• Journal of Korean Physical Therapy Science
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• v.6 no.4
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• pp.187-199
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• 1999

Functional Electrical Stimulation (FES) is used for muscle reeducation, reduction of spasticity, delay of atrophy, and muscle strengthening. FES stronger stimulation than other forms of electrical stimulation. The efficacy of FES in improving function has been substantiated in the literature. Treatment programs employing FES - activation of muscular tissue through the intact peripheral nervous system - can be broken into five major categories, according to the goal of treatment. These broad areas would include the use of FES to: (1) a direct excitation onto the alpha motoneuron, through peripheral stimulation of the Ia myotatic sensory system and ascending afferent information, which will be integrated at conscious and subconscious level of the CNS. (2) The quality of a stimulated muscle contraction is determined by combination of many parameters, including stimulus amplitude, pulse duration, stimulus frequency, and duty cycle. (3) A unit that has a pulse duration between 200 and $400{\mu}sec$ will be more than adequate for FES applications. (4) The neuromuscular plasticity is critically important to return of function using muscle re-education and facilitation applications. (5) Prior to using FES as an electrical orthosis, the patient should build up endurance in the muscles to be stimu1ated during the gait cycle.

• Journal of Electrical Engineering and Technology
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• v.7 no.3
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• pp.451-458
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• 2012

The voluntary EMG (vEMG) signal from electrically stimulated muscle is very useful for feedback control in functional electrical stimulation. However, the recorded EMG signal from surface electrodes has unwanted stimulation artifact and M-wave as well as vEMG. Here, we propose an event-synchronous adaptive digital filter for the suppression of stimulation artifact and M-wave in this application. The proposed method requires a simple experimental setup that does not require extra hardware connections to obtain the reference signals of adaptive digital filter. For evaluating the efficiency of this proposed method, the filter was tested and compared with a least square (LS) algorithm using previously measured data. We conclude that the cancellation of both primary and residual stimulation artifacts is enhanced with an event-synchronous adaptive digital filter and shows promise for clinical application to rehabilitate paretic limbs. Moreover because this algorithm is far simpler than the LS algorithm, it is portable and ready for real-time application.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.2029-2037
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• 2015

The purpose of this study was to investigate the effect the interferential current (IFC) stimulation level according to autonomic nerve system (ANS) of healthy adults. IFC measured with adhesive 2-pole electrodes pad on T1~T4 spinal cord segment level that electrode stimulation of 20 min after. A total of 45 healthy adults participated in the study, who were randomly divided into three groups: 15 of sensory level stimulus group (100 bps, 10~12 mA), 15 of exercise level stimulus group (5 bps, 45~50 mA), 15 of noxious level stimulus group (100 bps, 80~90 mA). Measured items were sympathetic activity and parasympathetic activity. In order to identify the changes in measurement variables before electrode stimulation and after and 30 min stimulation. The comparison of sympathetic and parasympathetic activity in each group revealed that they was changes of after vs 30 min in after electrical stimulation time(p<.05).

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.9-13
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• 1997

The present study was designed to develop the functional electrical stimulation system in order to restore motor function of paralytic patients. We attempt to establish adequate stimulus parameters for the recovery of work unction in lower limb paralysis patients and to develop the electrical stimulation system, which is effective to protect foot drop in these patients. In our animal and human experiment, adequate stimulus condition for surface electrode on the lower limb were 0.2-0.3ms at the duration and 50 Hz, which contain 600Hz train pulse. This parameter has efficiently prevented the foot drop from lower limb paralysis, decreased muscle fatigue and induced powerful contraction of lower limb muscle.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.4
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• pp.679-686
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• 1994

This paper describes an improved FES system to restorp paralyzed extremities in spinal-cord-injured patients. By using time-division method in the proposed FES system, we can reduce the size and weight of system despite of increasing channels. We designed a DC-DC converter to adapt the condition of each patient. We could reduce the cost by using easily available apparatus like an IBM-PC for the stimulus-pattern-creating system and standardized parts for the protable FES system.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.4
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• pp.42-49
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• 2009

This paper proposes a driving current control method for a back light unit (BLU), consisting of red, green, and blue (RGB) light-emitting diodes (LEDs), whereby an RGB optical sensor is used to check the output color stimulus variation to enable a time-stable color stimulus for light emission by the RGB LED BLU. First, to obtain the present color stimulus information of the RGB LED BLU, an RGB to XYZ transform matrix is derived to enable CIEXYZ values to be calculated for the RGB LED BLU from the output values of an RGB optical sensor. The elements of the RGB to XYZ transform matrix are polynomial coefficients resulting from a polynomial regression. Next, to obtain the proper duty control values for the current supplied to the RGB LEDs, an XYZ to Duty transform matrix is derived to calculate the duty control values for the RGB LEDs from the target CIEXYZ values. The data used to derive the XYZ to Duty transform matrix are the CIEXYZ values for the RGB LED BLU estimated from the output values of the RGB optical sensor and corresponding duty control values applied to the RGB LEDs for the present, first preceding, and second preceding sequential check points. With every fixed-interval check of the color stimulus of the RGB LED BLU, the XYZ to Duty transform matrix changes adaptively according to the present lighting condition of the RGB LED BLU, thereby allowing the RGB LED BLU to emit the target color stimulus in a time-stable format regardless of changes in the lighting condition of the RGB LEDs.

