Research And Clinical Application Of The Ultrasonic Examining Bed For Infant Hip Joint

objective: The measurement errors occur in Development dislocation of the hip(DDH) screened by ultrasound. The errors may lead to erroneous subsequent treatment and intervention. In order to reduce the measurement errors which is artificially created an ultrasonic examining bed for infant hip joint was designed in this research.Methods: The ultrasonic examining bed for infant hip joint was developed in this research. It consists of two parts : Bed frame and connecting. The ultrasonic examining bed can fasten infant hip and lower limbs and it also fasten the probe. Firstly, three ultrasound doctors scan 160 infants who is born 42 days(320 hip joints) use common examining bed,they fasten infant hip and lower limbs only by hand. Secondly, they scan again by the ultrasonic examining bed for infant hip joint. measurement combine two method: Graf method and Morin method. These parameter include:αangle,βangle and Femoral head percentage of cover(FHC). Compare the date, diagnosis and consistency of three doctors from these two beds.Results:1.quantitative data:(1)The standard deviation of common examining bed is below the common bed.(2)Intraclass correlation coefficient(ICC)<0.4 between three ultrasound doctors who use common examining bed,it has a poorer consistency,but ICC >0.75 between three ultrasound doctors who use the ultrasonic examining bed for infant hip joint.(3) Bland-Altman analytical data shows that standard deviation in the range of ±1.96,reflecting the good parallelism between ultrasonic examining bed for infant hip joint and common bed.2.qualitative data: date about Graf measurement method: left Kappa=0.5834(0.4235-0.7432),right weighted Kappa =0.5689-1~1(0.3815-0.7563). date about Morin measurement method: left weighted Kappa= 0.6483(0.4703-0.8263), right weighted Kappa=0.4784(0.3073-0.6496).Consistency is medium between ultrasonic examining bed for infant hip joint and common bed.3.The average examination time of common examining bed is 15 minutes and 20 seconds(920±88seconds).The average examination time of ultrasonic examining bed for infant hip joint is 9 minutes and 30 seconds(570±51seconds), Examining bed reduce the examination time by as much as 38%. Paired test shows that there were statistical differences between these two bed(M=240,P<0.0001)..Conclusions:(1) The design of ultrasonic examining bed for infant hip joint has a rational structure and a multiple function. It can meet the requirements about stability and flexible when DDH screened by ultrasound.(2) Ultrasonic examining bed for infant hip joint can eliminate the manmade influence so that it can improve correctness of measurement data.(3) There are good parallelism for the date between common bed and ultrasonic examining bed for infant hip joint,and the latter can substitute for the former.(4)When ultrasound doctors use common bed, the consistency is not satisfactory,But the consistency(precision) is good when ultrasound doctors use examining bed.(5) Examining bed of ultrasound for infant hip join can reduce the examination time and increase work efficiency.