Neuronavigation to precisely and accurately position your TMS coil or electrodes for HD-tES. The neural navigator is the only navigation system that is not affected by line-of-sight occlusion issues without compromising precision and accuracy.
TMS induces focused electrical current in desired brain regions via brief, time-varying magnetic fields produced by a coil, which is typically hand-held. The precise and reliable positioning of this coil is not a trivial task. A millimeter displacement from a specified target location may potentially compromise your results. Further, no two brains are alike; therefore coil placement simply based on head shape alone (‘5cm rule’) or the International 10-20 EEG is often ineffective. The Neural Navigator navigation system provides unmatched precision in positioning the TMS coil over a specified target based on an individual’s MRI. Desired brain targets can be identified by manually selecting them or by combining with fMRI determined regions of activity in real time.
Why immunity to line-of-sight occlusion is important?
Most navigation systems use either optical (infrared) or electromagnetic tracking technology. Both systems perform the same function- however, the technology used to provide information to the operator is substantially different. The optical system uses infrared sensors in combination with light emitting structures that are fixed to the subject’s head via a headband and fixed to a hand-held probe. Both the headband and the instrument must be “seen” by the system’s camera in order to allow navigation. Optical systems are typically more expensive. The electromagnetic systems like the Neural Navigator on the other hand use electromagnetic fields that use reference points on a device attached to the patient’s head (held via headband). Unlike the optical systems, electromagnetic systems do not have to be “seen” by a camera and therefore do not suffer from line of sight occlusion (LOS) issues. In fact, electromagnetic tracking dominates the surgical navigation field due to no LOS issues. Furthermore, the Neural Navigator system uses DC pulsed tracking enabling it to match the precision and accuracy of optical systems.
The net result therefore is a fundamental advance in Neuronavigation ‐ a system that matches the precision and accuracy of optical systems while not being affected by LOS occlusion and is more affordable.
Navigated TMS is significantly better than 5 cm rule or 10-20 method
No two brains are alike, making precision placement of the coils used in TMS Therapy tricky. Precise and reliable positioning can make the difference between a successful result and an unsatisfactory one. Conventional coil placement is done using anatomical landmarks like the bridge of the nose, the projecting part of the back of the skull, etc. to align the coil over an intended brain target. This is called the “non-navigated approach." This approach does not need the patient’s MRI
The “navigated approach”, on the other hand, uses the patient’s MRI, thereby taking into account the individual’s anatomy. From the MRI, one marks out desired brain targets using individual brain landmarks (gyri and sulci). Once marked, the coil can be positioned to within a mm precision over the target. Any subject or operator movement can be immediately compensated for- as the brain target is always visible. This approach is similar to the one taken in image-guided stereotaxy when performing brain surgery. Studies have shown unequivocally greater benefit (up to twice as much) when using a navigated approach over the non-navigated one for TMS treatment.
'Standard‘ indicates Non-Navigated approach
‘Targeted‘ indicates Navigated approach
"A randomized trial of rTMS targeted with MRI based neuro-navigation in treatment-resistant depression” Fitzgerald PB, Hoy K, McQueen S, et al. Neuropsychopharmacology 2009.
- Precision of 4mm or better
- Spatial accuracy better than 1 mm
- Universal TMS compatibility with coil sockets available for Magstim, Magventure, and Neurosoft TMS coils. Customization available for TMS coil from other manufacturers
- Import of standard MRI data types (Nifti, Analyze, and DICOM)
- 3D MR constructed scalp, brain and activation (fMRI) data
- Intuitive software workflow
- Complete setup fits in a small suitcase making it ideal for bed-side investigation and easy transportation
Soterix Medical High-Definition transcranial Electrical Stimulation (HD-tES) is a non-invasive technique where desired brain regions are targeted using arrays of scalp electrodes. Soterix Medical neurotargeting software HD-Targets leverages mathematical optimization to automatically determine the best HD electrode configuration for any target. For patient-specific optimization, localizing the HD sites onto the patients’ scalp based on patient’s MRI ensures precise electrode placement. This as a result ensures precise and consistent HD-tES application.
- Perform HD-tES Neuronavigation in three easy steps:
- Step 1: Use HD-Targets to determine optimal electrode placement for your brain target.
- Step 2: Load stimulation electrode voxel locations into Neural navigator software.
- Step 3: Navigate to stimulation electrode location using individual's MRI and mark location on scalp.