Biomedical subjects

Dae Woong Kim

Publications and source records attributed to Dae Woong Kim.

5 recordsLinked to original sources

PubMed2005

Simultaneous measurement of refractive index and temperature based on a reflection-mode long-period grating and an intrinsic Fabry-Perot interferometer sensor.

We have demonstrated a single fiber probe for simultaneous measurement of external refractive index and temperature based on two interferometers: a reflection-mode long-period grating (LPG) for refractometry and an intrinsic Fabry-Perot interferometer (IFPI) for temperature measurement. Since the output signal of the combined structure is a superposition of signals produced by both sensors, which have different spatial frequencies, the original signals needed for the index and temperature measurements can be separated and recovered through digital filters.

Journal Article↗

PubMed2005

In-fiber reflection mode interferometer based on a long-period grating for external refractive-index measurement.

We present two novel schemes for refractometry based on a long-period fiber grating- (LPG-) based Michelson interferometer. These schemes are designed to overcome the measurement dependence of previously demonstrated LPG-based refractometry on the immersion depth. The first utilizes an unshielded LPG and the second, a shielded one. Both schemes were tested over a certain refractive-index range, and the measurement of glucose concentration in water was experimentally demonstrated. In addition, the temperature sensitivity of the two schemes is discussed.

Journal Article↗

PubMed2004

Self-compensating fiber optic flow sensor system and its field applications.

A self-compensating fiber optic flow sensor system based on the principle of broadband white-light interferometers and cantilever beam bending is described. The fiber optic sensor system uses two fiber ferrule sensors that are bonded on either side of a cantilever beam to measure the flow rate by monitoring the air-gap changes caused by the bending of the cantilever beam. Cross sensitivity of the temperature and pressure dependence of the sensor can be compensated for automatically. The prototype sensor system was constructed, laboratory characterized, and field tested. The results from the field testing have demonstrated high resolution, repeatability, and stability for on-line detection of the flow rates of fluids.

Journal Article↗

PubMed2004

Comparison of preoperative templating with postoperative assessment in cementless total hip arthroplasty.

We studied how preoperative templating corresponded to the postoperative leg length in total hip arthroplasty. On average, the preoperative predictive value of the desired corrective change in leg length was +4.9 (+4.0-+6.7) mm, while the true postoperative assessed value of the corrective change in leg length was +4.7 (+4.0-+6.3) mm. On preoperative radiographs, the ratio of the horizontal offset of a pathological side to a normal side was 95%, on average, and it increased to 96%, on average, after an operation. Preoperatively planned sizes of the acetabular cup and the femoral stem by templating showed a high rate of coincidence with the sizes used intraoperatively. In conclusion, an accurate and careful preoperative templating can result in a balanced hip reconstruction by correcting the leg length differences and restoring the offsets.

Adult↗

PubMed2003

Fiber Fabry-Perot sensors for detection of partial discharges in power transformers.

A diaphragm-based interferometric fiberoptic sensor that uses a low-coherence light source was designed and tested for on-line detection of the acoustic waves generated by partial discharges inside high-voltage power transformers. The sensor uses a fused-silica diaphragm and a single-mode optical fiber encapsulated in a fused-silica glass tube to form an extrinsic Fabry-Perot interferometer, which is interrogated by low-coherence light. Test results indicate that these fiber optic acoustic sensors are capable of faithfully detecting acoustic signals propagating inside transformer oil with high sensitivity and wide bandwidth.

Journal Article↗