Jyung Hyun Lee

Implemented edge shape of an electrical stimulus capsule

Recently, a capsule endoscope has been developed and many researchers have been trying to develop locomotive capsules. To develop locomotive capsules, the inner volume of the capsule has to be large enough to insert actuators, and the edge shape of the exterior capsule has to be suitable for locomotion. There are many locomotional methods, but an electrical stimulus method provides the appropriate power consumption, plus the shape of the capsule is the same as general telemetry capsules. In this paper, the optimal shape of the electrical stimulus capsule (ESC) was designed and implemented to provide the appropriate inner volume and moving speed of the capsule.

Necessity of human middle ear characteristics at design of piezoelectric type round window vibrator

A new implantable hearing device, which vibrates round window (RW) of human cochlea, has been widely developed in the world. This device has been remarkable owing to compensate conductive hearing loss of hearing impaired people which was damaged their ossicles. Recently, piezoelectric actuator has been applied to RW drive type hearing devices because of flat and excellent vibrational characteristics at audible frequency range. However, in case of the RW vibration, patients cannot hear natural sound because the auditory pathway dont include middle ear. And human middle ear has resonant characteristics. Thus, piezoelectric vibrators need the resonance corresponding to the middle ear characteristics for hearing natural sound.

Implementation of adjustive latency compensation in a binaural hearing aid to prevent latency due to wireless transmission for using with multi-media devices

Binaural hearing aid has become an important topic in recent research on hearing aids. It employs two hearing aids, one for each ear. However, a short latency between the outputs of the two hearing aids will occur owing to the wireless data transmission between two aids. In this study, an adjustive latency compensation was designed and implemented in a binaural hearing aids to prevent the latency. It includes a static part for the basic transmission time, and the length of an adjustive part can be adjusted depending on the transmission time change caused by a transmission failed. Therefore, a time measurement program with real time clock was designed to measure the time of every data package transmission. As the experimental results show, the proposed compensation is able to ensure synchronisation between the two hearing aids even when a transient failure in the wireless communication between two hearing aids occurred.

Design a wireless capacitive sensor detection system with power line communication for liquid volume of intravenous drip measurement

U-healthcare industry has appeared and developed rapidly due to the development of the telecommunication and Health care technology, the increase of the needs of the Health care providers, and increment of the demands of the Health care users. The core factor of the U-Healthcare fields is the monitoring technique for the patients. In this paper, designed the system which was composed of power line communication (PLC) device and a telemetry intravenous (IV) drip monitoring device were proposed. An additional LAN network formation is not needed for data communication by using PLC and we were able to reduce the costs by using already formed power grid. In addition, the wireless capacitive sensor was used to detect the remaining amount of IV set, and microcontroller was used to transmit the results by using RF communications. According to the experiment results, using the power line for long distance communication is able to achieve the U-healthcare effect.

Verification of open platform board and bluetooth dongle for wireless controlling binaural hearing aids

Recently, the development of binaural hearing aids are rapidly developing with the improvement of wireless communication technology and integrated circuit design. The binaural hearing aids manufacturers are developing control technology using the multimedia equipment and smart-phone for its hearing aids control. In this paper, we designed and implemented the hearing aids system that is combined open platform board and bluetooth dongle for development of binaural hearing aids. And also, we implemented android based control GUI (graphical user interface) for hearing aids volume and fitting parameters control. From the experiment results, we verified open platform board and bluetooth dongle that was successfully controlled the hearing aids system volume using smart-phone GUI.

Membrane design of vibration transducer to drive round window to increase vibration displacement

Many kinds of hearing aids have been developed to overcome hearing loss. Each hearing aid has their own method to improve hearing threshold level of the patient. In case of vibration transducer to drive round window, a part of implantable hearing aid, uses the vibration displacement to compensate the hearing level. However, the vibration displacement is limited by membrane size made of metal, when it has been fixed dimensions. In this paper, several form of vibration transducer membrane to drive round window to increase vibration displacement has been proposed. It is calculated using finite element analysis. It is confirmed the vibration displacement can be higher in limited size.

Using small pressure transducers to measure the cerebral perfusion pressure of conscious rats

Cerebral perfusion pressure (CPP) is the net pressure gradient causing blood flow to the brain. It must be maintained within narrow limits because minute fluctuations in pressure could cause brain tissue to become ischemic or could raise intracranial pressure (ICP). In this paper, two types of transducers were proposed to measure the CPP from conscious rats. One transducer was manufactured with a pressure sensor within a screw cylindrical shell; it was made with stainless steel to allow for easier insertion of the sensor into the skull. For another type, a tube with screw-shaped outside feature that was inserted in skull and connected to the pressure sensor, the sensor was placed on the rat head. The two types of transducers were not intruded into the brain tissue. A digital physiograph system was used to acquire and analyze the CPP value. The results of the experiments showed that both types of transducers were able to measure the CPP effectively in normal conscious rats.