• The Journal of the Korea Contents Association
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• v.20 no.2
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• pp.472-477
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• 2020

The purpose of this study is to correct the error of lower weight input method as an alternative to reduce the specific absorption rate(SAR) in MRI. In order to prove that the SAR values not change according to the weight entered into the patient information, the 50kg phantom is placed in the coil and the input weight is changed from 10 to 100 in 10kg units to compare the SAR values. As a result, T1-weighted images had a SAR rate of 0.2W/kg and T2-weighted images had an average of 0.4W/kg. In conclusions, the SAR does not change according to the weight input by the technician before the scan, a lower weight when inputting patient information cannot be an alternative to reduce the SAR.

• Journal of Korean Neurosurgical Society
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• v.37 no.2
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• pp.112-115
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• 2005

Objective: Thalamic lesioning and deep brain stimulation(DBS) have proved to be beneficial to the treatment of essential tremor(ET). The authors compared the effects and complications of two modalities. Methods: A total of 34 patients with ET were treated with ventral intermediate(Vim) nucleus thalamotomy or Vim DBS from May 1999 to May 2003. The procedure of lesioning or stimulation were performed as usual manner with or without microelectrode recording. Postoperatively, utilizing the various combinations of frequency, voltage and pulse width optimized the stimulation. The degree of improvements of tremor and the occurrence of the complications were evaluated postoperatively and at follow-up. Results: There were 38 procedures, including 27 with Vim thalamotomy and 11 with DBS, in 34 patients. Of the thalamotomy group, left Vim lesioning is 25 and right one is 2. Follow-up duration ranged from 12 to 57 months. In the thalamotomy group, the rate of overall good outcome was 88.9% but 12 patients (44.4%) showed permanent adverse effects. In the cases of stimulation, the rate of overall good outcome was 90.9% and two patients had acceptable dysarthria. Conclusion: Both Vim thalamotomy and Vim DBS were effective for the treatment of ET, although perioperative adverse effects tended to be higher in patients who had thalamotomy. In cases of DBS, adjustments of stimulation parameters enabled an acceptable position to be achieved with tremor control and unwanted effects.

• Journal of Biomedical Engineering Research
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• v.36 no.4
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• pp.95-102
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• 2015

Epilepsy is a chronic neurological disease which produces repeated seizures. Over 30% of epileptic patients cannot be treated with anti-epileptic drugs, and surgical resection may cause loss of brain functions. Seizure suppression by electrical stimulation is currently being investigated as a new treatment method as clinical evidence has shown that electrical stimulation to brain could suppress seizure activity. In this paper, design of a real-time closed-loop neurostimulation system for epileptic seizure suppression is presented. The system records neural signals, detects seizures and delivers electrical stimulation. The system consists of a 6-channel electrode, front-end amplifiers, a data acquisition board by National Instruments, and a neurostimulator and Generic Osorio-Frei algorithm was applied for seizure detection. The algorithm was verified through simulation using electroencephalogram data, and the operation of whole system was verified through simulation and in- vivo test.

• Journal of Biomedical Engineering Research
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• v.39 no.1
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• pp.1-9
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• 2018

This study was carried out to evaluate the effect of micro-current therapy on muscle atrophy and delayed wound healing process caused by traumatic peripheral nerve injury. For this, twenty-five 5-week-old Sprague Dawley rat were used and assigned to five groups including the normal group (NOR, n=5), the wound group (WD, n=5), the wounded and treated with micro-current electrical therapy group (WD+MET, n=5), the sciatic nerve denervated and wounded group (WD+DN, n=5), and the sciatic nerve denervated, wounded and treated with micro-current electrical therapy group (WD+DN+MET, n=5). In order to assess the changes in length of incisional wound for 12 days and the muscle volume for 2 weeks, the ImageJ analysis of macroscopic analysis and micro-CT data were obtained and analyzed. As a result, significant delay in the process in wound healing were observed and micro-current therapy suppress the postponement of healing process. Furthermore, there were significant changes in muscle volume between electrically treated group and non-treated group. These result shows that electrical stimulation may improve the delayed healing process and muscle atrophy at once.

• Archives of Plastic Surgery
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• v.37 no.1
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• pp.71-74
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• 2010

Purpose: Nowadays spinal cord stimulator is frequently used for the patients diagnosed as complex regional pain syndrome. The lead is placed above the spinal cord and connected to the stimulation generator, which is mostly placed in the subcutaneous layer of the abdomen. When the complication occurs in the generator inserted site, such as infection or generator exposure, replacement of the new generator to another site or pocket of the abdomen would be the classical choice. The objective of our study is to present our experience of the effective replacement of the existing stimulation generator from subcutaneous layer to another layer in same site after the wound infection at inexpensive cost and avoidance of new scar formation. Methods: A 50-year-old man who was diagnosed as complex regional pain syndrome after traffic accident received spinal cord stimulator, Synergy$^{(R)}$ (Medtronic, Minneapolis, USA) insertion 1 month ago by anesthetist. The patient was referred to our department for wound infection management. The patient was presented with erythema, swelling, thick discharge and wound disruption in the left upper quadrant of the abdomen. After surgical debridement of the capsule, the existing generator replacement beneath the anterior layer of rectus sheath was performed after sterilization by alcohol. Results: Patient's postoperative course was uneventful without any complication and had no evidence of infection for 3 months follow-up period. Conclusion: Replacement of existing spinal cord stimulation generator after sterilization between the anterior layer of rectus sheath and rectus abdominis muscle in the abdomen will be an alternative treatment in wound infection of stimulator generator.

