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IV.A.2.f RUTGERS COMPUTERS IN BIOMEDICINE

Rutgers Research Resource
Computers in Biomedicine

Dr. Saul Amarel
Rutgers University
New Brunswick, New Jersey

(Grant NIH RR-00643-05, 3 years, $314,880 this year)

I. PROJECT GOALS AND APPROACHES

The fundamental objective of the Rutgers Resource is to develop a
computer based framework for significant research in the biomedical
sciences and for the application of research results to the solution of
important problems in health care. The focal concept is to introduce
advanced methods of computer science - particularly in artificial
intelligence - into specific areas of biomedical inquiry. The computer is
used as an integral part of the inquiry process, both for the development
and organization of knowledge in a domain and for its utilization in
problem solving and in processes of experimentation and theory formation.

The Resource community includes 46 researchers - 26 members, 8
associates and 12 collaborators. Members are mainly located at Rutgers.
Collaborators are located in several distant sites and they interact - via
SUMEX-AIM - with Resource members on a variety of projects, ranging from
system design/improvement to clinical data gathering and system testing.
At present, collaborators are located at the Mt. Sinai School of
Medicine, N.Y¥.; Washington University School of Medicine, St. Louis, Mo.;
Johns Hopkins Medical Center, Baltimore, Md.; Illinois Eye and Ear
Infirmary, Chicago, Ill.; College of Medicine and Dentistry of New Jersey
(CMDNJ); and the University of Miami.

Research in the Rutgers Resource is oriented to "discipline-~
oriented" projects in medicine and psychology, and to "core" projects in
computer science, that are closely coupled with the "discipline-oriented"
Studies. Work in the Resource is organized in three AREAS OF STUDY; in
each area ther are several projects. The areas of Study and the senior
investigators in each of them are:

(1) Medical Modeling and Decision Making (C. Kulikowski, A. Safir).
(2) Modeling Belief Systems (C. F. Schmidt, N. S. Sridharan).

(3) Representations, Modeling and Hypothesis Formation in AI (S.
Amarel).

In addition the Rutgers Resource is sponsoring an Annual National
AIM Workshop, whose main objective is to strengthen interactions between
AIM activities, to disseminate research methodologies and results, and to
stimulate collaborations and imaginative resource sharing within the
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framework of AIM. The first AIM Workshop was held at Rutgers on June 14
to 17, 1975. The Second Workshop is scheduled for June 1 to 4, 1976.

II, AREAS OF STUDY; SUMMARY OF GOALS AND ACTIVITIES

(1) Medical Modeling and Decision-Making

Present projects include:

(i)

(ii)

(iii)

(iv)

(v)

The

Development and clinical testing of the glaucoma consultation
program based on a causal-associational network (CASNET) model -
as a collaborative project of the ophthalmological network,
which has grown in the last year to include: Mt. Sinai School
of Medicine, Washington University, Johns Hopkins University,
University of Illinois at Chicago, and the University of Miami.

Investigation of descriptive models of diseases based on a
general semantic network representation, with associated
strategies of diagnosis, prognosis, and therapy. These models
subsume a variety of sub-models useful in general consultation.
A particular emphasis is placed on the analysis of the time
course of disease, and inter-relationships between various
disease sub-processes.

Development of a data base for clinical research associated with
the consultation programs. The results of the data analyses to

be used selectively in updating and improving the models of
diseases,

Investigation of various techniques for acquiring knowledge from
clinical experts. Incorporation of alternative expert opinions
within a model.

In collaboration with the Mt. Sinai Rutgers Health Care
Computer Laboratory, we are developing models for refraction and
neuro-ophthalmology.

following is a summary of accomplishments in this area.

(a) The ophthalmological network(ONET) is actively underway, with
consultation programs available through SUMEX-AIM to the five
collaborating institutions.

(b) The consultation system has been perfected by adding many details
of diagnosis, prognosis, and therapy; new observations and
decision criteria have been specified as the result of suggestions
by the ONET collaborators.

(ec) A data base for storing cases and providing a chronological model
based interpretation has been created.
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(d) A set of programs to analyze the case histories has been
developed. They are currently being used in collaborative
clinical studies by ONET members. Selected results are to be
incorporated into the glaucoma model.

(e) A semantic network based model for glaucoma has been implemented
with expanded capabilities for explanation and a greater facility
for being updated.

The progress in extending the collaborative activities of the
ophthalmological network has been made possible by the facilities and
Support provided by SUMEX-AIM. The semantic network model is being
developed on INTERLISP at SUMEX-AIM, Other program development activities
are evenly distributed between SUMEX-AIM and the Rutgers-10.

(2) Modeling Belief Systems

The overall goal of this project is to develop a computer based
psychological model of how persons reason about the causes of human
action. The common-sense notion of social causation which is used to
understand intentional actions has served as the focus of this effort The
construction of a system (called BELIEVER) to assist in the description of
the psychological theory and to facilitate the testing of the theory is a
principal goal of this project and to date we have accomplished the
following:

(a) A working system has been developed that accepts the descriptions
of Templates, Relations and their consistency conditions which are
concepts developed in the Meta Description System (MDS) framework.

(b) We have described PLANS, ACTS, PERSONS and SUMMARIES as templates;
we have defined the consistency conditions associated with the
relations among these.

(ec) Developed procedures in FUZZY for Instantiating Act Descriptions
and calculating presuppositions needed to form coherent
interpretations.

(d) We have provided for an easy-to-understand prompting scheme based
on the concept of templates and consistency conditions. The
prompting proceeds using the template descriptions and attempts to
fill in missing information by implication following based on the
consistency conditions,

(e) Developed a framework for submitting and analyzing the semantics

of experimental evidence when the subject responses are ;solely
unstructured natural language text.

Our goals for the immediate future are:

(a) To continue to gather experimental data and follow the analysis to
Suggest hypothesis in the Believer Theory.
129

(b) Develop strategy Plan Recognition based on a Theory of Motivation
and Consistency postulates of a Persons beliefs and knowledge.

