Biomedical Engineering Program

Tufts University

Department of Biomedical Engineering


 

2005

 

Table of contents

1.      Biomedical Engineering at Tufts University

2.      Minor in Biomedical Engineering

3.      Curriculum for a Minor in Biomedical Engineering

4.      Second Major in Biomedical Engineering

5.      Curriculum for a Second Major in Biomedical Engineering

6.      Master of Science and Doctor of Philosophy Degrees

7.      Engineering-Medical Degrees (EMD) Program

8.      Engineering-Dental Medicine Degrees (EDD) Program

9.      Biomedical Engineering Courses

10.  Related Courses

11.  Tufts Biomedical Engineering Student Club

12.  Research Projects in Vision and Ophthalmology

13.  Research Projects in Other Fields

 

1. Biomedical Engineering at Tufts University

Biomedical Engineering is an interdisciplinary domain which links many disciplines such as engineering, medicine, biology, physics, psychology, etc. This quickly growing field must meet the needs of industrial, clinical, and scientific research communities. It involves the application of state-of-the-art technology to the creation of methodologies and devices for human welfare and for better understanding of human biological processes. At Tufts we put the emphasis on the design and application of biomedical devices, an area where the Bay State has strong infrastructure.

The Biomedical Engineering Program at Tufts University is administered by the Biomedical Engineering Department. There are various options for studying Biomedical Engineering. At the undergraduate level we offer a Minor in Biomedical Engineering and a Second Major in Biomedical Engineering. Both options are opened to Liberal Arts as well as Engineering students. At the graduate level we offer the Master's and Ph.D. degrees.

Our mission is to provide students an excellent interdisciplinary research and educational atmosphere with an opportunity to develop strong academic and industrial links and an understanding of the indispensable relationship between people, technology, and the environment. For more information please contact:


Professor Vo Van Toi
Tufts University
Biomedical
Engineering Department

Science and Technology Center
Medford, MA 02155
Tel: (617) 627-5191
Fax: (617) 627-3220
E-mail: vovantoi@eecs.tufts.edu
WWW: http://www.tufts.edu/~vvo


 

2. Minor in Biomedical Engineering

Graduates of the Biomedical Engineering program may typically work in industry as designers, in hospitals as engineers, or go on to graduate or medical school. The greatest problem with many Biomedical Engineering undergraduate programs is that the student learns some medicine and some engineering, but not a sufficient amount of either to compete effectively with graduates of programs devoted to one or the other. Our Biomedical Engineering Minor addresses this problem by requiring all the courses for the Engineering major while specifying courses in engineering and the natural sciences that are normally electives. The Minor is open to students in all the engineering and liberal arts disciplines, and is an excellent fit for pre-medical students. For more information, please contact the BME Department, (617) 627-2580.

 

3. Curriculum for a Minor in Biomedical Engineering

At the present time the following courses are required:

 

  1. EN 64: Biomedical Engineering Primer (1/2 credit course)
  2. Another EN course (except EN 1 and EN 2)
  3. One course selected from:
    • ES 50 - Biomedical Engineering I
    • ES 75 - Biomedical Engineering II
  4. Two courses selected from:
    • Bio 1 - Biology for Engineering
    • Bio 13 - Cells and Organisms
    • Bio 14 - Organisms and Population
    • Chem 1 - Chemical Fundamentals
    • Phy 11 - General Physics
  5. One course selected from:
    • EE 100 - Design of Medical Devices
    • ES 121 - Engineering Challenges in Physiology I
    • ES 122 - Engineering Challenges in Physiology II
    • ES 150 - Biomedical Engineering I
    • ES 175 - Biomedical Engineering II
    • ChE 164 - Biomaterials and Tissue Engineering
    • ENP 161 - Human Factors in Product Design
    • ME 121 - Introduction to Biomaterials
    • BIO 115 - General Physiology I
    • BIO 116 - General Physiology II
    • BIO 132 - Biostatistics
    • MATH 150 - Math. Models in Biology
    • PSY 103 - Brain and Behavior
    • PSY 129 - Cognitive Neuroscience
    • PHIL 124 - Bioethics

These courses must be taken for a letter grade. No more than two courses used to fulfill a foundation or concentration requirement may be counted toward fulfillment of the minor. The course details are described in the Bulletin of Tufts University, College of Arts, Sciences and Engineering.

