Sangjoon Lee

Bio: Sangjoon Lee is an academic researcher from Yonsei University. The author has contributed to research in topics: The Internet & Leaching (agriculture). The author has an hindex of 8, co-authored 17 publications receiving 432 citations.

Ultrasonic energy in endoscopic surgery.

Abstract: The Harmonic Scalpel made by Ultracision is a system for endoscopic cutting. The energy source is vibration. The power box is attached to a forceps or blade, and the vibrational frequency of the blade approaches 55,500 cycles/second. This causes a knife-like action of the blade through tissue, with enough heating to create coagulation of small vessels. When this vibration energy is applied to the forceps configuration, coagulation occurs. By rotating the bottom blade of the forceps, the instrument becomes like a pair of scissors, and the tissue can divide. The Harmonic Scalpel allows the operator to cut using a tactile tissue. No smoke is created, only microaromized water droplets which are rapidly absorbed by the peritoneak surface. The instrument is extremely safe in that only tissue which is touched is cut; the energy source cannot travel through air, such as can happen with electrosurgery and laser surgery.

A Real-Time ECG Data Compression and Transmission Algorithm for an e-Health Device

Abstract: This paper introduces a real-time data compression and transmission algorithm between e-health terminals for a periodic ECGsignal. The proposed algorithm consists of five compression procedures and four reconstruction procedures. In order to evaluate the performance of the proposed algorithm, the algorithm was applied to all 48 recordings of MIT-BIH arrhythmia database, and the compress ratio (CR), percent root mean square difference (PRD), percent root mean square difference normalized (PRDN), rms, SNR, and quality score (QS) values were obtained. The result showed that the CR was 27.9:1 and the PRD was 2.93 on average for all 48 data instances with a 15% window size. In addition, the performance of the algorithm was compared to those of similar algorithms introduced recently by others. It was found that the proposed algorithm showed clearly superior performance in all 48 data instances at a compression ratio lower than 15:1, whereas it showed similar or slightly inferior PRD performance for a data compression ratio higher than 20:1. In light of the fact that the similarity with the original data becomes meaningless when the PRD is higher than 2, the proposed algorithm shows significantly better performance compared to the performance levels of other algorithms. Moreover, because the algorithm can compress and transmit data in real time, it can be served as an optimal biosignal data transmission method for limited bandwidth communication between e-health devices.

A real-time ECG data compression algorithm for a digital holter system

Abstract: This paper describes a real time ECG compression algorithm for a digital holter system. Proposed algorithm consists of five main procedures. First procedure is to differentiate signals, second is to choose a period of the differentiated signals and store them in memory, third is to perform the DCT(Discrete Cosine Transform) on the stored data, fourth is to apply a window filter, and fifth procedure is to apply Huffman Coding compression method on the data. This developed algorithm has been tested by applying 12 ECGs(electrocardiograms) from the MIT-BIH database and the PRD(Percent RMS Difference) and the CR(Compression Ratio) are calculated. It is found that the algorithm achieved a high level of compression performance with 1.82 of PRD and 8.82:1 of CR in average.

A design of the u-health monitoring system using a Nintendo DS game machine

Abstract: In this paper, we used the hand held type a Nintendo DS Game Machine for consisting of a u-Health Monitoring system. This system is consists of four parts. Biosignal acquire device is the first. The Second is a wireless sensor network device. The third is a wireless base-station for connecting internet network. Displaying units are the last part which were a personal computer and a Nintendo DS game machine. The bio-signal measurement device among the four parts the u-health monitoring system can acquire 7-channels data which have 3-channels ECG(Electrocardiogram), 3-axis accelerometer and tilting sensor data. Acquired data connect up the internet network throughout the wireless sensor network and a base-station. In the experiment, we concurrently display the bio-signals on to a monitor of personal computer and LCD of a Nintendo DS using wireless internet protocol and those monitoring devices placed off to the one side an office building. The result of the experiment, this proposed system effectively can transmit patient’s biosignal data as a long time and a long distance. This suggestion of the u-health monitoring system need to operate in the ambulance, general hospitals and geriatric institutions as a u-health monitoring device.