(c) Continue to investigate the innovative uses of our descriptive
methodology in empirical procedures.

The development of MDS - which provides a framework for designing
the BELIEVER system - was carried out at SUMEX-AIM until October 1975;
subsequently, most of the work on MDS was shifted to ISID. While early
versions of BELIEVER were developed at SUMEX-AIM, the last year saw a
shift in computing on this project from SUMEX-AIM to the Rutgers-10 -
since program development is being done on the FUZZY system which runs on
the Rutgers computer.

(3) Representations, Modeling and Hypothesis Formation in Artificial
Intelligence

A major part of our effort in this area is oriented to
collaborations with investigators in other Resource projects - involving
applications of AI ideas and programs and also identification and initial
exploration of new significant AI problems. The collaboration in the
BELIEVER area has lead to a close integration of the basic AI oriented
work (N. S. Sridharan) and the discipline oriented work (C. Schmidt) in
the area. This work is reported under 2 above.

"Core" projects in the present area include:

(i) Development and applications of FUZZY (R. LeFaivre). The FUZZY
system was transferred from UNIVAC 1110 LISP to UCI LISP on the
Rutgers-10. A number of improvements were made, both to the UCI
LISP system and to the FUZZY language to make it both more efficient
and more powerful. These changes include a new prettyprint package
for UCI LISP and functions for computing differences of associative
nets and creating multiple contexts in FUZZY. FUZZY is currently
being used in the initial implementation phase of the BELIEVER
system. Applications to reasoning in medical diagnosis are being
explored.

(ii) Applications of grammatical inference schemes to automatic
adjustment of medical models on the basis of clinical data (A.
Walker),

(a) An algorithm was found to eliminate loops from stochastic
causal models.

(b) A grammar model for the flow of control in programs was
formulated.

(c) A technique for progressively bounding a search space of
stochastic grammars, in terms of grammars already found, was
studied theoretically and tested in practice.

(d) The impact of this work on the automated construction of
production-rule based AI systems is now under study.
130

Computing in this project is done on the Rutgers-10.

(iii) Development of a grammatical inference system using a "developmental
paradigm" (W. Fabens). This is a hypothesis formation system which
attempts to change a given context free grammar so as to accommodate
new sentences that cannot be derived from the given grammar. The
system includes (a) a relaxation parser - which comes as close as it
can to an interpretation of a given "deviant sentence", (b) a rule
hypothesizer which uses such an interpretation to propose changes to
the current grammar, (c) a rule coalescer which summarizes with as
little loss or gain in generality as possible the newly hypothesized
grammar. We have developed programs in all of these areas and are
currently composing them into a single system. Computing in this
project is done on the Rutgers-10.

(iv) Development and study of systems for theory formation in programming
tasks (S. Amarel). A system is being developed for acquiring
knowledge about a program formation task. The system involves the
generation, management and evaluation of programs at various stages
of specification. In this project, major emphasis is given to
problems of representation and to the effect of shifts between

representations. Program development is being done on the Rutgers-
10.

While the first project discussed in this area is focusing on the
development of AI languages that can provide a stronger basis for system
development in the Resource, the last three projects are focusing on
different AI approaches to hypothesis (theory) formation - an area which
is essential to the automatic acquisition and improvement of a knowledge
base from experimental data.

III. AIM WORKSHOP

The first annual AIM Workshop was held June 14-17, 1975. The first
day was devoted to a General Session to provide an overview of current AIM
activities and a broad forum for discussion. The following three days
were devoted to discussions in depth of AIM designs, and to demonstrations
of current systems. Several AIM systems were effectively demonstrated on
SUMEX during the Workshop.

The second annual AIM Workshop will be held June 1-4, 1976. The
entire four days will be devoted to lectures and panel discussions on
current projects in the AIM community, and on problems of knowledge
representation, reasoning, and AI system design. Papers on language,
speech, vision, education and problem solving will summarize recent AI
approaches, while the role of biomathematical modeling and inference
methods will be the focus of summary papers and panel discussions.
Tutorials on languages and systems available to the AIM community will
also be presented. The Workshop will conclude with a panel on the
dissemination of scientific information and computer networking.

The SUMEX-AIM system is essential for the Workshop. Many of the AIM
programs will be running on SUMEX-AIM and accessed via TYMNET or ARPANET
131

from Rutgers. The message facilities of SUMEX=AIM are most useful for
planning, communicating and setting up the information pool for the AIM
Workshop.

IV. INTERACTIONS WITH THE SUMEX-AIM RESOURCE

During the past year we have continued to use the SUMEX-AIM resource
for program development and testing, for communications between
collaborators distributed in different parts of the country and for
preparation and running of the AIM Workshop.

Computing in the Rutgers Research Resource is distributed between
SUMEX-AIM and the Rutgers-10. The relative utilization of SUMEX-AIM by
"local" Rutgers users has decreased this year. The utilization of SUMEX-
AIM by our "remote" medical collaborators has been growing. The total
amount of computing at SUMEX by our Resource users and by our
collaborators has decreased relative to the previous year. One of the
reasons for this was the overloaded condition of SUMEX-AIM. Another
important related problem was the relatively poor quality of communication
facilities available to us via TYMNET.

In order to provide a more reliable and convenient network
environment for our investigators and their collaborators and also for the
AIM Workshop, we have proceeded this year with the implementation of
several enhancements to the Rutgers-10. These enhancements were planned
in consultation with AIM management, with the intention of bringing to the
AIM network complementary facilities and added capacity. Two stages of
enhancement have been completed this year: (a) core memory and fixed head
disk were augmented and the TOPS 6.02 operating system was installed; (b)
a TYMCOM communications unit was installed, making the Rutgers-10
accessible via TYMNET - in time for support of the second AIM workshop.

The SUMEX-AIM facility played a key role this year in consolidating
our network of collaborators in ophthalmology (ONET) and providing the

support needed for establishing a productive collaboration among the ONET
investigators.