Undergraduate Mirna Armaleh, Biology major, and Professor Vo Van Toi experiment with a prototype of an entoptoscope. This device, controlled by a personal computer, allows a non-invasive measurement of the retinal blood flow.

 

 

4. Second Major in Biomedical Engineering

The Second Major in Biomedical Engineering is offered to both liberal arts and engineering students. Students must enroll in conjunction with another undergraduate departmental major. Two tracks are offered: Biomedical Engineering Design and Biomedical Engineering Systems. Biomedical Engineering Design emphasizes the practical aspect and is for engineering students while Biomedical Engineering System emphasizes the multidisciplinary aspect and is for liberal arts students.

Students in each track are required to complete 10 courses. No more than 5 of these courses may be used to fulfill the Concentration requirement of the First Major. All required courses must be taken for a letter grade. Because this is a One-Degree-Two-Major program, students must have 4 years of residency at Tufts University, a minimum of 38 credits (for engineering students) or 34 credits (for liberal arts students), and may have additional majors but may not have a minor.

For more information, please contact the BME Department, (617) 627-2580.

 

5. Curriculum for a Second Major in Biomedical Engineering


Biomedical Engineering Design track
(for engineering students):


One Core course:

EE/ES 50 - Introduction to Biomedical Engineering

One course from:

CEE 154 - Principles of Epidemiology
ChE 164 - Biomaterials and Tissue Engin.
COMP 171 - Human Computer Interaction
EE 100 - Design of Medical Instrumentation
ENP 161 - Human Factors in Product Design
ME 121 - Introduction to Biomaterials

Two courses from:

BIO 1/ES 11 - Introduction to Biology
BIO 13 - Cells and Organisms
BIO 14 - Organisms and Populations
Chem 1 - Chemical Fundamentals
Chem 2 - Chemical Principles

Six Electives from the elective list below


Biomedical Engineering Systems track
(for liberal arts students):


One Core course:

EE/ES 50 - Introduction to Biomedical Engineering

Three courses from:

BIO 115 - General Physiology I
BIO 116 - General Physiology II
BIO 132 - Biostatistics
CHP 101 - Intro. to Community Health
COMP 171 - Human Computer Interaction
EE/BIO 131 - Principles of Medical Imaging
MATH 150 - Math. Models in Biology
PHY 25 - Intro. to Medical and Bio. Physics
PSY 31 - Statistics for Behavioral Sciences
PSY 103 - Brain and Behavior
PSY 129 - Cognitive Neuroscience
PHIL 124 - Bioethics

Six Electives from the elective list below


List of Elective courses (for both tracks):

BIO 1/ES 11 - Introduction to Biology
BIO 13 - Cells and Organisms
BIO 14 - Organisms and Populations
BIO 41 - General Genetics
BIO 46 - Cell Biology
BIO 115 - General Physiology I
BIO 116 - General Physiology II
BIO 132 - Biostatistics
BIO 134 - Neurobiology
BIO 187 - Human Central Nervous System
CEE 54 - Fundamentals of Epidemiology
CEE 70 - Intro. to Hazard. Mater. Manag.
CEE 137 - Public Health
CEE 154 - Principles of Epidemiology
CEE 164 - Epidemiologic Methods
ChE 164 - Biomaterials and Tissue Engin.
Chem 1 - Chemical Fundamentals
Chem 2 - Chemical Principles
Chem 156 - Biochemistry
Chem 157 - Medicinal Chemistry
CHP 101 - Intro. to Community Health
COMP 10 - Computer Science Primer
COMP 15 - Data Structures
COMP 131 - Artificial Intelligence
COMP 171 - Human Computer Interaction
COMP 175 - Computer graphics
EE 11 - Introduction to Analog Electronics
EE 14 - Microprocessors
EE 100 - Design of Medical Instrumentation
EE 101 - Intro. to Medical Optics and Lasers


 



