Surgical Navigation Technology: Optical and Electromagnetic Tracking

2001 ◽  
pp. 50-67
Keyword(s):  
Surgical Navigation ◽  
Electromagnetic Tracking

scholarly journals Assessment of Position Repeatability Error in an Electromagnetic Tracking System for Surgical Navigation

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 961 ◽  
Author(s):  
Gregorio Andria ◽  
Filippo Attivissimo ◽  
Attilio Di Nisio ◽  
Anna Maria Lucia Lanzolla ◽  
Mattia Alessandro Ragolia
Keyword(s):  
Surgical Navigation ◽  
State Of The Art ◽  
Tracking System ◽  
The State ◽  
Operating Table ◽  
Electromagnetic Tracking ◽  
Position Measurement ◽  
Sensor Position ◽  
Repeatability Error ◽  
Electromagnetic Tracking System

In this paper we present a study of the repeatability of an innovative electromagnetic tracking system (EMTS) for surgical navigation, developed to overcome the state of the art of current commercial systems, allowing for the placement of the magnetic field generator far from the operating table. Previous studies led to the development of a preliminary EMTS prototype. Several hardware improvements are described, which result in noise reduction in both signal generation and the measurement process, as shown by experimental tests. The analysis of experimental results has highlighted the presence of drift in voltage components, whose effect has been quantified and related to the variation of the sensor position. Repeatability in the sensor position measurement is evaluated by means of the propagation of the voltage repeatability error, and the results are compared with the performance of the Aurora system (which represents the state of the art for EMTS for surgical navigation), showing a repeatability error about ten times lower. Finally, the proposed improvements aim to overcome the limited operating distance between the field generator and electromagnetic (EM) sensors provided by commercial EM tracking systems for surgical applications and seem to provide a not negligible technological advantage.

scholarly journals Planar Body-Mounted Sensors for Electromagnetic Tracking

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2822
Author(s):  
Marco Cavaliere ◽  
Herman Alexander Jaeger ◽  
Kilian O’Donoghue ◽  
Pádraig Cantillon-Murphy
Keyword(s):  
Magnetic Field ◽  
Surgical Navigation ◽  
Cost Benefit ◽  
Cost Effective ◽  
Magnetic Sensors ◽  
Electromagnetic Tracking ◽  
Cost Effective Method ◽  
Pcb Manufacturing ◽  
The Cost ◽  
Planar Body

Electromagnetic tracking is a safe, reliable, and cost-effective method to track medical instruments in image-guided surgical navigation. However, patient motion and magnetic field distortions heavily impact the accuracy of tracked position and orientation. The use of redundant magnetic sensors can help to map and mitigate for patient movements and magnetic field distortions within the tracking region. We propose a planar inductive sensor design, printed on PCB and embedded into medical patches. The main advantage is the high repeatability and the cost benefit of using mass PCB manufacturing processes. The article presents new operative formulas for electromagnetic tracking of planar coils on the centimetre scale. The full magnetic analytical model is based on the mutual inductance between coils which can be approximated as being composed by straight conductive filaments. The full model is used to perform accurate system simulations and to assess the accuracy of faster simplified magnetic models, which are necessary to achieve real-time tracking in medical applications.

scholarly journals Distorter Characterisation Using Mutual Inductance in Electromagnetic Tracking

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3059 ◽  
Author(s):  
Herman Jaeger ◽  
Pádraig Cantillon-Murphy
Keyword(s):  
Magnetic Field ◽  
Measurement Errors ◽  
Surgical Navigation ◽  
Sensor Arrays ◽  
Medical Robotics ◽  
Mutual Inductance ◽  
Electromagnetic Tracking ◽  
Novel Method ◽  
Transmitter Design ◽  
The Magnetic Field

Electromagnetic tracking (EMT) is playing an increasingly important role in surgical navigation, medical robotics and virtual reality development as a positional and orientation reference. Though EMT is not restricted by line-of-sight requirements, measurement errors caused by magnetic distortions in the environment remain the technology’s principal shortcoming. The characterisation, reduction and compensation of these errors is a broadly researched topic, with many developed techniques relying on auxiliary tracking hardware including redundant sensor arrays, optical and inertial tracking systems. This paper describes a novel method of detecting static magnetic distortions using only the magnetic field transmitting array. An existing transmitter design is modified to enable simultaneous transmission and reception of the generated magnetic field. A mutual inductance model is developed for this transmitter design in which deviations from control measurements indicate the location, magnitude and material of the field distorter to an approximate degree. While not directly compensating for errors, this work enables users of EMT systems to optimise placement of the magnetic transmitter by characterising a distorter’s effect within the tracking volume without the use of additional hardware. The discrimination capabilities of this method may also allow researchers to apply material-specific compensation techniques to minimise position error in the clinical setting.