The SUMEX staff have continued to function as models of excellent
cooperation. They have been very helpful and responsive in sharing
information and keeping us aware of developments, problems, new ideas,
ete. SUMEX continues to be a good forum for communicating, linking and
talking with various investigators in our Resource as well as with others
in the AIM community.

The AIM Workshops rely heavily on SUMEX-AIM. In the first Workshop,
the demo sessions and the hands-on activities with remote systems were
found to be very effective in disseminating AIM methods and techniques to
a broad group of participants, The significant role played in these demos
by the SUMEX staff, and by the SUMEX resource, cannot be overstated. In
our planning for the second AIM Workshop we are also placing strong
emphasis on on-line activities, more so considering the broader class of
participants who will meet this year.
132

SUMEX-AIM has been most useful in communicating, planning and
helping to set up the information pool for this AIM Workshop.

In conclusion, the SUMEX-AIM facility is continuing to be an
essential part of our research environment. In view of our AIM Workshop
activities and the related enhancement of the Rutgers-10, we are moving to
a point where the interactions between the Rutgers project and SUMEX-AIM
are increasing in scope - as Rutgers is gradually adding to its "user"
role a "server" role for the national AIM project.

IV. LIST OF PROJECT PUBLICATIONS

[1] Amarel, S., and Kulikowski, C. (1972) "Medical Decision Making and
Computer modeling, Proc. of 5th International Conference on Systems
Science, Honolulu, January 1972.

[2] Amarel, S. (1974) "Computer-Based Modeling and Interpretation in
Medicine and Psychology: The Rutgers Research Resource", Proc. on
"Conference on the Computer as a Research Tool in the Life Sciences",
June 1974, Aspen, by FASEB; also appears as Computers in Biomedicine
TR-29. June 1974, Rutgers University.

[3] Amarel, S. (1974) "Inference of Programs from Sample Computations",
Proc. of NATO Advanced Study Institute on Computer Oriented Learning
Processes, 1974, Bonas, France.

[4] Bruce, B., (1972) "A Model for Temporal Reference and its Application
in a Question Answering Program", in "Artificial Intelligence", Vol.
3, Spring 1972.

[5] Bruce, B. (1973) "A Logic for Unknown Outcomes", Notre Dame Journal
of Formal Logic; also appears as Computers in Biomedicine, TM-35,
Nov. 1973, Rutgers University.

[6] Bruce, B. (1973) "Case Structure Systems", Proc. 3rd International
Joint Conference on Artificial Intelligence (IFCAI), August 1973.

(7] Bruce, B. (1975) "Belief Systems and Language Understanding",
Current Trends in the Language Sciences, Sedelow and Sedelow (eds.)
Houton, in press,

[8] Chokhani, S. and Kulikowski, C.A. (1973) "Process Control Model for
the Regulation of Intraocular Pressure and Glaucoma", Proc. IEEE
Systems, Man & Cybernetics Conf., Boston, November 1973.

[9] Chokhani, S. (1975) "On the Interpretation of Biomathematical Models
Within a Class of Decision-Making Procedures", Ph.D. Thesis, Rutgers
University; also Computers in Biomedicine TR-43, May, 1973.

[10] Fabens, W. (1972) "PEDAGLOT. A Teaching Learning System for
Programming Language", Proc. ACM Sigplan Symposium on Pedagogic
Languages, January 1972.
{11]

[12]

[13]

[14]

[15]

[16]

[17]

[18]

[19]

[20]

[21]

[22]

[23]

(24)

133

Kulikowski, C.A. and Weiss, S. (1972) "Strategies for Data Base
Utilization in Sequential Pattern Recognition", Proc. IEEE Conf. on
Decision and Control, Symp. on Adaptive Processes, December 1972.

Kulikowski, C.4. and Weiss, S. (1973) "An Interactive Facility for
the Inferential Modeling of Disease", Proc. 7th Annual Princeton
Conf. on Information Sciences and Systems, March 1973.

Kulikowski, C.A. (1973) "Theory Formation in Medicine: A Network
Structure for Inference", Proc. International Conference on Systems
Seience, January 1973.

Kulikowski, C.A., Weiss, S., and Safir, A. (1973) "Glaucoma
Diagnosis and Therapy by Computer", Proc, Annual Meeting of the
Association for Research in Vision and Ophthalmology, May 1973.

Kulikowski, C.A. (1973), "Medical Decision-Making and the Modeling
of Disease", Proc, First Intern. Conf. on Pattern Recognition,
October, 1973.

Kulikowski, C.A. (1974) "Computer-Based Medical Consultation"-- A
Representation of Treatment Strategies", Proc. Hawaii International
Conf. on Systems Science, Jan. 1974.

Kulikowski, C.A. (1974) "A System for Computer-Based Medical
Consultation", Proc. National Computer Conference, Chicago, May
1974.

Kulikowski, C.A. and Safir, A. (1975) "Computer-Based Systems
Vision Care", Proceedings IEEE Intercon, April 1975.

Kulikowski, C. and Trigoboff, M. (1975a) "A Multiple Hypothesis
Selection System for Medical Decision-Making", Proc. 8th Hawaii
International Conference on Systems Sciences, January 1975.

Kulikowski, C. & N.S. Sridharan, “Report on the First Annual AIM
Workshop on Artificial Intelligence in Medicine. Sigart Newsletter
No. 55, December 1975.

Kulikowski, C., "Computer-Based Consultation Systems as a Teaching
Tool in Higher Education, 3rd Annual N.J. Conference on the use of
Computers in Higher Education, March 1976,

Kulikowski, C., Weiss S., Safir, A. et al "Glaucoma Diagnosis &
Therapy by Computer: A Collaborative Network Approach" Proc. of
ARVO, April 1976.

Kulikowski, C., Weiss, S., Trigoboff, M. Safir, A., "Clinical
Consultation and the Representation of Disease Processes", Some AI
Approaches, AISB Conference, Edinburgh, July 1976.

LeFaivre, R., “Procedural Representation in a Fuzzy Problem-Solving
System", Proc. Natl. Computer Conf., New York, June 1966
[25]

[26]

[27]

[28]

[29]

[30]

[31]

(32]

[33]

[34]

C35]

[36]

134

LeFaivre, R. and Walker, A. "Rutgers Research Resource on Computers
in Biomedicine, H", Sigart Newsletter No. 54, October 1975.

