ables machines to talk to machines and, of course, it can also be used as a regular telephone for verbal communications.

(The Data-Phone sender illustration referred to follows:)

Mr. CALLAHAN. There are three types of data sets that are used in the transmission of EKG's. The sender, which is normally used in a small hospital or a nursing home, from where a number of EKG's would be sent regularly, is permanently installed like a telephone. There is a portable sending set that is used with a portable EKG machine and can be used with almost any telephone, whether it be in a hospital, a doctor's office, or even in the patient's home.

The Data-Phone receiver would be located in a cardiologist's office or a hospital or regional medical center.

In a typical transmission of electrocardiograms over a telephone line, a doctor, technician, or hospital staff member prepares a patient for a regular EKG examination. But before the examination begins, a phone call is dialed to a heart specialist. Before the EKG is transmitted, certain personal data about the patient is provided verbally— his name, his age, his sex, height, and weight. The examination takes about 5 minutes with both the transmitting and receiving locations getting simultaneous recordings of the tracing.

Once the electrocardiogram has been sent, the specialist can analyze and discuss the interpretation with the sending location.

Several medical centers are using Data-Phone service to provide EKG service to doctors and hospitals in their region. For instance, there are 29 hospitals and doctors' offices located in Nebraska, Iowa, and South Dakota which send EKG's to Creighton University School of Medicine's cardiac laboratory in Omaha.

In the picture we have on the screen now, an EKG is being received at Creighton University of a patient in a rural hospital, suffering from a severe heart disturbance. As a result, the patient was moved to a larger hospital, where he could receive proper treatment.

(The Data-Phone receiver illustration referred to follows:)

Mr. CALLAHAN. In his office in a small town in Iowa, a doctor reads a patient's electrocardiogram while, simultaneously, it is being sent over the ordinary telephone lines to Creighton's cardiac laboratory for interpretation. In this case, the portable data set is used by the local physician.

(The illustration referred to follows:)

Mr. CALLAHAN. In the third illustration, a technician sends the patient's EKG from the patient's bedside to the center.

Illustrating the flexibility of this service, the director of the Creighton Cardiac Laboratory receives EKG tracings in his home. At night, electrocardiograms are sent to him in the absence of a staff cardiologist or for consultation.

At this point, with the assistance of my associate, Mr. Richard Murray, we will demonstrate the transmission of an EKG, using a mechanical heart for a patient. We have the equipment over on this table.

Now, at his office or home or at the patient's home, the physician has a portable EKG machine about the size of a tape recorder, and he also has a portable EKG Data-Phone set. He attaches the leads of the EKG machine to his patient. In this case, that is a mechanical heart we will use to be the patient.

He then calls a cardiologist or medical center, using any telephone that happens to be convenient.

Upon receiving an answer, he describes the case and gives the name, age, height, weight, and sex of his patient. He then places the telephone handset in the Data-Phone data set and both he and the receiving location switch the Data-Phone over to an EKG transmission mode from the voice mode.

Now, he starts his EKG machine and simultaneously he and the doctor at the receiving location receive a tracing, an EKG tracing.

Senator NELSON. So the cardiologist who is being consulted 500 miles away, or 200, or whatever, is receiving this electrocardiogram on his machine at the same time that the local physician is receiving it on his

machine?

Mr. CALLAHAN. That is right; exactly, sir.

Senator NELSON. Then you are going to tell us how he makes his diagnosis and responds back to the consulting physician?

Mr. CALLAHAN. Yes, sir. Normally, this transmission would run 4 or 5 minutes, because there are quite a number of body leads, but we are going to end it here. We have sufficient tape to show what the doctors would have in their hands at each location.

Then, depending on the circumstances, they could either proceed with an immediate discussion, analysis, and interpretation. Or if it is a routine diagnosis, the cardiologist would call back and discuss his interpretation with the local physician back in his office.

Senator NELSON. Now, the cardiologist is not on the telephone all this time, taking the electrocardiogram; is he?

Mr. CALLAHAN. No, sir; the telephone handset is actually over there in the Data-Phone data set, which makes the connection between the EKG machine and the telephone network. By this means the signals can be transmitted to the distant end.

Senator NELSON. Then if the cardiologist determines from his examination of the electrocardiogram that there is a serious matter here and he ought to discuss it with the physician who transmitted the information on his patient, what does he do?

Mr. CALLAHAN. After he sends the EKG tracings, he then takes the handset

Senator NELSON. Who takes it?

Mr. CALLAHAN. Both the local doctor and the specialist. They can tell when the tracing ends. Then both the receiving end and the local doctor take the handsets, switch into a voice mode again, and discuss the case at hand before hanging up.

