Journal of clinical monitoring and computing
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J Clin Monit Comput · May 1998
Functional residual capacity measurement during tracheal gas insufflation.
Tracheal gas insufflation (TGI) is considered an adjunctive method to enhance carbon dioxide elimination during permissive hypercapnia in patients with acute respiratory distress syndrome. Due to increasing tidal volume and/or expiratory resistance, TGI may cause intrinsic PEEP (PEEPi), and may lessen the advantages of permissive hypercapnia. There is no reliable method to measure PEEPi during TGI. Using an argon washout method to evaluate dynamic hyperinflation, we developed a method to measure FRC with TGI flow. ⋯ The system developed in this study can be used as a method to detect air-trapping during TGI.
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J Clin Monit Comput · May 1998
Adaptive lung ventilation (ALV) during anesthesia for pulmonary surgery: automatic response to transitions to and from one-lung ventilation.
Adaptive lung ventilation is a novel closed-loop-controlled ventilation system. Based upon instantaneous breath-to-breath analyses, the ALV controller adjusts ventilation patterns automatically to momentary respiratory mechanics. Its goal is to provide a preset alveolar ventilation (V'A) and, at the same time, minimize the work of breathing. Aims of our study were (1) to investigate changes in respiratory mechanics during transition to and from one-lung ventilation (OLV), (2) to describe the automated adaptation of the ventilatory pattern. ⋯ Respiratory mechanics during transition to and from OLV are characterized by marked changes in R and C into opposite directions, leaving TC unaffected. The ALV controller manages these transitions successfully, and maintains V'A reliably without intervention by the anesthesiologist. VT during OLV was found to be consistently lower than recommended in the literature.
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J Clin Monit Comput · May 1998
Performance of a plastic optical fiber stylet for tracheal intubation of a dog.
We set out to establish whether a novel plastic optical fiber incorporated into an endotracheal tube (ETT) stylet could be used for intubation of a dog. A secondary objective examined the need for a direct illumination source from a laryngoscope. Lastly, the fragility of the system was tested. ⋯ A novel plastic optical fiber incorporated into an ETT stylet can be used with a laryngoscope for intubation of a dog. Direct illumination from a laryngoscope provides a better television monitor image than when only ambient light is used. The system was durable, withstanding over 20 uses and 40 sharp bend-and-straighten cycles before a lens separation failure occurred.
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J Clin Monit Comput · May 1998
Applying human factors to the design of medical equipment: patient-controlled analgesia.
Medical instruments commonly have poorly designed user interfaces that promote human errors with life-threatening consequences. The primary hypothesis of this study was that a specific user interface could be made safer and more efficient if redesigned using human factors techniques and principles. ⋯ Adopting a human factors approach to redesigning the PCA interface led to significantly faster, easier, and more reliable performance. These findings have important implications for improving the design of other computer-based medical equipment.