Knowledge Vault 3/61 - G.TEC BCI & Neurotechnology Spring School 2024 - Day 5
Neurophysiologically based brain state tracking & modulation:
integrating brain implants & cloud brain co-processors
Vaclav Kremen, Mayo Clinic (USA)
<Resume Image >

Concept Graph & Resume using Claude 3 Opus | Chat GPT4 | Llama 3:

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stimulation for neurological diseases 1] A --> C[Neuralink: BCI leap,
paraplegic controls computer 2] A --> D[Stimulators: treat diseases,
sensing estimates condition 3] D --> E[DBS: epilepsy treatment,
thalamus or RNS 4] A --> F[Epilepsy: recurrent seizures,
3% population affected 5] A --> G[VNS, Neurovista:
implantable epilepsy management 6] F --> H[Seizure frequency reporting
often inaccurate 7] A --> I[Platform: rich data collection,
optimize stimulation therapy 8] I --> J[System: implantable stimulator,
tablet, cloud platform 9] I --> K[Study: 5 patients implanted,
65-80% daily data 10] A --> L[Low frequency stimulation:
lower seizures, spike suppression 11] F --> M[Seizures: mostly waking,
spike rates lower day 12] L --> N[Stimulation: attenuated circadian,
longer spike rhythms 13] A --> O[High frequency stimulation:
disrupted sleep 14] A --> P[Impedance: variations over time,
dropped during sleep 15] A --> Q[Evoked potentials: differences
between wake and sleep 16] A --> R[Memory test: low frequency
better, high disrupts sleep 17] A --> S[ICU study: cortical stimulation
may facilitate word recall 18] B --> T[Large team effort:
Mayo, Yale, Dartmouth, Oxford 19] A --> U[Algorithms: seizure detection,
warning, cognitive testing 20] A --> V[Investigational device: two studies,
temporal lobe epilepsy 21] V --> W[Device: excellent battery,
lasts all day 22] A --> X[Data security: patient IDs,
HIPAA cloud, protocols 23] A --> Y[Caution: combining brain implants
with other stimulation 24] A --> Z[Troubleshooting: high impedance,
identify issues, replace 25] class A,B,T,Z kremen; class C neuralink; class D,E,L,N,O,Q,R,S stimulators; class F,H,M epilepsy; class G,P implantable; class K,U seizures; class I,J platform; class V,W study; class X,Y device;


1.- Vaclav Kremen from Mayo Clinic discusses new technologies and research in chronic brain recordings and stimulation devices for neurological diseases like epilepsy.

2.- Neuralink's brain-computer interface is a significant leap, allowing a paraplegic patient to control a computer mouse and play games.

3.- Brain stimulators treat diseases by delivering therapeutic stimulation. Sensing capabilities help estimate the patient's condition.

4.- Deep brain stimulation treats epilepsy by stimulating anterior nucleus of thalamus or using responsive neurostimulation. Reduction in seizure frequency is seen.

5.- Epilepsy is characterized by recurrent seizures from changes in brain electrical activity. 3% of population has active epilepsy. Large animals are affected similarly.

6.- Vagus nerve stimulator and Neurovista device were implantable technologies used for epilepsy management. Neurovista aimed to predict seizures by sensing brain signals.

7.- Reporting seizure frequency, the main treatment outcome measure, is often inaccurate as patients have difficulty recalling seizures that occurred months ago.

8.- A platform was designed to integrate a distributed system with an implanted device for rich data collection and optimizing stimulation therapy.

9.- The system included an implantable stimulator, tablet for patient interaction, and cloud platform for physicians to analyze data and adapt therapy.

10.- In a study, 5 patients were implanted and monitored for years, collecting data 65-80% per day. Some patients needed more follow-up.

11.- Low frequency stimulation showed lower seizure frequency and suppression of interictal spiking compared to high frequency in the patient group.

12.- Seizures mostly occurred during waking for the temporal lobe epilepsy patients. Spike rates were lower during day and higher at night.

13.- Stimulation attenuated circadian and longer rhythms seen in the power of interictal spike rates based on spectral analysis.

14.- High frequency stimulation disrupted sleep, with patients spending more wake time during sleep and having shortened non-REM sleep duration.

15.- Impedance between implanted electrodes showed variations over time and dropped during non-REM sleep, even during short daytime naps.

16.- Evoked potential measurements by stimulating thalamic nuclei and recording hippocampal response showed differences between wakefulness and sleep states.

17.- In a memory test, patients performed better when on long-term low frequency stimulation compared to high frequency, possibly due to sleep disruption.

18.- In an ICU study, cortical stimulation was found to potentially facilitate word recall better than hippocampal stimulation.

19.- The study involved a large team effort across Mayo Clinic, Yale, Dartmouth, Oxford, UCSF and industry partners.

20.- Algorithms can detect seizure onset to warn patients, trigger questionnaires assessing cognitive performance, and enable responsive testing.

21.- The investigational device is currently used in two studies with temporal lobe epilepsy patients, stimulating different thalamic and hippocampal targets.

22.- Battery life of the device is excellent, lasting the whole day until recharging. Battery performance is stable even after 7 years.

23.- Data security involves multiple levels - coding patient IDs, using HIPAA-compliant cloud, and securing device-tablet link with special protocols.

24.- Caution is needed if combining brain implants with other electrical stimulation as it may induce unsafe currents. Manufacturer guidance should be sought.

25.- If electrode impedance becomes too high, troubleshooting is required to identify issues like broken electrodes and proceed with replacement if needed.

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