- Email: [email protected]
An integrated approach to monitoring
AN INTEGRATED Eds J.S.
Gravenstein,
R.S.
APPROACH TO MONITORING Newbower,
A.K
Ream
and
N. Ty Smith
Buttenvorth & Co, UK, 1983, E32.00 This book, with 24 contributing authors, is concerned with medical monitoring; the clinician it is rightly claimed, needs guidance if he is to use effectively the embarassment of information provided by modern technology. Traditional monitoring has focussed on individual variables rather than on the integration of a number of variables so as to provide a more comprehensive picture of a patient’s medical state. The four sections of the book attempt to provide the clinician with the necessary physiological understanding and some mathematical tools for the integration of multivariate information in various monitoring applications. There is also a discussion of the education and management of personnel who carry out monitoring, but equipment and computing techniques are not considered directly. The first section treats the cardiovascular system, three of its chapters examining the implications for monitoring, of a study of physiological mechanisms and their interactions. Statistical studies are needed to assess the level of model complexity and to select particular variable combinations yielding the most useful clinical information. Chapter four contains the only example in the book of the use of sophisticated multivariate statistical methods; this in spite of the valid statement in the introduction, underlining the importance of multivariate analysis as a method for unravelling the complications introduced by the ability of modern recording techniques to provide much more information than has hitherto been available to clinical medicine. Cluster analysis is used to identify a set 01 discrete states of a vector whose elements are individually monitored variables. The vector states are associated with physiological states in the monitoring of critically ill patients, and a graphical representation of the states is given; unfortunately, no details of the cluster analysis are included. Section two deals with the respiratory system, whose monitoring has been traditionally more primitive than that of the cardiovascular system. The variety of approaches in this section includes suggestions for monitoring high-frequency ventilation which cannot now be implemented; they await an improved measurement technology. There is a novel use of a mass spectrometer for the continuous measurement of cutaneous gases during anaesthesia
Section three, on formal aspects of modelling complex systems, is the most disappointing of the book This is not due to the poor quality of the individual contributions, rather to the fact that too much material is peripheral to the central, largely ignored, statistical demands of monitoring experimental designs to assess variability over subjects and conditions, multivariate analysis to reveal redundancy and the derivation of indices of change and discrimination between physiological states. Given these omissions, it seems perverse to devote a chapter to the effect of ill conditioned .matrices on the errors associated with estimating model parameters, important as it is in regression analysis and linear differential equations. The final chapters, on modeling the medical decision-making _process, is an excellent introduction to the burgeoning field of expert systems. The VM system, used for interpretating measurements and the management of ventilators in intensive care, is ‘described, developed from MYCIN, VM incorberates both statistical information and the subjective knowledge of experienced medical opinion. The.final part considers the requirements and problems inherent in the implementation of sophisticated monitoring systems; one of those requirements, well presented, is the technological education of medical staff. Less obvious is the need to maintain vigilence in anaesthetists, subject to long periods of boredom between bursts of activity. Parallel problems in nuclear plants are apparent in a chapter presenting some computer- based decision aids used by operating crews. The book is strongest in its physiological insights and weakest in its coverage of multivariate statistical methods, both vital components in the premonitoring stage of investigation. A detailed presentation of multivariate analysis is not needed: there exist several good expositions written for psychologists. What is lacking is the interaction of physiological insight and multivariate analysis in the preliminary exploration of potential monitoring variables. Despite this reservation, the book may be warmly recommended to clinicians and bioengineers as the first step towards an important goal. E. Adams RAF Institute of Aviation Medicine
J. Biomed Eng
1985, vol. 7. October
343
Gravenstein,
R.S.
APPROACH TO MONITORING Newbower,
A.K
Ream
and
N. Ty Smith
Buttenvorth & Co, UK, 1983, E32.00 This book, with 24 contributing authors, is concerned with medical monitoring; the clinician it is rightly claimed, needs guidance if he is to use effectively the embarassment of information provided by modern technology. Traditional monitoring has focussed on individual variables rather than on the integration of a number of variables so as to provide a more comprehensive picture of a patient’s medical state. The four sections of the book attempt to provide the clinician with the necessary physiological understanding and some mathematical tools for the integration of multivariate information in various monitoring applications. There is also a discussion of the education and management of personnel who carry out monitoring, but equipment and computing techniques are not considered directly. The first section treats the cardiovascular system, three of its chapters examining the implications for monitoring, of a study of physiological mechanisms and their interactions. Statistical studies are needed to assess the level of model complexity and to select particular variable combinations yielding the most useful clinical information. Chapter four contains the only example in the book of the use of sophisticated multivariate statistical methods; this in spite of the valid statement in the introduction, underlining the importance of multivariate analysis as a method for unravelling the complications introduced by the ability of modern recording techniques to provide much more information than has hitherto been available to clinical medicine. Cluster analysis is used to identify a set 01 discrete states of a vector whose elements are individually monitored variables. The vector states are associated with physiological states in the monitoring of critically ill patients, and a graphical representation of the states is given; unfortunately, no details of the cluster analysis are included. Section two deals with the respiratory system, whose monitoring has been traditionally more primitive than that of the cardiovascular system. The variety of approaches in this section includes suggestions for monitoring high-frequency ventilation which cannot now be implemented; they await an improved measurement technology. There is a novel use of a mass spectrometer for the continuous measurement of cutaneous gases during anaesthesia
Section three, on formal aspects of modelling complex systems, is the most disappointing of the book This is not due to the poor quality of the individual contributions, rather to the fact that too much material is peripheral to the central, largely ignored, statistical demands of monitoring experimental designs to assess variability over subjects and conditions, multivariate analysis to reveal redundancy and the derivation of indices of change and discrimination between physiological states. Given these omissions, it seems perverse to devote a chapter to the effect of ill conditioned .matrices on the errors associated with estimating model parameters, important as it is in regression analysis and linear differential equations. The final chapters, on modeling the medical decision-making _process, is an excellent introduction to the burgeoning field of expert systems. The VM system, used for interpretating measurements and the management of ventilators in intensive care, is ‘described, developed from MYCIN, VM incorberates both statistical information and the subjective knowledge of experienced medical opinion. The.final part considers the requirements and problems inherent in the implementation of sophisticated monitoring systems; one of those requirements, well presented, is the technological education of medical staff. Less obvious is the need to maintain vigilence in anaesthetists, subject to long periods of boredom between bursts of activity. Parallel problems in nuclear plants are apparent in a chapter presenting some computer- based decision aids used by operating crews. The book is strongest in its physiological insights and weakest in its coverage of multivariate statistical methods, both vital components in the premonitoring stage of investigation. A detailed presentation of multivariate analysis is not needed: there exist several good expositions written for psychologists. What is lacking is the interaction of physiological insight and multivariate analysis in the preliminary exploration of potential monitoring variables. Despite this reservation, the book may be warmly recommended to clinicians and bioengineers as the first step towards an important goal. E. Adams RAF Institute of Aviation Medicine
J. Biomed Eng
1985, vol. 7. October
343