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Objective To research the diagnostic value of the wide band acoustic absorbance rate in children otitis media with effusion. Methods The wide band acoustic absorbance rate was tested in 114 children (a control group of 30 healthy children;50 patients shown middle ear effusion during tympanotomy;and 34 patients with chronic effusion shown no middle ear effusion during tympanotomy).The data of each group were analyzed, and the diagnostic value of wide band absorbance was analyzed with the receiver operating characteristic curve.Results The wide band acoustic absorbance rate of otitis media with effusion group was notably lower than that of non-effusion group and control group at the 0.5～4 kHz averaged absorbance (P＜0.05).After analyzing the receiver operating characteristic curve, it showed that the diagnosis value was highest in the range of 0.5～2 kHz (area under the curve0.984), followed by 1 kHz and 1.5 k Hz (area under the curve:0.973 and 0.967). Conclusion Compared with the conventional 226 Hz tympanometry, the wide band tympanometry is more accurate for the diagnosis of children otitis media with effusion.It can be used as a better method for the diagnosis of otitis media exudative lesions.
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Objective To study the shadowing effect when using UWB bio-radar to detect multiple static human targets to solve the problem in multi-target detection.Methods With simulated breathing apparatus as detection targets,the UWB bioradar multi static targets respiration detection experiment was designed,and the influences of distance and angle between targets and its respiratory frequency and amplitude on the shadowing effect were studied.Result The shadowing effect was mainly affected by the relative position of the multiple targets,while the respiratory frequency and amplitude of the target had less influence on it.Conclusion When multi static human targets are detected the shadowing effect does exist,and the effect mainly derives from the block of electromagnetic wave by the front target,while the change of respiratory parameters of the front target has little influence on the effect.
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Objective To investigate the effects of different intensity of wide band noise on acoustic stapedius reflex amplitude in sound field. Methods Acoustical reflex amplitude(at ART+10 dB)were obtained at three fre-quencies (1,2, 4 kHz) from 80 normally hearing subjects with wide band noise at 30,40,50 and 60 dB SL in sound field. Results Acoustical reflex amplitude was significantly decreased in the presence of wide band noise (P 0. 01). The most significant decrease of acoustic reflex amplitude could be observed in the present of 40 dB SL wide band noise. In comparison with the 1 kHz group, significant decrease was found in 2 kHz group and 4 kHz group(P <0. 01),but there was no difference between the 2 kHz group and 4 kHz group(P>0.05). Conclusion Since the decrease of the acoustic stapedius reflex amplitude is mediated by the auditory efferent system in sound field, in clini-cal practice the function of the auditory efferents can be evaluated by testing the change of acoustic stapedius reflex amplitude with the stimulation of the wide band noise in sound field.
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Transducer,which acts as both ultrasound emitter and echo receiver,is the most important acoustics part in medical ultrasonic imaging system.The development of ultrasonic imaging technology makes ultrasound image clearer and more intuitionistic.This paper mainly introduces the technical development and the prospects of piezocomposite transducer,piezoelectric single crystal transducer,wide-band transducer,3D imaging transducer and capacitive micromachined ultrasonic transducer(cMUT).
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Objective To realize excellent remote medical treatment for patients.Methods The ECG monitoring module based on Bluetooth technology was designed.The ECG module and Bluetooth radio-frequency module,which possessed the function of data acquisition and simple processing,were connected through data wire to act as ECG terminal.By using C8051F020 and ROK 101 007 Bluetooth module,ECG Bluetooth transmission module read in HCI command through serial port,thus realizing mutual communication.VC++6.0 was used as developing tool to edit remote monitoring server programme running on the computers in monitoring center.Results ECG monitoring module could acquire ECG data in real time and transmit it to personal computers,and then send it to the monitoring center through Wide Band.In this way,real-time information exchange between doctors and users was realized.Conclusion This module makes full use of the advantages of Bluetooth technology and has strong practicability.