Mauriello, D. (1974) "Simulation of Interaction Between Populations
in Freshwater Phytoplankton", Ph.D. Thesis, Rutgers University,
1974.

Schmidt, C. (1972) "A comparison of source unidimensional,
multidimensional and set theoretic models for the prediction of
judgements of trail implication", Proc. Eastern Psych. Assoc,
Meeting, Boston, April 1972.

Schmidt, C.F. and D’Addamio, J. (1973) "A Model of the Common Sense
Theory of Intension and Personal Causation", Proc. of the 3rd IJCAI,
August 1973.

Schmidt, C.F. and Sedlak, A. (1973) "An Understanding of Social
Episodes", Proc. of Symposium on Social Understanding in Children
and Adults: Perspectives in Social Cognition, American Psych. Assoc,
Convention, Montreal, August 1973.

Schmidt, C.F., Sridharan, N.S., & Goodson, J.L. Recognizing plans
and summarizing actions. Proceedings of the Artificial Intelligence
and Simulation of Behavior Conference, University of Edinburgh,
Seotland. July 1976.

Schmidt, C. Understanding human action: Recognizing the plans and
motives of other persons. In (eds. J. Carroll and J. Payne)
Cognition and Social Behavior. Potomac, Maryland:

Schmidt, C.F. (1975) "Understanding Human Action", Proc.
Theoretical Issues in Natural Language Processing: An
Interdisciplinary Workshop in Computational Linguistics, Psychology,
Artificial Intelligence, Cambridge, Mass., June 1975. Also appears
as Computers in Biomedicine, TM-47, June 1975, Rutgers University.

Sehmidt, C.F. (1975) "Understanding Human Action: Recognizing the
Motives", Cognition and Social Behavior, J.S. Carroll and J. Payne
(eds.), New York: Lawrence Earlbaum Associates, in press. Also
appears as Computers in Biomedicine, TR-45, June 1975, Rutgers
University.

Sedlak, A.J. (1974) "An Investigation of the Development of the
Child’s Understanding and Evaluation of the Actions of Others", Ph.D.
Thesis, Rutgers University

Sridharan, N.S., "The Frame and Focus Problems in AI: Discussion in
relation to the BELIEVER System. Proceedings of the Conference on
Artificial Intelligence & the Simulation of Human Behavior,
Edinburgh, July 1976.

Srinivasan, C.V. (1973) "The Architecture of a Coherent Information
System: A General Problem Solving System", Proc. of the 3rd IJCAI,

August 1973.
[37]

[38]

[39]

[40]

135

Tucker, S.S. (1974) "Cobalt Kinetics in Aquatic Microcosms", Ph.D.
Thesis, Rutgers University.

Vichnevetsky, R. (1973) "Physical Criteria in the Evaluation of
Computer Methods for Partial Differential Equations", Proc, 7th
International AICA Congress, Prague, Sept. 1973; reprinted in Proc.
of AICA, Vol. XVI, No. 1, Jan. 1974, European Academic Press,
Brussels, Belgium.

Vichnevetsky, R., Tu, K.W., Steen, J.A. (1974), "Quantitative Error
Analysis of Numerical Methods for Partial Differential Equations",
Proc. Eighth Annual Princeton Conference on Information Science and
Systems, Princeton University, March 1974,

Weiss, S. (1974) "A System for Model-Based Computer-Aided Diagnosis
and Therapy", Parts I and II, Ph.D. Thesis, Rutgers University; also
Computers in Biomedicine TR=27, Feb. 1974.
136

IV.B INFORMAL PROJECTS

The following is a summary of the various "pilot" projects which
have been admitted to SUMEX on a temporary basis pending development of a
formal proposal. Many of these projects reflect initial efforts at
formalizing analyses of experimental situations in preparation for the
development of DENDRAL-like heuristic inference generation and modeling.

IV.B.1 STANFORD PILOT PROJECTS

IV.B.1.a AI IN MOLECULAR GENETICS ~ MOLGEN

THE MOLGEN SYSTEM FOR EXPERIMENTAL MOLECULAR GENETICS

Prof. J. Lederberg
Stanford Department of Genetics

The MOLGEN system is designed to aid the experimental molecular
geneticist in many important phases of laboratory investigation. It will
be composed of three major interacting parts: an experiment planning
system, an enzymatic action simulation program, and a collection of
knowledge bases containing the rules and heuristics of molecular genetics.

The experiment planning program will collect information about a
problem from the user, select an appropriate methodology for solution
(information retrieval, simulation, hierarchical planning, or some
combination thereof) and then work interactively with him to solve the
problem. Some examples of the range of problems MOLGEN’s experiment
planner will deal with are:

1. The user wishes to know which enzymes will function under a given pH
or salt concentration--a straight information retrieval problem,

2. The user wants an accurate prediction of the ratio of linear to
circular DNA after application of ligase to a given starting
concentration of "sticky-ended" DNA--a problem best handled by a
discrete simulation.

3. The user wants a verification that a proposed experiment will
produce something like a desired result--probably a combination of
retrieval and simulation.

4, The user wants a plan to synthesize and then analyze a new DNA
Structure--a deep problem involving hierarchical planning methods
making full use of all program facilities.

The simulation program will provide detailed modeling of the action
of enzymes on nucleic acid structures. The program has been shown to
137

produce accurate and reproducible results on several diverse structures
for simple ligation, and is being extended to other common enzymatic
actions (exo and endo-nucleases, polymerase, etc.).

The knowledge bases will be composed of collections of the rules and
heuristics used by geneticists, as well as facts about enzymes,
experimental methods, and physical processes like de/renaturation. They
will be designed to allow access in retrieval, simulation, and planning
modes, so the major problem lies in represen-tation of diverse types of
knowledge in a common, consistent fashion.

