• 대한의용생체공학회:의공학회지
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• 제29권1호
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• pp.82-87
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• 2008

In this paper, the study was carried out to design and implement the medical compound stimulator based on the preexisting individual medical stimulators with Low frequency, High frequency and cooling stimulation. The proposed equipment is designed to compound all the functions including a cooling stimulation with a range of $0{\sim}20^{\circ}C$ and the verified low and high frequencies of 250Hz, 500Hz, 1KHz and 1MHz respectively from the previous clinical experiment with a consideration of its credibility and efficiency. Also, it was constructed by using a new technique, thermoelectricity semiconductor with a consideration of miniaturization and stability. In accordance with patients' treatment purpose, the hand piece of low frequency/cooling stimulation and High frequency/cooling stimulation were separately designed for convenience. The frequency, accuracy and other factors of implemented medical compound stimulator was satisfied according to its measurement. It was also tested by Korean Testing Laboratory (KTL) for its stability and efficacy and it confirmed that the medical compound stimulator is suitable for use as it fits in with the medical equipment standards.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 추계종합학술대회
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• pp.462-466
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• 2002

본 논문에서는 8Bit MPU를 이용한 신경자극 치료장치가 설계되었다. 개발되고 있는 시스템은 저전력 MPU와 전압 boosting회로, 과전류 감시 및 이상전류 보정회로, 펄스의 상태를 알려주는 LED display 및 BUTTO과 펄스를 우리 몸에 전달시켜주는 Pad로 이루어져있다. 입력된 9V의 전압은 전압 boosting회로를 통해 120V까지 승압된다. 펄스는 단상 직사각형파, 대칭성 이상파, 교대 대칭성 이상파등의 형태로 우리 몸에 입력되어 근육의 수축과 이완을 시켜주는 알고리즘을 적용하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.349-352
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• 2003

A personal low-frequency stimulator is a portable device to relax muscle pains of a person. The stimulator generates combined low-frequency pulses to be applied to pads attached to painful muscles. This paper reports a development of such device with its characteristic analyses. The major components of our stimulator are MCU, high-voltage generating circuit part, high-voltage switching circuit part, input switch part and display unit. High-voltage generating circuit is designed by using a boost converter circuit and allows user control of the output voltage. High-voltage switching circuit, controlled by MCU, generates output voltage to be applied to pads. Input switch part is composed of power supply, intensity selection, mode selection and memory. Display unit adopts a text LCD module to display modes, Intensity, output frequency and user set-up time. Our designed safety circuit, to protect human body from possible electric shock, slowly increases the output voltage to the selected output intensity. It continuously checks the output pulse shape and disable the output when dangerous pulses are detected. This paper also shows some experimental results.

• The Korean Journal of Pain
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• 제18권2호
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• pp.156-160
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• 2005

Background: Frozen shoulder is not an uncommon disease, which is associated with chronic pain and joint movement limitation. However, there are numerous devices to assist in the treatment of shoulder pain, but their efficacy has not been proven and their use remains immensely controversial. Therefore, a randomized clinical study was conducted to determine the effectiveness of a low-frequency stimulator for the treatment of frozen shoulder. Methods: A randomized clinical trial was carried out on 40 patients with frozen shoulder, with 40 patients assigned to two groups; a control treatment group (group C, n = 20) and a low frequency stimulator application group (group T, n = 20). Both groups were given a routine treatment modality, such as trigger point injection, intramuscular stimulation or suprascapular nerve block etc. The level of the shoulder pain was evaluated using a 100mm VAS (visual analog scale) at each visit, with the limitation in the range of motion simultaneously evaluated. Results: All the subjects improved after treatment, with the VAS scores after termination of treatment showed a statistically significant reduction (P < 0.05). However, there was no significant difference between the two groups. One month after termination of 5 cycles of treatment, group T maintained their improved state, whereas the pain in some of those in group C reemerged, which also showed a statistically significant difference (P < 0.05). The limitation in the range of motion improved, with most subjects able to resume daily activity. Conclusions: Although the low frequency stimulation provided no more pain relief than routine treatment, the effect was significantly prolonged. From this result, low frequency stimulation can be considered to aide the therapeutic effect of classical frozen shoulder therapy.

