Fraxicon for Optical Applications with Aperture ∼1 mm: Characterisation Study

Nanomaterials, Journal Year: 2024, Volume and Issue: 14(3), P. 287 - 287

Published: Jan. 30, 2024

Emerging applications of optical technologies are driving the development miniaturised light sources, which in turn require fabrication matching micro-optical elements with sub-1 mm cross-sections and high quality. This is particularly challenging for spatially constrained biomedical where reduced dimensionality required, such as endoscopy, optogenetics, or implants. Planarisation a lens by Fresnel approach was adapted conical (axicon) made direct femtosecond 780 nm/100 fs laser writing SZ2080™ polymer photo-initiator. Optical characterisation positive negative fraxicons presented. Numerical modelling fraxicon performance under illumination incoherent extended sources compared ideal case plane-wave illumination. Considering potential rapid replication soft polymers resists, this holds great promise most demanding technological applications.

Language: Английский

---

Graded optogenetic activation of the auditory pathway for hearing restoration

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2022, Volume and Issue: unknown

Published: Sept. 6, 2022

Abstract Optogenetic control of neural activity enables innovative approaches to improve functional restoration diseased sensory and motor systems. For clinical translation succeed, optogenetic stimulation needs closely match the coding properties targeted neuronal population employ suitable emitters at their optimal operation. This requires tailoring channelrhodopsins, strategies. Here, we provide a framework parametrize apply it auditory pathway that high temporal fidelity stimulation. We used viral gene transfer ultrafast targeting-optimized Chronos into spiral ganglion neurons (SGNs) cochlea. characterized light-evoked response by in vivo recordings from individual SGNs anteroventral cochlear nucleus (AVCN) detect coincident SGN input. Our results demonstrate spike probability can be gradually dialed adjusting width light pulses constant intensity, which optimally serves efficient laser diode identified an effective pulse 1.6 ms maximize information encoding SGNs. An upper boundary optical rates robust rate adaptation required few tens milliseconds recover. developed semi-stochastic paradigm rapidly (within minutes) estimate function firing. The stimulus evoked firing different statistics allowing approximate time integration AVCN. data pave way design sound strategies future implants.

Language: Английский

---

Implantes cocleares ópticos: una herramienta promisoria de tratamiento para la hipoacusia

Revista de otorrinolaringología y cirugía de cabeza y cuello, Journal Year: 2023, Volume and Issue: 83(3), P. 317 - 324

Published: Jan. 1, 2023

La hipoacusia afecta a más de 1.500 millones personas mundialmente. Los principales medios rehabilitación usados son los audífonos e implantes cocleares (IC). El IC eléctrico convierte el sonido en impulsos eléctricos que estimulan, directamente, las neuronas del ganglio espiral para proveer sensación auditiva. Tiene como desventaja una amplia dispersión espacial la corriente, limitando resolución espectral y rango dinámico codificación sonoro, lo conduce mala comprensión habla entornos ruidosos apreciación música. En últimos años se ha estudiado utilizar estimulación óptica vez eléctrica, pues emite estímulos con mayor selectividad espacial. Se han descrito ópticos usando luz infrarroja otros métodos optogenética, estos requieren expresión proteínas fotosensibles inducidas por virus adenoasociados. visto optogenética es indistinguible acústica, permitió tasas disparo casi fisiológicas buena precisión temporal hasta 250 Hz estimulación. Estudios compararon un sistema óptico uno concluyen uso permitiría restauración audición mejorada comparación eléctrico.

---