Project

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Minimally-invasive deployment of soft electrode arrays for monitoring of brain activity following traumatic brain injury

Applicant Fallegger Florian
Number 193764
Funding scheme Bridge - Proof of Concept
Research institution
Institution of higher education EPF Lausanne - EPFL
Main discipline Microelectronics. Optoelectronics
Start/End 01.08.2020 - 31.10.2021
Approved amount 129'760.00
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All Disciplines (4)

Discipline
Microelectronics. Optoelectronics
Surgery
Neurophysiology and Brain Research
Biomedical Engineering

Keywords (6)

Neurosurgery; Neuromodulation; Bioelectronics; Traumatic brain injury; surgery; Neurotechnology

Lay Summary (German)

Lead
Traumatische Hirnverletzungen sind die Hauptursache für Tod und Behinderung bei jungen Erwachsenen und stellen 1 Million Krankenhausaufenthalte pro Jahr in der EU dar. Diese Verletzungen können durch gewöhnliche Haushalts- oder Fahrzeugunfälle verursacht werden. Nach dem ersten Trauma weist eine große Subpopulation dieser Patienten so genannte sekundäre Hirnverletzungen auf, die durch intensive Aktivität des Gehirns an der Läsionsstelle verursacht werden. Diese erhöhte Aktivität des Gehirns wird als "Hirntsunami" bezeichnet, da sie alle vorhandene Aktivität überfordern und grosse Mengen an Sauerstoff verbrauchen. Die derzeit in der Klinik vorhandenen Elektroden für das Gehirn zur Aufzeichnung dieser anormalen Aktivität sind nicht dafür ausgelegt, diese Wellen effizient aufzuzeichnen und die Behandlung an den Patienten anzupassen.
Lay summary

In den letzten Jahren haben wir weiche Implantate entwickelt, die sich der komplexen Oberfläche des Gehirns anpassen können. Die mechanischen Eigenschaften dieser Geräte kommen denen innerer Organe sehr viel näher als die herkömmlicher starrer klinischer Geräte. Unsere Ergebnisse zeigen, dass die nahtlose Integration in den Körper, die durch die Anpassungsfähigkeit des Geräts ermöglicht wird, zu einer selektiveren Kommunikation zwischen dem Gewebe und dem Implantat führt. In diesem BRIDGE PoC-Projekt haben wir diese soft Implantate im Zusammenhang mit traumatischen Hirnverletzungen eingesetzt, wobei wir diese Hirn-Tsunamis in einem Tiermodell mit Schlaganfall über Tage hinweg aufzeichnen konnten. Dies wird als Nächstes bei Menschen eingesetzt werden, die nach einem Schädel-Hirn-Trauma oder einem Schlaganfall auf die Intensivstation kommen, um ihre Behandlung zu steuern. Parallel dazu haben wir ein soft, robotergestütztes Implantationssystem entwickelt, dass ein sehr großes Elektrodengitter (mit einem Durchmesser von mehr als 6 cm) anbringen kann, aber nur ein 2 cm großes Loch im Schädel benötigt, was die Infektionsrate und das Risiko für den Patienten verringert. Dieses System wurde unter Verwendung eines integrierten Sensors entwickelt, der dem Chirurgen beim Einsetzen des Implantats in das Gehirn ein Feedback gibt. Das Konzept wurde an einem großen Tiermodell im Operationssaal validiert, wo die Elektrode ohne Schädigung des Gehirns eingeführt werden konnte und die Aufzeichnung der evozierten Gehirnaktivität ermöglichte. Dieses neu entwickelte weiche Robotersystem mit integrierter Hirnelektrode wird einen breiteren Einsatz solcher Implantate an der Oberfläche des Gehirns auf einer großen Fläche ermöglichen, ohne dass große Gehirnoperationen erforderlich sind.