EE/ES 121 - Engin. Challenges in Physiol. I
EE/ES 122 - Engin. Challenges in Physiol. II
EE 131 - Principle of Medical Imaging
EE 133 - Digital Image Processing
EE 156 - Medical Optics Laboratory
ENP 61 - Intro. Human Fact. & Ergonomics
ENP 161 - Human Factors in Product Design
ENP 162 - Man-Machine System Design
ES 3 - Introduction to Electrical Engineering
ES 4 - Introduction to Digital Logic Circuits
ES 10 - Structure and Strength of Materials
MATH 126 - Numerical Analysis
MATH 150 - Math. Models in Biology
ME 41 - Machine Design I
ME 42 - Machine Design II
ME 121 - Introduction to Biomaterials
OTS 105 - Assistive Technology
PHIL 24 - Introduction to Ethics
PHIL 121 - Ethical Theory
PHIL 124 - Bioethics
PHIL 131 - Epistemology
PHY 18 - Ionizing Radia. in Bio. & Medicine
PHY 25 - Intro. to Medical and Bio. Physics
PHY 32 - Intermediate Mechanics
PHY 41 - Electronics
PSY 31 - Statistics for Behavioral Sciences
PSY 32 - Experimental Psychology
PSY 40 - Lab. in Physiological Psychology
PSY 103 - Brain and Behavior
PSY 129 - Cognitive Neuroscience


Notes:

         No more than 3 courses in any single discipline can be counted.

 

         The Engineering Senior Design Project of the first engineering major must have an emphasis on Biomedical Engineering.

 

         Liberal Arts students are encouraged to undertake an independent study, as an Elective, related to Biomedical Engineering at their senior year.

 

         Research, design projects, and courses not listed here may be counted toward electives by consent of the Program Director.

 

6. Master of Science and Doctor of Philosophy Degrees

The intention of the Master's and Ph.D. programs is to prepare proficient engineers with the tools they need to have a thorough understanding of medical issues. Graduates will be able to address technology and health care issues from scientific perspectives. We believe that these programs are critical to adequately educate students in the fundamental principles of engineering, physiology and clinical issues, as well as provide multiple opportunities for experiential learning with industry. Students will participate in the synergies between the Engineering, Liberal Arts, and Medical, Dental and Veterinary schools.

For more information, please contact the BME Department, (617) 627-2580. For admission information, please contact the Tufts Graduate School Admission Office, (617) 627-3395.

 

7. Engineering-Medical Degrees (EMD) Program

This is a joint program between the Tufts School of Engineering and Tufts School of Medicine. Currently we stop accepting new students into the program.

8. Engineering-Dental Medine Degrees (EDD)Program

This is a joint program between the Tufts College of Engineering and Tufts School of Dental Medicine. Currently we stop accepting new students into the program.  

9. Biomedical Engineering Courses

* EN 16-BME - Applications of Engineering Design and Methodology in the Life Sciences

This is a hands-on course involving the Department of Biomedical and the Department of Biology and is open to students in Engineering as well as in Liberal Arts. It is project oriented, allowing students to be aware of, and participate in research activities already in progress. Each course topic is carefully selected from among the research projects currently underway in these departments. The topics include: life sciences, engineering design and a hands-on project. Engineering solutions to life science problems will involve the following fields: electronics, electromechanics, mechanics, computer science, and optics. Written personal-activities reports will be required of each student. Half credit, no prerequisites, can be used to fulfill Mathematical Science requirements for Liberal Arts students, offered in Spring semester. For more information: BME department.

Students in the EN 16 course experiment with a tracking device to help study the migration of salamanders. This course has been designed and taught by Professor Vo Van Toi of the BME Department and Professors Frances Chew and George Ellmore, both of the Biology Department.

*EN 29-BME - Biomedical Engineering Primer

This course is intended to accomplish two goals: to give students a broad but accurate understanding of different aspects of the biomedical engineering field and to help students develop and focus their interest in a more specific orientation in this field. This course consists of three parts: an in-class lecture, field trips and a project. The in-class lectures are conducted by the instructor and guest speakers. In general, the guest speakers are selected from engineers and Tufts alumni who are currently working in local Biomedical Engineering industries, or are otherwise experts in the field. The field trips are to local medical device manufacturing companies. The project requires an independent study; typically, students have to identify and investigate a novel biomedical engineering technology, or a commercially available medical product. This course is open to engineering and liberal arts students. Half credit, no prerequisites, can be used to fulfill Mathematical Science requirements for Liberal Arts students, offered in Fall semester. For more information: BME department.

 

 

Professor George Ellmore of the Biology Department advises engineering students on the applications of engineering technology in biological problem.

