FIELD OF THE INVENTION

This invention relates to improved positioning and consistency for cranial therapy.

BACKGROUND

Many clinical applications such as transcranial magnetic stimulation (TMS) require the clinician to locate internal anatomical regions such as specific brain areas that are not visible to the human eye from the outside. Different approaches such as the “5 cm rule”, scalp measurements and marker-based navigation devices exist that allow one to place the TMS coil with varying levels of accuracy. However, all current techniques that increase targeting accuracy beyond the standard “5 cm rule” increase setup time and require extra training for the clinician. Due to the regular treatment schedule with 20-30 treatment sessions, most TMS operators therefore stick to the fast but inaccurate “5 cm rule” targeting method. This leads to two distinct problems: 1) poor accuracy of the therapy relative to the brain structures being targeted for treatment, and 2) poor consistency of the targeting between various therapy sessions. Accordingly, it would be an advance in the art to alleviate these difficulties in a cost-effective manner.

SUMMARY

Cost effective and accurate targeting of cranial therapy is provided by taking measurements of the patient's head shape, and then fitting a brain atlas to these head measurements to provide customized targeting to brain structures of the patient. In this manner, expensive imaging for targeting, such as magnetic resonance imaging (MRI), can be avoided. This approach can be further improved by measuring therapy device locations relative to the patient's face (either facial landmarks and/or a facial point cloud). By saving this information in a database and using it to position the therapy devices in subsequent therapy sessions, consistency of therapy targeting from one session to the next is improved.

This approach further allows one to track and save therapy device location and orientation without the need for a prior MRI scan, allowing one to collect valuable data that allows one to relate therapy device targeting with treatment outcome. Such a dataset that contains head shape, coil placement and treatment outcome can then be used to develop more effective therapy protocols.

One application for this approach is to transcranial magnetic stimulation. TMS is a clinical treatment for depression where the same localized brain region needs to be treated 5 times a week over the course of 4-6 weeks. The recurring need to localize the same brain area makes it an ideal application for this approach. However, the same principles can be extended to any other kind of cranial therapy, such as temporally interfering electric field therapy.

Significant advantages are provided. Currently the localization of internal anatomical regions for TMS is either based on very generalized atlases such as the most commonly used “5 cm rule”, leading to an imprecise localization that varies strongly between treatment sessions and has been shown to decrease treatment efficacy. The current alternatives are time-consuming scalp measurements that do not allow one to consistently reproduce coil orientation or expensive and difficult to use marker-based neuronavigation equipment that needs several minutes of setup before and during each treatment session.

With the present approach, the internal anatomical location only has to be calibrated to the head coordinate system once during the initial treatment session, and this is efficiently done by warping a brain atlas as needed to fit head measurements from the patient. Registration of facial landmarks and/or a facial point cloud to TMS coil positions efficiently provides improved consistency of treatment locations for all treatments in the treatment plan.

To summarize, significant advantages provided by the present approach include: Low cost; Ease-of-use compared to current marker-based clinical navigation devices; Short setup time; and Increased consistency, accuracy and treatment outcome compared to no navigation or scalp measurements.

