his was not an ‘expert-system’. A short poster-session preceded the concerence dinner on the second day, and a common topic was the application of comput- ing to biological measurement.

The final morning of the conference was dedicated to computer-aids for the disabled; the discussion here tackled the difficult problem of how to turn an academic or isolated project into a commercial ven- ture, capable of reaching the people who need it. One practical suggestion was that the BES could be used in some way as a vehicle for communication and coordination.

The alternative programme was a visit to the Lab- oratory for Molecular Biology at Cambridge. Here users came face to face with the interactive molecular graphics system which had been described at an earlier session.

The conference drew to a close with a workshop session on “expert and knowledge-based systems”, chaired by Professor van Bemmel (Free University, Amsterdam). Those participants seeking a clearer view of exactly what an expert system is, must have been disappointed, because although examples of such systems were described, those qualities which combined to form an expert system were never them- selves clearly defined. Nevertheless, there seemed to be a general feeling that “expert systems” were worth pursuing, and discussion centred on the rel- ative merits of “rules” in the decision-making process. The point was also raised that in future, computer- architecture would change to reflect in some form the structure of a particular “expert-system”.

W. Greer

BIOMATERIALS IN ARTIFICIAL ORGANS

University of Strathciyde, 12-l 4 September 1983

Bioengineers, surgeons and medical scientists from Europe, North America and Australia attended this, the fifth in the international series of StrathclydeBioengineering Seminars. Over 30 papers were presented outlining the latest developments in blood purification procedures, metabolic assist and the interaction of biomaterials with tissue and blood.

Blood purification techniques, for example haemo- dialysis by kidney machine, have been in use since the 1940’s and it is estimated that a quarter of a million patients world-wide are now receiving dialy- sis treatment for kidney disease. The more recent technique of CAPD (continuous ambulatory perito- neal dialysis) uses compact, lightweight equipment which allows the patient almost total freedom of movement during treatment, instead of being immobilized on a dialysis machine.

The relative efficacy and convenience of the treatments was debated, Jim Winchester (Washington, USA) and Leif Smeby (Trondheim, Norway) supporting their programmes of CAPD with encouraging clinical results, while Professor Eli Friedmann (New York) voiced doubts over the explosive growth rate of this treatment. “Who benefits?” he asked. He had canvassed a sample of qualified, involved clinicians, not one of whom would choose CAPD for himself. He stressed that physicians must examine their motives for prescri- bing treatment which they would not undergo themselves. Peter Farrell (New South Wales) sug- gested that the industrial tail was wagging the medical donkey in the overselling of CAPD before adequate long-term results had been assembled. There are still problems, mainly with a high

84 J. Biomed. Eng. 1984, Vol. 6, January

incidence of peritonitis (every 6.7 mnths in 2/3 patients). Professor Bob Lindsay (Toronto) describing their programme, now in its 3rd year, ,indicated that the dropout rate from CAPD was 50% whereas dialysis use was increasing. However, CAPD is more suitable in some cases, taking into account socio-economic factors, and “quality of life”.

Dr Henderson (Glasgow) presented promising results by incorporating a charcoal filter column into the dialysis system. Dr Martin (Sunderland) pointed out that in acute renal failure where both dialysis and assisted ventilation were necessary, the artificial organs themselves have adverse effects. The solution to the problem merely changes the nature of the problem. He called for improvement to the systems in use to avoid the problems of altered blood pressure and the use of drugs to counter atactic arrhythmia and hyper ventilation. Infec- tions may be introduced at many stages of implementation. The very resuscitation fluids may lead to patient death.

The relatively new technique of plasmapheresis for

purifying blood is also under question. Although a proliferation of devices is available, the treatment is clinically justified for only a few rare diseases which are resistant to conventional therapy. Professor Klinkmann and Dr Funck-Bretano asked pertinent questions as to the number of diseases which had been successfilly treated by plasmaphe- resis. Hans Gurland from Munich, the chief centre for this research, considered that trials should be conducted, especially for glomerulonephritis, but

Mike Lysacht pointed out that to test a parachute, one does not push out half the airmen with no apparatus. The application of plasmapheresis to arthritis is still under investigation and to MS or cancer is still speculative.

The highlight of the meeting was the 1983 Adam Thomson Lecture, delivered by Professor H. Klinkmann, President of the International Society for Artificial Organs and Director of the Clinic for Internal Medicine in the Wilhelm Pieck University, Restock, GDR. He gave a comprehensive overview of materials used in contact with living tissues or biological fluid, with specific reference to blood detoxification and cardiac devices, where the materials cannot be divorced from the device. The materials may be natural or synthetic, but most derive from industrial use; few are developed direc- tly or specifically designed. He called for International Standards to characterize and test biocompatibility: an interfacial problem of high complexity, where risk and benefit must be balanced. He emphasized an optimistic quotation:

Health Equipment Information:

Evaluation issues

The DHSS publishes regular reports evaluating various types of medical equipment. Each report carries the results of full technical and user assess- ments of a number of models. It also updates any previous issue on the same category by discussing the choice available between all models tested which are still on the market at the time of publication.

No 112 updates information on ECG recorders.

No 113 compares seven diluters and dispensers for laboratory departments.

No 114 contains full reports on six defibrillators and summaries of past reports.

No 116 continues the series on infusion pumps by considering volumetric pumps.

These reports are available free to NHS staff, who should request them from their Regional Adminis- trator, or at $3 per copy form DHSS (leaflets), PO box 21, Stanmore Middx, HA7 lAY, UK.

“If a man know the structure and function of one of the parts of his body, he should be able to build it”.

Recent advances in the development of vascular grafts, heart valve substitutes and bone implants were described. The final workshop sessions, led by Bob Lindsay, Peter Farrell and Bob Sparks (St. Louis, USA) evoked controversy as to the cause of hypersensitivity in dialysis; there is doubt whether the hypotension and bronchospasm are related to complement activation and that preparation of the membrane or initial heparin influx may be the driving factor.

Thanks are due to the organisers of the stimulating exchange; in particular John Gaylor, Jim Courtney and Professor John Paul of Strathclyde; and to the ISAO, BES and Scottish Development Agency for support.

Mary Komdorffer

BES Announcement

PRESIDENT’S PRIZE

The award of the president’s prize and certificate for an outstanding paper published in the Journal of Biomedical Engineering is made for the 1982 volume to

H.S. Ranu

Department of Biomedical Engineering, Louisiana Technical University, Ruston Louisiana 71272, USA for his paper Three dimensional surgical simulations of the spine. (J. Biomed. Engng., Vol. 4, No. 4 pp 285- 288)

J. Biomed. Eng. 1984, Vol. 6, January 85