Repository Community: null
http://hdl.handle.net/20.500.11750/894
2024-03-22T08:25:54Z
2024-03-22T08:25:54Z
전기습윤 구동 방식의 광자극기
조성준
변동학
김소희
http://hdl.handle.net/20.500.11750/17047
2022-11-04T07:30:04Z
2014-08-11T15:00:00Z
Title: 전기습윤 구동 방식의 광자극기
Author(s): 조성준; 변동학; 김소희
Abstract: 본 발명의 실시예에 따른 광 자극기는 체내의 특정 신경세포를 자극하여 신경신호를 얻기 위한 장치로서, 전극을 포함하고, 상기 전극과 연결되는 다수개의 전기 단자가 구비되는 본체부, 상기 본체부의 일측에서 연장되며, 전기습윤을 구동시키기 위한 다수개의 전도성 물방울이 소정의 거리로 이격되어 배치되는 광선로 기판; 및 상기 본체부에 배치되며, 상기 광선로 기판에 형성된 전도성 물방울이 배치되는 방향으로 광을 발생시키는 광원부를 포함하고, 상기 전기 단자 각각은 상기 각각의 전도성 물방울과 연결되며, 상기 전도성 물방울은 상기 전기 단자에 의해 전기장이 인가되는 경우에 광을 통과시키고, 전기장이 인가되지 않는 경우에 진행되는 광을 상기 전도성 물방울의 상부로 반사시켜 특정 신경세포를 자극하는 것을 특징으로 한다. 따라서, 단일 자극 지점의 신경세포를 자극할 뿐만 아니라 깊이 방향으로 여러 지점의 신경세포를 자극할 수 있어 더욱 정밀하게 신경신호의 측정 및 분석을 수행할 수 있다.
2014-08-11T15:00:00Z
Long-term in-vivo recording performance of flexible penetrating microelectrode arrays
Jang, Jae-Won
Kang, Yoo Na
Seo, Hee Won
Kim, Boil
Choe, Han Kyoung
Park, Sang Hyun
Lee, Maan-Gee
Kim, Sohee
http://hdl.handle.net/20.500.11750/15954
2022-12-29T07:10:19Z
2021-11-30T15:00:00Z
Title: Long-term in-vivo recording performance of flexible penetrating microelectrode arrays
Author(s): Jang, Jae-Won; Kang, Yoo Na; Seo, Hee Won; Kim, Boil; Choe, Han Kyoung; Park, Sang Hyun; Lee, Maan-Gee; Kim, Sohee
Abstract: Objective. Neural interfaces are an essential tool to enable the human body to directly communicate with machines such as computers or prosthetic robotic arms. Since invasive electrodes can be located closer to target neurons, they have advantages such as precision in stimulation and high signal-To-noise ratio (SNR) in recording, while they often exhibit unstable performance in long-Term in-vivo implantation because of the tissue damage caused by the electrodes insertion. In the present study, we investigated the electrical functionality of flexible penetrating microelectrode arrays (FPMAs) up to 3 months in in-vivo conditions. Approach. The in-vivo experiment was performed by implanting FPMAs in five rats. The in-vivo impedance as well as the action potential (AP) amplitude and SNR were analyzed over weeks. Additionally, APs were tracked over time to investigate the possibility of single neuron recording. Main results. It was observed that the FPMAs exhibited dramatic increases in impedance for the first 4 weeks after implantation, accompanied by decreases in AP amplitude. However, the increase/decrease in AP amplitude was always accompanied by the increase/decrease in background noise, resulting in quite consistently maintained SNRs. After 4 weeks of implantation, we observed two distinctive issues regarding long-Term implantation, each caused by chronic tissue responses or by the delamination of insulation layer. The results demonstrate that the FPMAs successfully recorded neuronal signals up to 12 weeks, with very stably maintained SNRs, reduced by only 16.1% on average compared to the first recordings, although biological tissue reactions or physical degradation of the FPMA were present. Significance. The fabricated FPMAs successfully recorded intracortical signals for 3 months. The SNR was maintained up to 3 months and the chronic function of FPMA was comparable with other silicon based implantable electrodes. © 2021 Institute of Physics Publishing. All rights reserved.
