• The Korean Journal of Physiology and Pharmacology
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• v.13 no.6
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• pp.443-448
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• 2009

For successful visual perception by visual prosthesis using electrical stimulation, it is essential to develop an effective stimulation strategy based on understanding of retinal ganglion cell (RGC) responses to electrical stimulation. We studied RGC responses to repetitive electrical stimulation pulses to develop a stimulation strategy using stimulation pulse frequency modulation. Retinal patches of photoreceptor-degenerated retinas from rd1 mice were attached to a planar multi-electrode array (MEA) and RGC spike trains responding to electrical stimulation pulse trains with various pulse frequencies were observed. RGC responses were strongly dependent on inter-pulse interval when it was varied from 500 to 10 ms. Although the evoked spikes were suppressed with increasing pulse rate, the number of evoked spikes were >60% of the maximal responses when the inter-pulse intervals exceeded 100 ms. Based on this, we investigated the modulation of evoked RGC firing rates while increasing the pulse frequency from 1 to 10 pulses per second (or Hz) to deduce the optimal pulse frequency range for modulation of RGC response strength. RGC response strength monotonically and linearly increased within the stimulation frequency of 1~9 Hz. The results suggest that the evoked neural activities of RGCs in degenerated retina can be reliably controlled by pulse frequency modulation, and may be used as a stimulation strategy for visual neural prosthesis.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.2
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• pp.43-52
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• 2017

PURPOSE: This study aimed to compare the impact of exercise with that of functional electrical stimulation (FES) and transcutaneous electrical nerve stimulation (TENS) on muscle tone, calf muscle stiffness, and balance ability in patients with stroke. METHODS: Thirty patients with stroke were randomly divided into an FES group (n=15) and a TENS group (n=15), and a progressive task-oriented exercise was assigned to them. These exercises were performed non-synchronously from December 5, 2016 to January 31, 2017. Patients underwent TENS and simultaneously exercised for 30 minutes daily, 5 times a week for 4 weeks. To determine the effect of the interventions, muscle tone and stiffness of the medial and lateral region of gastrocnemius muscle were measured using the MyotonPRO instrument and balance was assessed using the Berg Balance Scale. RESULTS: Both groups revealed a significant decrease in muscle tone and stiffness of the medial part of gastrocnemius muscle before and after the interventions (p<.05). Berg Balance Scale scores increased significantly (p<.05). However, none of the other parameters were significantly different (p>.05). CONCLUSION: Our results prove that progressive task-oriented exercise along with FES and TENS decreases muscle tone and stiffness of the gastrocnemius muscle in patients with stroke and improves balance. TENS could serve as a complementary replacement for functional electrical stimulation for in-house training, as TENS poses less risk of muscle fatigue and has lesser contraindications than does functional electrical stimulation.

• The Journal of Korean Physical Therapy
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• v.21 no.2
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• pp.109-116
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• 2009

Purpose: $17\beta$-estradiol is the most active endogenous estrogen, which is related to favorable changes in the plasma lipid profile, to relaxation of the coronary vessels, and to a decrease in platelet aggregation and vascular smooth muscle cell migration. However, although the beneficial effect of estrogens on plasma lipoproteins (ie, lowering low-density lipoprotein and increasing high-density lipoprotein cholesterol) contributes to cardiovascular protection, it does not fully account for the protective effect, particularly in the application of physical therapy, including low frequency electrical stimulation. Methods: The aim of this study was to demonstrate the inhibition of stressors, such as endothelin-1 (ET-1), serotonin (5-hydroxytryptamine, 5-HT), prostaglandin $F2\alpha$ ($PGF2\alpha$), and a protein kinase C (PKC) activator 12-deoxyphorbol 13-isobutyrate (DPB), induced isometric tension by $17\beta$-estradiol in vascular smooth muscle strips, respectively. In addition, the effects of low frequency electrical stimulation at the meridian points (CV-3, -4, Ki-12, SP-6, LR-3, BL-25, -28, -32, -52) on the indirect antihypertensive effect were examined by monitoring the changes in the serum $17\beta$-estradiol concentration in healthy volunteers. Results: Isometric tension analysis showed that the responses of inhibited tension by $17\beta$-estradiol were similar to the same stressors in rat aortic smooth muscle strips. Furthermore, although the continued amplitude modulation (AM) type of electrical stimulation was not increased significantly by electrical stimulation, the current of the frequency modulation (FM) type of low frequency electrical stimulation increased the serum $17\beta$-estradiol concentration in normal volunteers. Conclusion: These results, in part, suggest that $17\beta$-estradiol has the capacity to supress stressor-induced muscle tension, and electrical stimulation, particularly current of the FM type, has a modulatory effect on the sex steroid hormones, particularly $17\beta$-estradiol, in healthy volunteers.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.11 no.1
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• pp.45-52
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• 2013

