Development of an AVF Stenosis Assessment Tool for Hemodialysis Patients Using Robotic Ultrasound System

Abstract

With the aging population and lifestyle changes, the number of hemodialysis (HD) patients increases year by year. The arteriovenous fistula (AVF) is the gold standard vascular access used to access the blood for HD treatment. Since the status of stenosis affects HD efficiency, current clinical practices usually use a Doppler ultrasound imaging system to assess the parameters of the stenosis, such as the degree of stenosis (DOS). Unfortunately, this is a very time-consuming task. Furthermore, it is difficult to stably maintain the ultrasound probe for a prolonged period to give doctors clearer or reproducible images. In this study, a robotic ultrasound system (RUS) with ultrasound sequential imaging analysis was designed to evaluate the DOS of the AVF. The sequential imaging analysis was capable of image smoothing and vessel boundary detection. It enabled clinicians to mark the thickness of the plaque for further processing. Finally, the system was used to reconstruct 3D models of fistulas and calculated the DOS for clinical assessment. We also designed a pressure sensing module attached to the ultrasound probe to prevent the probe from coming loose, vibrating, and exerting abnormal pressure on the skin. In the phantom test, the results showed that the error of the DOS that was calculated by RUS was less than 3%. The results of clinical trials obtained from ten patients show that the error between the RUS and clinicians’ measurement was about 10% and had a highly linear correlation (R Square > 0.95). In addition, the reproducibility error was about 3% and could effectively save about 46% of the time during clinical examinations.

An Improved Sensing Method of a Robotic Ultrasound System for Real-Time Force and Angle Calibration

“…The minimum resolution of the angle calibration was less than 2°. As shown in Figure 12 b, when the system corrected the actual imaging angle, a tumor ultrasonic image with higher reproducibility could be obtained, and this was one of the advantages of the RUS in replacing manual scanning [ 3 , 4 , 5 , 6 ].…”

“…Thus, the performance of the RUS in image capture and control could be effectively improved, which increases the efficiency of ultrasonic image detection [ 3 , 4 ]. In addition, in recent years different robot arms integrated with real-time ultrasonic images were extensively used for preoperative and intraoperative examinations by different departments, and because the robot arms have high stability and system reproducibility, human errors have been greatly reduced [ 5 , 6 ]. According to an investigation by BIS Research in 2018, the global market scale of medical robot arms was USD 5.08 billion in 2017, and has been estimated to reach USD 12.6 billion by 2025, for a compound growth rate of 12.0%, and there would be more companies devoted to the field to perform related technological research and development [ 7 ].…”

Ergonomic evaluation and field validation of the insole padding system

“…The thickness of the inserted insole pressure system was 2.5 mm. The measuring system was very thin for collecting physiological measurements without less interference, and the sensor has been widely applied for pressure measurements in human studies (Chang et al, 2020; Du et al, 2018; Lee et al, 2018; Löhrich et al, 2018). Plantar pressure was measured in seven zones: hallux, second to fifth phalanges, first metatarsal, second to third metatarsals, fourth to fifth metatarsals, midfoot, and heel (Chiu & Wang, 2007).…”

A Survey on Analog-to-Digital Converter Integrated Circuits for Miniaturized High Resolution Ultrasonic Imaging System

“…Ultrasonic imaging is one of the most widely used imaging methods in nondestructive testing and medical diagnosis due to its advantages of safety, simplicity, cheapness, penetrability, and non-ionization [1][2][3][4][5][6]. Due to the demand of high-resolution medical imaging equipment, ultrasonic imaging systems (UIS) have been rapidly developed and applied in many fields [7][8][9][10][11][12][13].…”