• The Journal of Korean Physical Therapy
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• v.19 no.1
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• pp.11-22
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• 2007

Purpose: The purpose of this study were to analysis the effect on change of spinal neuron excitability during gait training of hemiplegia patients by the functional electrical stimulation. Methods: Thirty six hemiplegia patients participated in this study. Stimulation conditions of FES were pulse rate 35pps, pulse width $250{\mu}s$, and on-time 0.3 second, treatment hour was 30 min. and treatment period was once a day for five days a week through six weeks. For functional evaluations before and after treatment, Modified Ashworth Scale (MAS), active range of motion (AROM), Hmax threshold, H/Mmax ratio were measured and the following conclusions were obtained. Results: Functional evaluation showed significant changes in experimental group as MAS(p<0.01), AROM(p<0.001), compared to control group. In spinal neuron excitability evaluation, change of Hmax threshold was significantly reduced in both non weight bearing (p<0.001) and bearing condition (p<0.05), H/Mmax ratio was significantly reduced in non weight bearing (p<0.05) and bearing condition (p<0.05). Conclusion: In conclusion, application of FES to hemiplegia patients in recovery stage during gait training improved mitigation of muscular spasticity, balance adjustment and moving ability and it was interpreted that it was caused by mitigation of muscular spasticity by the spinal neuron excitability.

• The Journal of Korean Physical Therapy
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• v.19 no.1
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• pp.33-44
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• 2007

Purpose: To investigate and analyze effects of environmental enrichment(EE) and nerve stimulation that follows in application times with change of functional recovery(1, 3, 7 and 14 days). Methods: Focal ischemic brain injury was produced in 100 Sprauge-Dawley rats through middle cerebral artery occlusion(MCAO). Neurobehavioral assessment were selected, such as tilting plane testing, horizontal wire testing, vestibulomotor function testing and complex neuromotor function test, then they were randomly divided into five groups; Group I : Sham group, Group II: MCAO group, Group III: MCAO and ES group, Group IV: MCAO and EE group, Group V: MCAO and EE and ES group. Results: In neurobehavioral assessment, group V were significantly difference from other groups on between-subject effects. Conclusion: Our findings suggest that in focal ishemic brain injury, combined environmental enrichment and peripheral nerve electrical stimulation is more improved that the improvement of exercise function recovery than non treatment group.

• The Journal of Korean Physical Therapy
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• v.21 no.2
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• pp.1-8
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• 2009

Purpose: This study examined the effect of EMG-stim related to the functional recovery of the upper extremity in chronic stroke patients with an intensive massed practice protocol. Methods: The subjects were assigned randomly to either the EMG-stim group (n=10) or sham treatment group (n=10). Both groups received conventional physical therapy, occupational therapy and FES, five times per week over a four week period. In the EMG-stim group, EMG-stim was applied to the hemiplegic wrist and finger extensors for 2 sessions for 30 minutes per day, 5 times per week over a 4 week period. As the pre- and the post-test, the following four motor tests were assessed as the function of the upper extremity clinical functional test: extensor digitorum strength test, Box and Block test, Fugl-Mayer Assessment, and Jebson-Taylor Hand Function Test. Results: In the Box and Block test and Fugl-Mayer Assessment, there were statistically significant differences between both groups as well as between pre- and post-test. The extensor digitorum and wrist extensor strength were similar in both groups. In the Jebson-Taylor Hand Function Test, there was a significant difference in simulated page turning but not in the other subtests. Conclusion: Intensive massed practice with EMG-stim intervention applied to the hemiplegic upper extremity is an effective therapeutic method for chronic stroke patients. However, a variety of intervention methods designed for stroke patients in clinical settings are needed.

• Korean Journal of Applied Biomechanics
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• v.19 no.4
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• pp.681-688
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• 2009

To better delineate the changes in corticospinal excitability when older adults are asked to observe and/or imagine actions, 22 right-handed older adults without neurological abnormalities were included in this study. The amplitude and latency of motor evoked potentials (MEPs) by transcranial magnetic stimulation were recorded in the abductor pollicis brevis of the dominant hand during passive observation/imagery/active observation of slow/fast action of abduction of right thumb and also at resting state. Thus, active observation showed better changes than passive, but slow and fast action revealed no difference at all.

• The Korean Journal of Pain
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• v.2 no.2
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• pp.145-154
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• 1989

Pain is a common and important clinical symptom, and treatments aimed at relieving pain have a central position in medical practice. Recently Transcutaneous Electrical Nerve Stimulation (TENS) has been effectively used to control acute and chronic conditions that produce pain. But the mechanism of analgesia resulting from TENS remains obscure. In order to investigate the analgesic effect of TENS and it's action mechanism, TENS was applied in 40 rabbits with different frequencies, low frequency (2Hz) and high frequency (100Hz), for 20 minutes. And the pain threshold was measured by the temperature before and after stimulation, and an attempt was made to antagonize the stimulation effect with naloxone pretreatment (0.4 mg/kg) The results are as follows: 1) Both low frequency and high frequency TENS resulted in increasing the pain threshold significantly (Both p<0.01). 2) Naloxone pretreatment could antagonize the effect of increasing the pain threshold with low frequency TENS significantly (p<0.01), but not with high frequency TENS. Plasma beta-endorphin was measured by radioimmunoassay using an Beta-Endorphin Kit (Immunonuclear Corporation, Stillwater, Minnesota, USA) and Automatic Gamma Scintillation Counter (Micromedic System 4/2000) before and after stimulation. An attempt was made to reverse the stimulation effect with naloxone pretreatment (0.4 mg/kg). The results are as follows: 1) Low frequency TENS resulted in increasing the level of plasma beta.endorphin significantly (p<0.01), but high frequency TENS did not. 2) Naloxone pretreatment could reverse the effect of increasing the plasma beta-endorphin level with low frequency TENS significantly (p<0.01).