Hector Kay, Alan Kay, and the Future of Prosthetics and Orthotics Hector Kay Memorial Lecture


I am honored that ACPOC (Association of Children's Prosthetic and Orthotic Clinics) has asked me to give the 5th Hector Kay Memorial Lecture, and that I have opportunity to give it in my home area of Chicago. I want to dedicate the lecture to Hector Kay and to his close ACPOC associates, Dr. Claude Lambert and Dr. Tom Aitken, who were also close friends of mine. Hector was not only my friend and colleague, I considered him a father figure as well.

We first met by telephone in 1968. 1 was convalescing from surgery when Hector called from Washington, D.C. After introducing himself, he said he hoped I could go to Belgrade, Yugoslavia with him as part of his work with the Committee on Prosthetics Research and Development (CPRD) of the National Academy of Sciences. The site visit was to ascertain progress on evaluation of the Belgrade hand, a new multifunctional electric hand prosthesis. He wanted an electrical engineer to take part in the site visit with him. I told him I would be delighted to go, and did. Mrs. Kay, Katherine, also went and that is where I met her for the first time. Today she is somewhat like a mother to me.

This lecture has three parts. The first part is about Hector Kay. The second part is about Alan Kay, his son, and the third part is about how Hector Kay's field, prosthetics and orthotics, will be influenced in the future by his son's field, computers. The lecture had its genesis two or three years ago. Craig Heckathorne, a research engineer working with me at Northwestern University, and I were returning to Chicago by train from Springfield, Illinois. I noticed he was reading a scientific paper written by Hector Kay. I asked if he knew who the author was, and if he knew that Hector had been a friend of mine. In passing I commented that Hector's son was in the computer field. He asked if his son's name was Alan. I said yes, at which point he told me that Alan was one of the most well known people in the personal computer field. Because Hector Kay was one of the most well known and respected persons in the prosthetics and orthotics field, I thought that an interesting connection had been made.

Hector Kay

In a way, the story of Hector Kay's job with CPRD begins here in Chicago, because CPRD, through which he served so brilliantly and through which he influenced ACPOC so effectively, had its origins here. In January 1945, the Surgeon General of the United States convened an international meeting of surgeons, prosthetists, engineers, and others in Thorne Hall on the Chicago Campus of Northwestern University to consider what needed to be done concerning the returning allied soldiers who had amputations. As a result, the precursor organizations of CPRD and of several federally-supported programs in prosthetics and orthotics (clinical and research and development) in the United States were established here, beside Lake Michigan, forty-four years ago. Actually, in this sense, ACPOC's origins are here as well.

Thorne Hall no longer exists; a new building contains a new Thorne Auditorium-but back to Hector Kay and the visit to Yugoslavia.

Hector, Katherine, and I spent a month or so in Yugoslavia, mostly in Belgrade and Ljubljana. It was there I learned about their son, Alan, who was at that time in graduate school working on a PhD in Computer Science at the University of Utah. Little did we realize what a big impact his work would have on society and on the field of prosthetics and orthotics.

In 1968, rehabilitation research work in Yugoslavia was partially supported by funds established through Public Law 480. To monitor the work and its results, Hector would subsequently visit Yugoslavia many times. He was asked to go this first time because of his considerable skill in the evaluation of prosthetic and orthotic systems. He was to make use of those skills in the study of the Belgrade hand. Hector was also skilled in the use of the English language-and has had a great impact on terminology in our field. With a background in physical education he was knowledgeable about anatomy, kinesiology and recreational therapy and he soon learned the other aspects of the prosthetics and orthotics field. He was practical and tough minded, yet he could compromise. He understood people and got along well with everyone.

My experiences with Hector, both in Yugoslavia and through CPRD, and my later realization of his son's accomplishments are why I have chosen to title this lecture: Hector Kay, Alan Kay, and the Future of Prosthetics and Orthotics.

At the same time we were in Yugoslavia working with Belgrade hands, Alan Kay, in Utah, was beginning work which would play such an important role in ushering in the age of the personal computer-and his work, as I hope to explain, is of great significance to the future of his father's field.

Alan Kay

Mrs. Kay told me in Yugoslavia that Alan had had many problems in school. He apparently had not done particularly well where his thinking was regimented, in places like schools, in places like colleges, and in places like the Air Force, although he did get his introduction to computers through the Air Force. The Massachusetts Institute of Technology (MIT) would not take him into graduate school after he graduated from the University of Colorado, which is ironic, because later, they would offer him an endowed chair on the faculty. He now is a visiting professor there-but that is getting ahead again.