*EN 34-ME - Biomechanical Systems and Materials

This is a survey course of biomedical engineering highlighting how engineering mechanics is applied to understand and solve clinical problems of the human body. This course is designed to interest entry level students in biomechanical engineering. This course is organized so that each part of the body will be discussed with examples of research and current designs. For example, the heart will be discussed by briefly presenting a clinical problem, and then artificial hearts, valves, and other devices will be demonstrated. Other topics will include the skeleton, and articulating joints, soft tissue, sensory organs, kidney, lung and gastrointestinal and urologic organs. Rehabilitation engineering will also be a specific topic. There will be guest speakers from engineering and medical schools in the Boston area. There will be two labs where mechanical testing will be demonstrated. Half credit, no prerequisites, offered in Spring semester. For more information: ME department.

 

Professor Frances Chew, Biology Department instructs engineering students on a biological problem which requires engineering technology support.

 

*BME/EE/ES 50 - Introduction to Biomedical Engineering

The goals of the course are to offer a more focused view of biomedical engineering. It consists of two main parts: fundamental engineering technologies and methodologies, and clinical applications. In the first part students learn different engineering techniques and methods including mathematical modeling and simulation of dynamic systems, design methodology, geometrical optics, kinematics, and statistics. In the second part students learn how these techniques or methods are applied to medical problems. Study is focused on specific organs such as the eyes, ears, or lungs. In each case three aspects are covered: physiological, clinical, and instrumentation. In addition, a semester long project is assigned, which requires students to conceive, design and build a working device related to Biomedical Engineering. One credit. Sophomore standing,. Required for all Biomedical Engineering degrees. Can be used to fulfill Mathematical Science requirements for Liberal Arts students. Offered in Spring semester. For more information: BME department.

 

The early prototype of a visual stimulator "Papillometer" assembled from an Erector toy set. This device is used to study the sensitivity of the eyes to the flickering light. This sensitivity may be affected by diseases such as ocular hypertension, glaucoma, macular degeneration, diabetes or by drugs or medications such as LS and digitalis.

 

*BME/EE 100 - Design of Medical Instrumentation

The goal of the course is to encourage students to use the technical knowledge acquired in other classes to develop simple analog and digital circuits for medical devices. The course has three components: class lectures, laboratories, and a project. The lectures emphasize the design principles of medical instrumentation and biomedical signal analysis. Topics include the origin of bioelectric potentials; the characteristics of various biological signals, transducers, instrumentation amplifiers, analogue and digital devices; and computer interfaces. Labs include the design, construction and testing of electrical circuits and computer interfaces to measure diverse biological signals. The project consists of designing a medical instrument which may be used for advanced medical research. One credit. Senior standing, prerequisite: EE 11, recommended: EE 14. Required for Biomedical Engineering Minor. Offered in Fall semester. For more information: BME department.

 

*EE/ES 121 - Engineering Challenges in Physiology I and

EE/ES 122 - Engineering Challenges in Physiology II

Courses designed for students interested in advanced work in Biomedical Engineering. The first course contains modules that cover the central nervous system, muscles/bone, lungs and heart. The second course covers the endocrine and sensory systems and the digestive system including dentistry. The courses emphasize vital biological signals, their measurement, and the required instrumentation with examples drawn from current joint research efforts between the engineering faculty and the professional schools. Courses are team taught. Each course involves a semester long project. Prerequisites: Bio13 or equivalent, Engineering senior standing or consent. One credit each, offered alternately in Spring semester. For more information: BME department.

*OTS 294D/ES 96 Assistive Technology

This course is a survey of selected topics in assistive technology designed for engineering students, occupational therapy students, engineers, occupational therapists, special educators, speech and language pathologists and other health care professionals. You will have an opportunity to work with an interdisciplinary team, have hands-on exposure to a variety of technologies, and gain an appreciation of assistive technology available to people with disabilities. Also, you will have on-site laboratory experience with clientele, complete case studies, obtain feedback from experts in the field, and discuss funding and legislative issues. One credit, offered in Spring Semester. For more information: Occupational Therapy department.

 

 

Professor Vo Van Toi tests a mechanical wheelchair propeller designed by his undergraduate students as part of a class project.

  

*EE 101- Introduction to Medical Optics

Laser and optical instrumentation techniques in medicine. Medical areas include ophthalmology, dermatology, oncology, otolaryngology, gastroenterology. The course will contain lectures and demonstrations at various clinical and research facilities in the Boston area. One credit. Junior standing. For more information: BME Department.

