• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.53
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• pp.69-78
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• 1999

We developed an apparatus for odorous stimuli control to record olfactory evoked potentials from human scalp. The characteristics of the apparatus were as follows. 1. Translating the subjects respiration into electric signals with a sensor attached to the nose. The period and timing of odorous stimuli could be adjusted, so that stimuli could be synchronous with respiration. 2. The respirations translated into electric signals were made constant in amplitude by using an auto gain control circuit. 3. The interstimulus interval of odorous could be arbitrarily selected once every 1 to 9 respirations so that adaptation could be prevented. We obtained olfactory - evoked potentials (OEPs) to odorous stimuli using this apparatus from the site of Cz, whose positive peak latencies were approximately $180{\pm}23ms$. Such response were not recorded if oxygen stimuli were used instead of odorous or with click sounds produced by the switching electromagnetic valve.

• Journal of Biomedical Engineering Research
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• v.15 no.4
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• pp.481-488
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• 1994

In this paper a study of neuro-pathway estimation based on visual and somatosensory evoked potential is given. The evoked potentials which are caused by visual and somatosensory stimulation are detected by an average method. The forward problem that is estimating a scalp potential from a given electrical source in the brain is solved by using a triple concentric spherical shell model of the head and a single current dipole model of the neuron activity. The inverse problem which calculates a source position is solved by a least square fit between the model predicted potential and a given evoked potential measurement. The similarities between estimated sensory neuro-pathways and physiological brain function regions are verified.

• Neonatal Medicine
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• v.15 no.1
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• pp.94-99
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• 2008

Although neonatal hypoglycemia is a common metabolic abnormality in newborn infants, brain injuries resulting from isolated neonatal hypoglycemia are rare. Many infants who are hypoglycemic do not exhibit clinical manifestations, while other infants are symptomatic and at risk for permanent brain damage. There is no disagreement that hypoglycemia can cause neonatal encephalopathy and result in permanent brain injury. Occipital brain injury associated with neonatal hypoglycemia can result in long-term disability, epilepsy, and visual impairment. Infants should receive ongoing developmental and visual surveillance for lateonset epilepsy, and visual or cognitive impairment. We report two cases of newborn infants with abnormal visual evoked potentials (VEP) caused by neonatal hypoglycemic encephalopathy.

• Journal of Veterinary Clinics
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• v.18 no.4
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• pp.315-323
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• 2001

Changes in somatosensory evoked potentials (SEPs) which accompanied by insertion of foreign body in spinal canal were evaluated with clinical signs and positive contrasted myelography in dogs. Foreign bodies occupied 20∼50% of spinal canal. Foreign bodies occupying about 50% of spinal canal were inserted into the animals of group II and III for 1 week and 2 days, respectively. Foreign bodies occupying about 20% of spinal canal were inserted into the animals of group IV, V, and for 1 week, 2 days, and 8 weeks, respectively. in group I (control group), sham operation (lateral laminectomy) was performed. Group III, IV and V did not severely affect on SEPs latencies and clinical signs. Group VI affects on SEPs latencies but not on clinical signs. After foreign body removal, SEPs latencies showed similar recovery patterns with clinical signs. However, group II induced severe abnormalities in SEPs latencies and clinical signs. In group III, IV and V, thoracic potentials (TN1) were abnormally recorded after foreign body insertion and firstly/normally recorded on the 6th 9.5th and 3.5th day after foreign body (removal following) insertion. In group VI, TN1 was abnormally recorded after foreign body insertion and firstly recorded on the 7.7th day and normally recorded on 34th day after foreign body insertion. In group I, TN1 was not recorded from the 3rd day after foreign body insertion and until the 8th week after foreign body removal. In group I, TN1 was firstly recorded on the 1st day after laminectomy.

• Journal of Bio-Environment Control
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• v.9 no.2
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• pp.94-100
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• 2000

This study was conducted to investigate the changes of electric potentials of leaf surface induced by environmental stimuli in plant. The values of electric potentials varied with different intervals of light on and off, and light qualities and moreover, their changes were also varied according to the time of a day. Additionally, stimuli such as candle light, wind, or 5$^{\circ}C$ cool water spray also evoked considerable changes in leaf surface electric potentials and their signal patterns varied with species of plants tested. In frequency analysis of electric potentials, the distribution values by FFT were highest in 1-10 Hz frequency zone by the majority of stimuli. These results suggested that changes in leaf surface electric potentials depended upon plant species even though stimulus was the same and vice versa.

• Speech Sciences
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• v.11 no.3
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• pp.201-211
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• 2004

This paper introduces a development of an electrical stimulator for auditory stimulation. The electrical stimulator is useful in neurotological diagnosis, audiological evaluation, candidate selection for cochlear implantation, optimal device selection and decision making of MAP strategy for severe-to-profound hearing impaired persons. The development was based on sound parameters of auditory brainstem responses and auditory electrophysiological characteristic such as effective firing of auditory nerve and recording evoked potentials during refractory period of neuron. Besides pulse parameter could adjustable by programming for more varied electrical stimulation evoked response audiometry. Using the electrical stimulator, electrical square pulse was applied to promontory, and electrically evoked auditory brainstem response and electrically middle latency response were successfully recorded in cats.

