• Journal of Acupuncture Research
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• v.23 no.5
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• pp.23-29
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• 2006

Objectives : The present study was conducted to evaluate the effects of automatically controlled rotating acupuncture (ACRA) on thermal allodynia in neuropathic pain rats, and to examine whether the endogenous opioid system mediates the effects of ACRA. Methods : For the neuropathic surgery, the right superior caudal trunk was resected at the level between S1 and S2 spinal nerves innervating the tail. Two weeks after the nerve injury, ACRA stimulation with 4 different stimulation conditions (i.e., angle and frequency of rotation: 90o+1Hz, 90o+1/4Hz, 360o+/1Hz, and 360o+1/4Hz) was delivered to the Zusanli (ST36) acupoint for 15 min. The behavioral signs of thermal allodynia were evaluated by the tail immersion test (i.e., immersing the tail in cold $(4^{\circ}C)$ or warm $(4^{\circ}C)$ water and measuring the latency to an abrupt tail movement) before and after the stimulation. In an additional set of experiments, we examined the effects of naloxone (opioid Results : ACRA stimulations under all of the conditions above significantly relieved thermal antagonist, 2mg/kg, i.p.) on the action of ACRA stimulation. allodynia. There is no difference in the anti-allodynic effects among the 4 stimulation conditions. In addition, the effect of ACRA on thermal allodynia was reversed by naloxone pretreatment. Conclusion : These results indicate that ACRA stimulations have relieving effects on thermal allodynia in neuropathic pain rats, irrespective of stimulation parameters, and that this is mediated by the endogenous opioid system.

• The Journal of Korean Physical Therapy
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• v.23 no.2
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• pp.53-59
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• 2011

Purpose: This study was designed to compare the effects of transcutaneous electrical nerve stimulation (TENS) and silver spike point (SSP) therapy on current perception threshold (CPT) and mechanical pain threshold (MPT). Methods: Forty-five healthy adult male and female subjects were studied. Fourteen of them were males and twenty-one were females. Subject were randomly assigned to receive; (1) TENS (80/120 Hz alternating frequency), (2) SSP (3 Hz), or (3) no treatment (control group). Electric stimulation was applied over LI4 and LI11 on acupuncture points of the left forearm for 30 minutes. CPT and MPT were recorded before and after electrical stimulation. The data were analyzed using linear mixed models, with group treated as a between subject factor and time a within-subject factor. Results: At 30 minutes after cessation of electrical stimulation the CPT of C fibers and A${\delta}$fibers was reduced in the TENS group that of C fibers was reduced in the SSP group (p<0.05). After cessation of electrical stimulation, the MPT of C fibers and A${\delta}$fibers increased in the TENS group, and that of A${\delta}$fibers increased in the SSP group (p<0.05). Conclusion: After TENS and SSP stimulation, MPT of C fibers and A${\delta}$fibers were selectively increased. In particular, the TENS group showed increases in both C and A${\delta}$fibers, while the SSP group showed increases only in A${\delta}$fibers.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.9
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• pp.843-850
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• 2007

This paper proposes a somatosensory stimulation system for the improvement of postural stability using vibration as somatosensory stimulation. This system consists of vibratory stimulation and postural response measurement. To evaluate this system, the center of pressure(COP) was closely observed in turn with simultaneous or separate mechanical vibratory stimulations to flexor ankle muscles (tibialis anterior, triceps surae) and two plantar zones on both feet while standing on a stable and an unstable support. The simultaneous vibratory stimulations cleared influenced postural stability and the effects of vibrations were higher with the unstable support. In separate vibratory stimulations, the extent of the COP sway reduced when the direction of the vibratory stimulations and that of the inclination of body coincided for flexor ankle muscle stimulations. In the contrary, the extent of the COP sway increased when the direction of the stimulations and that of body inclination coincided for plantar zone stimulations. These results can be useful for the development of rehabilitation systems that utilizes somatosensory inputs for postural balance.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.12
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• pp.1121-1127
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• 2013

