Medical instrumentation最新文献

This study provides a comparison of self-measurement blood pressure devices, with respect to the standards published by the American National Standards Institute/Association for the Advancement of Medical Instrumentation and statements from the American Heart Association and the National High Blood Pressure Education Program. The results show a wide disparity among the recommendations of select committees, on issues of education and compliance and on design features of this instrumentation. Procedural problems in determining compliance in this study highlight the need for improved objectivity in statements in national standards and for improved awareness of those statements by manufacturers.

A statistical decision-making system, based on daily self measurements obtained at home, has been developed that will predict the clinical status of a patient with cystic fibrosis (CF). The data for the study were collected from patients randomly selected from those served by the University of Minnesota CF Center. Participants recorded four daily measurements (weight, vital capacity, breathing rate, and resting pulse) and one weekly measurement (height) and returned completed diaries to the coordinating center each week. The goal of the rule was to determine whether each patient's clinical status was deteriorating, remaining stable, or improving at the time of the most recent set of weekly measurements. This early detection and intervention criterion (EDIC) is being used in the clinical setting to aid in the management of patients with cystic fibrosis. The computer hardware and software, particularly the relational database, have provided an efficient basis for the continued use of EDIC.

Advances in technology and treatment have resulted in a growing population of very old and very young people whose lives are technology dependent. These people are being cared for in increasing numbers in their homes by care-givers inadequately trained for the task. The unintended negative consequences and the positive effects of such care are examined, and ethical concerns are raised.

This study examined the effects of initial-reading reactivity and measurement methods of blood pressure across different age groups. Subjects were men and women (n = 132), 17 to 96 years of age. Two measurements were obtained from each subject, with a 1-min interval between trials. Each trial consisted of concurrent measurements from each arm, using a standard mercury manometer and an automated blood pressure monitor for use at home. A double-blind control procedure was used. Significant effects were obtained for age (younger, middle, and older age groups), method by trial and age by trial. The blood pressure reactivity and the effect of observer bias varied across age groups. The results support the hypotheses that blood pressure readings decline across trials; that observer bias using traditional methods is sufficient to mask this decline; and that the extent of reactivity and subsequent decline is dependent on age or an age-related increase in blood pressure. Implications of these findings for the use of automated monitoring instruments designed for use at home are discussed.

A three-pronged approach was taken to the development of receptor-based bisensors. First, asymmetric bilayer membranes were developed with one monolayer adaptable to the particular receptor of interest and the other monolayer polymerized to enhance membrane stability. Second, alamethicin and calcium channel complexes were introduced into the stabilized membrane and tested for ion-channel function. Third, a porous support for the receptor-containing membrane was fabricated, which is compatible with silicon technology. Preliminary devices incorporating these components were constructed.

The acceptance and assimilation of new medical technologies into the health-care arena is a complex process involving financial, humanistic, and clinical considerations. This experimental research compared nurses' attitudes regarding the clinical acceptability of conventional methods of measuring vital signs with their attitudes toward a new, automated method, using the IVAC Model 4000 Vital-Check. Two studies were conducted, at different university-affiliated hospitals, involving different nursing-care-delivery models. The 102 nurses who participated in the studies generally favored the automated method with respect to provider convenience, patient acceptance, and the opportunity to simultaneously perform other nursing assessments. Conventional techniques were preferred for patients on isolation precautions and in some very specific clinical situations such as those requiring detection of abnormalities in the heart rhythm. Interviews of patients were also conducted at both sites and their comments supplemented and supported the quantitative findings for the nurses. Patients seemed to adapt very well to the new technology. They were particularly interested in being better able to monitor their own measurements with the automated process.

The induction of inspiration by delivering a burst of short-duration stimuli to body-surface electrodes is over a century old. The authors have used the term electroventilation to describe the technique. Inspiration can be produced with stimuli applied to electrodes placed bilaterally at the base of the neck, over the phrenic nerve motor points. Transchest electrodes placed anterior to the axillae can be used to stimulate the long thoracic and phrenic nerves. Paraxiphoid electrodes can be used to stimulate the phrenic nerves as they enter the diaphragm. With any of these electrode placements, inspired volumes in excess of spontaneous tidal volumes can be achieved in man, baboon, and dog. Of major importance is the need to use short-duration (less than 10-microseconds) pulses in the train of stimuli that produces contraction of the inspiratory muscles. The duration of inspiration is determined by the duration of the train, which is typically 0.5-1 s. The use of short-duration pulses minimizes the risk of producing cardiac arrhythmias and results in very little sensation at the skin.