• 디지털산업정보학회논문지
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• 제19권2호
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• pp.11-25
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• 2023

With the increasing advancement of VLSI technology, health care system is also developing to serve the humanity with better care. Therefore, biomedical implantable devices are one of the amazing important invention of scientist to collect data from the body cell for the diagnosis of diseases without any pain. This Biomedical implantable transceiver circuit has several important issues. Oscillator is one of them. For the design flexibility and complete transistor-based architecture ring oscillator is favorite to the oscillator circuit designer. This paper represents the design and analysis of the a 9-stage CMOS ring oscillator using cadence virtuoso tool in 180nm technology. It is also designed to generate the carrier signal of 403.5MHz frequency. Ring oscillator comprises of odd number of stages with a feedback circuit forming a closed loop. This circuit was designed with 9-stages of delay inverter and simulated for various parameters such as delay, phase noise or jitter and power consumption. The average power consumption for this oscillator is 9.32㎼ and average phase noise is only -86 dBc/Hz with the source voltage of 0.8827V.

• Journal of Yeungnam Medical Science
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• 제24권2호
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• pp.97-106
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• 2007

Functional electrical stimulation (FES) has developed over the last 35 years to become a scientifically, technologically and clinically recognized field of interest in clinical medicine. FES has been applied to locomotion, grasping, ventilation, incontinence, and decubitus healing. However, all of these achievements illustrate the initial applications of FES; its true potential has not yet been realized. Recently, FES systems, which are miniaturized stimulation devices, have been utilized in the clinical setting. However, because the stimulating electrodes of the current FES devices are percutaneous electrodes, which are susceptible to wire breakage, and skin infection an implantable FES stimulating electrode has been introduced in the U.S. and Japan. In the present study, an external power supply method using radio frequency (RF) coupling and data transmission was developed for the control of the implantable FES device. In addition, we review the current understanding of FES devices and their application in clinical medicine.

• 센서학회지
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• 제14권2호
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• pp.78-84
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• 2005

A contactless recharging device for totally implantable middle ear systems has been designed as a pillow type that the user can recharge the implanted battery with taking a rest. The proposed device uses the electromagnetic coupling between the transmitting coil and the receiving coil. To supply sufficient power for the implanted circuits, each coil uses LC resonance and the implanted device uses voltage doubler. A power MOSFET is used for switching the DC voltage of LC parallel circuit and the switching frequency demands on a programmable frequency generator which is controlled by microcontroller. In order to improve the electromagnetic coupling efficiency at specific positions of coil which may vary with the displacement of head, the optimal location of receiving coil was studied, and the 5 transmitting coils in a pillow for recharging the implant module was designed. From such a recharging experiment, it was found that the proposed device could provide the sufficient operating voltage within the distance of 4 cm between pillow and the implanted device.

• 재활복지공학회논문지
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• 제1권1호
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• pp.29-36
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• 2007

최근 기존 공기 전도형 보청기의 문제점과 불편함을 해결하기 위해 이식형 보청기인 인공중이 (Implantable middle ear hearing devices, IMEHDs)가 미국, 일본, 한국 등에서 활발히 연구 개발되고 있다. 본 논문은 인공중이용 진동체로서 PZT 적층 압전체 기반의 플로팅 매스 트랜스듀서의 설계 및 구현에 관한 것이다. 인공중이용 압전 플로팅 매스 트랜스듀서 (piezoelectric floating mass transducer, PFMT)의 기계적 진동 특성을 구하기 위한 근사적 모델링과 이의 해석을 위한 전기적 변환을 통한 진동 특성 분석을 수행하여 트랜스듀서 설계에 반영하여 구현하였다. 구현된 PFMT를 본 연구팀이 개발한 완전 이식형 인공중이 시스템 시작품에 적용하였으며, PFMT의 성능을 확인하기 위해 PFMT를 사체 이소골에 장착한 후 이소골 진동변위를 측정하는 실험을 행하였다. 이를 통해 본 논문에서 설계 및 구현된 PFMT의 인공중이용 진동 트랜스듀서로서 유효성을 확인하였다.

• 센서학회지
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• 제21권2호
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• pp.144-150
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• 2012

A microphone for fully implantable hearing device was generally implanted under the skin of the temporal bone. So, the implanted microphone's characteristics can be affected by the accompanying noise due to masticatory movement. In this paper, the implantable microphone with 2-channels structure was designed for reduction of the generated noise signal by masticatory movement. And an experimental model for generation of the noise by masticatory movement was developed with considering the characteristics of human temporal bone and skin. Using the model, the speech signal by a speaker and the artificial noise by a vibrator were supplied simultaneously into the experimental model, the electrical signals were measured at the proposed microphone. The collected signals were processed using a general adaptive filter with least mean square(LMS) algorithm. To confirm performance of the proposed methods, the correlation coefficient and the signal to noise ratio(SNR) before and after the signal processing were calculated. Finally, the results were compared each other.

