International journal of clinical monitoring and computing
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Int J Clin Monit Comput · Feb 1997
The Sophus anaesthesia simulator v. 2.0. A Windows 95 control-center of a full-scale simulator.
The Sophus group was founded in Denmark in 1992 with the aims of doing research into human error in anaesthesiology. Development of a simulation-environment was seen as one of the tools for research and training. This article describes the PC user interface of the SOPHUS anaesthesia simulator, SOPHUS v. 2.0 for Windows 95, and the script language, SASL v. 1.2. The script language provides possibilities of making scenarios, which develop in different directions according to the treatment of the patient by means of IF/THEN-statements, loops etc.
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This review considers the some of the methods of automatic control which are usable in medicine. The features of each type of control system are explained and the advantages and disadvantages summarised. The author has attempted to maintain a balance between what is possible with the excellence of modern engineering, and what is feasible in the clinical area, and practical when working with patients. The problem of lack of knowledge of an individual patient is emphasised, as is the potential of fuzzy logic methods in the future.
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Int J Clin Monit Comput · Feb 1997
Effect of local limb temperature on pulse oximetry and the plethysmographic pulse wave.
We attempted to evaluate prospectively local thermoregulatory vasoconstriction and vasodilatation in 15 volunteers by means of pulse oximetry and plethysmography as measured by a finger tip-pulse oximeter. Recent studies [1] concluded that the plethysmo time interval (PTI) between the QRS complex on ECG and the upstroke of the plethysmographic wave of the pulse oximeter is useful in evaluating the peripheral circulatory status. Venous (both Vv cubitae) blood samples for determination of SvO2 were drawn, as well as pulse oximetry SpO2 oxygen saturation measurements and calculation of PTI were performed under conditions of normothermia, hypothermia and hyperthermia, before and after immersing the hands of the volunteers in a cold (15 degrees C) and warm (45 degrees C) waterbath. ⋯ Finger-tip pulse oximetry SpO2 readings change with limb temperature. The change in venous oxygen saturation can be explained by temperature dependent arteriovenous shunts in the periphery. The observed change in SpO2 probably reflects altered transmission of arterial pulsations to venous blood in the finger.
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Int J Clin Monit Comput · Feb 1997
Delirium and cognitive disorders after cardiac operations: relationship to pre- and intraoperative quantitative electroencephalogram.
We examined the incidence of delirium and cognitive disorders after cardiac operations and the related risk factors. The value of pre- and intraoperative QEEG was determined. Using the Mini-Mental State Examination and the Saskatoon Delirium Checklist, 321 patients were tested during the immediate postoperative period. ⋯ Different risk factors for delirium and cognitive disorders are a possible explanation for the controversies in the literature, where neuropsychologic complications were grouped together. A low intraoperative Hb is an important risk factor for the development of delirium and can be treated. The preoperative QEEG may have prognostic significance in the occurrence of cognitive disorders, while the intraoperative QEEG may have prognostic significance in the occurrence of delirium.
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Int J Clin Monit Comput · Feb 1997
Comparative StudyTechnology evaluation report: obtaining pulse oximeter signals when the usual probe cannot be used.
We studied the function of four different monitoring probes used with the Satlite pulse oximeter (Datex, Helsinki). The aim was to evaluate ease of use and compare the function of the probes and their attachment methods in different locations (finger, toe, ear, thumb web, instep, wrist, and ankle). Two similar pulse wave oximeters were used in the study. ⋯ Probes were compared on awake normal adult volunteers (N = 13), in anesthetized adult patients (N = 12), and in neonates weighting 500-1000 g (N = 8). In all the adult trials, the clip-on finger probe was used as a reference, and probes taped or clipped onto the finger provided adequate signal from the ear or from the thumb web, however. In the neonates, taped-on probes were most satisfactory.