Document Detail


Design of an integrated sensor for in vivo simultaneous electrocontractile cardiac mapping.
MedLine Citation:
PMID:  14765708     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
While there is extensive mapping of the spread of electrical activity in the heart, there have been no measurements of electrical and localized mechanical, or contractile, activity. Yet the development of effective treatments for diseases like chronic heart failure and cardiac hypertrophy depend on the ability to quantify improvements in electrocontractile function. In this paper, we present a sensor that is capable of making simultaneous, electrocontractile measurements. Its small size facilitates placement in multiple myocardial sites for multichannel studies. Semiconductor strain gages are used for force sensing, and Ag/AgCl-plated tungsten electrodes act as electrogram sensors. The sensor contains electronics on-board, including instrumentation amplifiers and a microprocessor for data sampling and analog-to-digital conversion. Each sensor can accurately detect 0-245+/-5 mV in two electrogram channels with a sensitivity of 0.96+/-0.2 mV/step and less than 2% error, and 0-144+/-29 g of contractile force with a sensitivity of 0.56+/-0.11 g/step in the analog-to-digital conversion and less than 6% error. The sensor has been tested in vivo in open-chest rabbit and pig mapping studies. These studies indicated that the average peak-to-peak contractile force at the apex is smaller in the rabbit than the pig (13.3 versus 40.3 g), that the average peak-to-peak contractile force in the pig is smaller near the base than near the apex (31.3 versus 40.3 g), and that contractile force is visibly decreased during ventricular fibrillation compared to normal sinus rhythm.
Authors:
Benjamin A Schnitz; Dong Xu Guan; Robert A Malkin
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Publication Detail:
Type:  Comparative Study; Evaluation Studies; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.; Validation Studies    
Journal Detail:
Title:  IEEE transactions on bio-medical engineering     Volume:  51     ISSN:  0018-9294     ISO Abbreviation:  IEEE Trans Biomed Eng     Publication Date:  2004 Feb 
Date Detail:
Created Date:  2004-02-09     Completed Date:  2004-04-06     Revised Date:  2009-11-11    
Medline Journal Info:
Nlm Unique ID:  0012737     Medline TA:  IEEE Trans Biomed Eng     Country:  United States    
Other Details:
Languages:  eng     Pagination:  355-61     Citation Subset:  IM    
Affiliation:
Joint Program for Biomedical Engineering, The University of Memphis, Memphis, TN 38152, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Body Surface Potential Mapping / instrumentation*,  methods*
Electrodes*
Electronics
Equipment Design
Equipment Failure Analysis
Myocardial Contraction / physiology*
Rabbits
Reproducibility of Results
Sensitivity and Specificity
Stress, Mechanical
Swine
Systems Integration
Transducers*
Ventricular Function*
Grant Support
ID/Acronym/Agency:
R01-HL64050-01/HL/NHLBI NIH HHS

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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