• Journal of Biomedical Engineering Research
• /
• v.28 no.4
• /
• pp.577-584
• /
• 2007

Uroflowmetry is non-invasive and easily performed to diagnose benign prostatic hypertrophy(BPH) frequent in aged men. Weight change during urination is usually measured to estimate the urinary flow rate by a load cell, but sensitive to any impacts against the bottom of the container, leading to unnecessary noise generation. Moreover, load cells are relatively expensive raising the production cost. The present study proposed a new technique, measuring hydraulic pressure on the bottom of the urine container to evaluate the urinary volume. Low cost pressure transducer enabled almost perfectly linear relationship between the urine volume and the hydraulic pressure. During both the simulated and human urination experiments, variance of the pressure signal was more than 50% smaller than the weight signal acquired by a load cell, which demonstrated that the impact noise was decreased to a great degree by pressure compared to weight measurement.

• Journal of Biomedical Engineering Research
• /
• v.31 no.4
• /
• pp.302-309
• /
• 2010

The present study proposed a method of measuring uroflow and urophonography at the same time for more accurate diagnosis in case uroflow looks normal due to compensatory function hypertrophy in the expression of early obstruction. In case of early obstruction, there happens turbulent uroflow by the obstruction even if the uroflow looks normal and thus obstruction can be detected by measuring and analyzing signal caused by turbulent flow. We implemented a system that can measure both uroflow and urophonography, and evaluated its performance. In the experiment, we observed changes in uroflow and urophonography according to artificial pressure and the degree of obstruction, and confirmed that it is possible to determine the effect of compensatory function hypertrophy by analyzing urophonographyic parameter under the same uroflow. The results of our experiment show that the effect of compensatory function hypertrophy in the early-stage obstruction of lower urinary tract, which is not detectible with uroflowmetry alone, can be assessed through urophonographic analysis.

• Proceedings of the IEEK Conference
• /
• 2002.06e
• /
• pp.293-296
• /
• 2002

In this study, the object is a development on uroflowmetry system to detect a voiding symptom conveniently in home or hospital. The hardware was composed of mechanism and system circuit part, the software was divided into firmware and PC program part. The following experiment was performed to evaluate an ability of classification and fitness. First, the following parameters was calculated in each flow curve pattern. The parameters are MFR, AFR, VOL, VT, FT, and TMF. A significant difference among parameters was examined through a statistical analysis for extracted parameters between normal and abnormal group. In the next work, the following experimentation was performed to classify the voiding symptom. Analysis of congregate rate was examined to find out classification possibility about each symptom of BPH, voiding difficulty, detrusor failure and hyperreflexia, unstable bladder. The uroflow data with the above symptom was divided into normal and abnormal group using fuzzy classifier. and that was performed appending the other group again. Fuzzy classification result using MFR and AFR was superior by 89.6 % more than grouping evaluation including VOL.

• Journal of Sensor Science and Technology
• /
• v.18 no.6
• /
• pp.423-431
• /
• 2009

Standard uroflowmetry measures the urine weight using single load cell to evaluate the urinary flow rate. Impact noise should be introduced due to gravity when the urine stream falls down into the container upon the load cell. The present study placed three load cells on the three vertices of a regular triangle and the three signals were ensemble averaged to enhance the signal-to-noise ratio(SNR) regardless of how the urination was made. Simulated urination experiment was performed with three different urine collection methods. In all three methods, SNR of the averaged signal was much higher than each load cell signals. With no urine collection device, the present signal averaging technique resulted in SNR values higher by 10~15 dB than when dual funnels or upper funnel were used to guide the urine stream. Therefore, it was demonstrated that the three point measurement followed by with ensemble averaging could enable accurate uroflowmetric test without any specially made urine collection devices.

• Journal of Sensor Science and Technology
• /
• v.16 no.3
• /
• pp.202-210
• /
• 2007

The aim of this study is to acquire useful information of lower urinary tract symptom (LUTS) diagnosis through urophonography signal as a noninvasive method. The hardware and software which could evaluate the function of compensatory hypertrophy with noninvasive and comfortable method was implemented to measure uroflow and urophonography signal during urination. The PSD (power spectrum density) and the log-log plot gradient analysis were accomplished in frequency domain. For evaluation of the system and analysis method, a model system for the lower urinary system of men was used. From the evaluation of the model system, the PDS and the log-log plot gradient were dependent on the occlusion degree significantly. In a pilot study on normal and abnormal male subjects, the PSD and the log-log plot gradient were highly correlated with the artificial urethral obstruction.