This study deals with experimental studies on electromyogram (EMG) measurements and functional electrical stimulation (FES) for the rehabilitation of a shoulder-joint. Based on the structure, motion, and main functions of the musculoskeletal system in a shoulder-joint, the muscles playing a major role for the motion in the sagittal plane were selected for the experiment. First, the surface electromyogram of the main muscles was measured according to the joint angle. The results showed that the change in the surface EMG was linearly proportional to the change in the joint angle. Second, the joint angle was measured during FES at shoulder muscles. The results showed that the joint angle increased as the FES current increased in a certain range of FES. It was confirmed that the willingness of muscles to move could be detected by measuring EMG and that the generation of muscle tension could be assisted by FES for active rehabilitation.

• The Korean Journal of Pain
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• v.34 no.2
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• pp.165-175
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• 2021

Background: Management of pain from open wounds is a growing unmet healthcare need. However, the models available to study pain from wounds or to develop analgesics for the patients suffering from them have primarily relied on incisional models. Here, we present the first characterized and validated model of open wound pain. Methods: Unilateral full-skin excisional punch biopsy wounds on rat hind paws were evaluated for evoked pain using withdrawal responses to mechanical and thermal stimulation, and spontaneous pain was measured using hind paw weight distribution and guarding behavior. Evaluations were done before wounding (baseline) and 2-96 hours post-wounding. The model was validated by testing the effects of buprenorphine and carprofen. Results: Pain responses to all tests increased within 2 hours post-wounding and were sustained for at least 4 days. Buprenorphine caused a reversal of all four pain responses at 1 and 4 hours post-treatment compared to 0.9% saline (P < 0.001). Carprofen decreased the pain response to thermal stimulation at 1 (P ≤ 0.049) and 4 hours (P < 0.011) post-treatment compared to 0.9% saline, but not to mechanical stimulation. Conclusions: This is the first well-characterized and validated model of pain from open wounds and will allow study of the pathophysiology of pain in open wounds and the development of wound-specific analgesics.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.8
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• pp.755-760
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• 2015

For proper wound healing, dermal contraction and remodeling are critical; during the natural healing process, differentiated fibroblasts called "myofibroblasts" typically undertake these functions. For severe wounds, however, a critical mass of dermal matrix and fibroblasts are lost, making self-regeneration impossible. To overcome this impairment, synthetic wound patches with embedded functional cells can be used to promote healing. In this study, we developed a polydioxanone (PDO)-based cell-embedded sheet on which dermal fibroblasts were cultured and induced for differentiation into myofibroblasts, whereby the following combinatorial physicochemical stimuli were also applied: aligned topology, electric field (EF), and growth factor. The results show that both the aligned topology and EF synergistically enhanced the expression of alpha smooth-muscle actin (${\alpha}$-SMA), a key myofibroblast marker. Our proof-of-concept (POC) experiments demonstrated the potential applicability of a myofibroblast-embedded PDO sheet as a wound patch.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.6
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• pp.675-681
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• 2010

It is well known that mesenchymal stem cell(MSCs) can be differentiated into fibroblasts, chondrocytes, and osteoblasts and that they develop into fibrous tissue, cartilage, or bone, as a result of mechanical stimulation. In this study, we developed a bioreactor system, which is composed of a reactor vessel that provides the required cell culture environment, an environment controlling chamber to control the media, a gas mixer, and a reactor motion control subsystem to apply mechanical stimuli to the cells. For the MSC culture, We used a poly-urethane (PU) scaffold, with a collagen coating to ensure improved cohesion ratio. Then, we transferred the cultivated MSCs in the PU scaffold, cultured the cells in the bioreactor system, and confirmed the proliferation, differentiation, and ossification processes, resulting from mechanical stimuli.