Along with the major system components discussed above, certain
themes remain dominant in all phases of system design. Primary
consideration is given to making the system an easy and natural tool for
the molecular geneticist to use. Nucleic acid structure entry, editing,
and display is by way of an interactive, user-oriented program.
Explanation facilities (in the manner of the MYCIN system) will be
provided whenever possible, and all knowledge bases made easily extendable
and modifiable, We consider the trust and cooperation of the expert user
vital to continued system development, and consider the best way to
provide for this cooperation is to make the system immediately useful and
intelligible to geneticists.
138

IV.B.1.b BAYLOR=METHODIST CEREBROVASCULAR PROJECT

BAYLOR=-METHODIST CENTER FOR CEREBROVASCULAR RESEARCH
DATA SERVICES RESEARCH LABORATORY

John L. Gedye, M.D.
Department of Neurology
Baylor College of Medicine
Houston, Texas

During the year the data services research laboratory has had a
total of about 3,000 hours of man-effort available, of which about 50% has
been devoted to implementation of the local facilities described below,
and a further 5% has been devoted to the SUMEX pilot study.

A) GENERAL GOALS

Clinical research in neurology, as exemplified by the program of the
Bay lor-Methodist Center for Cerebrovascular Research, creates a large
number of data handling problems of a wide variety of types. The Data
Services Research Laboratory seeks to Support the program of the center by
developing and making available a comprehensive range of data acquisition
storage, processing and display techniques for the center’s investigative
laboratories. These techniques are being designed to facilitate the
Systematic study of inter-relationships between the different types of
data gathered from the various cerebrovascular disease patient groups
being studied by the center.

Technical Resources

At the beginning of last December the Data Services Research
Laboratory accepted delivery of a Digital Equipment Corporation (DEC) PDP-
11/35 computer configuration with 32K core, 2 RKO5 disks, a TSO3 magnetic
tape unit, a Terminet 1200 printer acting as console and hard-copy device,
and 2 modified Hazeltine 1200 video display terminals for general
interactive use. the system has incoming (1) and outgoing (1) 300 baud
modem interfaces to the public switched network the latter incorporating a
Bell 801C autodialler. This configuration supports time-shared services,
both interactive and batch, based on a Single user-language (this is an
extended basic called BASYS - the system is currently operating under the
commercially supported version of BASYS V3P, known as AIMS V3P - for
details see the latest edition of the AIMS-11 programming manual, November

1975, obtainable from ARBAT Systems Limited, 61 Broadway, New York, N.Y.
10006).

Access to SUMEX

This has been by means of TYMNET, which we access through one of the
Houston TYMSAT’s. At the beginning of the project we used a 300 baud TI
139

Silent 700 terminal in the normal manner, but sinee the installation of
our local PDP-11/35 configuration in December, we have taken advantage of
our autodial facilities and the supporting facilities provided in BASYS
V3P and have used our BAYSYS terminals for this purpose. As a result of
this experience we are now considering implementing software which will
allow an easier interface between our local system and the resources of
SUMEX. We have in mind an ability to create files on our system and pass
them to SUMEX and to pick up files from SUMEX and store them locally. It
is felt that implementing such facilities will greatly facilitate
interaction with the SUMEX resource and will lead naturally to the
procedures needed to support our AI research.

B) MEDICAL RELEVANCE

The system designed and implemented for the Center for
Cerebrovascular Research (BAYSYS - not to be confused with BASYS) allows:

1) Maintenance of an immediately accessible, up-to-date, cross-
referenced directory of all patients who have, at any time, come
under the care or investigation of members of the clinical staff of
the Department of Neurology, together with a record for each showing
what data has been gathered and where it is located. On March 31,
1976 the directory contained 570 entries, and experience to date
Suggests that in order to keep up with the patient throughput of the
center, new names will be added at a rate of about 100/month. As
presently configured the system has a directory capacity of 6,000.

2) Storage in a readily accessible, computer-compatible form, of all
data gathered on patients which may be relevant to the current and
future research interests of the center. Investigatory data is
regularly archived on industry compatible magnetic tape in a format
which allows subsequent collation using standard sort and merge
software.

The work of the Data Services Research Laboratory is organised
around the assumption that the research activities of the center can, for
all practical purpose, be regarded as a set of inter-related projects,
each of which includes planned data acquisition by one or more of the
investigative laboratories of the center in accordance with a
predetermined schedule.

AS a result of providing these primary data gathering services to
the investigatory laboratories of the center, the Data Services Research
Laboratory will acquire access to a reliable data base covering in
principle, the entire range of activities of the center, and this will
allow a range of secondary data handling activities to be undertaken on
behalf of the center.

It appears that the main technical problem that will have to be
solved before it is possible to keep up with the potential flow of data is
the design and implementation of a suitable range of data input procedures
to cope with the wide variety of data types. It is hoped that the new
hand held OCR wand recently developed by Recognition Equipment, Inc. of
140

Dallas, Texas will allow us to develop a suitably flexible data entry work
station for our purposes.

C) PILOT STUDY

The aim of this study has been to formulate a project relevant to
the activities of the center which will provide an acceptable and
legitimate "point of entry" for artificial intelligence research, and
which will allow the systematic formulation of objectives for the future.
We are, at the present time, focussing on situations in which a researcher
working in the Center for Cerebrovascular Research is required to respond
to information from a new source and in some way incorporate it into his
understanding of a class of clinical situations.