• Journal of Sensor Science and Technology
• /
• v.15 no.6
• /
• pp.449-456
• /
• 2006

The purpose of urodynamic investigation is to obtain the information on the function of the urinary system. The aim of this study is to acquire the useful information of lower urinary tract symptom (LUTS) diagnosis through void force signal as noninvasive method. The system which could evaluate the function of compensatory hypertrophy with noninvasive and comfortable method was implemented to measure uroflow and void force during urination. The implemented system composes of the sensor parts, signal conditioning parts and PC monitoring program. For the evaluation of the implemented system, the simulation of control part of the system was performed and the model system for the lower urinary system was designed. The superiority of a measuring characteristic of the implemented system was verified using the model system. From the evaluation of the model system, we have found out that the void force was dependent on the occlusion degree and compensatory hypertrophy significantly.

• Archives of Reconstructive Microsurgery
• /
• v.10 no.2
• /
• pp.81-85
• /
• 2001

In the treatment of urethral stricture, many problems still remain with the current methods making it a field of further exploration for reconstructive surgeon. Furthermore, when total or multiple strictures of the penile urethra exist, the methods of surgery become difficult due to a necessity for a long neourethra. Introduction of vascularized free flap has broadened the choice and improved the results of reconstruction for the urethra. The authors used a sensate ulnar forearm free flap in a patient with multiple penile urethral strictures for reconstruction. Uroflowmetry, 30 months after surgery, revealed that maximal flow rate was 15.5 ml/sec, average flow rate was 9.5 ml/sec, and voided volume was 157 ml. A urethrogram was performed 30 months postoperatively and a good result was achieved. The ulnar forearm free flap used by the authors are thin and pliable and is good for providing sufficient length to reconstruct the neourethra for a long urethral defect.

• Childhood Kidney Diseases
• /
• v.28 no.1
• /
• pp.27-34
• /
• 2024

Purpose: The ability to concentrate urine becomes an important index in determining nocturnal enuresis (NE) treatment. The aim of our study was to investigate first-morning urine osmolality (Uosm) changes at the end of treatment compared to before treatment in children with NE. Methods: A total of 71 children with NE were divided into two groups according to the level of first-morning Uosm before treatment: high group (≥800 mOsm/kg) and low group (<800 mOsm/kg). Baseline parameters were obtained from uroflowmetry, frequency volume charts for at least 2 days, and a questionnaire for lower urinary tract symptoms. All patients were basically treated with standard urotherapy and medication. The first-morning Uosm was measured twice, before treatment and at the end of treatment. Results: The response rate was higher in the low group after 3 months of treatment than in the high group (P=0.041). However, there was no difference between the two groups at the end of the treatment. In the high group, the first-morning Uosm at the end of treatment did not show a significant change compared to before treatment. In contrast, the first-morning Uosm increased in the low group at the end of treatment (P<0.001). However, it was still lower than that of the high group (P=0.007). Conclusions: The ability to concentrate nocturnal urine improved at the end of treatment compared to before treatment in the low Uosm NE children. In addition, NE improved faster in the low Uosm group before treatment than in the high group.

• Journal of Yeungnam Medical Science
• /
• v.15 no.2
• /
• pp.297-305
• /
• 1998

Recently, several alternatives have been attempted in the management of benign prostatic hyperplasia (BPH) to reduce morbidity of traditional transurethral resection of the prostate (TURP). Among new modalities, transurethral electrovaporization (TEVP) is considered as a promising alternative. To evaluate the safety and initial efficacy of JEVP using the roller loop electrode (ProSurg Inc. USA) on BPH patients, we compared the results of TEVP with those of TURP and visual laser ablation of the prostate (VLAP). In this study, a total of 115 patients with symptomatic BPH were underwent TEVP (n=17), TURP (n=59) or VLAP (n=39) since 1995. Before treatment, patients were evaluated with an International Prostate Symptom Score (IPSS) and the measurement of maximal uroflow rate (MFR) and postvoid residual urine (PVR). After treatment, the operative and hospital records were reviewed. The uroflowmetry and IPSS were re-evaluated 3-10 months after treatment. In clinical outcome of re-evaluation compared to the preoperative parameters, there was a clinically significant improvement in three procedures. TEVP resulted in 62% reduction in IPSS (TURP, 73% : VLAP, 69%), 84% improvement in MFR (TURP, 113% : VLAP, 91%), and 74% reduction in PVR (TURP, 88% : VLAP, 78%). TEVP had shorter duration of hospitalization and catheterization than the others. TEVP was associated with lower rates of treatment-related complication than TURP. In conclusions, TEVP is considered as a useful procedure to treat symptomatic BPH. And, the advantages of TEVP over TURP include excellent intraoperative hemostasis, lower morbidity, shorter hospital stay and simple technique. In addition the advantages over VLAP include lower cost, shorter duration of catheterization and early symptom improvement.