Electromagnetic tracking in image‐guided laparoscopic surgery: Comparison with optical tracking and feasibility study of a combined laparoscope and laparoscopic ultrasound system

Abstract

PurposeIn image‐guided laparoscopy, optical tracking is commonly employed, but electromagnetic (EM) systems have been proposed in the literature. In this paper, we provide a thorough comparison of EM and optical tracking systems for use in image‐guided laparoscopic surgery and a feasibility study of a combined, EM‐tracked laparoscope and laparoscopic ultrasound (LUS) image guidance system.MethodsWe first assess the tracking accuracy of a laparoscope with two optical trackers tracking retroreflective markers mounted on the shaft and an EM tracker with the sensor embedded at the proximal end, using a standard evaluation plate. We then use a stylus to test the precision of position measurement and accuracy of distance measurement of the trackers. Finally, we assess the accuracy of an image guidance system comprised of an EM‐tracked laparoscope and an EM‐tracked LUS probe.ResultsIn the experiment using a standard evaluation plate, the two optical trackers show less jitter in position and orientation measurement than the EM tracker. Also, the optical trackers demonstrate better consistency of orientation measurement within the test volume. However, their accuracy of measuring relative positions decreases significantly with longer distances whereas the EM tracker's performance is stable; at 50 mm distance, the RMS errors for the two optical trackers are 0.210 and 0.233 mm, respectively, and it is 0.214 mm for the EM tracker; at 250 mm distance, the RMS errors for the two optical trackers become 1.031 and 1.178 mm, respectively, while it is 0.367 mm for the EM tracker. In the experiment using the stylus, the two optical trackers have RMS errors of 1.278 and 1.555 mm in localizing the stylus tip, and it is 1.117 mm for the EM tracker. Our prototype of a combined, EM‐tracked laparoscope and LUS system using representative calibration methods showed a RMS point localization error of 3.0 mm for the laparoscope and 1.3 mm for the LUS probe, the lager error of the former being predominantly due to the triangulation error when using a narrow‐baseline stereo laparoscope.ConclusionsThe errors incurred by optical trackers, due to the lever‐arm effect and variation in tracking accuracy in the depth direction, would make EM‐tracked solutions preferable if the EM sensor is placed at the proximal end of the laparoscope.

Shape Reconstruction Processes for Interventional Application Devices: State of the Art, Progress, and Future Directions

“…Electromagnetic tracking is widely used in different medical applications starting from image-guided interventional surgery (Xiao et al, 2018) (Cleary et al, 2005), more recently, to medical device navigation (Linte et al, 2012), (Aufdenblatten and Altermatt, 2008), thanks to their miniaturization, precision, easy to set up installation, and freedom from the line-of-sight. Consequently, electromagnetic tracking is a promising method for tracking and localizing the devices in clinical applications such as bronchoscopy (Leong et al, 2012), endoscopy (Fried et al, 1997), knee arthroplast (Lionberger et al, 2008).…”

Repurposing Molecular Imaging and Sensing for Cancer Image–Guided Surgery

“…It combines the high resolution of optical imaging with the depth penetration of ultrasound (93,94). This technology has been used in the clinic for breast tumor margin assessment (93)(94)(95)(96), SLN mapping and assessment of the metastatic status in breast cancer (97), melanoma resection (98), and neurovascular bundle identification during prostate surgery (Supplemental Table 6) (99). Photoacoustic microscopy has also been used for label-free evaluation of breast tumor margins, with images that were comparable to processed histology slides (96).…”

Visuo-Haptic Mixed Reality Simulation Using Unbound Handheld Tools

“…The nominal accuracy of fusionTrack 250 is 90 µm within 1.4 m [29], which covers our simulation workspace. The tool's velocity also affects accuracy [30]. The hexapod has 3 µm resolution and 0.5 µm repeatability.…”

“…The MAE and RMSE values were 0.1503 and 0.2089 respectively. Oscillations in the visual tip position (i in Figure 13) were mostly due to the typical jitter of the optical tracker [30] and partly due to the shaking of the user's hand. We designed a final experiment to evaluate the synchronization between visual and haptic rendering.…”