 

*EE 156 - Medical Optics Laboratory

Radiation delivery systems, non-invasive and minimally invasive diagnostic techniques, ablation and ablation diagnostics, dosimeter, photobiology, medical imaging and image processing. The student will measure the properties of scattering media, such as tissue, evaluate ablative and thermal tissue removal and denaturalization, measure photoacoustic processes, and use spectroscopic diagnostics. In the laboratory the students will employ a variety of lasers, spectroscopic instruments, imaging devices, and computer based systems for experimental control and data acquisition. One and half credit. For more information: BME Department.

 

*ME 121 - Introduction to Biomaterials

This course presents the following topics: elementary solid mechanics; aspect of materials science applied to metals, polymers, ceramics, and biological tissues; tissue reactions to artificial materials; pathohistology; and inflammatory and immune responses. This course is completed by a survey of artificial materials and devices in clinical use, emphasizing vascular and orthopedic prostheses. A literature review and oral presentation covering a current device is assigned. One credit, offered in Fall semester. For more information: ME department.

 

*ChE 164 - Biomaterials and Tissue Engineering

Synthesis, characterization and functional properties of organic and inorganic biomaterials and the process of tissue engineering are covered. Fundamental issues related to the utility of biomaterials will be explored based on their biocompatibility, stability, interfaces and fate in the body. Clinical applications for biomaterials will be explored as will new directions in design and synthesis to achieve better biocompatibility. Tissue engineering and biomedical implants will be emphasized as key uses for biomaterials. Testing methods, regulatory issues, legal constraints, and emerging research directions will also be discussed. Students will prepare a project report on a key aspect of the field of biomaterials and tissue engineering. One credit. For more information: contact Chemical Engineering department.

 

 

 

Strabismus detector: this device examines cross-eye problem in children. It is based on the after-image effect.

10. Related Courses

The following is a sample of courses whose contents are related to the Biomedical Engineering field. For more information, please contact the listed departments. Description of these courses can be found in the Bulletin of Tufts University, College of Arts, Sciences and Engineering.

Biology Department

  • BIO 115/6 General Physiology I/II
  • BIO 132 Biostatistics

Chemistry Department

  • CHEM 135 Biophysical Chemistry
  • CHEM 155 Organic Spectroscopy

Civil Engineering and Environmental Department

  • CEE 137 Public Health
  • CEE 158 Occupational Environmental Health

Electrical and Computer Engineering Department

  • EE 133 Digital Image Processing

Computer Science Department

  • Comp 150bio Computational Biology
  • Comp0150cb Data Warehousing/Data Mining
  • Comp 171 Human-Computer Interaction

Engineering Psychology Program

  • ENP 162 Man-Machine System Design

Mathematics Department

  • MATH 150 Mathematical Models in Biology

Mechanical Engineering Department

  • ME 121 Introduction to Biomaterials

Philosophy Department

  • PHIL 124 Bioethics

Psychology Department

  • PSY 129 Cognitive neuropsychology
  • PSY 140 Mathematical psychology

11. Tufts Biomedical Engineering Student Club

The Tufts University Biomedical Engineering Club (TUBEC) is a student organization that helps its members pursue their interests in the biomedical field. TUBEC provides its members with both academic and social opportunities. Club members have access to many biomedical related events, national design competitions, career information and corporate contacts. For more information: contact BME department.

 

A toy designed and built by undergraduate students as part of the ES 50 class project. It allows two handicapped children to play in collaboration. In observing these children playing researchers can assess the children's cognitive behavior. This toy won the Design Contest sponsored by the Tufts University Biomedical Engineering Club.

Click here to surf the homepage of the Tufts University Biomedical Engineering Club.

 

12. Research Projects in Vision and Ophthalmology

Click here for the List of Patents and Publications

Click here for the Portfolio of the medical devices

 

Our research covers three main fields: instrumentation design, experimental study, and theoretical investigation. The following is a brief description of some current projects.

Automatic eyedroplet dispenser

Patients having dry eyes experience much pain and may eventually go blind. It is estimated that between 9 to 15 million Americans suffer from this disease. Currently, therapy is tedious and costly. We have developed a new instrument, mounted on a patient's eyeglass frame, which automatically ejects droplets at an adjustable pace into the patient's eyes. The functions of the device are monitored by a built-in microcontroller which is battery powered. The efficiency of this device and the study of new therapeutic methods are in progress.