• Journal of Biomedical Engineering Research
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• v.20 no.2
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• pp.183-190
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• 1999

The purpose of this study was to develop a portable and convenient closed-loop contrel type electrical stimulator for patients with foot drop. This system restores walking movement as well as prevents from atrophy or necrosis of lower limb muscles and increases blood circulation in hemiplegic patients caused by traffic accident, industrial disaster or stoke. This system detects the changes of the ankle joint angle during walking, and then controls the stimulus intensity automatically to maintain the programmed level of the ankle joint angle. Also, this automatic system controls the stimulus intensity which is affected by increased electrode impedance resulting from long time use. The system detects the joint angle by an optical sensor and includes modified PID control which adjusts the stimulus intensity if the joint angle deviates from the preset value. Stimulus parameters are 30~80 volt, 40 Hz, and 0.2 ms. The system was applied to five hemiplegic patients for 42 days. Duration of stimulation was 15 min/day for the first week and then the duration was gradually increased to 30, 60, 90 and 120 min/day. The muscle force was increased up to 29.7%, muscle fatigue was decreased compared with the level before stimulation and the pattern of locomotion was improved. These results suggest that the electrical stimulator with closed-loop control type is more convenient and effective in restoration of locomotion of patients with foot drop than open-loop system.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.240-242
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• 1996

Use of electrical stimulation for diagnosis and treatment of pyhsiolgocial impairment on the auditory system was reported by many researchers since 1800. Unfortunately, there were no standard methods or theoretical bakground for choosing stimulus conditions because of the lack of understanding on the transmission of sound through the auditory pathways. Therefore, if we could find the mechanisms of normal and abnormal functions for the system objectively, it may be possible to establish the conditions for the appropriate treatment This study was devised with three experimental conditions of electrical stimulation(0.1, 1, and 10mA) to verify the effect of electrical stimulation on the auditory system. ABRs and ECochGs were obtained from 3 Guinea Pigs before and after each stimulation, and five parameters were extracted from ABR and ECochG waveforms. The results showed that the mean differences of the first peaks of ABR, I, before and after all the stimulus conditions were significant at the significant level of p<0.05. Also, amplitude of ECochGs peak(AP) showed higher degrees of differences for the electrical stimulation than that of ABRs. Based on the results of this experiment establishment of an electrical model which characterizes the auditory system could be achieved by computer simulation. This will lead to the design of most accurate model for the real auditory system, which provide the quantitive information regarding diagnosis and treatment.

• Journal of IKEEE
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• v.7 no.1 s.12
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• pp.22-31
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• 2003

Conventional stimulus patterns have used DC for discrimination of acupoint and meridian which is the basic object of diagnosis and medical treatment in oriental medicine. Those discriminate conduction points by stimulation on body skin with DC. But, it is insufficient to reliability in discrimination ratio, coincident ratio, body effect, reproductivity. Therefore, this paper has extracted the optimal parameter of frequency and waveform in order to improve conventional pattern, and proposed the SPAC(Single Power Alternative Current) stimulus pattern applying that. Also, We proposes algorithm which is able to discriminate with low pressure of the electrode by displaying in the level meter both the absolution and relation value of the skin current. It can decrease pain and body effect by electrode pressure and discriminate acupoint regardless of skin current in difficult discrimination spot. We have compared the performance of system applying the extracted optimal parameter and algorithm. We have compared discrimination, coincident ratio of both conduction point and traditional acupoints by acupoint stimulation pattern. In the results, we confirmed reliability of SPAC stimulus pattern.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.2
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• pp.367-372
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• 2023

In this paper, we analyzed through the EEG signals how musical stimulus affects learning activities. Musical stimuli were divided into sedative and stimulative tendency music, preferred and non-preferred music, and the learning activity tasks were divided into mathematics tasks and memorization tasks. The signals measured in the EEG experiments were analyzed with the power spectrum of SMR waves known to be related to human concentration. Those spectra used for quantitative comparison in this paper. As a result the power of the EEG signals was observed to be greater than the case where music was given as a stimulus. Regardless of the type of task, the power of the EEG signals was observed to be greater in the case of sedative tendency than in the case of stimulative tendency, and the power of the EEG signals was observed to be greater in the case of favorite music than in the case of unfavorite music. From these results, it is estimated that if the musical stimulus exists, in the case of sedative tendency music, and in the case of favorite music, concentration can be increased than in the relative case.