Controlling magnetoelectric nanoparticles for wireless stimulation and recording of neuronswith electromagnetic systems
Nöronların kablosuz stimülasyonu ve kaydı için manyetoelektrik nanoparçacıkların elektromanyetik sistemlerle kumanda edilmesi
- Tez No: 770049
- Danışmanlar: PROF. DR. SAKHRAT KHİZROEV
- Tez Türü: Doktora
- Konular: Elektrik ve Elektronik Mühendisliği, Electrical and Electronics Engineering
- Anahtar Kelimeler: Belirtilmemiş.
- Yıl: 2022
- Dil: İngilizce
- Üniversite: University of Miami
- Enstitü: Yurtdışı Enstitü
- Ana Bilim Dalı: Elektrik ve Bilgisayar Mühendisliği Ana Bilim Dalı
- Bilim Dalı: Belirtilmemiş.
- Sayfa Sayısı: 131
Özet
Özet yok.
Özet (Çeviri)
Recently, Magnetoelectric nanoparticles (MENPs) have been introduced as a potential enabler of a wireless brain-machine interface (BMI). MENPs convert externally applied magnetic fields into electric dipole fields, which in turn can stimulate neurons without the need for invasive electrodes. Both stimulation and recording based on MENPs obey novel underlying physical principles which are quite different from the traditional stimulation approaches, e.g., the popular intracortical microstimulation (ICMS) based on using microelectrodes. In ICMS, electric currents were flown between two microelectrodes to excite neurons; as a result, the stimulation region is defined by the current propagation region and thus is relatively large. In contrast, with MENPs, the stimulation is due to the electric fields (not currents) by individual nanoparticles. These electric fields are localized in the 50-nm proximity range around activated nanoparticles. As for the nanoparticles' activation process, the physical properties of the nanoparticles, such as the magnetic coercivity are used. So far, the main challenges with this approach have been to provide sufficiently high magnetic-to-electric field coupling to locally depolarize the resting membrane potential of neurons, thus evoking action potentials, and to engineer an electromagnetic system capable of testing these novel MENPs-based write/read approaches. In this dissertation, we addressed these challenges and successfully developed several electromagnetic systems designs capable of controlling the properties of MENPs, thus enabling wireless writing and recording processes. Herein, ~30 nm polyethylene glycol (PEG) coated MENPs consisting of a magnetostrictive core (CoFe2O4) and piezoelectric shell (BaTiO3) with a coercivity field of ~300 Oe have been used in E18 rat hippocampal cell culture of ~100,000 neurons. Neuronal cultures were loaded with Cal-520 (fluorescent Ca2+ sensitive indicator) to do an optical read-out of action potentials. When stimulated, MENPs were shown to wirelessly induce calcium spikes which were synchronized with the application of 2-seconds-long trains of ~1200 Oe bipolar magnetic pulses from an electromagnet driven by an audio amplifier at the rate of 20 pulses/sec, with a pulse width of 25 msec. The observed calcium spikes were compared with the traditional electrical stimulation with a 50 μA current applied by two silver electrodes placed in the cell culture and showed similar spikes in terms of shape and magnitude. Also, a common control study was made with sodium channel blocker tetrodotoxin (TTX) and no neural activity was observed after adding TTX. As expected according to the nanoparticles' coercivity driven on/off operation, MENPs operated below their coercivity value of 300 Oe failed to induce synchronized calcium spikes. Furthermore, localization and channelization were demonstrated with a special two-headed electromagnet design in vitro as well as in vivo (rats) with sub-50-ms temporal resolution. Moreover, the physics of recording neural activity with MENPs is explained, and preliminary in vitro experiments successfully proved the theory. Research is ongoing on this topic to collect more statistically significant data. Overall, this dissertation provides evidence for MENPs-induced non-invasive and wireless stimulation and recording of neural activities with high temporal and spatial resolution
Benzer Tezler
- Co2MnAl/PMN-PT manyetoelektrik heteroyapılarda voltaj modülasyonu ile anizotropi kontrolü
Anisotropy tuning via voltage modulation in Co2MnAl/PMN-PT magnetoelectric heterostructures
OKAN ÖZDEMİR
Doktora
Türkçe
2023
Fizik ve Fizik MühendisliğiYıldız Teknik ÜniversitesiFizik Ana Bilim Dalı
PROF. DR. AHMET ALTINDAL
PROF. DR. LEYLA ÇOLAKEROL ARSLAN
- Magnetic properties of Mn5Ge3/PZT heterostructures
Mn5Ge3/PZT hetero yapıların manyetik özellikleri
CAN TANER
Yüksek Lisans
İngilizce
2022
Bilim ve TeknolojiGebze Teknik ÜniversitesiFizik Ana Bilim Dalı
DOÇ. DR. LEYLA ÇOLAKEROL ARSLAN
- İşletme bütçeleri yoluyla üretim giderlerinin kontrolü
Controlling production expenditures via enterprise budgets
İLKER MAMAK
- İşletmelerde kontrol, finansal kontrol ve bütçeleme
Controlling, financial controlling and budget
ASIM GÜN
- İnşaat projelerinde nakit akışı sorunlarının iş programları yoluyla denetimi
Controlling of cash flow problems in construction projects via work programs
ARZU BODUR
Yüksek Lisans
Türkçe
1999
İnşaat MühendisliğiEskişehir Osmangazi Üniversitesiİnşaat Mühendisliği Ana Bilim Dalı
DOÇ. DR. İLKER ÖZDEMİR