At the University of Utah

Fortunately, there were people who saw something special in this young man with the independent mind. One was Dr. David Evans, Chairman of Computer Science at the University of Utah. He took a chance on Alan Kay helping him get admitted to graduate school at Utah, and this is why the lecture today is about Alan Kay, as well as about Hector. It also is why, when I am judging a potential graduate student's application folder, I give pause to ask, "Is this another Alan Kay?"

At Utah from 1966 to about 1970, Alan Kay was in one of the hot spots of advanced computer thinking. For one thing, Dr. Evans had attracted the young PhD, Ivan Sutherland, from MIT to be on the faculty at Utah. Sutherland had already written Sketchpad, what some persons have called "the most important computer program ever written." This program opened the way to new ways of human-computer interaction because it permitted the user to manipulate geometric figures on the monitor screen. Human-computer interaction thereafter was no longer limited to alpha-numeric representations. This importantly influenced Kay's thinking about what a computer could be like-what a computer should be-like. Of course, Evans and Sutherland formed the well known company that bears their names and which is currently so important in flight simulation and image generation.

While a student at Utah, Kay was also able to hear Doug Englebart's 1968 media presentation about the results of the Augmentation Research Center's work on humancomputer interaction and human augmentation at the Stanford Research Institute (SRI). This introduced him to the "mouse" and to other new interactive concepts.

Research and Development

Out of these experiences Alan Kay was to synthesize new ideas about how humans can interact with computers and about how computers can interact with humans. From Utah he moved to an even more intense computer research and development environment-the Stanford Research Institute where Englebart was located. Subsequently, he went to Xerox's Palo Alto Research Center (PARC), and it is from there that we know of him as one of the contemporary leaders of the personal computer revolution. In fact, Alan Kay coined the term "personal computer," which is so ubiquitous in our language today. He is often regarded as the "father" of the personal computer, but he says he acted more as a "midwife" to its birth. He is regarded as a visionary in the field and currently is a research fellow with Apple Computer.

I recommend the book Tools for Thought by Howard Rheingold (Prentice Hall Press) for an overall viewpoint concerning personal computer development and the role that Alan Kay played in this field. For a view of some of his current work, Media Lab by Stewart Brand (Penguin Press) contains information about his work with MIT. His impact at PARC, as well as the influence of PARC on the field at large, is well documented in an interesting article in IEEE SPECTRUM, October 1985, called "Inside the PARC: The 'Information Architects' " by Tekla S. Perry and Paul Wallich. They call Alan Kay, "perhaps PARC'S most famous alumnus." This article also contains an interesting drawing of the "PARC Tree," its trunk appropriately initialed (in two places) by Alan Kay, which vividly illustrates the economic and technical growth that can result from industrial research funding.

One of Alan Kay's dreams was to develop the "Dynabook," which Rheingold has described more or less as a "machine-book" incorporating a combination of the addictive allure of a good video game with the cultural resources of a library and museum, mixed with the expressive power of finger painting or the direction of an orchestra. It is to provide a person with information and enable one to write, paint, and otherwise be creative and productive.

At PARC, Kay developed Smalltalk, a new computer operating system.

The Alto Computer, also developed at PARC, when operated with Smalltalk were dubbed the first "interim Dynabook" in 1974. This system was about ten years ahead of its time. Although marketed later as Xerox's STAR system, its concepts were not to reach the mass market until much later through Apple's Macintosh. Smalltalk made use of multiple overlapping windows, icons, popup menus, and many other innovations that are now commonplace. In fact, I have written this Hector Kay Memorial Lecture on a Macintosh that makes use of many of the ideas of Alan Kay.

Although the Dynabook is yet to be built, optical disk storage, and related technology will undoubtedly soon move us closer to its realization. The Kay connection will truly be complete when all we know of the prosthetics and orthotics field, and more, are contained in a prosthetics and orthotics Dynabook. Alan Kay would visualize such systems becoming inexpensive enough for each of us to have one.

How did Alan Kay approach his work? For one thing, he investigated LOGO-which had been developed under the direction of Seymour Papert (an MIT mathematician who studied with the developmental psychologist Jean Piaget) to enable children to interact with computers easily. Kay also worked with children. He brought children to PARC and they were the first to use his revolutionary approaches to computers. He said after these experiences, "I knew I would never write another program that was not set up for children." He used icons so that even children who could not read could operate the system.

I cannot help but notice at this point the connection between Hector and his son Alan. They were both interested in children. Hector was interested in prosthetics and orthotics to empower disabled children and to enhance their physical abilities. Alan was interested in the education of children, and in giving them tools to enhance their intellectual capacities and abilities. His objective was to empower them to solve problems in interesting and rewarding ways. In a sense, the Kay's, Hector and Alan, were both in the same business.