Background

A continual source of background guidance for our work has been the
writings of Stephen Toulmin, particularly his book "Human Understanding"
(the first volume of which appeared in 1972) in which he develops a
evolutionary approach to the subject in terms of a "populational" account
of conceptual change in intellectual disciplines. From the standpoint of
Toulmin’s approach "men demonstrate their rationality not by ordering
their concepts and beliefs in tidy formal structures, but by their
preparedness to respond to novel situations with open minds -
acknowledging the shortcomings of their former procedures and moving
beyond them", The emphasis in his approach to rationality is thus on
"change", on the circumstances under which and the means by which men
change their concepts and beliefs. Our work to date can be thought of as
an attempt to model this approach to the growth of human knowledge in a
specific situation - assimilating the results of the new 133XE inhalation
regional cerebral blood flow assessment technique. The approach requires
at least 3 levels of activity:

1. Choice of goals of rational enterprise
2. Development of concepts
3. Formulation of arguments

The basic approach has been to design as system which will, when
provided with with a set of descriptions of paradigmatic patients
representing two clinical conditions, automatically formulate an optimal
algorithm (or in other words a set of decision rules which makes the best
use of the available information) for discriminating between those two
conditions, and which can then be used on a new set of patients for
various purposes. The approach has been tested on regional cerebral blood
flow data by checking an algorithm developed from a representative set of
32 patients who acted as paradigms on a similar set of 32 patients and a
diagnostic success rate of 90% was obtained in relation to the request
"Tell me, on the basis of regional cerebral blood flow measurements alone,
whether this individual is normal or abnormal".
141

The approach appears to have a wide range of applications in the
context of the work of the center and effort is currently being
concentrated on applying the technique to the systematic exploration of
regional cerebral blood flow differences in relation to such contrasts as
"male/female", “left-hemisphere/right hemisphere" and so on. The
technique can be applied to data as it accumulates, thus allowing the
detection of trends at an early stage of the research.

It is inappropriate to go into details of the approach here, but
it’s essential feature is that it permits revision of both conceptual
boundaries (such as what is meant by "high" as opposed to "low" flow in a
particular brain region) and of arguments expressed in terms of a given
set of concepts (such as: "high" flow in region x, together with “low”
flow in region y, and "high" flow in region z implies multi-infarct
dementia as opposed to Alzheimer’s dementia) as a result of the
acquisition of new data.

II) INTERACTIONS WITH THE SUMEX-AIM RESOURCE

A) Collaborations Through the Network

We have not yet reached a stage at which we are able to support
regular collaboration through the network. We hope that this will develop
naturally as soon as we have been able to develop interface between our
local PDP-11/35 system and SUMEX so that we can handle interaction as a
natural part of our day to day activities. Dr. David Bowen is planning to
cooperate with us during the summer from London over ARPANET, and we
intend to work together on his neurochemical data.

B)} Contacts and Cross Fertilisations

The Rutgers workshop was the most valuable feature of SUMEX-AIM
participation during the year, providing an opportunity to get an overview
of work in progress and to see directions in which our work here could
develop to complement what was being done elsewhere. On the clinical
application side the "INTERNIST (DIALOG)" project was the most
stimulating, as it demonstrated the challenges that would have to be met
by any practically useful approach, for example: the ability to handle
multiple problems presenting together.

At a more fundamental level "DENDRAL" confirmed the value of the
approach to which we are committed - trying to model the research process
itself. As a result of the Rutgers workshop, a working relationship has
been established with Drs. Lindberg and Blackwell of the University of
Missouri and there have been reciprocal visits between our respective
locations. On my last visit to Columbia, I gave an invited paper called
"A Jurisprudential Approach to Artificial Intelligence" and have since
been invited to write this up for "Biosciences Communications".

Dr. Lindberg’s work on the encipherment of electrolyte patterns has
proved to be a useful stimulus to our own work on the encipherment of
142

neurological data, and suggestions from myself that it might be valuable
to look at electrolyte pattern transitions has been taken up and developed
as an application of the theory of finite state machines.

C) Critique of Resource Service

Our use of the computational resources of SUMEX has so far been
largely confined to experimentation with the various modules of the system
described above. This was particularly valuable before our own resources
became available. We now see ourselves moving to a new mode of operation
in which we try to find out which things are best done on SUMEX and which
locally. Our main criticism to date has been slowness of response during
peak hours, when, unfortunately we have sometimes had to try to operate
because of constraints on manpower availability.

FUNDING STATUS

Work is currently being supported by departmental funds. However,
we have recently received unofficial notification from NIH that funds have
been approved for the support of the Data Services Research Laboratory in
the center grant renewal effective February 1, 1977. Approval is for one
year in the first instance with support for a further two years subject to
satisfactory administrative arrangements.
143

IV.B.1.¢ AUTOMATIC LY MODELING

Automatic Radiographic Image Analysis by LV Modeling

Donald C. Harrison, Professor of Medicine
Edwin L. Alderman, Assistant Professor of Medicine
Lynn Quam,Ph.D., Research Associate in Computer Science

Stanford University

A proposal to carry out this research has been submitted to the NIH.
Medical applications of computer image processing was part of the original
collaborative research goals of SUMEX. This has been supported as a pilot
project to facilitate the development of independent grant support.

The proposal is to use the facilities of SUMEX-Aim to develop a
mini-computer system for the automatic analysis of left ventricular
angiography in a clinical cardiac catheterization laboratory setting. This
system will be designed to 1) provide frame by frame quantitative volume
measurements 2) analyze wall motion abnormalities and 3) generate new
information about left ventricular function. In conjunction with the
SUMEX systems staff, Dr. Lynn Quam has done the initial development work
on an interactive graphics and image display system as summarized below.

SUMMARY:

A general purpose hardware and software system for interactive
graphics and grey-level image display has been developed on the SUMEX
Tenex system, using a Tektronix 611 storage scope controlled by a PDP-
11/10 processor. The system is capable of producing limited displays
dynamically using the non-storage mode of the 611, whereas complex
displays require the use of storage mode or photography.

A general purpose graphics package has been developed, which is
essentially compatible with the graphics software at the Stanford A-I Lab.
Consequently, with minor revisions, many of the graphics programs written
at the A-I lab can be used at SUMEX.

Many of the image processing algorithms originally developed at the
A-I lab by L. H. Quam have been revised to run in the Tenex environment.

The combined effect of the graphies and image display hardware and
software is the capability for SUMEX users to perform a wide variety of

image enhancement operations on grey-level images, and to display both
line drawing graphics and grey-level images.

