The first experiments on electrical safety.

This paper discusses the experiments conducted by physicist and physician Arsenne d'Arsonval on the effect of sinusoidal ac on the body, well before the era of electronics. d'Arsonval's first experiments were on the effect of ac on muscle contraction using frog muscle. He contrived a most ingenious device, which displayed the voltage curve and the force of muscle contraction on a smoked-drum kymograph. By using this instrument, along with various alternators such as the Gramme machine, d'Arsonval was able to show that the muscular contraction force decreased with increasing frequency of the electric current. d'Arsonval then turned his attention to the effect of high-frequency ac on the human body. To this end, he created a spark-gap generator of the type described by Hertz in 1888. d'Arsonval demonstrated two important facts: 1) muscle contraction force decreased with increasing frequency of the current and 2) substantial current could be passed through the body and it produced a sensation of warmth. This he proved with conductive and capacitive coupling. By his experiments, d'Arsonval laid the foundation for two new medical techniques: 1) electrosurgery and 2) diathermy. Today both fields are well established in medicine     

Implantable biomedical microsystems for neural prostheses.

In the following article, the technologies to fabricate polyimide-based thin and flexible substrates with monolithically integrated electrode arrays and printed circuit boards (PCB) for hybrid electronic assemblies as well as an assembling technique that connects bare electronic dice with flexible PCBs are presented. The concept of modular, flexible biomedical microsystems as neural prostheses is introduced in general and described in detail in three examples. A cuff electrode with integrated multiplexer circuitry and standard implantable cables represents the combination of microtechnology with precision mechanics; a sieve electrode used as an implant in peripheral nerve regeneration studies demonstrates the next level of integration density but still uses a cable connection; and last, joint effort to fabricate the demonstrator of a vision prosthesis that is completely implantable in the eye with a wireless link for energy supply and data transmission is presented. System design, hybrid assembling technology, and flexible multilayer encapsulation using parylene and silicone rubber are the key components for creating a new generation of neural prostheses for complex and challenging new applications.     

L.A. Geddes: a biomedical engineering activist

Brief biographical notes are given on the achievements of Leslie A. Geddes, the Showalter Distinguished Professor Emeritus of Bioengineering at Purdue University     

Acquisition of biomedical signals databases

Aspects to consider when building a database are presented. The work is based on experiences from the SIESTA project which identified sleep disorders     

Organizational development of biomedical engineering

The evolution of biomedical engineering is traced, beginning with its roots in electrophysiology about 200 years ago. Significant research and professional developments during the 1940s, '50s, and '60s are sketched. Five major events that contributed to these developments are discussed. They are the split between biophysics and bioengineering (1957), S. Talbot's BME study grant (1958-60), the impact of the National Institutes of Health (since 1958), the IEEE ;BME-crisis' (1967/68), and the IEEE Bioengineering Society's founding (1968) and its BME view as an extension of physiology.     

Experimental study on simulated lunar soil. High voltage breakdownand electrical insulation characteristics

A low-mass solution to electrical insulation in the lunar environment may be possible by embedding bare HV conductors within the lunar soil itself. In the paper, a `standard' NASA soil (lunar simulant) representing chemical and physical conditions found in some lunar samples was used in laboratory experiments, and its HV electrical breakdown data were presented for the first time. Insulation characteristics and leakage currents representative of variations in nonlinear resistivity of the soil were investigated. The data were compared to earlier published data for a typical lunar soil's electrical characteristics. A pair of bare planar transmission lines, having a parallel plate geometry, was buried in the lunar soil simulant and used to measure the simulant's electrical parameters. The soil simulant and the electrode assembly were in a high vacuum environment throughout the experiment series. For this parallel plate electrode configuration, electrical breakdown limits and temporal evolution of voltage breakdown of the simulated lunar soil were measured. The data were analyzed in terms of physical mechanisms. Results presented may find applications in terrestrial uses of porous ceramics as insulators as well as in future lunar colony transmission line insulation techniques and design purposes     

Eddy current magnetic levitation. Models and experiments

We present a simple demonstration of eddy-current magnetic levitation using a small copper coil, energized with 60 Hz AC and levitated over an aluminum plate. The processes that generate magnetic forces are identified using Maxwell's equations. Through this experiment, a method for determining lift-off power, levitation height and suspension resonant frequency is shown. The principles outlined in this article have numerous applications to magnetic levitation, induction heating and other electrodynamic processes involving induced eddy currents. Scaling laws show how to size a suspension conductor and power supply for a given levitated load     

An industry perspective on senior biomedical engineering design courses

Most senior design courses involve lectures covering the various aspects of the typical product development cycle followed by the selection of a design project from one of several areas of biomedical engineering (BME). This article summarizes a four-year relationship between Datex-Ohmeda, Vanderbilt University [the senior design course and VaNTH (Vanderbilt University; Northwestern University; the University of Texas at Austin; and Health, Science and Technology at Harvard/MIT) Engineering Research Center (www.vanth.org) programs], and the cooperative (co-op) and summer internship programs with Marquette University and the University of Wisconsin. The involvement of industry in the senior design curriculum has been beneficial to students, the university, and industry. Datex-Ohmeda has successfully accomplished its goals in working closely with the universities. The company has provided a guest lecturer, projects for the seniors to work on, equipment, and input to the curriculum via the Biomedical Engineering Industrial Board and the VaNTH Engineering Research Council. Datex-Ohmeda has gained input on research projects and the opportunity to look at potential employees.     

Teaching of ethics in biomedical engineering

The teaching of ethics in biomedical engineering is discussed with particular reference to the teaching of ethical principles in the B.S. Biomedical Engineering program at Louisiana Tech University. Consideration is given to such issues as organ transplantation and artificial organs, conducting research in new biomedical technology, the costs of health care, and developing and regulating new technology     

A personal view of biomedical engineering

The author describes the history of biomedical engineering from the viewpoint of his own career. He discusses the early debate over what biomedical engineering is, funding considerations, and the steady growth of the field during the 1960s. The development of a research base and the establishment of international links are also examined. Future paths for the discipline are predicted     

Some experiments on semiconductor laser characteristics

The use of an off-axis holograpic optical element (HOE) as a powerful spectrograph to observe the buildup of laser oscillation as excitation is increased through the threshold value is described. The spectrum in the focal plane may be sensed by a charge-coupled device with output displayed on an oscilloscope screen. The lessons that can be learned from this experiment are discussed