• 한국유체기계학회 논문집
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• 제11권1호
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• pp.40-45
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• 2008

This paper proposes a tube pump composed of small-sized cams and followers for an implantable intrathecal drug infusion device. Each followers is driven by a cam and liquid is discharged by a sequential reciprocal motion of the followers. The advantage of this structure is that it allows the pump to be clean and valveless. To design a small-sized, low power pump some analysis were performed to determine the design parameters of the cam, follower and the tube. To verify the feasibility of the experiment, a prototype was manufactured and its operating characteristics were investigated. Experimental results were in accordance with the expected results obtained from analysis.

• 한국멀티미디어학회논문지
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• 제19권2호
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• pp.189-199
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• 2016

Many implantable hearing aids are being developed as alternatives to conventional hearing aids which has inconveniences for use and social stigma that make hearing-impaired people avoid to wear it. Particularly, the fully-implantable middle ear hearing devices (F-IMEHD) are being actively studied for mixed or sensorineural hearing impaired people. In development of F-IMEHD, the most difficult problem is improving the performance of implantable microphone. Recently, Cho et al. have studied the tympanic membrane installed microphone which has better sensitivity and is easier to operate on patient than the microphone implanted under the skin. But, it may cause howling problem due to the feedback signal via oval window and ossicle chain from the transducer on round window in the middle ear cavity, therefore, a feedback canceller is necessary. In this paper, we designed NLMS (normalized least mean square) adaptive feedback canceller for F-IMEHD with tympanic membrane installed microphone and a transducer implemented at round window, and computer simulation was performed to verify its operation. The designed adaptive feedback canceller has a delay filter, a 64 point FIR fixed filter and a 8-tap adaptive FIR filter. Computer simulation of the feedback path is modeled by using the data obtained through human cadaver experiment.

• 대한의용생체공학회:의공학회지
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• 제31권5호
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• pp.395-400
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• 2010

Hypertension is the chronic disease that the 16% of total population are suffering, and it needs to be studied to find alternative treatment because of the tolerance and side effect of medications that may bother some patients. in this paper, we verified practicality of implantable electrical stimulator that can readily change stimulus magnitude and frequency. And this device is possible to stimulate baroreflex or parasympathetic nerve. Therefore we performed in vitro tests and animal experiment for device's operating conditions. This device consist of implantable electrical stimulator and extracorporeal control/monitoring system. Stimulator was designed to make 1Hz~100Hz pulses and it can change continuous or periodic pulse train type. And this device can control stimulator's function and monitor stimulator's status and patients' blood pressure at exterior of body using ZigBee module as wireless telecommunication. We verified that stimulator have error rate under 5% at 50mm depth of organs and, stimulator makes high-efficiency energy with closer position of two electrodes. Also we can confirm the performance of device that decreasing blood pressure and heart rate of a rat by electrical stimulation.

• 대한의용생체공학회:의공학회지
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• 제44권6호
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• pp.414-427
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• 2023

Implantable bioabsorbable combination products undergo inherent degradation and systemic absorption within the physiological environment, thereby streamlining the therapeutic regimen and obviating the imperative for invasive extraction procedures. This inherent property not only enhances patient convenience and therapeutic efficacy but also underpins a paradigm of support characterized by heightened safety parameters. Within the regulatory landscapes of Korea, the United States, and Europe, implantable bioabsorbable combination products are meticulously classified into distinct categories, either as pharmaceutical implants or as implantable medical devices, depending on their primary mode of action. This scholarly investigation systematically examines the regulatory frameworks governing implantable bioabsorbable combination products in South Korea, the United States, and Europe. Notable discrepancies across national jurisdictions emerge concerning regulatory specifics, including terminology, product classification, and product name associated with these products. The conspicuous absence of standardized approval regulations presents a formidable barrier to the commercialization of these advanced medical devices. This academic discourse passionately emphasizes the critical need for formulating and implementing a sophisticated regulatory framework capable of streamlining the product approval process, thereby paving the way for a seamless path to commercializing implantable bioabsorbable combination products.

• 전기학회논문지P
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• 제64권3호
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• pp.175-181
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• 2015

In this paper, the neuromuscular electrical stimulation medical devices for non-implantable incontinence treatment other than vaginal insertion type was developed and commercialized. The structure of medical devices for electrical stimulation based on the anatomy of the pelvic floor muscle designed. Then, the optimum parameters that may be effective in pelvic floor muscle electrical stimulation was set. The circuit system based on the optimum parameters were designed and manufactured. The frequency of the pulse voltage for electrical stimulation is 75[Hz], the pulse width is 300[${\mu}s$], the development of medical devices was to have seven program functions to the various treatments. The circuit system of medical devices was composed of microcontroller, comparator and converter. The performance of the developed circuit system in KTC(Korea Testing Certification) were carried out medical equipment inspection test. Test results, test specifications were satisfied with the medical device, the performance was verified to be commercialized as a medical device. The development of medical devices were validated risk assessment and product performance through a software validation. Commercialization of medical equipment was acquired to enable the certification standards of the international standard IEC 60601-1.