Development of an accuracy assessment phantom for surgical navigators

Abstract

The objective of this study was to design a calibration phantom for a surgical navigator used in a hospital environment. It addresses two major issues: the design of an accuracy phantom and the accuracy analysis of the surgical navigator in a hospital setting. The designed phantom was used to assess the accuracy of the optical tracking modality of the surgical navigator used at Oulu University Hospital, Oulu, Finland. The phantom functioned according to the design criteria, it was easy to use and it had enough calibration points that were localized by the navigator according to the accuracy assessment protocol to assess the accuracy error. The distances measured from a fixed origin with the surgical navigator were compared to the known phantom calibration point coordinates. The mean error was within the manufacturer specifications of 1.00 mm. The analysis done using the designed phantom and accuracy assessment protocol showed that the error increased with the distance from the center of the phantom. The accuracy assessment protocol using the present phantom proved to be a suitable method for accuracy analysis of a surgical navigator in a hospital setting.

Technical accuracy of an O-arm registered surgical navigator

“…These results have earlier been published by the authors of this paper in 2009 at the IEEE EMBS -conference in Minneapolis, MN, USA[3].…”

“…After imaging, the phantom was fixed on the measurement platform and the error analysis was conducted according to the accuracy assessment protocol as earlier presented by the authors of this paper [1], [3].…”

An improved method for assessing the technical accuracy of optical tracking systems for orthopaedic surgical navigation

“…This volume was chosen to largely include the volume of the largest human bones such as tibia and femur and the working volume of instruments during typical surgical interventions (e.g., total knee arthroplasty ‐ TKA). This is in line with literature, where phantoms with a range of 12 till 147 measurement points have been used 14,25,28,36 . To mimic the situation of surgical navigation, a DRB was rigidly attached to the phantom to enable pointer measurements relative to the DRB.…”

“…Setups used for TTRE assessment resemble the clinical application using a DRB and a tracked pointer much closer. A commonly used approach is the measurement of points with a tracked pointer on a static mechanical phantom with holes at known positions, optionally a DRB to which the pointer measurements are referenced is attached to the phantom 1,8,14,25–28 . Although this approach is closer to the application, the assumption that the phantom, which represents a body part, and its attached DRB does not move during the surgery can result in an underestimation of the error during clinical application 14 .…”