Engineering in medicine (1974)

Start. First hurdle 3 seconds. Landing 4 seconds. Spring off the third hurdle 7 seconds. Straight run between hurdles 8 1/2 seconds. 11 seconds. Final landing 12 seconds. Finish 50. My colleague is a doctor and I am an engineer. We're carrying out tests on an athletes heart during strenuous activity. For me, as a doctor, I need to know how the heart behaves under different conditions while it's subject to those conditions. My problem was how to measure the heart's performance on an active subject. Answer: a transmitter small enough and light enough to carry on the body to pick up the heart signals. I need the results permanently recorded for future comparison and analysis. We have provided a receiver which puts the signals from the transmitter onto a tape recorder and a videograph monitor which shows the heart rate changes. In this way, medicine and engineering are in partnership. [Music] No wooden legs anymore. Medical and engineering research have combined to produce artificial limbs which work as near to the real thing as possible. Recent developments in bearings, hinges, hydraulics, and lightweight metal alloys have helped Yes, the more we get to know about artificial limbs, the science of prosthetics, the more we realize we are only just starting. For instance, this man's artificial leg is having its response to pressure and action recorded. The terminals on the fiberglass socket carry electric impulses which register the pressures, torqus, and tensions at points where they appear. The impulses are carried by overhead cables to the recorders. [Applause] In this way, we can check that each individual will have the best limb for his use and by using a computer add to the store of knowledge which will lead to future improvements. What we do right from the start is to translate the medical requirements into engineering terms. Drawings and plans are the first step in the partnership. You see this elastic fabric? Well, it's being tested before it's used to make a socket for an artificial leg. The stump is measured and a sleeve made of the elastic is tailored to fit the individual patient. A mold or matrix is made to the exact size and shape of the stump by applying plaster of Paris. From this a master is made and put through various stages. Finally, a fiberglass socket is molded which fits the stump exactly. This socket on a temporary frame and foot is fitted to the patient and rigorously tested for faults or the possibility of improvement for this patient's individual requirements. 18,000 legs a year, including replacements, are made in this country. Their designs embody physical, hydraulic, and engineering principles applied to the making of an efficient substitute for the original limb. The artificial ankle joint, for instance, is made up of rubber components free to roll under compressive stress, combined with rotors engineered from fine steel to simulate the movement of an actual ankle. Strong yet light. Providing workable limbs is one obvious branch of medicine where we link up with engineering, but there are many others. For example, some people have hearts which periodically and without warning fail to maintain sufficient circulation causing unconsciousness. What's needed for these is some form of stimulation and that must be applied instantly when it's needed. So the pacemaker was designed. Only a small operation is needed to place it in the body with its electrodes in the heart. And when the heart flags, the pacemaker sends out impulses which stimulate the heart by giving it a series of small electric shocks. This invisible heart controller enables the patient to go about his daily life normally and comfortably. This life-saving invention had to be designed to very exact requirements, very light, durable, and completely reliable. The case must withstand any possible corrosion from body fluids and the batteries be able to power it for the two or 3 years in the body. Incidentally, we are now working towards making them last for 10 years or more. Of course, to get the maximum benefit from this medical engineering partnership, its products must reach the widest possible range of patients. That means full-scale industrial production. [Applause] Hello. the design stage. That's where a medical requirement becomes an engineering fact. Today, what we call hardware technology helps us treat diseases of the body. For instance, a defective kidney can be a killer because it is the main organ for getting rid of waste from the body. If this isn't cleansed regularly from the bloodstream, the body becomes poisoned. So, the alternative to transplanting another human kidney is to cleanse the whole bloodstream at regular intervals artificially. To do this, plastic tubing is inserted in an artery and the whole bloodstream, 5 L of it, is drawn by a pump into this cleansing coil where it is filtered through cuprane textile and is chemically treated. The clean blood is returned by the pumping system back into the body. The process takes a matter of hours and after a rest and a cup of tea, the patient goes back to normal life until it is necessary to cleanse the blood again. The whole process is electronically controlled and if anything goes wrong, it's signaled automatically. In the treatment of some illnesses, we saturate the tissues of the body with oxygen by putting the patient into a pressure chamber. Nowadays, instead of a large chamber in which the staff as well as the patient are exposed to the pressurized atmosphere, the patient is put into a transparent cylinder from which he can communicate through an intercom system. What we have done here is to make a cylinder strong enough to withstand the necessary pressure above that of the normal atmosphere and large enough to contain a human body and the necessary controls to register his reactions. A closedcircuit control unit is mounted in a console and oxygen under the required pressure is fed into the cylinder, recirculated and the body's reactions registered on the monitor so that the staff can know exactly what is happening to the patient. Poor blood supply and the effects of carbon monoxide poisoning are two of the conditions these machines can be used to treat. Hyperbaric oxygen machines are also used for the resuscitation of babies at birth. Thrombosis, the modern scourge, starts with a blocking of the arteries. We are examining methods of clearing the veins so that blood can flow freely again. One way is to use a flexible probe which is inserted through the artery wall and pushed along inside until it meets the obstruction. Within the probe is a miniature high-speed drill. This cuts the obstructing material into very small pieces which are then sucked back up the tube in saline solution. So far we have seen machines used to replace missing limbs and for treatment. But they are also used to help in nursing patients who need intensive care when a nurse would have to report any setbacks or variations immediately. Well, here again is where we can help. Electronic engineers have developed instruments to record the heart rate, blood pressure, and respiration and show them immediately. In this equipment, responses are shown on an oscilloscope and recorded on magnetic tape. And this information can easily be processed by a computer. That's what we needed. Automatic monitoring. Now, if necessary, a dayto-day, hour to hour, or even continuous report can be obtained. And the collected histories of a number of patients processed by a computer for research. The number of patients who can be cared for by this means is practically limitless. It is a great help to busy hospitals and it is not only in the intensive care unit the machines can be used. They can also help to diagnose what is wrong or may be going wrong with patients. Take blood testing for instance. These tests are simple and standard, but they take time. Time that could be more profitably used for other purposes. This machine can analyze 300 samples of blood or other fluid an hour and give us measurements of up to 12 different constituents. The blood sample is put into a special vial. The sample is coded for each specimen. The vials are then put into magazines which hold 38 at a time. A mechanical conveyor belt system now takes over. The plasma from each vial is siphoned out into a container and sent on its way to the consoles which have been set for specific analysis. Sufficient of this plasma is dispensed each time so that the chemical part of the job can be carried out. Rotors bring in reagents at specific time intervals and inject a new dilluent into the test tubes. This machine is doing exactly what is done by hand, but is doing it hundreds at a time, freeing laboratory staff for tasks requiring human skills. The result of each test is electronically recorded under its original code. A teletype machine automatically provides a record of results and simultaneously a punched paper tape is produced both for record purposes and for further processing by computer. Years of research, planning and intricate design go into the producing of a machine like this. It needs imagination and foresight even to visualize the possibilities and benefits that such developments could bring. It needs determination and sheer professionalism to turn the idea into reality and bring those benefits within the reach of mankind. [Applause] And this doesn't dehumanize medicine. You know, new technology gives us more time for the doctor patient relationship. When all is said and done, our real triumphs are helped by engineering. [Music] We have seen something of how medicine and technology in partnership help to raise the quality of human life. But how the challenges of the future are met will still depend on the creativeness and ingenuity of the engineer. Heat. Heat. [Music]