 

Automatic eyedroplet dispenser designed by Professor Vo Van Toi and commercialized by the Technological Ophthalmic Instruments Inc.

Inside view of the Automatic eyedroplet dispenser. The microcomputer monitors the device functions in programmable, automatic or manual mode.

 

Noninvasive method to evaluate visual fatigue

Workers who use video display units (VDU) often experience visual fatigue. How to quantify visual fatigue is still a controversial topic. It is known that the technique of measuring the sensitivity of the eyes using sinusoidal waveform flickering light is a powerful tool for evaluating human visual function. Currently, we are designing a new and practical visual stimulator, to be made commercially available, using the delta modulation method and single chip microcomputer. Experiments are planned using this instrument to establish the visual functions of VDU users to test for visual fatigue.

 

Blink Rate Recorder

It was reported that blinking is associated with the state of the eye as well as the state of the mind. We have developed a portable device which automatically records the blink rate in a non-invasive way and without coming in contact with the subject eyes, obstructing the subject’s view, or interfering with the subject’s activities. The device is self-contained and battery powered and consists of an infrared sensor mounted on an eyeglass frame. Data are recorded for up to 24 hours and then down loaded into a personal computer, and processed for further analysis or plotting. This device is an important tool for our research on the relationship between blinking and visual fatigue, dry eye, and the mechanism of blinking.

 

 

 

This is a prototype of the Blink Rate Recorder. It records the blink rate in a non-invasive way and without coming in contact with the subject eyes, obstructing the subject’s view, or interfering with the subject’s activities.

 

A chart generated by our Blink Rate Recorder which indicates the blink rate fluctuation of a subject while he was not using the computer (from 0 to 60 minutes) and while he was using it (from 60 to 120 minutes). The average blink rate when using a computer was considerably reduced.

 

Relieving visual fatigue of visual-display-terminal operators

Studies have shown that VDT operators blink three times less frequently than non-VDT operators, therefore they may experience dry eyes which results in visual fatigue. We hypothesize that: (1) the reduction of visual fatigue will improve the VDT operators’ comfort, (2) visual fatigue conditions can be monitored and measured, and (3) visual fatigue is produced by eye dryness which may be relieved by administering eye drops or by increasing the blinking rate. The proposed techniques consist of stimulating, in a non-invasive way, the blinking rate of VDT users and of supplying additional tears to their eyes automatically. This work could have a significant impact on people who are engaged in various professions involving repetitive eye strain, for instance, air traffic controllers. It should benefit the search for an adequate working environment and provide methods for a better understanding of the visual fatigue mechanism.

 

 

Using a computer for long hours may cause visual fatigue. To test our new way to relieve this visual impairment, Biology student Xuan Mai Vo, wears our Blink Rate Recorder to monitor the blinking and used the Automatic Eyedrop Dispenser to constantly keep her eyes moist.

 

Psychophysical method for measuring retinal blood flow

Looking at a bright, homogeneous blue field one can perceive the white blood cells (leukocytes) moving in one's own retinal vessels. This is known as the blue-field entoptic phenomenon. Knowing the density and speed of these leukocytes, one can investigate, in vivo, the subject's retinal blood flow and therefore may be able to develop a diagnostic method for glaucoma, ocular hypertension and diabetes. We have successfully developed a method to measure these characteristics in a reliable way. We also have developed a portable and efficient entoptoscope using a single chip microcomputer and electro-optic materials such as LCD and PLZT. A laptop computer can be used to monitor this instrument and process the obtained experimental data. This device also allows measuring the size of the fovea avascular zone, the area on the retina which contains no blood vessels.

 

We have developed the blue-field entoptoscope which allows for in vivo and non-invasive measurements of the retinal blood flow in the human eye. It can also be used to measure the size of the fovea avascular zone. A laptop computer can be used to monitor this device and the experimental protocols and to process the obtained data. This device is used to investigate eye diseases such as glaucoma and diabetic retinopathy.

 

Laser Doppler technique for measuring eye fundus blood flow

A direct and objective method of measuring the retinal blood flow is based on the Doppler technique which consists of passing a laser beam into the subject's eye, targeting it on moving red blood cells inside a retinal blood vessel and recording the scattered light emitted from the eye. Measurements on animals have been successful. We are developing a device using an eye-tracker to compensate eye motions. This device will be useful for the study of human fundus blood flow.

