A novel remote hands-on training for neuroendovascular-based treatment in the era of the COVID-19 pandemic

The COVID-19 pandemic has demanded a change in learning modalities, which led us to develop a remote personal training system for clinicians performing neuroendovascular procedures. A portable vascular model designed for practicing catheter navigation guidance, thrombus retrieval, and intracranial aneurysm coil embolisation was established. We created an environment that enabled interactive dialogue and communication across long distances using the Internet. The instructor conducted approximately 2 h of hands-on training with two to four trainees at a time. Despite the restrictions enforced by the Government of Japan due to the COVID-19 pandemic, 17 online hands-on training were successfully conducted throughout Japan over 1 year for a total of 48 trainees. The developed remote training programme, to avoid the aggregation of a large number of trainees at a developed time, proved to be at par with the conventional learning system. The training was well-received since the operation time was longer and the question and answer sessions were more fulfilling compared to the conventional format in which a group of trainees had got a brief opportunity to receive actual hands-on experience.

Electromagnetic-Guided Interstitial Catheter Navigation for Gynecological Brachytherapy: a Phase I Trial (E-MINT)

<div>Catheter insertion for gynecological interstitial brachytherapy is a challenging surgical procedure due to the lack of real-time guidance available to Radiation Oncologists. To mitigate the limitations associated with catheter placement, electromagnetic navigation (EMN) was proposed as a solution to the current interstitial brachytherapy workflow. The sequence of events leading up to the completion of this project were as follows, the validation of the system and then the application of the EMN system in a clinical trial. Using a phantom-based validation method, submillimetric accuracy and jitter was characterized for the operational performance of an EMN system in a brachytherapy operating room environment.</div><div>Following validation, the EMN system was used for catheter placement in 5 patients, in an ongoing prospective clinical study. The mean catheter deflection documented was 3.52 +/- 2.53 mm when adopting EMN as a form of real-time guidance compared to 5.48 +/- 3.63 mm when the standard clinical workflow (SCW) was employed. The mean catheter spacing when using EMN was 9.31 +/- 4.81 mm compared to 7.09 +/- 6.06 mm when the SCW was followed. Also, the mean intraoperative time was 50.00 +/- 18.80 minutes for EMN and 38.20 +/- 15.29 minutes for the SCW.</div><div>The results of this project demonstrate that electromagnetic navigated interstitial catheter placement is promising as a real-time guidance option for the interstitial gynecological brachytherapy workflow. <br></div>

Electromagnetic-Guided Interstitial Catheter Navigation for Gynecological Brachytherapy: a Phase I Trial (E-MINT)

<div>Catheter insertion for gynecological interstitial brachytherapy is a challenging surgical procedure due to the lack of real-time guidance available to Radiation Oncologists. To mitigate the limitations associated with catheter placement, electromagnetic navigation (EMN) was proposed as a solution to the current interstitial brachytherapy workflow. The sequence of events leading up to the completion of this project were as follows, the validation of the system and then the application of the EMN system in a clinical trial. Using a phantom-based validation method, submillimetric accuracy and jitter was characterized for the operational performance of an EMN system in a brachytherapy operating room environment.</div><div>Following validation, the EMN system was used for catheter placement in 5 patients, in an ongoing prospective clinical study. The mean catheter deflection documented was 3.52 +/- 2.53 mm when adopting EMN as a form of real-time guidance compared to 5.48 +/- 3.63 mm when the standard clinical workflow (SCW) was employed. The mean catheter spacing when using EMN was 9.31 +/- 4.81 mm compared to 7.09 +/- 6.06 mm when the SCW was followed. Also, the mean intraoperative time was 50.00 +/- 18.80 minutes for EMN and 38.20 +/- 15.29 minutes for the SCW.</div><div>The results of this project demonstrate that electromagnetic navigated interstitial catheter placement is promising as a real-time guidance option for the interstitial gynecological brachytherapy workflow. <br></div>

Localization accuracy of multiple magnets in a myokinetic control interface

Magnetic localizers have been widely investigated in the biomedical field, especially for intra-body applications, because they don’t require a free line-of-sight between the implanted magnets and the magnetic field sensors. However, while researchers have focused on narrow and specific aspects of the localization problem, no one has comprehensively searched for general design rules for accurately localizing multiple magnetic objectives. In this study, we sought to systematically analyse the effects of remanent magnetization, number of sensors, and geometrical configuration (i.e. distance among magnets—Linter-MM—and between magnets and sensors—LMM-sensor) on the accuracy of the localizer in order to unveil the basic principles of the localization problem. Specifically, through simulations validated with a physical system, we observed that the accuracy of the localization was mainly affected by a specific angle ($$\theta$$ θ = tan−1(Linter-MM / LMM-sensor)), descriptive of the system geometry. In particular, while tracking nine magnets, errors below ~ 1 mm (10% of the length of the simulated trajectory) and around 9° were obtained if θ ≥ ~ 31°. The latter proved a general rule across all tested conditions, also when the number of magnets was doubled. Our results are interesting for a whole range of biomedical engineering applications exploiting multiple-magnets tracking, such as human–machine interfaces, capsule endoscopy, ventriculostomy interventions, and endovascular catheter navigation.

An agglutinate magnetic spray transforms inanimate objects into millirobots for biomedical applications

Millirobots that can adapt to unstructured environments, operate in confined spaces, and interact with a diverse range of objects would be desirable for exploration and biomedical applications. The continued development of millirobots, however, requires simple and scalable fabrication techniques. Here, we propose a minimalist approach to construct millirobots by coating inanimate objects with a composited agglutinate magnetic spray. Our approach enables a variety of one-dimensional (1D), 2D, or 3D objects to be covered with a thin magnetically drivable film (~100 to 250 micrometers in thickness). The film is thin enough to preserve the original size, morphology, and structure of the objects while providing actuation of up to hundreds of times its own weight. Under the actuation of a magnetic field, our millirobots are able to demonstrate a range of locomotive abilities: crawling, walking, and rolling. Moreover, we can reprogram and disintegrate the magnetic film on our millirobots on demand. We leverage these abilities to demonstrate biomedical applications, including catheter navigation and drug delivery.

Autonomous guidewire navigation in a two dimensional vascular phantom

The treatment of cerebro- and cardiovascular diseases requires complex and challenging navigation of a catheter. Previous attempts to automate catheter navigation lack the ability to be generalizable. Methods of Deep Reinforcement Learning show promising results and may be the key to automate catheter navigation through the tortuous vascular tree. This work investigates Deep Reinforcement Learning for guidewire manipulation in a complex and rigid vascular model in 2D. The neural network trained by Deep Deterministic Policy Gradients with Hindsight Experience Replay performs well on the low-level control task, however the high-level control of the path planning must be improved further.