• 대한의용생체공학회:의공학회지
• /
• 제31권4호
• /
• pp.292-301
• /
• 2010

To restore visual sensation of blind patients, we have proposed a fully implantable retinal prosthesis comprising an three dimensionally (3D) stacked retinal chip for transforming optical signal to electrical signal, a flexible cable with stimulus electrode array for stimulating retina cells, and coupling coils for power transmission. The 3D stacked retinal chip is consisted of several LSI chips such as photodetector, signal processing circuit, and stimulus current generator. They are vertically stacked and electrically connected using 3D integration technology. Our retinal prosthesis has a small size and lightweight with high resolution, therefore it could increase the patients` quality of life (QOL). For realizing the fully implantable retinal prosthesis, we developed a retinal prosthesis module comprising a retinal prosthesis chip and a flexible cable with stimulus electrode array for generating optimal stimulus current. In this study, we used a 2D retinal chip as a prototype retinal prosthesis chip. We fabricated the polymide-based flexible cable of $20{\mu}m$ thickness where 16 channels Pt stimulus electrode array was formed in the cable. Pt electrode has an impedance of $9.9k{\Omega}$ at 400Hz frequency. The retinal prosthesis chip was mounted on the flexible cable by an epoxy and electrically connected by Au wire. The retinal prosthesis chip was cappted by a silicone to pretect from corrosive environments in an eyeball. Then, the fabricated retinal prosthesis module was implanted into an eyeball of a rabbit. We successfully recorded electrically evoked potential (EEP) elicited from the rabbit brain by the current stimulation supplied from the implanted retinal prosthesis module. EEP amplitude was increased linearly with illumination intensity and irradiation time of incident light. The retinal prosthesis chip was well functioned after implanting into the eyeball of the rabbit.

• 재활복지공학회논문지
• /
• 제8권1호
• /
• pp.1-7
• /
• 2014

본 연구에서는 기존의 시/청각 방식의 운전정보 전달체계의 한계를 극복하고 더불어 교통약자들의 운전 수행에 도움이 되는 자동차용 햅틱시트 기술을 개발하고자 하였다. 이를 위해 동전형 모터 30개를 사용한 진동자극용 시트커버형 시제품과 모터드라이버모듈을 제작하였고 촉각이상이 없는 젊은 남녀 10명을 대상으로 6자유도 모션베이스 상에 구축된 가상운전 시뮬레이터를 사용하여 가상운전상황에서의 시트진동자극에 대한 실험을 진행하였다. 모터의 동작전압(1.5V, 2.5V, 3.5V)에 따라 세기가 가변되는 30개소의 진동자극의 위치별 인지율을 측정하여 분석하였다. 피험자들은 2.5V,3.5V로 동작하는 30개소의 모터 진동자극을 모두 인지하였고 최저작동전압인 1.5V에서도 일정수준 이상의 인지율을 보여주는 결과를 얻었으며 이 결과는 차량 내에서의 시트를 통한 진동자극의 운전정보 유용성을 보여주는 것으로 사료된다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 ITC-CSCC -1
• /
• pp.702-705
• /
• 2002

This paper describes effects of visual information influencing sound localization in the peripheral visual Held under dynamic conditions. Presentation experiments of an audio-visual stimulus were carried out using a movie of a moving patrol car and its siren sound. The tallowing results were obtained: first, the sound image on the timing at the beginning of the presentation was more strongly captured by the visual image than that at the end, i.e., the "beginning effect" was occurred; second, in the peripheral regions, the "beginning effect" was strongly appeared in near the fixation point of eyes.

• 한국실내디자인학회:학술대회논문집
• /
• 한국실내디자인학회 2003년도 춘계학술발표대회 논문집
• /
• pp.44-49
• /
• 2003

Exhibition can be a type of mass-communication since it should contains some 'meaning' or 'message' that is to be delivered. The purpose of visiting museum is to view exhibits. Thus, factors, such as exhibits, exhibition media, show-case, direction signs, and gates, form visual perception, which means there exists homogeneity between visual perception and action. Visitors acquire knowledge by the space interaction when one can acknowledge the consecutive time flow while moving along the exhibition space. Visitors' movements can be formed by visual and perceptive experience that follows environmental stimulus and individual desire. Therefore, museum visitors experience certain shift flow with visual perception caused by the continuity of space. Thus, the research on development of focus in continuity is required. In addition, if the quality of exhibition space and organized continuity with visual diversity can be improved in exhibition design, it would expand the function of communication in exhibitions.

• Annals of Clinical Neurophysiology
• /
• 제20권1호
• /
• pp.12-17
• /
• 2018

Visual evoked potentials (VEPs) are frequently used to assess the anterior and posterior visual pathways. In particular, the use of VEPs have been increasing in various fields such as evaluation of the optic nerves in patients with multiple sclerosis. The performance of VEP test can be affected by various factors such as stimulus type and subject condition, and its interpretation is also difficult. However, there have been no guidelines for performing and interpreting VEPs in Korea. Therefore, we aimed to provide comprehensive information regarding basic requirement and interpretation for VEPs.

• 전기의세계
• /
• 제21권5호
• /
• pp.7-12
• /
• 1972

Applying the theory of physiology and control systems, the visual system was studied as a regulator of impining light. The characteristics function of visual system is mainly analysed by spato-temporal characteristics based upon Enroth's model, Broca-Sulzer phenomenon and Mach effect. Some aims of this paper are as follows. (1) In order to get the excitatory and inhibitory potential of the intermediated cell layer in the retina, the exponential value, {exp(FM/kT)- $I_{mn}$ } is caculated based on the physiological theory in neuro-phenomena. (2) To show the visual characteristics by analog simulation for generating stimulus waveforms and analysis, the visual adaptation was recorded as electrical stimulation in the form of step functions. Furthermore, ti is shown that the above experimental data agrees satisfactorily with the theoretical (psychophysiological) values. This study is expected to lead to further studies concerned with human observer and human operator in control and especially pattern recognition systems.stems.