• International journal of advanced smart convergence
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• v.9 no.1
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• pp.37-46
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• 2020

Cerebral vascular surgery can damage patients' motor and sensory nerves; therefore, neuromonitoring is performed intraoperatively. Patients with diabetes often have peripheral neuropathy and may be prone to nerve damage during surgery. This study aimed to identify factors that should be considered when diabetic patients undergo intraoperative neuromonitoring during brain vascular surgery and to present new criteria. Methods: In patients with and without diabetes who underwent cerebrovascular surgery (n = 30/group), we compared the intraoperative stimulation intensity, postoperative motor power and sensory, glycated hemoglobin (HbA1c) and glucose levels, and imaging findings. Results: Fasting glucose, blood glucose, and HbA1c levels were 10%, 12.1%, and 9.7%, respectively; they were higher in patients with than in patients without diabetes. Two patients with diabetes had weakness, and 10 required increased Somato sensory evoked potential (SSEP) stimulation, while in 16, motor power recovered over time rather than immediately. The non-diabetic group had no weakness after surgery, but 10 patients required more increased SSEP stimulation. The diabetic group showed significantly more abnormal test results than the non-diabetic group. Conclusion: For patients with diabetes undergoing surgery with intraoperative neuromonitoring, whether diabetic peripheral neuropathy is present, their blood glucose level and the anesthetic used should be considered.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.603-611
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• 1997

The motor evoked potentials (MEPs) have been advocated as a method of monitoring the integrity of spinal efferent pathways in various injury models of the central nervous system. However, there were many disputes about origin sites of MEPs generated by transcranial electrical stimulation. The purpose of present study was to investigate the effect of major extrapyramidal motor nuclei such as lateral vestibular nucleus (VN) and medullary reticular nucleus (mRTN) on any components of the MEPs in adult Sprague-Dalwey rats. MEPs were evoked by electrical stimulation of the right sensorimotor cortex through a stainless steel screw with 0.5mm in diameter, and recorded epidurally at T9 - T10 spinal cord levels by using a pair of teflon-coated stainless steel wire electrodes with 1mm exposed tip. In order to inject lidocaine and make a lesion, insulated long dental needle with noninsulated tips were placed stareotoxically in VN and mRTN. Lidocaine of $2{\sim}3\;{\mu}l$ was injected into either VN or mRTN. The normal MEPs were composed of typical four reproducible waves; P1, P2, P3, P4. The first wave (P1) was shown at a mean latency of 1.2 ms, corresponding to a conduction velocity of 67.5 m/sec. The latencies of MEPs were shortened and the amplitudes were increased as stimulus intensity was increased. The amplitudes of P1 and P2 were more decreased among 4 waves of MEPs after lidocaine microinjection into mRTN. Especially, the amplitude of P1 was decreased by 50% after lidocaine microinjection into bilateral mRTN. On the other hand, lidocaine microinjection into VN reduced the amplitudes of P3 and P4 than other MEP waves. However, the latencies of MEPs were not changed by lidocaine microinjection into either VN or mRTN. These results suggest that the vestibular and reticular nuclei contribute to partially different role in generation of MEPs elicited by transcranial electrical stimulation.

• Journal of Korean Academy of Nursing
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• v.34 no.7
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• pp.1255-1264
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• 2004

Purpose: The purpose of this study was to determine the effect of a 3-week somatosensory stimulation program on the integrity of the somatosensory pathway of patients with brain damage. Method: The sample consisted of two groups of patients with brain damage matched by Glasgow Coma Scale (GCS) scores and age:8 patients with a mean age of 56.75 years who were treated with somatosensory stimulation, and 8 patients with a mean age of 58.88 years, who were not treated with sensory intervention program. A repeated measures matched-control group design was used to assess functional recovery of the brain. The instrument used in this study was SSEP (somatosensory evoked potentials), a neurophysiological parameter, for the integrity of the somatosensory pathway. Results: The hypothesis that patients with brain damage who were treated with the somatosensory stimulation program will show higher SSEP wave form scores than the non-treatment group was supported (3rd week.: U=13.000, p=.014). Additional repeated measures analysis showed that there were no significant differences in recovery trends between the groups (F=1.945, p=.159). Conclusion: This study demonstrates that a somatosensory stimulation program is effective in promoting recovery of the integrity of the somatosensory pathway of patients with brain damage.

• Journal of the Ergonomics Society of Korea
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• v.9 no.2
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• pp.29-35
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• 1990

To investigate and analyze of the human brain-wave changes during 3-dimenslonal image load were expected to take not only an important basic information of 3-dimensional TV usage but also 3-dimensional image design. In this experiment, to analyze the difference of visual analyze handing system for which we present the 2- dimensional image having no parallex and 3-dimensional image by visual evoked potentials(VEP). 2-dimensional image and 3-dimensional image displayed on the screen through video. In the test, the time interval was one sec for presentation of stimulus considering united time of visual information of right eye and left eye during watching the 3-dimensional image also display time interval was 200 mesc for each stimulus image. Results are as follow, (1) N190 appears faster 16msec-20msec in the point of Fz, Cz, Pz, Oz when loaded 3D4 angle than 2D3 angle. (2) About of the P300, 3D4 angle(Otherwise, Oz point was reverse) and in the case of no equipment of liquid crystal shutter, there appeared PEAK near the P250. (3) There were 5% significant difference when the liquid crystal shutter was equiped and didn't, Therefore, this phenomenon show the possibility that Liquid crystal shutter influences on Visual Evoked Potentials.