Seong-Su Choi

Comparison of Blood Glucose Measurements Using Samples Obtained from the Forearm, Finger Skin Puncture, and Venous Serum

BACKGROUND Blood glucose testing (BGT) at the forearm minimizes the pain experienced during sampling of capillary blood. We compared the BGT results for forearm sampling with those for standard finger skin puncture and venous serum to evaluate the clinical validity of forearm BGT. METHODS BGT was performed on the finger (G(F)) and forearm (G(A)) with a portable glucometer in 555 subjects, including 61 diabetic patients, under fasting conditions. BGT with venous serum (G(V)) was followed within an hour in 514 subjects. Simple linear regression, intraclass correlation, and Passing-Bablok regression analyses were performed using the G(A)-G(F) and G(A)-G(V) data. RESULTS G(A) showed an excellent linear relationship with both G(F) and G(V) with a Pearson correlation coefficient (r) of 0.97 (P<0.0001) in the patient group, which was similar to the findings in the normal group except for the lower r values. The mean bias between G(A) and G(F) and between G(A) and G(V) were within +/- 10 mg/dL in both groups. The intraclass correlation coefficients were slightly smaller than the corresponding r values, but they showed the same tendency in both groups. In the Passing-Bablok analyses, the 95% confidence intervals of the slope and intercept parameters were <+/-20% of unity and <+/-20 mg/dL, respectively, which were within the acceptable ranges. All 3 statistical analyses supported the satisfactory agreement of G(A) with G(F) or G(V). CONCLUSIONS BGT at the forearm was highly consistent with the standard BGT, thereby confirming its applicability in clinical practice for self-testing under steady fasting conditions.

Conductive rubber belt to monitor respiratory changes

Conductive rubber material was molded in a belt shape to incorporate with patients pants for continuous monitoring of breathing activity. Dimension changes of the abdomen resulted in corresponding resistance changes, which successfully monitored respiration. When the standard air flow rate was simultaneously measured by a pneumotachometer, mean relative error was approximately 15%, presumably due to lack of chest signal. Wireless Zigbee transmission also provided a great convenience for monitoring. The present device would be of advantages for wearable applications for its simplicity, low cost, and being washable.

Measurement Accuracy of Blood Glucose Test on the Forearm

Abstract The present study aimed to evaluate the accuracy of the blood glucose test with almost painless vacuumassisted auto-lancing technique. The blood glucose concentration measurements in the capillary blood sampled from the alternative (forearm) site were compared with the standard venous or finger sampling techniques. Capillary blood wassampled from both the left index finger and the forearm, followed by the venous blood sampling in 531 patients whovisited the C University Hospital. Blood sugar test was performed for each blood samples for comparative analysis. Mean blood glucose concentration measured on the forearm was closer to the venous glucose level than that of the finger, but the difference was approximately 10 mg/dL small enough to ignore from the clinical point of view. Thecorrelation coefficients of the measured blood glucose levels between finger and vein and between forearm and vein were 0.94 and 0.92, respectively (p<0.001). The blood glucose measurement on the forearm also well correlated with the finger, showing a correlation coefficient of 0.94, and both data were very much close to each other. Therefore, theblood sugar test on the alternative capillary blood sampling site such as forearm was accurate enough for clinical practice. The vacuum assisted auto-lancing technique on the alternative site would be of particular interest for the disease management of the chronic diabetes, since it induces almost no pain when sampling blood from the capillaries.

Automation of urine dipstick test by simultaneous scanning : A pilot study

Urinalysis is an important clinical test to diagnose urinary diseases, and dipstick method with visual inspection is widely applied in practice. Automated optical devices recently developed have disadvantages of long measurement time, big size and heavy weight, accuracy degradation with time, etc. The present study proposed a new computer scanning technique, in which the test strip and the standard chart were simultaneously scanned to remove any environmental artifacts, followed by automated differentiation with the minimum distance algorithm, leading to significant enhancement of accuracy. Experiments demonstrated an accuracy of 100 % in that all test results were identical with the human visual inspection. The present technique only uses a personal computer with scanner and shortens the test time to a great degree. The results are also stored and accumulated for later use which can be transmitted to remote locations through a network, thus could be easily integrated to any ubiquitous health care systems.

Enhancement of signal-to-noise ratio for uroflowmetric test regardless of urination situation

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.

Accuracy evaluation of diagnostic parameters estimated by uroflowmetry technique measuring hydraulic pressure

Uroflowmetry is of great convenience to diagnose benign prostate hypertrophy common in aged men. The urinary flow rate is obtained by weight measurement using load cell, however, sensitive to impact noise. An alternative technique was recently proposed to measure hydraulic pressure instead of weight and demonstrated to introduce significantly reduced noise. In this paper, we described the measured diagnostic parameters between the weight and pressure measuring techniques in 10 normal men. The weight and pressure signals were simultaneously acquired during urination, converted into urine volumes, then differentiated to obtain flow rate signals, which showed very similar waveforms. Diagnostic parameters evaluated by pressure measuring technique were well correlated with the standard weight measuring technique (correlation coefficient > 0.99). Therefore, the new uroflowmetry based on hydraulic pressure measurement can provide accurate diagnostic parameters, which would be clinically valid.