Purpose : The goal of this study is to estimate the effect of SSP electrical stimulation applied to acupoints as conducted in oriental medicine on the swallowing function of patients with swallowing difficulties caused by stroke. Methods : Twenty-two hemiplegic stroke patients with swallowing difficulties were divided into an intervention-only group (Group I; n=11) and an intervention-SSP electrical stimulation group (Group II; n=11). Therapeutic intervention was performed on participants in the intervention-only group and the intervention-SSP electrical stimulation group, for 20 minutes per session, three times per week, for four weeks. In this study, SSP electrical stimulation to the acupoints (Cheondol, Yomchon, Budol, Pungji, and Sanyinjian) of stroke patients with swallowing difficulties was applied, and to investigate the effects of SSP electrical stimulation, Clinical dysphagia scale (CDS) and ultrasonography assessment was used to measure pre and post-intervention scores. Results : In the clinical dysphagia scale assessment, the post-intervention score for group II had significant enhancement unlike group I. In the ultrasonography assessment, the hyolaryngeal movement in group II showed significant increase in the swallowing function unlike group I. Conclusion : From the above results, significant effects came from SSP electrical stimulation of 3Hz, biphasic wave, continuous current when applied to the acupoints as conducted in oriental medicine to improve the swallowing function of stroke patients.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.3
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• pp.37-52
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• 2022

Purpose : The purpose of this meta-analysis was to evaluate the effects of electrical stimulation on patients with non-specific low back pain. Methods : Domestic databases were gathered from studies that conducted clinical trials associated with electrical stimulation and its impact on pain of non-specific low back patients. A total of 681 studies were identified, with 12 studies satisfying the inclusion data. The studies consisted of patient, intervention, comparison, outcome, and study design (PICO-SD). The search outcomes were items associated with low back pain. Cochrane risk of bias 2 (RoB 2) was used to evaluate the quality of 12 randomized controlled trials. Effect sizes (Hedges's g) in this study were computed as the corrected standard mean difference (SMD). A random-effect model was used to analyze the effect size because of the high heterogeneity among the studies. Egger's regression and 'trim-and-fill' tests were carried out to analyze the publication bias. Cumulative meta-analysis and sensitivity analysis were conducted to analyze the effect according to the sample size and the consistency of the effect size. Results : The following factors had a large overall effect size (Hedges's g=1.28, 95 % CI=.20~2.36) involving electrical stimulation on non-specific low back pain. The subgroup analysis all showed a statistical difference in the types of study design, electrical stimulation, and assessment tool. No statistically significant difference was found in the meta-regression analysis. Publican bias was found in the data. Conclusion : The findings in this study indicate that electrical stimulation interventions have a positive effect on patients with non-specific low back pain. However, due to the low quality of studies and publication bias, the results of our study should be interpreted cautiously.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.7 no.1
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• pp.7-10
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• 2009

Purpose : The purpose of this study was to investigate the effect of electrical stimulation applied in dominant forearm on autonomic nervous system response of both hands. Methods : Fourteen healthy subjects (women) received low frequency-high intensity electrical stimulation to one forearm. The subjects assigned to two groups; a ipsilateral stimulation group (n=7) and a contralateral stimulation group (n=7). The electrode attachment was arranged on the forearm of the dominant arm and the electricity stimulus time was set as 15 minutes. Measuring items were the skin conduction velocity, the blood flow, and the pulse rate, which were measured total 3 times (pre, post, and post 10 min.). Results : The skin conduction velocity showed a significant difference according to the change of the time in both hands, but there was no significant difference according to time in the blood flow, and the change of the pulse frequency regardless of stimulus side. Conclusion : These results demonstrate that the low frequency-high intensity electrical stimulation applied dominant forearm can increase selectively only with the skin conduction velocity, which may be helpful for the activation of the sudomotor function of both hands by the activation of sympathetic nerve.

• The Journal of Korean Physical Therapy
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• v.23 no.1
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• pp.45-51
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• 2011

Purpose: This study investigated the effect of needle electrode stimulation at various frequencies on change in wound healing in excision wound rats Methods: Twenty-four Sprague-Dawley adult male rats were assigned to one of four groups: control (n=6), acupuncture group (n=6), low rate (2 Hz) percutaneous electrical stimulation group, high rate (100 Hz) percutaneous electrical stimulation group (n=6). We analyzed morphological effects by measuring the area of the excision wound, the contraction rate, and chromatic red. A digital camera and an image analysis program were used to measure and analyze the wound area,which was also used for the contraction rate. Chromatic red was obtained by calculating red, green, and blue (RGB) values of the wound area. Results: The electro acupuncture stimulation groupsshowed significant healing effects compared to the control and acupuncture groups. Conclusion: The results of this study showed that various frequencies of percutaneous electrical stimulation have a therapeutic effect on wound healing.

