Electrode construction Patent

Electrode attached to helmets for detecting low level signals from skin of living creature

Helmet system broadcasts electroencephalograms of wearer

EEG monitoring system consisting of nonirritating sponge-type electrodes, amplifiers, and a battery-powered wireless transmitter, all mounted in the subjects helmet, obtains electroencephalograms /EEGs/ of pilots and astronauts performing tasks under stress. After a quick initial fitting, the helmet can be removed and replaced without adjustments

Narrowband, crystal-controlled biomedical telemetry system

Telemetry system utilizing miniature, single-channel, crystal-controlled transmitter is described suitable for biomedical applications. Receiver used in conjunction with transmitter is narrowband superheterodyne FM receiver with crystal control in both conversion stages

Estimating returns to scale with large imperfect panels

In this paper, the authors provide systematic panel-based econometric estimates of plant-level returns to scale for various 3-digit and 4-digit manufacturing industries, using panel data for Chilean plants. The paper attempts to answer two questions: 1) Do policies that promote"bigness"in manufacturing plants also promote greater productivity?; and 2) As plants grow, do they become more efficient? The paper is organized as follows. First, the author's assumptions regarding technology and behavior are presented. The following section discusses alternative estimators that deal with different aspects of the econometric problems they faced. Finally, applications of the alternative estimators to various 3-digit and 4-digit industries are reported and an attempt is made to determine which returns to scale estimates are the most reliable.Scientific Research&Science Parks,Science Education,Environmental Economics&Policies,Economic Theory&Research,Statistical&Mathematical Sciences

Theory and observations of ice particle evolution in cirrus using Doppler radar: evidence for aggregation

Vertically pointing Doppler radar has been used to study the evolution of ice particles as they sediment through a cirrus cloud. The measured Doppler fall speeds, together with radar-derived estimates for the altitude of cloud top, are used to estimate a characteristic fall time tc for the `average' ice particle. The change in radar reflectivity Z is studied as a function of tc, and is found to increase exponentially with fall time. We use the idea of dynamically scaling particle size distributions to show that this behaviour implies exponential growth of the average particle size, and argue that this exponential growth is a signature of ice crystal aggregation.Comment: accepted to Geophysical Research Letter

A solid-state digital temperature recorder for space use

A solid-state, digital, temperature recorder has been developed for use in space experiments. The recorder is completely self-contained and includes a temperature sensor; all necessary electronics for signal conditioning, processing, storing, control and timing; and a battery power supply. No electrical interfacing with the particular spacecraft on which the unit is used is required. The recorder is small, light, and sturdy, and has no moving parts. It uses only biocompatible materials and has passed vibration and shock spaceflight qualification tests. The unit is capable of storing 2048, -10 to +45 C, 8-bit temperature measurements taken at intervals selectable by factors of 2 from 1.875 to 240 min; data can be retained for at least 6 months. The basic recorder can be simplified to accommodate a variety of applications by adding memory to allow more data to be recorded, by changing the front end to permit measurements other than temperature to be made, and by using different batteries to realize various operating periods. Stored flight data are read out from the recorder by means of a ground read-out unit

A long-range and long-life telemetry data-acquisition system for heart rate and multiple body temperatures from free-ranging animals

The system includes an implantable transmitter, external receiver-retransmitter collar, and a microprocessor-controlled demodulator. The size of the implant is suitable for animals with body weights of a few kilograms or more; further size reduction of the implant is possible. The ECG is sensed by electrodes designed for internal telemetry and to reduce movement artifacts. The R-wave characteristics are then specifically selected to trigger a short radio frequency pulse. Temperatures are sensed at desired locations by thermistors and then, based on a heartbeat counter, transmitted intermittently via pulse interval modulation. This modulation scheme includes first and last calibration intervals for a reference by ratios with the temperature intervals to achieve good accuracy even over long periods. Pulse duration and pulse sequencing are used to discriminate between heart rate and temperature pulses as well as RF interference