Technical Note: Assessment of electromagnetic tracking systems in a surgical environment using ultrasonography and ureteroscopy instruments for percutaneous renal access

Abstract

PurposeElectromagnetic tracking systems (EMTSs) have been proposed to assist the percutaneous renal access (PRA) during minimally invasive interventions to the renal system. However, the influence of other surgical instruments widely used during PRA (like ureteroscopy and ultrasound equipment) in the EMTS performance is not completely known. This work performs this assessment for two EMTSs [Aurora® Planar Field Generator (PFG); Aurora® Tabletop Field Generator (TTFG)].MethodsAn assessment platform, composed by a scaffold with specific supports to attach the surgical instruments and a plate phantom with multiple levels to precisely translate or rotate the surgical instruments, was developed. The median accuracy and precision in terms of position and orientation were estimated for the PFG and TTFG in a surgical environment using this platform. Then, the influence of different surgical instruments (alone or together), namely analogic flexible ureterorenoscope (AUR), digital flexible ureterorenoscope (DUR), two‐dimensional (2D) ultrasound (US) probe, and four‐dimensional (4D) mechanical US probe, was assessed for both EMTSs by coupling the instruments to 5‐DOF and 6‐DOF sensors.ResultsOverall, the median positional and orientation accuracies in the surgical environment were 0.85 mm and 0.42° for PFG, and 0.72 mm and 0.39° for TTFG, while precisions were 0.10 mm and 0.03° for PFG, and 0.20 mm and 0.12° for TTFG, respectively. No significant differences were found for accuracy between EMTSs. However, PFG showed a tendency for higher precision than TTFG. AUR, DUR, and 2D US probe did not influence the accuracy and precision of both EMTSs. In opposition, the 4D probe distorted the signal near the attached sensor, making readings unreliable.ConclusionsUreteroscopy‐ and ultrasonography‐assisted PRA based on EMTS guidance are feasible with the tested AUR or DUR together with the 2D probe. More studies must be performed to evaluate the probes and ureterorenoscopes’ influence before their use in PRA based on EMTS guidance.

The use of endoscopic combined intrarenal surgery in the treatment of nephrolithiasis

“…The authors have noted that the new technology allowed safe, accurate, fast and efficient puncture of the renal collecting system. These findings are reflected in the work from 2020 by medical physicists, who also studied this technique [54], mathematically confirmed the accuracy of the puncture of CPS with the help of electromagnetic control system and GPS navigation.…”

A comprehensive quality assurance protocol for electromagnetic tracking in brachytherapy

“…The jitter magnitude was generally lower than 0.1 mm, which is indicative of the improvement of EMT technology in recent years. While studies from the early days of EMT application in the clinical environment observed jitter errors of 0.9 mm 34 and 0.4 mm, 39 more recent studies report average jitter errors of 0.19 mm, 40 0.10 mm, 36 and 0.06 mm 41 . It is important to note here that, due to the leeway in the catheter, the sensor was not mechanically fixed to the phantom, which means that our jitter error results can also comprise mechanical jitter to some degree.…”

“…Existing studies designed and tested assessment protocols for EMT either in a very general setup that does not account for the requirements of EMT in BT, [32][33][34] or in a very specialized setup for other dedicated applications. [35][36][37] This study explicitly focuses on the application of EMT in BT with a hybrid treatment delivery system 18 (Elekta Brachytherapy, Veenendaal, The Netherlands) using a dedicated QA phantom (Elekta Brachytherapy) that can hold most of the common BT applicators. Our first goal is to design, test and introduce a protocol that covers all necessary aspects of EMT-related QA and is applicable to clinical routine, that is, is easy to apply, even on a daily basis, and does not require extensive training and time.…”

“…Yet there is no definition of the requirements for the use of EMT in BT, nor is there a comprehensive and standardized quality assurance (QA) protocol. Existing studies designed and tested assessment protocols for EMT either in a very general setup that does not account for the requirements of EMT in BT, 32–34 or in a very specialized setup for other dedicated applications 35–37 …”