• The Korean Journal of Physiology
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• v.22 no.2
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• pp.231-243
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• 1988

This study was performed to investigate the mechanism of changes in arterial blood pressure, as a typical example of somatosympathetic reflex, induced by activation of muscular afferent nerves. Cats were anesthetized with ${\alpha}-chloraloae$ (60 mg/kg, i.p.). Afferent fibers in muscle nerve were activated by various method muscle contraction, electrical stimulation of muscle nerves, intraarterial injection of some algesic substances and noxious mechanical stimulation etc-and the evoked changes in arterial blood pressure were monitored. The effects of intravenous or direct spinal administration of morphine on the changes in arterial blood pressure induced by activation of the muscle afferent fibers were observed and also the effects of spinal lesions made in the $L1{\sim}L3$ spinal cord on them were studied to identify the ascending spinal pathways of the somatosympathetic reflexes. Followings are the results obtained. 1) The stimulation of medial gastrocnemius nerve under non-paralyzed condition with C-strength, low frequency (lower than 20 Hz) stimuli elicited a depressor response and a pressor response was elicited with C-strength, high frequency stimuli, of which the maximal response was observed at 100 Hz stimulation. 2) When the animal was paralyzed, depressor response to stimulation of the medial gastrocnemius nerve was observed with C-strength, $0.5{\sim}5Hz$ stimuli although the amplitude of the depressor response was decreased. The maximal pressor response was observed during stimulation with C-strength, $20{\sim}100Hz$ stimuli. 3) Intraarterial injection of some algesic substances induced marked pressor responses while noxious mechanical stimulation of the medial gastrocnemius muscle was not enough to elicit any significant changes (larger than 10 mmHg) in arterial blood pressure. 4) Systemically administered morphine (2 mg/kg) lowered the arterial blood pressure immediately and persistently and it was reversed by administration of naloxone. Direct spinally administered morphine did not elicit any changes. 5) The pressor response elicited by the activation of muscle afferent nerves was strengthened by systemic morphine administration while the depressor response tended to decrease. 6) Morphine administered on the spinal cord directly, decreased pressor response but did not change depressor response. From the above results it is concluded that there are separate groups of afferent nerves in the medial gastrocnemius nerve, which elicit pressor and depressor responses and the spinal ascending pathways of them are also separated from each other.

• Journal of the Ergonomics Society of Korea
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• v.18 no.3
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• pp.1-12
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• 1999

This study investigated human operator's perceptual and psychophysical responses to vibrotactile stimulation on various parts of the hand. Using a small vibrotactile display, the effects of three mechanical parameters consisting vibrotactile stimulations, i.e., vibration frequency, pulse-width modulation duty cycle, and number of contactors, on differential thresholds were examined at five different loci of the hand. It was observed that differential threshold varies with vibration frequency and number of active contactors. Differential sensitivity was the greatest at the vibration frequency of 120 Hz. The differential sensitivity was not found to be affected by loci on the hand. The area of stimulation on the hand was also found to be significant in that the sensitivity increased with the number of active contactors. It should be noted that the conclusions from this study generally correspond to those from the previous study on the absolute sensitivity. which means that tactile sensitivity to vibrotactile stimulations can be controlled with a systematic and consistent passion for emulating normal everyday contact on human hands in teleoperation and virtual reality applications.

• Journal of the Ergonomics Society of Korea
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• v.17 no.2
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• pp.1-10
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• 1998

The objective of this study is to investigate hwnan operator's perceptual and psychophysical responses to vibrotactile stimulation on various parts of the hand. Using a small vibrotactile display, five different loci of the hand along with two other mechanical parameters consisting vibrotactile stimulations, which are vibration frequency and number of active contactors, were examined for the effects on absolute thresholds. All test variables were found to have significant effects on thresholds. It was observed that absolute threshold is a function of vibration frequency and number of active contactors. Tactile sensitivity was the greatest at the vibration frequency of 240 Hz, and the fingertip was found to be the most sensitive locus on the hand. The area of stimulation on the hand was also found to be significant in that the sensitivity increased with the number of active contactors. The results of the study generally supported those of other previous studies. It should also be noted, however, that the conclusions from the study should be limited to the absolute sensitivity, not to the suprathreshold intensities of normal everyday contact with the hands.