scholarly journals A virtual platform for real-time performance analysis of electromagnetic tracking systems for surgical navigation

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 103
Author(s):  
Mattia Alessandro Ragolia ◽  
Filippo Attivissimo ◽  
Attilio Di Nisio ◽  
Anna Maria Lucia Lanzolla ◽  
Marco Scarpetta
Keyword(s):  
Magnetic Field ◽  
Real Time ◽  
Surgical Navigation ◽  
Surgical Instruments ◽  
Accurate Estimation ◽  
Electromagnetic Tracking ◽  
Tracking Systems ◽  
Virtual Platform ◽  
Magnetic Field Generator ◽  
The Magnetic Field

<p class="Abstract">Electromagnetic Tracking Systems (EMTSs) are widely used in surgical navigation, allowing to improve the outcome of diagnosis and surgical interventions, by providing the surgeon with real-time position of surgical instruments during medical procedures. However, particular effort was dedicated to the development of efficient and robust algorithms, to obtain an accurate estimation of the instrument position for distances from the magnetic field generator beyond 0.5 m. Indeed, the main goal is to improve the limited range of current commercial systems, which strongly affects the freedom of movement of the medical team. Studies are currently being conducted to optimize the magnetic field generator configuration (both geometrical arrangements and electrical properties) since it affects tracking accuracy. In this paper, we propose a virtual platform for assessing the performance of EMTSs for surgical navigation, providing real-time results and statistics, and allowing to track instruments both in real and simulated environments. Simulations and experimental tests are performed to validate the proposed virtual platform, by employing it to assess the performance of a real EMTS. The platform offers a real-time tool to analyze EMTS components and field generator configurations, for a deeper understanding of EMTS technology, thus supporting engineers during system design and characterization.</p>

Image-Guided Spinal Surgery and Robotics in MIS: Where Are We Now?

2018 ◽  
Vol 1 (2) ◽  
pp. 2
Author(s):  
Chiung Chyi Shen
Keyword(s):  
Pedicle Screw ◽  
Spinal Surgery ◽  
Surgical Navigation ◽  
Improve Patient Safety ◽  
Intraoperative Imaging ◽  
Spinal Instrumentation ◽  
Pedicle Screws ◽  
Computer Assisted ◽  
Navigation Systems ◽  
Image Guided

Use of pedicle screws is widespread in spinal surgery for degenerative, traumatic, and oncological diseases. The conventional technique is based on the recognition of anatomic landmarks, preparation and palpation of cortices of the pedicle under control of an intraoperative C-arm (iC-arm) fluoroscopy. With these conventional methods, the median pedicle screw accuracy ranges from 86.7% to 93.8%, even if perforation rates range from 21.1% to 39.8%.The development of novel intraoperative navigational techniques, commonly referred to as image-guided surgery (IGS), provide simultaneous and multiplanar views of spinal anatomy. IGS technology can increase the accuracy of spinal instrumentation procedures and improve patient safety. These systems, such as fluoroscopy-based image guidance ("virtual fluoroscopy") and computed tomography (CT)-based computer-guidance systems, have sensibly minimized risk of pedicle screw misplacement, with overall perforation rates ranging from between 14.3% and 9.3%, respectively."Virtual fluoroscopy" allows simultaneous two-dimensional (2D) guidance in multiple planes, but does not provide any axial images; quality of images is directly dependent on the resolution of the acquired fluoroscopic projections. Furthermore, computer-assisted surgical navigation systems decrease the reliance on intraoperative imaging, thus reducing the use of intraprocedure ionizing radiation. The major limitation of this technique is related to the variation of the position of the patient from the preoperative CT scan, usually obtained before surgery in a supine position, and the operative position (prone). The next technological evolution is the use of an intraoperative CT (iCT) scan, which would allow us to solve the position-dependent changes, granting a higher accuracy in the navigation system. 

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