Health, Medicine, & Biotechnology

Microfluidic Devices for Studying Biomolecular Interactions

These devices can be fabricated rapidly and inexpensively.

Microfluidic devices for monitoring biomolecular interactions have been invented. These devices are basically highly miniaturized liquid-chromatography columns. They are intended to be prototypes of miniature analytical devices of the “laboratory on a chip” type that could be fabricated rapidly and inexpensively and that, because of their small sizes, would yield analytical results from very small amounts of expensive analytes (typically, proteins). Other advantages to be gained by this scaling down of liquid-chromatography columns may include increases in resolution and speed, decreases in the consumption of reagents, and the possibility of performing multiple simultaneous and highly integrated analyses by use of multiple devices of this type, each possibly containing multiple parallel analytical microchannels.

Posted in: Briefs, Bio-Medical, Medical, Downsizing, Integrated circuits, Biological sciences, Product development, Test equipment and instrumentation

Neuro-Prosthetic Implants With Adjustable Electrode Arrays

Depths of penetration of electrodes would be adjusted to maximize received signals.

Brushlike arrays of electrodes packaged with application-specific integrated circuits (ASICs) are undergoing development for use as electronic implants — especially as neuro-prosthetic devices that might be implanted in brains to detect weak electrical signals generated by neurons. These implants partly resemble the ones reported in “Integrated Electrode Arrays for Neuro-Prosthetic Implants” (NPO-21198), NASA Tech Briefs, Vol. 27, No. 2 (February 2003), page 48. The basic idea underlying both the present and previously reported implants is that the electrodes would pick up signals from neurons and the ASICs would amplify and otherwise preprocess the signals for monitoring by external equipment.

Posted in: Briefs, TSP, Bio-Medical, Medical, Architecture, Integrated circuits, Nervous system, Prostheses and implants

Biomimetic/Optical Sensors for Detecting Bacterial Species

Bacteria in liquid samples could be detected in real time.

Biomimetic/optical sensors have been proposed as means of real-time detection of bacteria in liquid samples through real-time detection of compounds secreted by the bacteria. Bacterial species of interest would be identified through detection of signaling compounds unique to those species. The best-characterized examples of quorum- signaling compounds are acylhomoserine lactones and peptides. Each compound, secreted by each bacterium of an affected species, serves as a signal to other bacteria of the same species to engage in a collective behavior when the population density of that species reaches a threshold level analogous to a quorum.

Posted in: Briefs, TSP, Bio-Medical, Medical, Sensors and actuators, Bacteria, Identification, Test equipment and instrumentation

Analysis of Membrane Lipids of Airborne Micro-Organisms

A method of characterization of airborne micro-organisms in a given location involves (1) large-volume filtration of air onto glass-fiber filters; (2) accelerated extraction of membrane lipids of the collected micro-organisms by use of pressurized hot liquid; and (3) identification and quantitation of the lipids by use of gas chromatography and mass spectrometry.This method is suitable for use in both outdoor and indoor environments; for example, it can be used to measure airborne microbial contamination in buildings (“sick-building syndrome”). The classical approach to analysis of airborne micro-organisms is based on the growth of cultureable micro-organisms and does not provide an account of viable but noncultureable micro-organisms, which typically amount to more than 90 percent of the micro-organisms present. In contrast, the present method provides an account of all micro-organisms, including cultureable, noncultureable, aerobic, and anaerobic ones. The analysis of lipids according to this method makes it possible to estimate the number of viable airborne micro-organisms present in the sampled air and to obtain a quantitative profile of the general types of micro-organisms present along with some information about their physiological statuses.

Posted in: Briefs, Bio-Medical, Medical, Biological sciences, Glass fibers, Test equipment and instrumentation, Test procedures

Noninvasive Diagnosis of Coronary Artery Disease Using 12-Lead High-Frequency Electrocardiograms

Diagnostically significant signal features can be identified automatically by computational analysis.

A noninvasive, sensitive method of diagnosing certain pathological conditions of the human heart involves computational processing of digitized electrocardiographic (ECG) signals acquired from a patient at all 12 conventional ECG electrode positions. In the processing, attention is focused on low-amplitude, high-frequency components of those portions of the ECG signals known in the art as QRS complexes. The unique contribution of this method lies in the utilization of signal features and combinations of signal features from various combinations of electrode positions, not reported previously, that have been found to be helpful in diagnosing coronary artery disease and such related pathological conditions as myocardial ischemia, myocardial infarction, and congestive heart failure.

Posted in: Briefs, Bio-Medical, Medical, Cardiovascular system, Diagnosis, Diseases, Medical equipment and supplies

Multichannel Brain-Signal-Amplifying and Digitizing System

An apparatus has been developed for use in acquiring multichannel electroencephalographic (EEG) data from a human subject.