PURPOSE:

The primary purpose for developing the graphics and image display
144

system was to support the needs of an NHLI proposal in the division of
Cardiology. The proposed research was to develop algorithms to automate
the procedure for outlining ventricular margins in angiograms, for the
purpose of cardiac dynamic performance evaluation. The images are
obtained by passing x-rays thru the patient who has a catheter placed in
the heart. The x-ray target is viewed by both a cine film camera and a
vidicon. The vidicon output is both viewed directly, and recorded on a
video disc. Several cardiac cycles are recorded on the disc, then a
radio-opaque dye is injected into the heart using the catheter, and
several (at least 3) more cycles are recorded. This procedure produces
about 150 images which must be analyzed.

In the normal clinical operation, a technician manually traces the
ventricular margins using a light pen which is connected to a mini-
computer which computes the desired performance measurements and produces
hard copy output. The manual tracing is quite tedious and slow.

The primary difficulty with automating ventricular margin outlining
is that during part of the cardiac cycle the margin is of very low
contrast (poor signal to noise ratio), making it impossible to detect
without taking adjacent (in time) images into consideration. In order to
develop techniques for automatic margin definition, it was necessary to
have hardware and software for image and graphics display.

HARDWARE:

The hardware consists of four component parts: a Tektronix 611
scope, a display controller, a PDP-11/10, and a PDP-10 to PDP-11
communication interface.

Tektronix 611 Scope:

A Tektronix 611 storage oscilloscope is used to generate the images.
Briefly, the 611 scope has high resolution (about 100 points to the inch
on a 7 by 9 inch screen), and storage and non-storage modes. Using non-
Storage mode increases the resolution by about a factor of 2, and allows
the the display of grey-level images. Unfortunately, the 611°s deflection
system is too slow for direct viewing of very large images without an
intolerable flicker. For large grey-level images one of two approaches
must be used: photographic recording of the 611 screen, or halftone grey-
level simulation using storage mode.

Display Controller:

The X, Y and Z axis signals to the 611 scope are generated by a
display controller designed at SUMEX. Basically, the X and Y deflection
Signals are generated by two 12-bit digital to analog converters which are
driven by X and Y position registers in the display controller. The Z-
axis signal is controlled by a digital level which turns the 611 beam on
for a time proportional to the binary number in the Z axis register.
145

The display controller is capable of two primary modes of operation:
vector and raster. Vectors are generated as a sequence of discrete
points. Vectors are specified to the hardware by the starting X, Y
location, the DX, DY distance between the discrete points of the vector,
and N the number of points in the vector. Grey-level rasters are
generated as a sequence of discrete points (pixels) each of which can have
an arbitrary intensity. To the controller, a single raster line is
specified exactly the same as a vector with the addition of N 8-bit bytes
of Z-axis intensity information.

The display controller is connected to a PDP-11 Unibus.

PDP-11/10:

A PDP-11/10 minicomputer is used to control the display. For images
in non-storage mode, the PDP-11 dynamically refreshes the screen at about
3 microseconds per point (depending on the brightness: 3 microseconds is
the minimum time). For halftone grey-level simulation, the PDP-11
executes the halftone algorithm.

PDP=10 to PDP-11 Interface:

A general purpose communication interface connects the PDP-~10 to the
PDP-11. This hardware consists of two 32-bit registers, one for each
direction of data transfer, 2 status registers, and 2 control registers.
Using this interface, data can be transferred between the PDP-10 and the
PDP-11 at about 20 microseconds per word data rates (potentially).

SOFTWARE:

The software to to utilize the display hardware consists of many
modules some of which execute on the PDP-10 and others on the PDP-11.

Communication Module:

Communication between the PDP-10 and the PDP-11 is accomplished by
transferring blocks of data thru the communication interface which is
controlled by programs running in each machine. The basic operations are:

. Load a program in the PDP~11

. send a block of data to the PDP-11

. Get a block of data from the PDP-11

. Start a program running in the PDP-14
- Stop the program running in the PDP-11
+» anda few other operations

oadaop

PDP-11 Display Module:
146

The display module interprets blocks of data sent thru the
communication interface as commands to the display. The basic display
commands are:

a. move the beam to position X,Y

b. draw a line consisting of N points, incrementing the
beam position by DX,DY¥ between each point.

generate a grey-level raster

generate a half tone raster

. set beam brightness

display a string of text

display subroutine call

display subroutine return

Twa oO A0

From these primitive commands all higher level display functions are
built.

PDP-10 Display Module:

The PDP-10 display module interprets SAIL procedure calls and
produces blocks of data to send to the PDP-11 display module. In addition
to the primitives listed above, many higher level display functions are
implemented:

a. display a circle
b. display an are of a circle
ec. plot a graph of the data in a array: labelling the axes

PDP=10 Image Processing Functions:

Many of the image processing functions developed at the Stanford
Artificial Intelligence Laboratory have been modified to run under Tenex.
The following is a partial list:

Input an image from a disk file

Output an image to a disk file

Input a window of an image from a disk file
. Display an image on the 611 scope

Enhance the contrast (stretch) of the image
Rotate the image 90 degrees clockwise
High-pass filter the image

Low-pass filter the image

Display the histogram of the image

Expand the image

- Remove "noise" from the image (local sigma test)
. Difference two images

Pwr om yO AO oD
147

IV.B.1.d INFORMATION PROCESSING PSYCHOLOGY PROJECT

INFORMATION PROCESSING PSYCHOLOGY

Prof. E. Feigenbaum (Computer Science)
and Prof. H. Cohen (U. C. San Diego)

May 1976 Report

Information Processing Psychology is concerned with the construction
of models of human cognition, using the methodologies of computer
simulation and artificial intelligence. The attempt is to give a precise
characterization of the human information processes and information
structures that underly human problem solving, learning, and perceptual
behavior. Over the past two decades, research in this scientific area has
produced computer models of behavior in puzzle-solving, game-playing, and
theorem-proving tasks; rote learning laboratory tasks; linguistic
understanding and long-term memory tasks; pattern extrapolation tasks,
e.g., as are found in intelligence tests; children’s seriation tasks;
concept attainment tasks; visual scene understanding tasks; tasks
involving mental imagery; and many others. A type of human
cognitive/perceptual activity that has not been much studied is the
behavior associated with the production of works of art. In the past,
neither graphical/visual art-making nor musical composition has been
studied in depth.