 

Perception of raggedness of dot-matrix characters

The raggedness of characters or patterns formed by dot matrix printing techniques is unaesthetic and sometimes disturbing to the reader. Optimization of the number of dots is still a subject of discussion due to a fundamental lack of comprehension on the part of the designer concerning human visual perception of this kind of stimulus. Using the concept of Fourier analysis, we are simulating the scalloped edge of the characters as a patterned stimulus modulated sinusoidally in an attempt to relate this problem to the human eye's sinusoidal vernier acuity. This investigation is important to the designers of characters that are generated by ink jet, laser, and needle printers.

 

High rate pattern visual stimulator

The pattern visual stimulation technique is a common tool used by physiologists, biologists, psychologists and ophthalmologists in the investigation of the human visual system. A great number of investigations that are devoted to stimulation at a low rate have been reported. We designed an electro-mechanical visual stimulator to generate pattern stimuli which was modulated up to 220 reversals/sec. and found that human pattern reversal VEPs are not, as previously thought, limited to low frequencies. These results open the door to other physiological and clinical investigations.

 

Miniature eyedrop monitor

Success in the development of new drugs for the treatment of glaucoma, ocular hypertension and eye infections requires investigators to know how patients use them. We are developing a prototype which records the time and date when a patient inserts the prescribed eyedrops. The data can be later read by a computer.

Artificial increase of intraocular pressure

Glaucoma and ocular hypertension are the two most severe eye diseases. Glaucoma is the leading cause of blindness in the United States, and its cause is still speculative. Accurate and early diagnosis and the comprehension of the mechanisms of these diseases, are important. It has been reported that psychophysical flicker sensitivity, ERG, PERG and VEP responses, and retinal blood flow are affected by these diseases and by high intraocular pressure (IOP). In the study of the effect of the IOP that is increased artificially we discovered a phenomenon called "curtain phenomenon" which may be an important element in this study.

Effect of LSD on flicker-fusion sensitivities

LSD and similar agents may alter visual perceptions continuously and permanently in certain users resulting in a condition called hallucinogen persisting perceptual disorder (HPPD). We have found that the flicker sensitivities at lower frequencies vary markedly. At 5 Hz the sensitivities of a control group were more than 3 times those of LSD subjects without HPPD, and 5 times those of LSD subjects with HPPD. Decreased sensitivity to flicker is consistent with the hypothesis that HPPD is associated with disinhibition of visual information processing.

 

Professor Vo Van Toi helps monitor the use of his visual stimulator "Papillometer" as graduate student Barbara Dumery tests her visual flicker-fusion sensitivity.

 

Mathematical modeling of the human visual system responses to flicker stimulation

The main purpose of this project is to establish a mathematical model which relates experimental data that we obtained in psychophysics, electrophysiology, and laser fundus reflectometry to physiological facts. This model would describe the mechanism of the human color vision system.

 

13. Research Projects in Other Fields

 

Fracture behavior of viscoelastic biological membranes

A major obstacle in the development of implantable micro-biosensors or microelectrodes is designing a method to insert these devices through a membrane wrapped around a nerve without breaking the micro-electrode or destroying the nerve and at the same time positioning them in a predetermined place. We investigated the interaction between the viscoelastic membrane and the electrodes during the piercing procedure through experiments, mathematical modeling, and computer simulation. This study is a cornerstone in the development and design of chronically implantable biosensors, neural prostheses or surgical instruments, and it may help investigators to understand the factors involved in the fracturing of the human fetal membrane and the fetal skull.

 

Cognitive skill development of handicapped infants.

Children with motor impairments have varying motor skills. Although some children with motor impairments also have concomitant brain damage (and consequent mental retardation), others have normal or even above normal levels of intelligence. Standard evaluation instruments rely heavily on motor skills. The cognitive skills of children with motor impairment are seldom fully recognized. We designed and built an appropriate tool to study the behavior of young handicapped children. This tool is built in such a way that a child can use it in spite of his/her motor impairment. While a child is playing with it, researchers are able to study his/her proficiencies.

 

A toy designed and built by undergraduate students as part of a class project which was used by researchers at the University of Massachusetts to study the cognitive development of handicapped toddlers.