• Biomolecules & Therapeutics
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• v.1 no.1
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• pp.37-43
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• 1993

Electrical or chemical stimulation of many areas in the brainstem modulates activity of dorsal horn neurons (DHN). This is known to be mediated by a population of bulbospinal neurons. Yet, little is known about responses of DHNs to stimulation of the caudal ventrolateral medulla (CVLM). Thus, the purpose of the present study is to see if there is any change in activity of DHNs when CVLM is stimulated electrically. Thirty-one DHNs were recorded from dorsal horn of the spinal cord. Fourteen DHNs (45%) were classified as wide dynamic range neurons and 9 (19%) were high threshold cells, and 4 (13%) and 4 (13%) were deep and low threshold neurons, respectively. Among 31 neurons tested for responses to stimulation of CVLM, 21 DHNs (68%) were inhibited by the electrical stimulation of CVLM ($200{\mu}A,\;100{\mu}s$ duration, 100 Hz), and 9 cells (39%) did not show any change in neuronal activity. One neuron was excited by the stimulation. The electrical stimulation of CVLM not only inhibited spontaneous activity of DHNs but also inhibited evoked responses of DHNs to somatic stimulation in the receptive field. These data suggest that CVLM is one of the pain-modulatory areas that control transmission of ascending information of noxious input to the brain from the spinal cord.

• Journal of Korean Physical Therapy Science
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• v.10 no.2
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• pp.193-198
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• 2003

Acupuncture has been used as a clinical treatment in Oriental medicine for various diseases. In the present study was carried out to investigate the effects of acupuncture and electrical stimulation on the change neuronal nitric oxide synthase(nNOS) immunoreactive cells in the periaqueductal gray(PAG) area of the male SD rats. Enhanced expression of nNOS was detected in the dorsolateral-PAG(DL-PAG) area of rat with stress by fixed body, and acupuncture and needle electrode electrical stimulation groups at Hapgok like acupoint decreased the stress-induced enhancement in the expression of nNOS. The present results demonstrate that acupuncture and needle electrode electrical stimulation is effective in the modulation of expression of nNOS in the DL-PAG area under stress conditions.

• Journal of Embryo Transfer
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• v.13 no.1
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• pp.11-19
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• 1998

This study was to determine the effect of ionomycin and 6-dimethylaminopurine (6-DMAP) and/or elcetrical stimulation on the oocyte activation and production of rabbit nuclear transplant embryos. The oocytes were collected from the oviduct of superovulated rabbits at 14 h post hCG injection and cultured in TCM-199 containing 10% FBS until 19 h post hCG injection. To determine the optimum concentration and exposure time of 6-DMAP, some oocytes were activated with 5 $\mu$M ionomycin for 5 min and then in 2.0 mM 6-DMAP for 0.5 to 3.0 h, or in 1.0 to 3.0 mM 6-DMAP for 2.0 h. Other control oocytes were stimulated electrically(3X, 1.25 kV/cm, 60 $\mu$sec) in 0.3 M mannitol solution supplemented with 100 $\mu$M CaCl$_2$ and MgCl$_2$. The nuclear donor embryos of 8-cell stage were synchronized to G$_1$ phase of 16-cell stage, and the recipient cytoplasms were obtained from removal of the first polar body and a portion of membrane bound cytoplasm of the oocytes collected at 15 h post hCG injection. A separated blastomere was injected into the perivitelline space of the enucleated oocytes. The oocytes injected with nucleus were cultured until 19 h post hCG and then electrofused and activated by electrical stimulation with or without ionomycin and 6-DMAP. These nuclear transplant embryos were cultured in TCM-199 containing 10% FBS in 39˚C, 5% CO2 incubator for 120 h. For the oncytes activated parthenogenetically with electrical stimulation with or with-out ionomycin and the various concentration of exposure time of 6-DMAP, the highest cleavage(92.3%) and development to blastocyst stage(41.0%) were resulted from the oocytes activated by ionomycin and 2.0 mM 6-DMAP for 2.0 h, which were found to be significantly(P<0.05) higher than the cleavage(45.2%) and developement to blastocyst stage(14.3%) from the oocytes activated with electrical stimulation. The significantly(P<0.05) more oocytes(71.4%) developed to 4 cell stage at 24 h post activation by ionomycin and 6-DMAP than those by electrical stimulation(18.9%). For the nuclear transplant embryos, the cleavage rate was similarly high in oocyte activation by electrical stimulation with(79.4%) or without ionomycin and 6-DMAP(70.5%). However, the embryo development to blastocyst stage was significantly(P<0.05) higher in oocyte activation by electrical stimulation with ionomycin and 6-DMAP(44.4%) than by electrical stimulation only(25.0%). The significantly(P<0.05) more nuclear transplant embryos(45.6%) developed to 4 cell stage at 18 h post activation by electrical stimulation with ionomycin and 6-DMAP than those by electrical stimulation only(10.6%). These results indicated that the supplemental oocyte activation by ionomycin and 6-DMAP with electrical stimulation enhanced and accelerated the preimplanted in vitro development of the rabbit nuclear transplant embryos.