2021-11-30T15:00:00Z
A 3D flexible neural interface based on a microfluidic interconnection cable capable of chemical delivery
Kang, Yoo Na
Chou, Namsun
Jang, Jae-Won
Choe, Han Kyoung
Kim, Sohee
http://hdl.handle.net/20.500.11750/15292
2022-11-08T18:05:08Z
2021-07-31T15:00:00Z
Title: A 3D flexible neural interface based on a microfluidic interconnection cable capable of chemical delivery
Author(s): Kang, Yoo Na; Chou, Namsun; Jang, Jae-Won; Choe, Han Kyoung; Kim, Sohee
Abstract: The demand for multifunctional neural interfaces has grown due to the need to provide a better understanding of biological mechanisms related to neurological diseases and neural networks. Direct intracerebral drug injection using microfluidic neural interfaces is an effective way to deliver drugs to the brain, and it expands the utility of drugs by bypassing the blood–brain barrier (BBB). In addition, uses of implantable neural interfacing devices have been challenging due to inevitable acute and chronic tissue responses around the electrodes, pointing to a critical issue still to be overcome. Although neural interfaces comprised of a collection of microneedles in an array have been used for various applications, it has been challenging to integrate microfluidic channels with them due to their characteristic three-dimensional structures, which differ from two-dimensionally fabricated shank-type neural probes. Here we present a method to provide such three-dimensional needle-type arrays with chemical delivery functionality. We fabricated a microfluidic interconnection cable (µFIC) and integrated it with a flexible penetrating microelectrode array (FPMA) that has a 3-dimensional structure comprised of silicon microneedle electrodes supported by a flexible array base. We successfully demonstrated chemical delivery through the developed device by recording neural signals acutely from in vivo brains before and after KCl injection. This suggests the potential of the developed microfluidic neural interface to contribute to neuroscience research by providing simultaneous signal recording and chemical delivery capabilities. © 2021, The Author(s).
2021-07-31T15:00:00Z
Ab‑interno surgical technique for the implantation of a wireless subretinal prosthesis in mini‑pigs
Choi, Kwang‑Eon
Ahn, Vu Thi Que
Seo, Hee Won
Kim, Namju
Kim, Sohee
Kim, Seong‑Woo
http://hdl.handle.net/20.500.11750/12487
2022-11-08T18:03:24Z
2020-09-30T15:00:00Z
Title: Ab‑interno surgical technique for the implantation of a wireless subretinal prosthesis in mini‑pigs
Author(s): Choi, Kwang‑Eon; Ahn, Vu Thi Que; Seo, Hee Won; Kim, Namju; Kim, Sohee; Kim, Seong‑Woo
Abstract: We sought to describe the surgical techniques required in the ab-interno method to implant subretinal prostheses in mini-pigs and suggest tips to facilitate optimal outcomes. During vitrectomy, the use of valved trocar cannulas was essential to stabilize the detached retina and implanted chip. As a first step in retinal detachment, a 23-gauge cannula with very small amount of viscoelastic material was used to establish the retinal hole and promote retinal detachment. Then, balanced salt solution was applied to increase the retinal detachment and diathermy was used to make opening for subretinal prosthesis. For easy positioning of the subretinal prosthesis, a curved laser probe was adopted when handling the subretinal prosthesis under the retina. After surgery, the sclerotomy sites were tightly sutured to prevent silicone oil leakage. Without special equipment, such as a 41-gauge tip, retinal detachment could be induced easily, while the prosthesis was also successfully inserted and manipulated under the retina without an iatrogenic retinal tear. Two weeks after the operation, the oil fully occupied the intraocular volume without leakage. The subretinal prosthesis remained stable without complication. Understanding the principle of the ab-interno method and considering several tips for improving surgical access may help to enhance surgical success rates of subretinal prostheses implantation. © 2020, The Author(s).
2020-09-30T15:00:00Z