear access can be planned by the surgeon, resulting in a minimally invasive surgical approach that minimizes trauma to the endosteal membrane and other cochlear tissues (Brett et al, 2007; Coulson et al, 2008; Majdani et al, 2009). In a comparison of manual versus robotic cochleostomy, there are significantly less intracochlear pressure disturbances using a robotic micro-drill (Assadi et al, 2013; Coulson et al, 2013; Dillon et al, 2016). A minimally traumatic cochleostomy can be achieved using an automatic or semi-automatic robotic drill, hand-guided robotic drill, or with laser (Brett et al, 2014; Hussong et al, 2008; Wimmer et al, 2014; Zhang et al, 2014).…”

A Static Balancing Method for Variable Payloads by Combination of a Counterweight and Spring and Its Application as a Surgical Platform

“…Lessard et al [29] developed a static balancing parallel robot for medical 3D ultrasound using counterweights and torsional springs on actuated and passive revolute joints. Dillon et al [30] designed a milling device as an otology surgery robot. They produced patient-specific plans, optimizing the velocity and incidence angles for spherical cutting burrs using image-based density.…”