CHANGES IN THE THORACIC IMPEDANCE DISTRIBUTION UNDER DIFFERENT VENTILATORY CONDITIONS

被引:117
作者
HAHN, G [1 ]
SIPINKOVA, I [1 ]
BAISCH, F [1 ]
HELLIGE, G [1 ]
机构
[1] DLR,INST AEROSP MED,W-5000 COLOGNE,GERMANY
关键词
D O I
10.1088/0967-3334/16/3A/016
中图分类号
Q6 [生物物理学];
学科分类号
071011 ;
摘要
The present study was performed with the aim of checking the suitability of EIT in imaging regional thoracic impedance variations during lung ventilation under predefined conditions and to compare EIT with established reference techniques. A new technique of functional EIT imaging designed to visualize physiologically relevant information from the sequentially registered series of thoracic impedance distributions. was introduced. Experiments were performed on five spontaneously breathing healthy subjects and on 12 anaesthetized supine pigs. 16 electrodes were placed around the thorax and consecutive transthoracic impedance distributions were measured at a rate of 1 Hz (Sheffield; APT. system mark I, IBEES, Sheffield, UK). Several voluntary breathing manoeuvres were performed. in human subjects and the tracings of local impedance were compared with standard spirometry. In animal experiments EIT was applied during artificial ventilation at different ventilation rates and during stepwise passive emptying and filling of either one or both lungs while the respiratory muscles were relaxed. Further, selective blockade of lung regions resulting in regionally reduced ventilation was performed and the capability of EIT to follow and differentiate local ventilatory disturbances was checked by reference techniques (x-ray and staining methods). The experiments revealed an overall agreement between the spirometric and impedance data in all breathing patterns performed. A linear relationship between changes of the air content of the lungs and the regional thoracic impedance was shown (intraindividual correlation coefficient range, 0.986-0.999; n = 12 animals). The functional images of the impedance distribution across the thorax reproduced adequately the typical anatomical characteristics of the pig and the human thorax. The spatial resolution of EIT functional images was sufficient to differentiate lung areas corresponding to approximately 20 ml tissue volume. EIT with the additional evaluation procedure of functional imaging was shown to be a suitable and reliable method of imaging different ventilatory conditions with the potential to become a useful tool for monitoring respiratory function.
引用
收藏
页码:A161 / A173
页数:13
相关论文
共 10 条
[1]   APPLIED POTENTIAL TOMOGRAPHY [J].
BARBER, DC ;
BROWN, BH .
JOURNAL OF PHYSICS E-SCIENTIFIC INSTRUMENTS, 1984, 17 (09) :723-733
[2]  
Brown B H, 1987, Clin Phys Physiol Meas, V8 Suppl A, P91, DOI 10.1088/0143-0815/8/4A/012
[3]   CLINICAL-APPLICATIONS OF ELECTRICAL-IMPEDANCE TOMOGRAPHY IN THE MONITORING OF CHANGES IN INTRATHORACIC FLUID VOLUMES [J].
CAMPBELL, JH ;
HARRIS, ND ;
ZHANG, F ;
BROWN, BH ;
MORICE, AH .
PHYSIOLOGICAL MEASUREMENT, 1994, 15 :A217-A222
[4]  
HAHN G, 1995, IN PRESS P SCI RESUL
[5]  
HAHN G, 1904, BIOMED TECHNIK SB, V39, P199
[6]  
Harris N D, 1987, Clin Phys Physiol Meas, V8 Suppl A, P155, DOI 10.1088/0143-0815/8/4A/020
[7]   Applied potential tomography: A new technique for monitoring pulmonary function [J].
Harris, N.D. ;
Suggett, A.J. ;
Barber, D.C. ;
Brown, B.H. .
Clinical Physics and Physiological Measurement, 1988, 9 (SUPPL. A) :79-85
[8]  
HOLDER DS, 1993, CLINICAL AND PHYSIOLOGICAL APPLICATIONS OF ELECTRICAL IMPEDANCE TOMOGRAPHY, P277
[9]  
NEWELL JC, 1994, IEEE T BIOMED ENG, V35, P828
[10]  
POMERANT.M, 1969, SURGERY, V66, P260