Ultrasonic System for Diagnosis of Functional Gastrointestinal Disorders: Development, Verification and Clinical Trials

Abstract

Functional gastrointestinal disorders affect millions of people spread all age regardless of race and sex. There are, however, rare diagnostic methods for the functional gastrointestinal disorders because functional disorders show no evidence of organic and physical causes. Our research group identified recently that the gastrointestinal tract well in the patients with the functional gastrointestinal disorders becomes more rigid than healthy people when palpating the abdominal regions overlaying the gastrointestinal tract. Aim of this study is, therefore, to develop a diagnostic system for the functional gastrointestinal disorders based on ultrasound technique, which can quantify the characteristic above related to the rigidity of the gastrointestinal tract well. Ultrasound system was designed. The system consisted of transmitter, ultrasonic transducer, receiver, TGC, and CPLD, and verified via a phantom test. For the phantom test, ten soft-tissue specimens were harvested from porcine. Five of them were then treated chemically to mimic a rigid condition of gastrointestinal tract well, which was induced by functional gastrointestinal disorders. Additionally, the specimens were tested mechanically to identify if the mimic was reasonable. The customized ultrasound system was finally Manuscript received November 30, 2006. This research was supported by Regional Research Center Program which was conducted by the Ministry of Commerce, Industry and Energy of the Korean Government. Eun Geun Kim is with Department of Biomedical Engineering, Yonsei University, Wonju, Korea (phone: +82-33-760-2805; fax: +82-33-760-2805; e-mail: kimeg917@gmail.com). Won Pil Park is with Department of Biomedical Engineering, Yonsei University, Wonju, Korea (phone: +82-33-760-2913; fax: +82-33-760-2913; e-mail: pwpil@cabe.yonsei.ac.kr). Dae Gon Woo is with Department of Biomedical Engineering, Yonsei University, Wonju, Korea (phone: +82-33-760-2913; fax: +82-33-760-2913; E-mail: dragon1180@yonsei.ac.kr). Chang Yong Ko is with Department of Biomedical Engineering, Yonsei University, Wonju, Korea (phone: +82-33-760-2913; fax: +82-33-760-2913; e-mail: cyko@cabe.yonsei.ac.kr). Dohyung Lim is with Institute of Medical Engineering, Yonsei University, Wonju, Korea (phone: +82-33-760-2913; fax: +82-33-760-2913; e-mail: pwpil@cabe.yonsei.ac.kr). Yong Heum Lee is with Institute of Medical Engineering, Yonsei University, Wonju, Korea (phone: +82-33-760-2805; fax: +82-33-760-2805; e-mail: koaim@yonsei.ac.kr). Tae Min Shin is with Institute of Medical Engineering, Yonsei University, Wonju, Korea (phone: +82-33-760-2805; fax: +82-33-760-2805; e-mail: tmshin@yonsei.ac.kr). Han Sung Kim is with Institute of Medical Engineering, Yonsei University, Wonju, Korea (phone: +82-33-760-2913; fax: +82-33-760-2913; e-mail: hanskim@yonsei.ac.kr). Gyoun Jung Lee is with Department of Biomedical Engineering, Yonsei University, Wonju, Korea (corresponding author to provide phone: +82-33-760-2805; fax: +82-33-760-2805; e-mail: fa1472@gmail.com). verified through application to human subjects with/without functional gastrointestinal disorders (Normal and Patient Groups). It was identified from the mechanical test that the chemically treated specimens were more rigid than normal specimen. This finding was favorably compared with the result obtained from the phantom test. The phantom test also showed that ultrasound system well described the specimen geometric characteristics and detected an alteration in the specimens. The maximum amplitude of the ultrasonic reflective signal in the rigid specimens (0.2±0.1Vp-p) at the interface between the fat and muscle layers was explicitly higher than that in the normal specimens (0.1±0.0Vp-p). Clinical tests using our customized ultrasound system for human subject showed that the maximum amplitudes of the ultrasonic reflective signals near to the gastrointestinal tract well for the patient group (2.6±0.3Vp-p) were generally higher than those in normal group (0.1±0.2Vp-p). Here, maximum reflective signals was appeared at 20mm depth approximately from abdominal skin for all human subjects, corresponding to the location of the boundary layer close to gastrointestinal tract well. These results suggest that newly designed diagnostic system based on ultrasound technique may diagnose enough the functional gastrointestinal disorders. Keywords—Functional Gastrointestinal Disorders, Diagnostic System, Phantom Test, Ultrasound System.