Health, Medicine, & Biotechnology

Determining Glucose Levels From NIR Raman Spectra of Eyes

Spectra are processed by principal-component analysis, then artificial neural networks to obtain Bayesian probabilities.

A developmental noninvasive method of determining the concentration of glucose in blood is based on (1) the acquisition of a near-infrared (NIR) Raman spectrum from the aqueous humor of an eye, (2) analyzing the spectrum by a combination of techniques described below, and (3) recognition that the glucose level in the aqueous humor of the eye is about 80 percent of that in the blood 30 minutes before the spectrum was acquired. More specifically, what the analysis yields is a probabilistic indication that the glucose concentration represented by the Raman spectrum lies in one of three ranges of physiological interest; hypoglycemic (5.8 mM). The method involves less NIR laser power and shorter data-collection times than have been used in previous efforts to use Raman scattering to measure glucose concentrations in blood.

Posted in: Briefs, TSP, Bio-Medical, Medical, Lasers, Lasers, Diagnosis, Fluids and secretions

Wearable Sensor Patches for Physiological Monitoring

Noninvasive sensors resembling adhesive bandages would be interrogated by nearby hand-held units.

Wearable sensor patches — miniature biotelemetric units — have been proposed for use in measuring temperature, heart rate, blood pressure, and possibly other physiological parameters. The sensor patches would be small and could be mass-produced inexpensively by use of state-of-the-art techniques for batch fabrication of integrated circuits and microelectromechanical systems.

Posted in: Briefs, TSP, Bio-Medical, Medical

Improved Sensor Pills for Physiological Monitoring

These pills would measure temperature and sense the presence of blood, bacteria, and chemicals.

Improved miniature biotelemetric units resembling large pills have been proposed for use in physiological monitoring of the gastrointestinal tract. The broad principles of design, operation, and inexpensive mass production of these sensor pills would be the same as those of the sensor patches described in the preceding article. Of course, the details of design and operation would differ because the patches and pills would be used in different locations and would sense different phenomena.

Posted in: Briefs, TSP, Bio-Medical, Medical, Architecture, Sensors and actuators, Telemetry, Architecture, Sensors and actuators, Telemetry, Body regions, Medical equipment and supplies

Urine-Sample-Collection Device for Use on the Space Shuttle

Lightweight design, small size, and ease of use encourage routine collection of samples.

The in-flight urine collection absorber (IUCA) is a Johnson Space Center (JSC) breakthrough. It features a lightweight, compact design and is easy to use for collection of urine samples by male and female space shuttle crewmembers. The IUCA is superior to currently available hardware for flight urine-sampling protocols that do not require measurement of sample volumes. In addition, its lightweight design makes it desirable for space flight, where weight is a prime concern. Its utility has been confirmed in tests employing stable isotopes (oxygen-18 and deuterium) conducted at JSC. These tests showed that the IUCA, which can be placed in either male or female urine-collection funnels of the shuttle-waste-collection system, outperforms the standard urine collection device (UCD). Although there is no apparent commercial use at this time, the IUCA will benefit the space program by increasing capabilities for research in life sciences research capabilities.

Posted in: Briefs, TSP, Bio-Medical, Medical, Fluids and secretions, Medical equipment and supplies, Test equipment and instrumentation, Lightweighting, Spacecraft

Noninvasive Test Detects Cardiovascular Disease

Spinal taps would no longer be necessary.

A technique for noninvasive determination of the pressure in the cerebrospinal fluid (CSF) has been proposed. This technique would involve two main steps: First, an optical coherence tomographic scanner would be aimed into an eye and used to image the optical disk (see figure). Next, the resulting tomographic imagery would be digitized and processed to determine the thickness of the neural fiber layer, which thickness is known to increase with the CSF pressure.

Posted in: Briefs, TSP, Bio-Medical, Medical, Cardiovascular system, Medical equipment and supplies, Test procedures

Improved Urine Preservative

This solution combines antibacterial and antioxidant properties.

An improved solution for preserving samples of urine has been formulated. This solution preserves a much broader spectrum of analytes in urine than do other urine-preservative solutions here-tofore in use by NASA, and is safe for use by humans. When this solution is used, (1) refrigeration of urine samples is not necessary for preserving them and (2) the solution does not alter the pH values of the samples — two important considerations for collecting and storing urine samples in outer space. By eliminating the need to ship frozen samples, this preservative will enable the collection of urine samples — not only in outer space but also in terrestrial remote settings where it was previously not feasible.

Posted in: Briefs, Bio-Medical, Medical, Fluids and secretions, Medical equipment and supplies, Test equipment and instrumentation, Spacecraft

Primers for Amplifying CMV DNA in Body Fluids and Tissue

A novel set of primers enables high-volume, rapid, inexpensive viral diagnostic testing.

A novel set of primers has been developed for use in a polymerase chain reaction (PCR) to amplify the deoxyribonucleic acid (DNA) of cytomegalovirus (CMV). The purpose of this development is to enable faster, more sensitive detection of CMV virus infecting body fluids and tissues.

Posted in: Briefs, Bio-Medical, Medical, Diagnosis, Diseases, Fluids and secretions, Medical equipment and supplies, Chemicals

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