Senator NELSON. So they are connected all the time?

Mr. CALLAHAN. Oh, yes. Therefore, as you said, if there is an indication of an immediate need, they can make that analysis and interpretation right away and take appropriate action.

Senator NELSON. I see.

Is this being done anyplace now?

Mr. CALLAHAN. Yes. In addition to Creighton, we know of at least 17 other locations in the United States where such groupings are in operation.

Senator NELSON. I know, but are they using this equipment?

Mr. CALLAHAN. Oh, yes, sir. This is now standard equipment which is available to all of the Bell telephone companies, and there are installations in various parts of the country-New York, New Jersey, a number of them-out in Wyoming and West Virginia and Illinois; and almost weekly, there are new groups. By groups I mean you have to start with a regional center or a cardiologist, who then arranges the service with other local physicians in his area for whom he will do the specialist work.

In this communications system I have just described, the medical data is interpreted and analyzed by a specially trained person. It is apparent that the processing of millions of EKG's annually in the fight against heart disease imposes a tremendous burden on these specialists. A research program presently sponsored by the U.S. Public Health Service is proving the feasibility of applying modern data communications and data processing techniques to the rapid, accurate interpretation of electrocardiograms and other medical signals by computer. A computer is being used to analyze electrocardiograms transmitted over telephone lines from cooperating hospitals and Government clinics to the U.S. Public Health instrumentation field station.

Senator NELSON. Are you saying that the computer does the analysis. without the intervention of a doctor?

Mr. CALLAHAN. Yes.

Senator NELSON. Will that not upset what the medical profession is always worried about, the physician-patient relationship?

Mr. CALLAHAN. Well, in this case, it is an analysis and interpretation, but it is not telling the doctor what to do; it is telling him what the condition of the heart is, which can be, as is being effectively demonstrated by the U.S. Public Health Service, very dependably performed by the computer.

Senator NELSON. Is that kind of analysis of an electrocardiogram by a computer being done in practice now anyplace?

Mr. CALLAHAN. Yes.

Senator NELSON. Where?

Mr. CALLAHAN. We will show you some interpretations which yesterday were transmitted from the Hartford Hospital in Connecticut to the U.S. Public Health Service computer and the analysis and

interpretations which were sent back to Hartford Hospital. We will show you copies that we have here today. It is actually a working system.

Senator NELSON. Does it just interpret normal electrocardiograms, or does it also interpret or analyze disease situations?

Mr. CALLAHAN. It does all of the analysis and interpretative work which would normally be performed on an EKG tracing by a specialist. It actually removes the burden of that interpretative work from the cardiologist or specialist.

Senator NELSON. What does the cardiologist do with this information? Does he use it?

Mr. CALLAHAN. The hospital then acts upon that information just as if they had received the interpretation from a cardiologist.

Senator HATFIELD. Do I understand that the hospital actually will receive a monitor signal to be seen on their encephalographs or cardiographs?

Mr. CALLAHAN. Yes, Senator.

This question really does get over into the field of medicine more that communications, and, if it pleases you, I would ask Dr. Meyer of the University of Wisconsin if he would care to make some comment to describe that more clearly.1

Dr. MEYER. Thank you, Mr. Callahan.

Senator NELSON. Dr. Meyer, of the University of Wisconsin, we are pleased to have you here today.

Dr. MEYER. Thank you very much.

With an electrocardiogram, there are a great number of measurements, and a great number of judgments that have to be made, that can be done mechanically. The actual judgment of what the implication of this is to the patient cannot be done by a computer. This has to be done by somebody who knows the history and what they have found on physical examination. It is a synthesis of all the data that can only be done by the physician. But the mechanical reading of the electrocardiogram can quite easily be automated.

Senator NELSON. I still do not understand it very well. What has it done that the cardiologist does not have to do over again? The cardiologist gets the machine's mechanical analysis. How does that save the cardiologist from repeating himself, and what good does it do him?

Dr. MEYER. It saves him a tremendous amount of time in doing all these basic measurements that have to be done. It gives him these measurements in a form in which he can interpret from them what this cardiogram means to the patient, knowing the background of the patient, knowing the symptoms and the physical signs of the patient. A cardiologist spends perhaps, oh, 8 to 10 minutes looking at a cardiogram and taking these measurements and this data from this. Senator NELSON. You are talking about actually

Dr. MEYER. Physically doing this.

Senator NELSON. Measuring in terms of centimeters and so forth?

1 See complete prepared statement of Dr. Meyer, p. 1204, infra.