• 대한의생명과학회지
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• 제27권2호
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• pp.99-104
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• 2021

Treatment techniques that affect homeostasis by non-invasive regulation in peripheral organs will advance disease research. Here, we demonstrate a non-invasive method of conditioning within an organ using a low-frequency stimulator superposition of alternating microcurrent wave in stages. It is first applied to the inflammatory response in H3N2-infected sinusitis mice. To check the progress of the treatment, mice were sacrificed every week for 3 weeks, nasal tissue was removed, and the inflammatory response was investigated through H & E staining. The low-frequency stimulation treatment group was found to alleviate the proliferation of epithelial cells and invasion of inflammatory cells compared to the control group as the passage of treatment time. The reduction of inflammatory cytokines in the nasal lavage fluid was observed in H3N2-infected sinusitis mice treated with of low-frequency stimulation using superposition of alternating microcurrent wave compared to H3N2-infected sinusitis mice after 3 weeks. These data demonstrate that low-frequency stimulation device in the form of using alternating current wave superposition on within organs provides a new method to regulate specific physiological functions. Therefore, it is necessary to prove the inhibitory effect of low-frequency stimulation using alternating current wave superposition on inflammatory diseases by various methods through further studies and clinical studies.

• 대한의용생체공학회:의공학회지
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• 제27권6호
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• pp.343-350
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• 2006

Medical magnetic stimulator generates strong magnetic field pulses. Clinical applications of the magnetic pulse are the stimulation of nervous system and the contraction of muscle. The unique source of the strong magnetic pulse is a capacitor-inductor resonator and this inductor generates a strong sinusoidal magnetic pulse by discharging the capacitor with high initial voltage. Continuous muscle contraction needs sequential generation of the magnetic pulses. However, to keep the magnitude of sequential pulses identical, an expensive high-voltage power supply have to support voltage drop of the capacitor between the pulses. A protection circuit between the supply and the resonator is necessary to protect the supply from reverse current caused by capacitor voltage reversal. In this paper, a new circuit structure of the magnetic stimulator adopting a low-frequency fly-back switching is proposed. The new circuit supports sequential pulse generation and allows the reverse current without damage. Performance of the new circuit is examined and a low-cost magnetic stimulator for urinary incontinence therapy is being developed using the presented method.

• 한국산학기술학회논문지
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• 제13권10호
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• pp.4768-4772
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• 2012

전기감전 사고를 예방하기 위해서는 주입식 교육 보다는 체험식 교육이 더욱 효과적이다. 그러나 전기감전 체험형 교육 시스템을 위해서는 감전을 체험할 수 있도록 인체에 대한 적절한 물리적 자극이 필요하다. 본 논문에서는 간섭전류형자극기(Interferential Current Type Low Frequency Stimulator)를 감전사고 체험교육에 이용하기 위하여 인체에 대한 자극의 임계값을 실험하였다. 그리고 아동과 성인으로 구분된 연령별 자극 값을 산출하였다. 본 연구의 결과는 전기 감전 체험형 교육 시스템에 적용 가능할 것이다.

• 감성과학
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• 제13권4호
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• pp.703-710
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• 2010

본 연구에서는 선행 연구에서 개발된 촉각 자극 시스템의 시스템적인 문제, 자극 제어에 관한 문제, 기타 부가적인 문제들을 보완할 수 있는 촉각 자극기를 개발하였다. 개발된 장치는 제어부(control unit), 구동부(drive unit), 진동부(vibrator)의 세부분으로 구성된다. 제어부는 E-Prime 소프트웨어로부터 명령을 전송받고 진동 자극 신호를 발생한다. 구동부는 촉각 자극기가 효과적으로 진동 자극을 발생할 수 있도록 충분한 전류를 공급한다. 진동부는 작은 동전(coin) 형 진동기(vibrator)와 벨크로(velcro)로 구성되며 피험자의 손에 쉽게 고정 할 수 있도록 제작하였다. 개발된 장치는 소형, 경량, 저전력 구동, 간단한 구조, 최대 35개의 자극 채널, 시각 및 청각과의 다양한 자극 조합을 지연시간 없이 제시할 수 있도록 설계 되어 시스템적인 문제들을 보완하였다. 자극의 크기와 시간을 10단계로 조절할 수 있도록 하고, 넓은 동작주파수 범위를 확보하여 자극 제어에 관한 문제들을 보완하였다. 저전압 구동으로 인체에 대한 안정성을 확보하고, 손가락 이외에 신체의 어느 부분이든 자극 제시가 가능하도록 제작하였다. 특히 본 시스템은 인지과학 연구에서 범용으로 사용되는 소프트웨어인 E-Prime을 기반으로 개발되었기 때문에 활용성이 매우 높을 것으로 판단된다.

