Mark L. Manwaring

A protocol for automatic sensor detection and identification in a wireless biodevice network

As transducer devices continue to shrink in size, they become increasingly suitable for implantation, enabling the creation of an exciting new class of wireless biodevice networks. A biodevice consists of sensor(s), actuator(s) and microcontroller(s) used to monitor and control biological processes. A wireless biodevice uses the principle of electromagnetic induction to receive power and data communications from an external interrogator. Multiple wireless biodevices and interrogator devices may be organized into a wireless instrumentation network (WIN). This paper starts by examining the motivations for WIN design, followed by a description of the proposed WIN architecture for subcutaneously implanted biodevices. Next, the design of a data-link layer protocol for the automatic detection and identification of implanted biodevices is described and analyzed. Finally, the advantages and disadvantages of the network and protocol are discussed.

Magnetic Field Guided Endoscopic Dissection through a Burr Hole May Avoid More Invasive Craniotomies A Preliminary Report

The neuroendoscope, coupled with radiofrequency or laser dissecting tools, can effectively resect obstructing membranes, biopsy and debulk tumor, and evacuate hematomas when the pathology is within the ventricular system. This less invasive approach through a burr hole usually avoids craniotomies. When the abnormal condition is within parenchyma or in the presence of opacifying bloody fluid, landmarks are not recognizable and the neurosurgeon quickly becomes disoriented. A more extensive craniotomy or a stereotaxic-guided procedure is then necessary. We describe our preliminary experience with a geographic intracranial navigation system using realtime measurement of electromagnetic field strength in multiple planes to precisely indicate the position of the tip of the endoscope. A transmitting antenna is positioned beneath the patients head. A 1.5 centimeter cubic antenna receiver is mounted upon a lenscope with instrument channel. The scope is guided into the surgical field after insertion through a burr hole. A square wave pulsed electromagnetic field measurement is made 140 times per second with correction for the earths magnetic field once per second. Intracranial position data for the dissecting tip in regard to X, Y, Z, pitch, roll and yaw are output to a digitized computer map of the patients MRI or CT scan. Also displayed on the computer screen is the video image from the endoscope. The neurosurgeon thus has simultaneous realtime geographic and near-field localization as he dissects. Electromagnetic field guided accuracy is within 2.0 mm inside the allowable 24 inch working sphere about the patients head. Coupled with near-field video precision, accuracy is within 1 mm of recognizable dissection planes.(ABSTRACT TRUNCATED AT 250 WORDS)

Issues in developing a communication protocol for wireless (implanted) biodevices

Describes current research in the development of subcutaneously implanted biological sensor devices (biodevices). In particular, the matter presented here is the issue of developing a safe digital communication protocol for communicating through a wireless link between a data interrogator and an implanted system.

Universal logic implementer: a general purpose tool for a digital logic design laboratory

The authors present a general purpose digital logic implementer, a tool designed to serve as a workstation for laboratory experiments in the digital logic and computer architecture courses taught in the Department of Electrical and Computer Engineering at Washington State University. The logic implementer is a versatile tool suitable for a wide spectrum of experiments, from simple gate-level implementation of logic circuits to the implementation of microprogrammed bit-slice processors. The basic features of the logic implementer include generality of applications, easy-to-use environment, and robust, reliable interconnections. >

In Vivo Brain Tissue Water Measurement

A two-wire probe is investigated as a possible sensor for brain edema monitoring. A dual monopole antenna model for a two-wire dielectric probe is presented. Model results for water and saline are found to agree closely with measured data. A model of brain tissue permittivity and loss as a function of tissue water fraction is developed and used in the probe model to predict probe operation.

An architecture for parallel interpretation: performance measurements

An innovative architecture for parallel interpretation of high-level machine languages has been described by Manwaring et al. (1994). Performance measurements of the architecture, obtained by running representative benchmark programs on a cycle level simulator, are presented. The results show that a speed up of about two is achieved compared to the traditional sequential machine language interpretation on a single processor.<<ETX>>

A design methodology for an analog module generator that includes operational sensitivities

The stringent requirement of precision in the design of analog integrated circuits (for correct functionality and reasonable performance) warrants the use of parametrized module generators. A methodology for the design of a module generator which outputs the mask-level topological description of the layout of the specified analog circuit and a circuit-level simulation model that includes the operational sensitivities of the circuit is developed. The effectiveness of this methodology is demonstrated by an example of a generator for an operational transconductance amplifier.<<ETX>>

In vivo brain tissue water measurement

A two-wire probe is investigated as a possible sensor for brain edema monitoring. A dual monopole antenna model for a two-wire dielectric probe is presented. Model results for water and saline are found to agree closely with measured data. A model of brain tissue permittivity and loss as a function of tissue water fraction is developed and used in the probe model to predict probe operation.

Detection and identification communication protocols for wireless biodevice networks

This paper presents the definition and analysis of three detection and identification protocols for a future wireless biodevice network (WBDN). These protocols represent the first part of a complete communication protocol for a WBDN. The number of detected and identified biodevices depends only on the time the user accepts to assign for the detection and identification phase of a communication session.

Evaluating the performance of dynamic branch prediction schemes with BPSim

BPSim (Branch Prediction Simulator) is a trace-driven simulator for predicting branch outcomes in high performance processors. It incorporates various dynamic prediction schemes widely reported in the literature and practiced in existing processors such as the MIPS R10000, Pentium Pro and Alpha 21164 [1, 10, 13]. Users can benefit from the completeness and flexibility of this simulator in gaining an understanding of the trade-off between prediction accuracy and hardware cost especially in an education environment.