A Simple Rapid Method for Measuring Liver Steatosis Using Bioelectrical Impedance

Abstract

Background/Aim: Easy measurement of liver steatosis without pathological diagnosis may help improve donor surgery efficiency and increase the chances of organ donations. We analyzed the correlations between bioelectrical impedance (BI) in human livers, liver fat content, and pathological findings. Materials and Methods: Sixteen tumor-free liver specimens resected during elective oncological surgery were analyzed. All samples were stored in ice chilled saline before BI measurement. The BI measurement was performed using a device with the tetrapolar circuit method in which the current and voltage electrodes are independent. Liver cholesterol and triglyceride levels were investigated from the same specimen using the Soxhlet extraction method. Pathological findings were examined by counting the number of hepatocytes with fatty changes per high-power field. Results: The median liver steatosis percentage was 0.4%. The liver steatosis percentage was significantly correlated with the intrahepatic triglyceride content (r=0.82, p<0.001). Linear regression of the measurements and predicted values yielded an r 2 of 0.63 between the BI at 100 kHz and liver steatosis, indicating reasonable agreement (p<0.001). Conclusion: BI analysis is a simple, non-invasive method that can be easily applied to evaluate liver steatosis.

Regional Pulmonary Ventilation Assessment Method and System Based on Impedance Sensing Information from the Pentapulmonary Lobes

“…The data from the repeated trials for each subject were nonlinearly fitted according to (15). The results of fitting the data from 20 consecutive sets of repeated trials for one of the subjects are shown in Table 4.…”

“…It can be seen that the standard errors are all within 5%, indicating that the estimates of each regression parameter are good. The matrix of characteristic coefficients A for this subject is obtained from (15) as shown in (19): Based on the fitting effects of repeated trials with 60 subjects, it was found that the nonlinear fit of the five-lobe impedance data for a single individual was good, but the characteristic coefficient matrix A obtained from the fitting of different individuals differed significantly. To seek a model for calculating regional lobar ventilation parameters that can be used for different individuals, the individual factor with the greatest degree of influence was introduced to optimize the characteristic coefficient matrix A.…”

“…Therefore, the evaluation of the method in this paper adopts the medical lung function testing instrument as a benchmark instrument and compares the ventilation parameters of the whole lung region to verify the consistency. Then, the pulmonary function parameters of the five lung lobes are calculated using (15), and the ventilation parameters of the whole lung area can be obtained via (16). Conventional pulmonary function parameter testing instruments are not yet equipped to provide ventilation parameters for lung regions, and imaging devices only provide a qualitative assessment of ventilation impairment in lung regions.…”

“…Therefore, the evaluation of the method in this paper adopts the medical lung function testing instrument as a benchmark instrument and compares the ventilation parameters of the whole lung region to verify the consistency. Then, the pulmonary function parameters of the five lung lobes are calculated using (15), and the ventilation parameters of the whole lung area can be obtained via (16).…”

“…Biosensing technology employs biomaterials and sensors to capture biological data from tissues and organs, transforming these data into clinically relevant information that reflects the physiological status of the human body [12]. The effectiveness of using biosensors for measuring body impedance to identify internal structural abnormalities in the human body has been well documented [13][14][15][16]. Given the significant changes in medium and tissue structure within the lungs during respiration, bioelectrical impedance techniques have increasingly been applied to evaluate lung ventilation [17][18][19].…”