• 재활복지공학회논문지
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• 제7권2호
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• pp.85-90
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• 2013

복부 중심근육(core muscle)은 근골격계 및 신경계 환자의 재활에 있어 통증, 균형 및 상 하지의 기능적 움직임을 이끌어내는데 중요한 역할을 한다. 본 연구에서는 복부 운동근(global muscle)인 배곧은근과 고정근(local muscle)인 배가로근, 배속빗근 및 배바깥빗근의 두께 및 근력을 증가시킬 목적으로 저주파 전기자극기를 개발하였다. 연구대상자는 20대 여성 15명으로, 대조군과 실험군(기존제품 사용군 및 개발제품 사용군)으로 나뉘었다. 실험군에서는 저주파 전기자극을 4주 동안 주 4회, 30분씩 시행한 후 근전도 및 초음파 검사를 하였다. 연구 결과, 대조군, 기존제품 사용군, 개발제품 사용군의 세 군 중 개발제품 사용군에서 배곧은근의 근활성도가 의미있게 증가하였다(p<.05). 초음파로 측정된 근육 두께 변화율에서는 기존제품 사용군에서는 배가로근이, 개발제품 사용군에서는 배가로근과 배바깥빗근이 모두 유의하게 증가하였다(p<.05). 본 연구 결과를 통해 심각한 중추신경계 손상으로 인해 자발적인 근수축이 어렵거나 허리 수술 후 재활운동의 시작단계를 위해 근거 중심의 선택적 저주파 전기자극은 효과적인 중재방법의 하나로써 활용가치가 있다고 사료된다.

• 한국전문물리치료학회지
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• 제10권3호
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• pp.17-27
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• 2003

Repetitive transcranial magnetic stimulation (rTMS) modulates cortical excitability beyond the duration of the rTMS trains themselves. Depending on rTMS parameters, a lasting inhibition or facilitation of cortical excitability can be induced. Therefore, rTMS of high or low frequency over motor cortex may change certain aspects of motor learning performance and cortical activation. This study investigated the effect of high and low frequency subthreshold rTMS applied to the motor cortex on motor learning of sequential finger movements and brain activation using functional MRI (fMRI). Three healthy right-handed subjects (mean age 23.3) were enrolled. All subjects were trained with sequences of seven-digit rapid sequential finger movements, 30 minutes per day for 5 consecutive days using their left hand. 10 Hz (high frequency) and 1 Hz (low frequency) trains of rTMS with 80% of resting motor threshold and sham stimulation were applied for each subject during the period of motor learning. rTMS was delivered on the scalp over the right primary motor cortex using a figure-eight shaped coil and a Rapid(R) stimulator with two Booster Modules (Magstim Co. Ltd, UK). Functional MRI (fMRI) was performed on a 3T ISOL Forte scanner before and after training in all subjects (35 slices per one brain volume TR/TE = 3000/30 ms, Flip angle $60^{\circ}$, FOV 220 mm, $64{\times}64$ matrix, slice thickness 4 mm). Response time (RT) and target scores (TS) of sequential finger movements were monitored during the training period and fMRl scanning. All subjects showed decreased RT and increased TS which reflecting learning effects over the training session. The subject who received high frequency rTMS showed better performance in TS and RT than those of the subjects with low frequency or sham stimulation of rTMS. In fMRI, the subject who received high frequency rTMS showed increased activation of primary motor cortex, premotor, and medial cerebellar areas after the motor sequence learning after the training, but the subject with low frequency rTMS showed decreased activation in above areas. High frequency subthreshold rTMS on the motor cortex may facilitate the excitability of motor cortex and improve the performance of motor sequence learning in normal subject.