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Biomedical subjects

H Hsiao

Publications and source records attributed to H Hsiao.

7 recordsLinked to original sources
PubMed1995

A new non-invasive approach for monitoring respiratory movements of sleeping subjects.

We have developed a minimally intrusive system to monitor respiratory movements of sleeping subjects. This system is based on a pressure transducer which measures the changes in air pressure inside an inflatable mattress on which the subject sleeps. Using a mechanical filter to protect the transducer against the large pressure changes due to sudden movements and subject weight, we can detect the more subtle movements of the subject's chest. This paper discusses the design of the monitoring system, including the design and modelling of the mechanical filter.

Adult↗
PubMed1995

FDDI information management system for centralizing interactive, computerized multimedia clinical experiences in pediatric rheumatology/Immunology.

This paper describes the design, authoring, and development of interactive, computerized, multimedia clinical simulations in pediatric rheumatology/immunology and related musculoskeletal diseases, the development and implementation of a high speed information management system for their centralized storage and distribution, and analytical methods for evaluating the total system's educational impact on medical students and pediatric residents. An FDDI fiber optic network with client/server/host architecture is the core. The server houses digitized audio, still-image video clips and text files. A host station houses the DB2/2 database containing case-associated labels and information. Cases can be accessed from any workstation via a customized interface in AVA/2 written specifically for this application. OS/2 Presentation Manager controls, written in C, are incorporated into the interface. This interface allows SQL searches and retrievals of cases and case materials. In addition to providing user-directed clinical experiences, this centralized information management system provides designated faculty with the ability to add audio notes and visual pointers to image files. Users may browse through case materials, mark selected ones and download them for utilization in lectures or for editing and converting into 35mm slides.

Allergy and Immunology↗
PubMed1992

Nephropathology consultation via digitized images.

Investigations into a digitized image communications system were prompted by a need to bring expert consultation to physicians in community practice. Pathologists desired the capability to concomitantly view, annotate, and discuss images with referring physicians at distant sites. Methods included evaluation of the human and procedural domain into which the system was to be integrated. The GDCN computer consultation system has the consultant nephropathologist first evaluate the processed biopsy slides, digitize representative images, transmit them with the diagnosis to referring nephrologist, and, finally, conduct an interactive consultation and review of the biopsy and case. Image resolution and compression variables must be set for each individual medical consulting application. For the GDCN, it was found that the 640 x 496 x unlimited color with compression ratios not exceeding 1:32 are acceptable. An obvious improvement of this computerized system over the noncomputerized review sessions is the ability to immediately share and discuss a new image that had not been previously sent. In the old noncomputerized consultation, only images that had been mailed could be discussed. The computerized sessions allow transmission (10 sec) of a new image that the consultation might demand. The computerized sessions also provide the ability to show the referring nephrologist an area of biopsy interest that the pathologist had not previously transmitted. Biopsy slides can be viewed during the consultation, an area digitized, and that image transmitted to the nephrologist during the consultation. Hardware and costs for the sending station were: [table: see text] This system far exceeds the requirements for this particular application; however, it is sufficient to support future, higher-technology computer applications. If necessary, this same system could be used with a less expensive computer, a less expensive camera, software compression, and a single monitor. These alterations could lessen the expenditures by some $8000 and result in a total cost of $10,000. Hardware and costs for the receiving station were: [table: see text] Cost of the receiving station could be reduced by using a less expensive computer and a single monitor system, thereby saving up to $5000 and resulting in a total cost of $7,400. DCCEC and GDCN have elected to use the more expensive, user-friendly and more rapid image transmission system SEND-->IT, rather than the less expensive system mainly because of experience with incorporating the system into the daily activities of the GDCN. SEND-->IT best met the essentials for GDCN.(ABSTRACT TRUNCATED AT 400 WORDS)

Biopsy↗
PubMed1990

A three-dimensional ultrasonic system for posture measurement.

A time-efficient, cost-effective, and accurate system has been developed for measuring static three-dimensional joint coordinates in the laboratory. This system uses a personal computer interface to determine the distance between transmitters positioned at body joints and receivers positioned near the subject by measuring the travel time of ultrasound. Distance data are then converted to spatial coordinates and joint angles. The system can determine the location of 14 joints at one time. An experiment using three distances and five orientations between a transmitter and a receiver was performed to investigate the significance of measurement errors for the new system. The results showed that the standard deviation of the distance measurement was about 0.2 cm for single orientation conditions and was about 1 cm for all conditions tested. A second experiment using 11 transmitters and four receivers was performed to investigate the significance of measurement errors when determining three-dimensional coordinates. The results showed no significant difference between actual and measured coordinates. The system was then used to study the posture of a subject's upper extremity. Eight postures representing a variety of typical reaching tasks were examined. The results showed that the system was suitable for three-dimensional posture measurement.

Ergonomics↗
PubMed1981

Lung compliance and its transient elevations measured with pulse-flow method.

We describe a pulse-flow method of measuring static lung compliance (CL) that is sensitive to rapid transients in CL. CL is measured by blowing air at a constant flow into the mouth and lungs for 2 s and calculated by dividing airflow in 1/s by the change in transpulmonary pressure in CMH2O/s. Pulse and static inspiratory CL was measured in five normals, four obstructives, five obese, and two patients with pulmonary fibrosis, Pulse CL after tidal breathing was correlated with static CL measured after deep breaths (r = 0.96). Pulse CL after deep breaths was higher than pulse CL after tidal breathing (p less than 0.01) and then static CL after deep breaths (p less than 0.05). In all subjects the lower the forced expiratory volume in 1 s, expressed as a percentage of vital capacity (FEV1/FVC), the greater the increase in pulse CL after a deep breath will be (r = 0.93). After deep breaths pulse CL fell from maximum CL to base-line CL at a rate related to 1/t2 where t equals the time in seconds from the last deep breath. We conclude that the increase in CL after a deep breath is related to the degree of airway obstruction and that the subsequent fall in CL is related to 1/t2.

Adult↗
PubMed1975

Intra-aortic balloon counterpulsation: potential for therapy in hemorrhagic shock with associated myocardial failure.

After attaching appropriate monitoring devices enabling the measurement of the slope of the left ventricular function curve, left atrial pressure, mean aortic pressure, peak left ventricular pressure, and tension time index, three groups of ten dogs were subjected to varying periods of hemorrhagic shock until a slope of their ventricular function curve was reduced to either 75% (Group I), 50% (Group II), or 25% (Group III) of their baseline value. Resuscitation was attempted in all dogs by the intravenous infusion of shed blood plus additional balanced salt solution. This infusate was administered to maintain either the mean aortic pressure within 15 mm Hg of the baseline value or a left atrial pressure of 15 mm Hg, whichever occurred forst. One half of the dogs received, in addition, intra-aortic balloon counterpulsation. All dogs not receiving counterpulsation expired within two hours. There was no apparent effect of counterpulsation on Group I animals. Three of five animals (Group II) and four of five animals (Group III) receiving counterpulsation survived to the end of the experiment with significant (p smaller than .01) improvement in the parameters monitored. The utilization of counterpulsation as an adjunct to treatment in hemorrhagic shock is suggested.

Animals↗