Alan Kay believed the computer should be for people, all people; it should be more than a gadget for computer programmers- more than a machine to solve complicated equations. Instead he believed it could also be a system for augmenting the human intellect, a system for mind amplification, and a system that could enable people to use their minds freely together, in concert. For example, he believed computers should be a new medium for artists, musicians, and others who might be thought of as far removed from the computer field. This is the democratic view, the independent viewpoint, not believing in an elite computer aristocracy, but in augmentation systems that everyone can use easily in order do better what they do best. He believed computer systems should augment people by doing what the computer does best-manage complexity. This seems to me to be the kind of viewpoint one might expect from a son whose father was Australian and whose mother is American, strong individuals from Melbourne and from Massachusetts.

I speak of Alan Kay somewhat symbolically. He symbolizes all the people who work and who have worked to bring about the computer revolution that is making computers accessible to all. Nevertheless, he is more than just symbolic because he is regarded by the field as one of its luminaries, and this justifies my emphasis, I think. This brings me to the third part of my talk.

Alan Kay's Field and the Future of His Father's Field (Prosthetics and Orthotics)

The acronyms CAD (computer-aided-design), CAM (computer-aided-manufacturing), CAE (computer-aided-engineering), and all the others that come when the words "computer aided" are added to whatever is being done, are symbolic of what is happening as a result of today's computer technology. I do not need to be a prophet to conclude, as I do, that this technology is going to have an enormous influence on the future of orthotics and prosthetics. All one has to do is look at the impact this technology is having on other fields to realize that the impact will be great on prosthetics and orthotics. One might even wonder why computer technology has not already advanced in the field more quickly than it has. Nevertheless, we already have our own acronyms and names, CASD (computer-aided socket design), CAPOD (computer-aided-prosthetic and orthotic-design), AFMA (automatic fabrication of mobility aids), CAPA (computer-aided prosthesis alignment), and others. Throughout the remainder of this century we will see a remarkable expansion of what we might call "computerized prosthetics and orthotics".

Computer applications in prosthetics and orthotics

Developments of computer aided design and manufacturing in other fields give indication of the direction that will be taken in prosthetics and orthotics. In most fields the first step has been to use the computer to more or less automate what is already being done. For example, drafting, mechanical drawing, and the layout of electronic circuit boards, which originally were done by hand at a drafting table, are now done in essentially the same way, but through the use of computers. The computer allows the work to be done more quickly, with more accuracy, with better quality, and with better documentation. Also, the approach allows copies, upgrades and modifications to be made efficiently and easily. The first CASD systems, developed in the Medical Engineering Resource Unit (MERU) at the University of British Columbia and in the Bioengineering Centre of the University College London (both presently available on the commercial market), are essentially systems of this nature. They automate the methods presently used by prosthetists. Although still quite new to the clinical scene, these systems appear to allow sockets to be made with accuracy, with excellent documentation, and to facilitate socket modifications. It is interesting to note that the system developed at the Bioengineering Centre in London has a "user friendly" interface that epitomizes the computer development work of Alan Kay and his associates at PARC almost twenty years ago. Besides the early work in Canada and in the United Kingdom, there are now research and development activities concerning the computerization of prosthetic and orthotic techniques in Belgium, Germany, Japan, the Netherlands, Sweden, United States, and other countries.

Applications in other fields

Many other fields, while still retaining this first level of computerization, have advanced beyond CAD to CAE. At this level the computer not only assists with drawings and the replication of previous design methods, but the system is now used to do many of the engineering computations and determinations using data bases (e.g. data tables), design equations, and computational approaches such as finite element methods. These methods also make extensive use of high quality computer graphics. Examples of the graphical images that result from these kinds of systems are illustrated well in the June 1989 issue of National Geographic. The methods are particularly prevalent in aerospace, automotive, and construction industries. Architecture, which like prosthetics is a blend of art and engineering, provides an excellent example of where computerization has enabled architects and building designers to improve designs from esthetic, functional, and structural viewpoints and to do so with more accuracy and lower cost even in the face of greater design complexities. Interestingly, computer design itself would be impossible without the aid of large-scale computers. This means that computer systems themselves are being improved in a kind of "bootstrapping" fashion. Other examples of work of this nature, perhaps closer to home, are in the orthopaedic surgery field where a significant percentage of total joints (particularly hip prostheses) are custom designed and manufactured for patients through use of CAE and CAM techniques. The construction of physical models of internal bony structures of the human body for surgical planning is now a reality and the use of computer-assisted surgery is on the horizon.