The particular project described below has sought to bring under
examination one of the least well-defined areas of higher intellectual
functioning -- the activities of art-making performance -- and to develop
a computer model (i.e., information processing model) capable of verifying
the plausibility of a number of hypotheses concerning such activities. We
have addressed the subset of art-making behavior which is concerned with
the production of freehand drawings, and in particular drawings which
might be characterized by their imagistic richness as opposed to formal
complexity.

The computer model has followed the format used in many A.I.
programs: a production system in which an explicit body of knowledge is
encoded as a set of rules linking the recognition of complex prior program
behavior (in the making of the drawing) and current states within the
drawing itself, to the exercise of appropriate subsequent rules, which in
turn move the drawing into new states. The model is to be regarded as an
expert or specialist, in the sense that the encoded knowledge is
specifically concerned with the mechanics of image-building and does not
encompass any other aspect of the world.

Since much of what we understand by "meaning" in images -- as
elsewhere -- clearly involves world knowledge, there may seem to be
something anomalous in a program without world knowledge designed to
generate imagistically rich drawings. However, our belief has been that a
large part of "meaning" is signalled by the image-structure itself, and
that this is related more to the nature of underlying perceptual processes
than to any particular stored perception of the world. There should be a
148

set of pre-acculturated behavioral patterns of so fundamental a kind that
their very exercise would persuade the viewer that some "meaning" was
intended,

Following from this position, our selection of appropriate
production rules in the production system has tended to stress a number of
low level perceptual activities. Early versions of the model were able to
differentiate figure from ground, closed forms from open forms, inside
from outside; and also to perform tasks -- like generating a path from one
point to another under certain constraints -- in feedback mode, which

required a continually updated model of the state of the drawing under
construction.

More recently, the model has been given enough knowledge of the
mechanics of representation to permit it to manipulate the emerging
drawing more fully. Thus, it knows that a closed form may function as a
delineated area upon which other markings may be made; or whose flatness
may be stressed by cross-hatching; or that the form may “stand for" a
solid object which may be shaded or cast shadows.

The protocols referred to above are families of behavioral rules
which are distributed throughout the system and become enmeshed into
complex structures. For example, one aspect of the model’s awareness of
figure-ground relationships is a set of avoidance protocols, which prevent
the invasion of existing elements in the drawing. Which of the set will
be invoked will depend upon both what is being done -~ in terms of
currently "open" protocols == and what is being avoided.

The major protocols currently available to the model may be
summarized as follows:

closure: forms may be closed by preplanning or, at a later stage, as
suggested by the state of the drawing. Reinforced by hatching, shading,
marking (recursive repetition, see below), piercing, accretion.

placement: the model is able to select unused areas of the drawing of a
shape and size appropriate to its current plan; its subsequent behavior
is then determined in large part by the precise consideration of its
environs. The model has no aesthetic criteria or compositional
Strategies beyond providing itself with adequate space.

avoidance: may result in the discontinuation or the modification of the
current plan, with or without the development of an alternative plan; or
in an attempt to circumvent the obstructing form.

repetition: in the "placement" area of the production system, this would
result in similar sub-histories being repeated, subject to local
conditions, in other parts of the drawing. In other conditions it will
result in a recursive use of closed forms as fields upon which other
closed forms may be made; in multiple division or extension of an area;
in zigzags or groups of parallel lines, or in concentricity.

Long term plans include the provision of Simple "world knowledge" to
the problem, in order to investigate plausible specialist/non-specialist
149

interactions in the drawing process as a source of imagistic richness. We
have done some recent experimentation with people, designed to isolate and
examine the protocols actually employed by a group of drawing students in
a visual arts class at U.C., San Diego. The results of these experiments
are now undergoing statistical analysis, and it is anticipated that much
useful material will be available for the next stage of program
development.

The program described above was developed in SAIL on the SUMEX
facility, partly during the period when Professor Harold Cohen, of the
Visual Arts Department of U.C., San Diego, was on leave at Stanford
University, and partly upon his return to his campus. He has assumed the
Directorship of a new Project for Art/Science Studies at UCSD, and has by
gifts and grants procured for the Center a PDP/11-type facility capable of
supporting the research described above on the modeling of artemaking
behavior. The innovative work of this SUMEX pilot project will therefore
be “spun off" to a fruitful environment at UCSD. As a SUMEX activity,
this particular research has effectively terminated.

Bibliographic References

1. Cohen, H. "Steps toward a Theory of Meaning", invited paper,
International Sculpture Conference, U. of Kansas, March, 1974

2. Cohen, H. “Qn Tools and People, Including Computers and Artists",
invited paper, Conference on Computers in Art, Purdue Univ., 1975.

3. Cohen, H. "The Simulation of Perception: Problems in Generating
Drawings by Machine", invited paper AAAS Annual Meeting, 1972.

4, Cohen, H. "On Purpose", <<Studio International>>, January, 1974.

5. Cohen, H. "Parallel to Perception", <<Proceedings of the Edinburgh
Conference on Art and Computing>>, 1973
150

IV.B.1.e AIM RESEARCH - UNIVERSITY OF ROCHESTER

AIM Research - University of Rochester

Drs. Feldman, Rovner, and Low
Rochester University

(Grant NSF DCR74-24203, 2 years, $149,956 total and
Sloan Fdn. 74-12-5, 3 years, $120,000 last year)

SUMEX facilities are being used at the University of Rochester by a

group of about 10 second-year medical students
Charles Odoroff, Biostatistics. Their work is
a course in biostatistics and epidemiology, or
They have studied some of the documentation of
experimented with using it both on canned case

under the direction of
either an optional part of
an individual project.

the MYCIN system, and have
histories and on cases from

the files of microbiologists at the U. of R. Medical School. At least one
evaluative paper has been written. It is planned to use the CASNET system

in the same way.

There is continuing system development work, especially for the SAIL

language system,