ESHRE Guideline: management of women with premature ovarian insufficiency

Abstract: study question: What is the optimal management of women with premature ovarian insufficiency (POI) based on the best available evidence in the literature? summary answer: The guideline development group (GDG) formulated 99 recommendations answering 31 key questions on the diagnosis and treatment of women with POI. what is known already: NA. study design, size, duration: This guideline was produced by a multidisciplinary group of experts in the field using the methodology of the Manual for ESHRE Guideline Development, including a thorough systematic search of the literature, quality assessment of the included papers up to September 2014 and consensus within the guideline group on all recommendations. The GDG included a patient representative to ensure input from women with POI. After finalization of the draft, the European Society for Human Reproduction and Embryology (ESHRE) members and professional organizations were asked to review the guideline. participants/materials, setting, methods: NA. main results and the role of chance: The guideline provides 17 recommendations on diagnosis and assessment of POI and 46 recommendations on the different sequelae of POI and their consequences for monitoring and treatment. Furthermore, 24 recommendations were formulated on hormone replacement therapy in women with POI, and two on alternative and complementary treatment. A chapter on puberty induction resulted in five recommendations. limitations, reasons for caution: The main limitation of the guideline is that, due to the lack of data, many of the recommendations are based on expert opinion or indirect evidence from studies on post-menopausal women or women with Turner Syndrome. wider implications of the findings: Despite the limitations, the guideline group is confident that this document will be able to guide health care professionals in providing the best practice for managing women with POI given current evidence. Furthermore, the guideline grouphas formulated research recommendations on the gaps in knowledge identified in the literature searches, in an attempt to stimulate research on the key issues in POI.

Methods and apparatus for renal neuromodulation

Abstract: Methods and apparatus are provided for renal neuromodulation using a pulsed electric field to effectuate electroporation or electrofusion. It is expected that renal neuromodulation (e.g., denervation) may, among other things, reduce expansion of an acute myocardial infarction, reduce or prevent the onset of morphological changes that are affiliated with congestive heart failure, and/or be efficacious in the treatment of end stage renal disease. Embodiments of the present invention are configured for percutaneous intravascular delivery of pulsed electric fields to achieve such neuromodulation.

Methods and systems for thermally-induced renal neuromodulation

Abstract: Methods and system are provided for thermally-induced renal neuromodulation. Thermally-induced renal neuromodulation may be achieved via direct and/or via indirect application of thermal energy to heat or cool neural fibers that contribute to renal function, or of vascular structures that feed or perfuse the neural fibers. In some embodiments, parameters of the neural fibers, of non-target tissue, or of the thermal energy delivery element, may be monitored via one or more sensors for controlling the thermally-induced neuromodulation. In some embodiments, protective elements may be provided to reduce a degree of thermal damage induced in the non-target tissues. In some embodiments, thermally-induced renal neuromodulation is achieved via delivery of a pulsed thermal therapy.

Methods and apparatus for thermally-induced renal neuromodulation

Abstract: Methods and apparatus are provided for thermally-induced renal neuromodulation. Thermally-induced renal neuromodulation may be achieved via direct and/or via indirect application of thermal energy to heat or cool neural fibers that contribute to renal function, or of vascular structures that feed or perfuse the neural fibers. In some embodiments, parameters of the neural fibers, of non-target tissue, or of the thermal energy delivery element, may be monitored via one or more sensors for controlling the thermally-induced neuromodulation. In some embodiments, protective elements may be provided to reduce a degree of thermal damage induced in the non-target tissues. In some embodiments, thermally-induced renal neuromodulation is achieved via delivery of a pulsed thermal therapy.

Methods and apparatus for performing a non-continuous circumferential treatment to a body lumen

Abstract: Methods and apparatus are provided for non-continuous circumferential treatment of a body lumen. Apparatus may be positioned within a body lumen of a patient and may deliver energy at a first lengthwise and angular position to create a less-than-full circumferential treatment zone at the first position. The apparatus also may deliver energy at one or more additional lengthwise and angular positions within the body lumen to create less-than-full circumferential treatment zone(s) at the one or more additional positions that are offset lengthwise and angularly from the first treatment zone. Superimposition of the first treatment zone and the one or more additional treatment zones defines a non-continuous circumferential treatment zone without formation of a continuous circumferential lesion. Various embodiments of methods and apparatus for achieving such non-continuous circumferential treatment are provided.