Future applications in prosthetics and orthotics

The progress made in other fields would indicate that CAD/CAM in prosthetics and orthotics will not be static and that it will advance quickly from CAD to CAE. Instead of basing socket and prosthesis design on the empirical methods that have traditionally been used, it is probable that designs of sockets and components in the future will be increasingly based on fundamental mechanics and biomechanics principles. For example, finite-element modeling of complex bone-tissue, prosthesis-orthosis interfaces-made practical by computers-may assist in the design of sockets with predetermined pressure patterns. Work of this nature is already going on in research laboratories here and elsewhere. Quantitative and objective design methods will improve prosthetic/orthotic systems and improve our understanding of what is done and why.

Improved shape sensing and a better understanding of soft tissue mechanics are needed to create better input data for prosthetic-orthotic CAD systems. On the manufacturing side, future systems will not use positive molds of the residual limb but will create the socket directly from a plastic material (e.g. as with the new laser system from 3-D Systems, Inc.), through laminated cross sections, or through direct milling of the socket from a material like wood. It would be ironic if the high technology of CAM would bring back the use of wood sockets. An ultimate dream that may be possible someday is to make the whole prosthesis as a single unit automatically by CAM techniques that take into account the socket shape, proper prosthesis compliance, prosthesis alignment, external shape, and other factors.

Prosthesis simulation through computer techniques may also be important in controls training of amputees, particularly upper-limb amputees, and in helping prosthetists fabricate prostheses with preplanned work space. The powered limb program at the Hugh MacMillan Centre in Toronto, Canada has already demonstrated the efficacy of using computers for (1) electric hand simulation for myoelectric control training, (2) an aid for automatically setting optimal myoetectric system thresholds, and (3) as an aid for helping establish optimal electrode positions on residual limbs. Availability of the new computer technologies will enable much better evaluation systems to be developed to evaluate the efficacy of prosthetic-orthotic systems. Alan Kay's developments will influence Hector Kay's speciality, evaluation. Finally, the computer technologies will influence approaches to prosthetic-orthotic education, another of Hector Kay's special interests.


The computer is not like the tools or computing machines of the past. It is not like an analog computer for solving differential equations, although it can do that. It is not just a device for calculating the trajectories of artillery shells, although it can do it, and did during its infancy. It is more than just a computational device. Alan Kay, Doug Englebart and others changed our perception of the computer and have introduced a new era. It is like a new mutation in our cultural evolution that changes our outlook in many ways. It is a device that can build upon itself, a machine that allows knowledge to build on knowledge and to give us rapid access to information and answers. It is a device that not only can represent our world but a device that can devise completely new worlds. That is what I think it will ultimately do in prosthetics and orthotics: usher in a new world. It is, however, not a world to fear, because if Alan Kay's philosophy is followed, the augmentation systems that assist us will be simple and intuitive to operate.

Prosthetics and orthotics is small enough that even a preliminary "Alan Kay Dynabook" could help us substantially. A problem will be with how to get the information into the machine, and with how to work out the problem of what to do with what is known that is also not true.

Prosthetics and orthotics is, I think, entering a new age. Most fields are-- some faster than others. It is an age symbolized by Alan Kay, the lover of music and children, and the prophet of new ways to augment the intellect and to empower individuals and groups. Our age in prosthetics and orthotics is still influenced by his father, but the future will be influenced strongly by the computer systems his son has helped develop. Hector Kay would have embraced the new concepts, I think, but always from a practical and pragmatic viewpoint-that was Hector's way. I am sure if he were alive today he would suggest that personal computers and the mind amplifiers of the future should have the objective of empowering the surgeon, the prosthetist/orthotist, the nurse, the therapist, and the engineer so as to enhance what they can do for disabled people. I am sure he would see the potential of these new ideas and be at the forefront of welcoming this kind of computer technology to the prosthetics and orthotics field. I know he would have been proud that important aspects of these new methods are due to the work of his son.

The laboratories of the Northwestern University Prosthetics Research Laboratory and the Rehabilitation Engineering Program are open for you to visit. You will see concrete examples of trends in the computerization of prosthetics and orthotics. Perhaps while there, you will visualize what may happen in the future. Perhaps, in this laboratory, you will feel the influence of Hector Kay, the man we now memorialize, because he certainly influenced me. I am sure you will catch a glimpse of the influence of his son, Alan Kay. In addition, you can meet Mrs. Kay. She will be able to tell you more about Hector, and about Alan. She may even be able to tell you more about the future of prosthetics and orthotics, because she has been very closely involved with "inventing the future".

Northwestern University Rehabilitation Engineering Program, 345 East Superior Street Room 1441, Chicago, IL 60611