A leukaemic acute lymphoblastic leukaemia presenting with cutaneous lesions.
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Biopsy↗
Biomedical subjects
T Cochrane
Publications and source records attributed to T Cochrane.
The low temperature storage of skin: a preliminary report.
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Animals↗
Netherton's disease in two sisters.
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Amino Acid Metabolism, Inborn Errors↗
Software control of sensing and stimulation for cardiac electrophysiological study.
A software-controlled cardiac stimulator for clinical investigations is described. The stimulator is programmed by the user at a keyboard, while current status and values of parameters are presented on a visual display screen. A menu of predefined cardiac electrophysiological tests is available for user selection. Validity checks on data keyed in by the user and internal checks on safe pacing limits are incorporated in case of malfunction or user error. The system consists of a separate relatively simple isolated sensing and stimulation unit which communicates, via a standard digital input output interface, with a controlling microcomputer. All timing and control functions are performed in software by the computer. The use of high-level FORTRAN as the main programming language provides the system with a high degree of adaptability.
Computers↗
A comparison of the effects of xylometazoline on nasal airflow, and on blood flux as measured by laser Doppler flowmetry.
The purpose of this study was to examine whether changes in mucosal blood flow measured directly by laser Doppler flowmetry corresponded to changes in turbinate blood volume measured indirectly as changes in nasal airflow. Fifteen healthy subjects underwent active anterior rhinomanometry and laser Doppler flowmetry prior to and following the topical application of 100 micrograms of xylometazoline to each nostril. A significant decrease in nasal resistance occurred in the probe nostril (p less than 0.001) and the non probe nostril (p less than 0.005) following xylometazoline. A significant fall in blood flux occurred with xylometazoline (p less than 0.05). There was no correlation between the percentage change in airflow (rhinomanometry) and the percentage change in blood flux (laser Doppler) following xylometazoline. These results suggest that laser flowmetry and rhinomanometry measure different parts of the inferior turbinate vascular bed.
Adult↗
A comparison of the effects of two commonly used vasoconstrictors on nasal mucosal blood flow and nasal airflow.
This study compared two commonly used vasoconstrictors, cocaine and xylometazoline. Non-invasive techniques of measurement were utilised, with active anterior rhinomanometry indirectly assessing changes in nasal mucosal blood volume, and laser Doppler flowmetry assessing changes in nasal mucosal blood flow. Twelve healthy volunteers received 0.1 ml of the topical vasoconstrictor at the anterior end of both inferior turbinates. Following the application of xylometazoline, a significant rise in nasal airflow (p less than 0.005), and a significant fall in blood flux occurred in the probe nostril (p less than 0.05). Following the application of cocaine, no significant change in nasal airflow occurred (p less than 0.05), but a significant fall in blood flux occurred in the probe nostril (p less than 0.02). A comparison of the paired data for the same subject demonstrated no significant difference in the change in blood flux produced by xylometazoline and cocaine, but a significant difference in the change in airflow produced by the two vasoconstrictors (p less than 0.005).
Adrenergic alpha-Agonists↗
A solid state recorder for ambulatory monitoring of pulmonary-artery pressure.
A compact, portable recording system has been developed to record pulmonary-artery pressure in ambulatory patients. A transducer mounted on the tip of a conventional cardiac catheter is inserted percutaneously and positioned in the main pulmonary artery. Analogue circuitry, including peak and trough detectors, pre-processes the pressure/voltage waveform to yield sampled values for the systolic and diastolic pressures. Systolic and diastolic values sampled every 30 s are digitized and stored in CMOS semiconductor memory. Data acquired over a prolonged period is transferred to a microcomputer for permanent storage and subsequent analysis. Five patients were each successfully monitored for at least 24 h. The zero-level drift was less than 1% and gain stability was also better than 1% over 48 h. This device allows practical, safe, reliable and prolonged pressure recording and has wide-ranging clinical potential.
Ambulatory Care↗
A microcomputer-controlled cardiac stimulator.
Detailed investigation of abnormal heart rhythms requires electrical stimulators that can deliver sophisticated sequences of stimuli to the heart under controlled laboratory conditions. A dual-channel stimulator that provides an appropriate hardware interface between a controlling microcomputer and the patient is described. The computer gives the system power and flexibility and, most importantly, provides a suitable user interface. The hardware interface is designed to have an ergonomic division between set-up and run-time tasks. Both software and hardware are discussed, and clinical examples of typical usage of the stimulator are given.
Cardiac Pacing, Artificial↗
A portable system for monitoring physiological responses to hypoglycaemia.
Hypoglycaemia is the most common complication affecting people with Type 1 insulin dependent diabetes mellitus. Its onset is characterized by symptoms which include sweating, tremor, palpitations, loss of concentration and tiredness. As part of a research project to investigate the mechanisms of hypoglycaemia we have developed an ambulatory system to monitor and record pulsatile changes in blood flow, pulse interval, body temperature and skin impedance. The system uses a pocket computer (Atari Portfolio) to collect and store the data on a memory card. The analogue system consists of two thermocouples, an infrared photoplethysmograph and skin impedance monitoring circuit. To conserve power the system is programmed to make measurements for 2 min every 10 min: using this regimen over 16 h of data can be stored. Data collected during a spontaneous overnight hypoglycaemic episode are presented and also a comparison between continuous and intermittent data collection during a period of induced hypoglycaemia. The system is being used to investigate the physiological responses to hypoglycaemia but could easily be adapted for monitoring other physiological signals.
Arrhythmias, Cardiac↗
Building strategic partnerships between employers and managed care firms to enhance quality of care.
The challenges of integrating behavioral healthcare delivery and the demand for better management of behavioral healthcare benefits require corporate risk managers to focus on issues of quality and outcomes. A strategic partnership between the employer and a managed care organization is one tool for reducing risk and improving the quality of services for beneficiaries, using the techniques of total quality management. The following article describes a six-step process for launching such a strategic partnership, along with some potential pitfalls.
Contract Services↗
Some aspects of computer modelling in cardiac electrophysiology.
A computer model simulating the electrical activity of the heart is described. The model is designed for use in clinical cardiological research. Its implementation is based on the methods of discrete process simulation. The simulation program is written in FORTRAN, has approximately 12,000 lines and requires 160 kilobytes of memory to run. The whole heart is modelled, including a realistic description of the conduction system and a 'hollow shell' structure with a central plane representing the atrial, ventricular and septal components of the cardiac musculature. The myocardium itself is represented by simple hexagonal elements, which are pieced together to form the 'hollow shell'. The ideas used to develop the model are briefly described, but emphasis is given to clinical applications. The model is first validated by examining its output under well-known pathological conditions. Clinical applications, including predictive value, testing of hypotheses, and evaluation of pacemaker function, are then described, results being presented in the form of orthogonal lead projections.
Computers↗