Direct link to Lay Summary Last update: 07.01.2022

Lay Summary (English)

Lead
Traumatic Brain Injury (TBI) is the leading cause of death and disability in young adults, representing 1M yearly hospitalisations in the EU. These injuries can be sustained by common household or motor vehicle accidents. After the initial trauma, a large subpopulation of these patients exhibits so-called secondary brain injuries, which are caused by intense activity of the brain at the lesion site. This augmented activity of the brain is called « brain tsunamis » due to the fact that they overrun all existing activity and consume large quantities of oxygen leading to more damages to the brain. Electrodes for the brain currently existing in the clinic to record this abnormal activity are not designed to efficiently record these waves and adapt the treatment for the patient.
Lay summary

In the past years, we have developed soft implants that can conform to the complex surface of the brain. The mechanical properties of these devices are much closer to these of internal organs, compared to conventional rigid clinical devices. Our results show that the seamless integration in the body enabled by the device’s conformability leads to more selective communication between the tissue and the implant. In this BRIDGE PoC project, we have used these soft devices in the context of traumatic brain injury where we could record the brain tsunamis in an animal model of stroke over days. This will be used next in humans coming in the intensive care unit after a TBI or stroke to guide their treatment. In parallel, we have come up with a soft robotic deployment system that can interface a very large electrode grid (>6 cm in diameter) but only requiring a 2 cm hole in the skull, that will reduce infection rate and risk to the patient. This system was developed using an integrated sensor to enable feedback for the surgeon while inserting the implant on the brain. The concept was validated in a large animal model in the surgery room where the electrode could be inserted without damaging the brain and enabled recording of evoked brain activity. This newly developed soft robotic system integrating the neural interface will enable more widespread use of such implants at the surface of the brain over a large surface without needing massive brain surgeries.

Direct link to Lay Summary Last update: 07.01.2022

Responsible applicant and co-applicants

Employees

Collaboration

Group / person Country
Types of collaboration
University of Heidelberg - Dr Santos Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
- Exchange of personnel
HUG - Neurosurgery department Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
University of Cincinatti - Prof. Hartings United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results

Use-inspired outputs


Start-ups

Name Year

Abstract

Traumatic Brain Injury (TBI) is the leading cause of death and disability in young adults, representing 1M yearly hospitalizations in the EU. After the initial trauma, 50% of patients suffer from Secondary Brain Injuries characterized by spreading depolarizations (SD), electrical waves of intense brain activity around the initial lesion that further contribute to brain damage. Currently there are no appropriate tools to record SDs, but they are needed to adapt TBI treatment. One procedure to treat TBI is to drill a small hole in the skull to drain blood. Monitoring SDs through that opening would help diagnostic for better outcome for the patient. However, current clinical electrodes, characterized by thick metallic disks embedded in a rigid silicone can only be used in a limited fashion for this purpose. In the past years, we have developed and patented soft implants that can conform to the complex surface of the brain. The mechanical properties of these devices are much closer to these of internal organs, compared to conventional rigid clinical devices. Our results show that the seamless integration in the body enabled by the device’s conformability leads to more selective communication between the tissue and the implant. We have tested and shown the reliability of this technology in large animal models up to 6 months of implantation. At the moment, controlled manufacturing in a medical grade cleanroom is being put in place to produce human-grade implants.Due to the softness of these implants, we plan to deploy them through small holes in the skull onto a large surface of the brain with only minimal impact on the surgical procedure. With the BRIDGE project, we plan to integrate our soft electrode arrays onto deployment devices and insert them into the brain using a minimally-invasive approach. First, we want to iterate on the device design in surgical training dummies and cadaver heads. Next, in minipigs we want to deploy the soft electrodes in healthy animals then in TBI models that would reflect the clinical setting. Overall with this project, soft electrodes for minimally-invasive neuromonitoring of the brain after TBI are going to be developed in pre-clinical models. This development is crucial for future neuromonitoring of SDs waves, a large factor for the morbidity in the case of TBI. This project’s outcome will open up the possibility to test this approach in preliminary trials in humans and pave the way for better outcomes after TBI.
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