EEG apparatuses with many channels in use heretofore have been too heavy and bulky to be worn, and have been limited in dynamic range to no more than 18 bits. The present apparatus is small and light enough to be worn by the subject. It is capable of amplifying EEG signals and digitizing them to 22 bits in as many as 150 channels. The apparatus is controlled by software and is plugged into the USB port of a personal computer. This apparatus makes it possible, for the first time, to obtain high-resolution functional EEG images of a thinking brain in a real-life, ambulatory setting outside a research laboratory or hospital.

Posted in: Briefs, Bio-Medical, Medical, Computer software and hardware, Sensors and actuators, Medical equipment and supplies, Nervous system

Multistage Magnetic Separator of Cells and Proteins

Purifications and separations can be carried to higher degrees than were previously possible.

The multistage electromagnetic separator for purifying cells and magnetic particles (MAGSEP) is a laboratory apparatus for separating and/or purifying particles (especially biological cells) on the basis of their magnetic susceptibility and magnetophoretic mobility. Whereas a typical prior apparatus based on similar principles offers only a single stage of separation, the MAGSEP, as its full name indicates, offers multiple stages of separation; this makes it possible to refine a sample population of particles to a higher level of purity or to categorize multiple portions of the sample on the basis of magnetic susceptibility and/or magnetophoretic mobility.

Posted in: Briefs, TSP, Bio-Medical, Medical, Biological sciences, Magnetic materials, Test equipment and instrumentation

Radiation Dosimetry via Automated Fluorescence Microscopy

With further development, this instrument could enable biodosimetry on a large scale.

A developmental instrument for assessment of radiation-induced damage in human lymphocytes includes an automated fluorescence microscope equipped with a one or more charge coupled device (CCD) video camera(s) and circuitry to digitize the video output. The microscope is also equipped with a three-axis translation stage that includes a rotation stage, and a rotary tray that holds as many as thirty specimen slides. The figure depicts one version of the instrument. Once the slides have been prepared and loaded into the tray, the instrument can operate unattended. A computer controls the operation of the stage, tray, and microscope, and processes the digital fluorescence image data to recognize and count chromosomes that have been broken, presumably by radiation.

Posted in: Briefs, Bio-Medical, Medical, Charge coupled devices, Microscopy, Optics, Diagnosis, Automation, Radiation

Elastic-Tether Suits for Artificial Gravity and Exercise

Body suits harnessed to systems of elastic tethers have been proposed as means of approximating the effects of normal Earth gravitation on crewmembers of spacecraft in flight to help preserve the crewmembers’ physical fitness. The suits could also be used on Earth to increase effective gravitational loads for purposes of athletic training. The suit according to the proposal would include numerous small tetherattachment fixtures distributed over its outer surface so as to distribute the artificial gravitational force as nearly evenly as possible over the wearer’s body. Elastic tethers would be connected between these fixtures and a single attachment fixture on a main elastic tether that would be anchored to a fixture on or under a floor. This fixture might include multiple pulleys to make the effective length of the main tether great enough that normal motions of the wearer cause no more than acceptably small variations in the total artificial gravitational force. Among the problems in designing the suit would be equalizing the load in the shoulder area and keeping tethers out of the way below the knees to prevent tripping. The solution would likely include running tethers through rings on the sides. Body suits with a weight or water ballast system are also proposed for very slight spinning space-station scenarios, in which cases the proposed body suits will easily be able to provide the equivalency of a 1-G or even greater load.

Posted in: Briefs, Bio-Medical, Medical, Simulation and modeling, Personnel, Elastomers, Mountings, Spacesuits

Chamber for Growing and Observing Fungi

A chamber has been designed to enable growth and observation of microcolonies of fungi in isolation from the external environment.

Unlike prior fungus growing apparatuses, this chamber makes it possible to examine a fungus culture without disrupting it. Partly resembling a small picture frame, the chamber includes a metal plate having a rectangular through the thickness opening with recesses for a top and a bottom cover glass, an inlet for air, and an inlet for water. The bottom cover glass is put in place and held there by clips, then a block of nutrient medium and a moisture pad are placed in the opening. The block is inoculated, then the top cover glass is put in place and held there by clips. Once growth is evident, the chamber can be sealed with tape. Little (if any) water evaporates past the edges of the cover glasses, and, hence there is little (if any) need to add water. A microscope can be used to observe the culture through either cover glass. Because the culture is sealed in the chamber, it is safe to examine the culture without risking contamination. The chamber can be sterilized and reused.

Posted in: Briefs, Bio-Medical, Medical, Biological sciences, Containers, Glass, Test equipment and instrumentation

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