• 대한인간공학회지
• /
• 제30권1호
• /
• pp.221-227
• /
• 2011

Objective: The aim of this study is to investigate the quantitative effects of various emotions and retention periods on the color vividness of visual memory. Background: Although numerous studies have focused on the effects of emotions on memory such as visual detail and vividness of emotional events compared to neutral events, the relationship between emotion and visual memory is ambiguous yet. Furthermore, there were few studies on the effect of emotion on vividness of visual memory. Method: A total of 68 subjects were participated in serial experiments proceed on online and the experiments had two phases: recognition phase and reproduction phase. The 15 photographs were used as visual stimuli and all experiments were conducted over the internet(experiment website) and the results were collected on the web database. Results: The retention period, sleep-arousal emotion and subjective saturation of visual stimuli had a significant effect on the color vividness of visual memory. Conclusion: The results suggested that the color of visual stimulus might be more vividly remembered when it is arousing, the subjective saturation is higher and the retention period is longer. Application: The findings of this study may help clarify the relationship between human emotions and visual memory.

• 대한의용생체공학회:의공학회지
• /
• 제38권1호
• /
• pp.16-24
• /
• 2017

For the development of feasible retinal prosthesis, one of the important elements is acquiring proper judging tool if electrical stimulus leads to patient's visual perception. If evoked potential to electrical stimulus is recorded in primary visual (V1) cortex, it means that the stimulus effectively evokes visual perception. Therefore, in this study, we established VEP recording system on V1 cortex using BioPAC modules as the judging tool. And the measuring system was evaluated by recording VEP of mice. After anesthesia, normal mice (C57BL/6J strain; n = 6) were secured to stereotaxic apparatus (Harvard Apparatus, USA). For the recording of VEP, the stainless steel needle electrode (impedance: $2-5k{\Omega}$) was positioned on the surface of the cortex through the burr hole at 2.5 mm lateral and 4.6 mm caudal to bregma. DA 100C and EEG 100C BioPAC modules were used for the trigger signal and VEP recording, respectively. When left eye was blocked by black cover and right eye was stimulated by flash light using HMsERG (RetVet Corp, USA), VEP response at left V1 cortex was detected, but there was no response at right V1 cortex. Amplitudes and latencies of P2, N3 peaks of VEP recording varied according to the depths of the electrodes on V1 cortex. From the surface upto $600{\mu}m$ depth, amplitudes of P2 and N3 increased, while deeper than $600{\mu}m$, those amplitudes decreased. The deeper the insertion depth of the electrode, the latency of N1 peaks tends to be delayed. However, there was no statistically significant difference among the latencies of P2 and N3 peaks (P > 0.05, ANOVA). Our VEP recording data such as the insertion depth and the latency and amplitudes of peaks might be used as guidelines for electrically-evoked potential (EEP) recording experiment in near future.

• 대한시과학회지
• /
• 제20권4호
• /
• pp.523-530
• /
• 2018

목적 : 본 연구는 근거리 동체시력(Dynamic visual acuity) 측정장치를 이용하여 측정된 근거리 동체시력과 원거리에서 측정된 동체시력과의 차이를 알아보고, 플러스렌즈 가입에 의한 조절자극의 변화가 동체시력에 미치는 영향을 알아보고자 하였다. 방법 : 대상은 전신질환 및 안질환이 없고, 시력이 1.0 이상인 성인 남 여 40명($22.84{\pm}2.43$세)으로 선정하였다. 원거리와 근거리 동체시력의 비교, 플러스렌즈 가입(+0.50D, +1.00D, +1.50D)으로 유도된 동체시력의 변화를 알아보았다. 결과 : 완전교정상태에서 원거리 동체시력과 근거리 동체시력은 각각 $78.86{\pm}19.46deg/sec$, $76.90{\pm}18.05deg/sec$로 원거리 동체시력이 약간 높게 나타났다(p=0.04). 원거리 동체시력이 높을수록 근거리 동체시력이 높은 양의 상관관계를 보여 원거리 동체시력이 우수한 사람이 근거리 동체시력도 우수한 것으로 나타났다(r=0.95, p=0.00, Fig. 4). 조절자극변화에 따른 근거리 동체시력은 완전교정상태에서 $75.95{\pm}18.85deg/sec$이었고 +0.50D 구면도수를 가입한 상태에서 동체시력은 $76.95{\pm}16.45deg/sec$로 통계적으로 유의한 차이가 없었으나(p>0.05), +1.00D를 가입한 상태는 $79.02{\pm}13.51deg/sec$로 약간 높게 나타났으며, +1.50D를 가입한 상태에서는 $84.28{\pm}18.96deg/sec$로 통계적으로 유의한 차이가 있었다(p<0.05). 결론 : 원거리와 근거리의 동체시력의 차이는 없지만 원거리 동체시력이 우수한 경우 근거리 동체시력도 우수하며, 조절자극 변화를 위해 플러스렌즈가 가입됨에 따라 동체시력이 증가함을 알 수 있었다.

• 대한자기공명의과학회:학술대회논문집
• /
• 대한자기공명의과학회.한국자기공명학회 2005년도 공동학술대회
• /
• pp.59-59
• /
• 2005