Dynamic Characteristics of a New Three-Dimensional Linear Homeomorphic Saccade Model.

A linear homeomorphic eye movement model that produces 3D saccadic eye movements consistent with anatomical and physiological evidence is introduced in this second part of a two-paper sequence. Central to the model is the implementation of a time-optimal neural control strategy involving six linear muscle models that faithfully represent the dynamic characteristics of 3D saccades. The muscle is modeled as a parallel combination of viscosity [Formula: see text] and series elasticity [Formula: see text], connected to the parallel combination of active-state tension generator [Formula: see text], viscosity element [Formula: see text], and length tension elastic element [Formula: see text].

Static Characteristics of a New Three-Dimensional Linear Homeomorphic Saccade Model.

A linear homeomorphic saccade model that produces 3D saccadic eye movements consistent with physiological and anatomical evidence is introduced. Central to the model is the implementation of a time-optimal controller with six linear muscles and pulleys that represent the saccade oculomotor plant. Each muscle is modeled as a parallel combination of viscosity [Formula: see text] and series elasticity [Formula: see text] connected to the parallel combination of active-state tension generator [Formula: see text], viscosity element [Formula: see text], and length tension elastic element [Formula: see text].

A neuron-based time-optimal controller of horizontal saccadic eye movements.

A neural network model of biophysical neurons in the midbrain for controlling oculomotor muscles during horizontal human saccades is presented. Neural circuitry that includes omnipause neuron, premotor excitatory and inhibitory burst neurons, long lead burst neuron, tonic neuron, interneuron, abducens nucleus and oculomotor nucleus is developed to investigate saccade dynamics. The final motoneuronal signals drive a time-optimal controller that stimulates a linear homeomorphic model of the oculomotor plant.

A physiological neural controller of a muscle fiber oculomotor plant in horizontal monkey saccades.

A neural network model of biophysical neurons in the midbrain is presented to drive a muscle fiber oculomotor plant during horizontal monkey saccades. Neural circuitry, including omnipause neuron, premotor excitatory and inhibitory burst neurons, long lead burst neuron, tonic neuron, interneuron, abducens nucleus, and oculomotor nucleus, is developed to examine saccade dynamics. The time-optimal control strategy by realization of agonist and antagonist controller models is investigated.

A new linear muscle fiber model for neural control of saccades.

A comprehensive model for the control of horizontal saccades is presented using a new muscle fiber model for the lateral and medial rectus muscles. The importance of this model is that each muscle fiber has a separate neural input. This model is robust and accounts for the neural activity for both large and small saccades.

A portable, inexpensive, wireless vital signs monitoring system.

The University of Connecticut, Department of Biomedical Engineering has developed a device to be used by patients to collect physiological data outside of a medical facility. This device facilitates modes of data collection that would be expensive, inconvenient, or impossible to obtain by traditional means within the medical facility. Data can be collected on specific days, at specific times, during specific activities, or while traveling.

Linear homeomorphic models for muscles in the head-neck region.

The linear homeomorphic muscle model proposed by Enderle and coworkers for the rectus eye muscle is fitted to reflect the dynamics of muscles in the head-neck complex, specifically in muscles involved in gaze shifts. This parameterization of the model for different muscles in the neck region will serve to drive a 3D dynamic computer model for the movement of the head-neck complex, including bony structures and soft tissues, and aimed to study the neural control of the complex during fast eye and head movements such as saccades and gaze shifts. Parameter values for the different muscles in the neck region were obtained by optimization using simulated annealing.

An updated time-optimal 3rd-order linear saccadic eye plant model.

A linear third-order model of the ocular motor plant for horizontal saccadic eye movements is presented consisting of a linear ocular motor plant and a time-optimal saccadic controller based on physiological considerations. The ocular motor plant consists of the eyeball and two extraocular muscles. All parameters and initial conditions are estimated or measured from physiological data.

3D dynamic computer model of the head-neck complex.

A 3D dynamic computer model for the movement of the head is presented that incorporates anatomically correct information about the diverse elements forming the system. The skeleton is considered as a set of interconnected rigid 3D bodies following the Newton-Euler laws of movement. The muscles are modeled using Enderle's linear model.

Design of computerized maintenance management system for the chilean naval hospital biomedical engineering department.

The purpose of this project was to design and implement a computerized maintenance management system (CMMS) to be used at the Chilean Naval Hospital Biomedical Engineering Department. It is designed to meet the specific needs of this military facility and follows the generic clinical engineering maintenance management system suggested by Association for the Advancement of Medical Instrumentation (AAMI).

Porting GENESIS to SIMULINK.

This paper describes the porting of the general simulation system (GENESIS) to Matrix Language Laboratory language (MatLab) SIMULINK, based in the cable theory to simulate the behavior of neurons. A graphic programming approach serves as ideal platform for teaching physiological modeling and neuroengineering courses. The ultimate goal of this project is to integrate all of the chemical, electrical, material, mechanical and neural interactions into a single model that can be viewed seamlessly from a molecular model to the large scale model.

The DaVinci Group: a second modern Ophthalmotrope.

A group of undergraduate students at the University of Connecticut Biomedical Engineering Program has formed a "club" in order to more fully understand and educate themselves in modeling anatomical processes. This group is called the DaVinci Robot or DaVinci Group. Experiments to mechanically model the six extraocular muscles of the eye have been performed, each meeting little success.

Infra-red radiant intensity exposure safety study for the Eye Tracker.

With any device that is used to record or evaluate biosignals, it is in the inventor's interest to determine how that device withstands a rigorous examination in regards to its inherent safety during use. For this, a Risk Management (Hazard) Analysis is a useful exercise. With this in mind, the most probable hazard concerning the Eye Tracker System (a device used to measure saccadic eye movements utilizing Reflective Differencing of Infra-Red light) is the exposure effect to the human eye caused by the Radiant Intensity of the IR emitters mounted on the Head Mounted Transducer.

Firing rate relationship in the saccade system neural pathway.

This paper describes the relationship among the structures of the brain involved in the control of the saccadic system. The eye position information is pre-processed by the cerebral cortex and then projected to the cerebellum where this signal is propagated to several structures that are in charge of the control and correction of the eye movement signal. Once this processing is completed, the output is propagated to the final neural stage (the motor neurons), and then to the Rectus and Oblique group of muscles of the eye.

The University of Connecticut Biomedical Engineering Mentoring Program for high school students.

For the past four years, the Biomedical Engineering Program at the University of Connecticut has offered a summer mentoring program for high school students interested in biomedical engineering. To offer this program, we have partnered with the UConn Mentor Connection Program, the School of Engineering 2000 Program and the College of Liberal Arts and Sciences Summer Laboratory Apprentice Program. We typically have approximately 20-25 high school students learning about biomedical engineering each summer.

Eye movement detector calibration device.

Presented is a device developed for specifically calibrating and validating the operation of Eye Movement Detectors or Monitors. The Calibrator centers on two one inch diameter HPDE spheres representing the eyes. A Laser Module is embedded in the rear of each sphere emitting a beam against a target divided in equal measurement intervals mounted as part of the device.