Robots in the 20th century have been valued mainly for their enhancement of productivity. According to Professor Ichiro Kato of Waseda University, 21st-century robots will be valued because they enhance amenity. The development of robot systems for health care, detailed in this special issue of Robotica, is an affirmation of this forecast.

Several factors have combined to cause this development, although economic factors are paramount. Industrialised countries, where robots are most likely to be used, face an ageing population-a result of lower birth rates, reduced infant mortality and increased life expectancy. This ‘ageing society' is expected to have enormous impact upon these countries’ health and social security systems which devote a large proportion of their resources to the care of older people.

This paper surveys the scientific literature on present and future applications of robotics to health care. The term ‘health care’ refers to different forms of assistance rendered to people who are unable without such assistance to perform physical tasks that ‘healthy’ people accomplish unaided. Research efforts and accomplishments to date are concentrated in four main application areas: rehabilitation; patient transfer; assistance to surgery; and ‘microrobots’ suitable for use inside people. Some initial work has been done in other areas including robotic diagnosis and therapy.

Even as the first industrial robot started earning its keep, researchers were dreaming of using robots in servicejobs, intimately serving human mentors as Isaac Asimovwould have had it. But that was not to be. Initially therewas a paucity of appropriate technology. Then the barriers became economic and institutional.

These barriers will be discussed to set the scene. The discussion then will focus on a spectrum of technologythat has been channelled into a cost-effective commercialproduct. HelpMate utilises an array of sensors andsensor fusion to succeed as a courier in multi-storeyedcluttered hospitals. Our advice for all researchers whowould have robots serve in health care is: “Get out intothe real world as soon as you can”.

More than 50 ‘Handy 1’ robotic aids are now in use that enable some handicapped people to feed themselveswithout assistance from a carer. The benefits of thisdevice include much greater control of the eating process by the user as well as the development of eating skills. The article describes the genesis of this device and its subsequent development and early evaluation.

It is expected that an appropriate robotic appliance can play a major role in providing long periods of independence, which in turn will lead to improved quality of life, for people who are severely physically limited. As part of its research programme over the past several years the Neil Squire Foundation has been developing a workstation-based robotic assistive appliance (RAA) for use by such persons. We feel that robotic aids initially will have their most profound impact when applied in a vocational environment. Although other rehabilitation researchers have similar interests there is a great need for the utility of robots in these environments to be more fully substantiated and assessed. A formal evaluation process currently is under way in an attempt to quantify and to understand the cost/benefit results of using the RAA in office situations.

This paper describes the first prototype of the robot system ‘MASTER’ for helping disabled people. The results of evaluations after one year of experiments in French rehabilitation centres are reported. Following comments and criticisms by staff and users, many improvements were made to the first version and have been taken into account in the design of a new version which will be evaluated in 1992–93 in French and European projects.

Interactive robot systems are under active investigation as aids for people with impaired manipulating ability. Under the direction of a disabled operator, a robot can manipulate objects, thereby increasing the independence of the operator in home, school and work activities. This paper describes a high-level control language CURL developed to facilitate communication between a disabled operator and the task environment. CURL is a Windows-based application. Interactive robotics requires a different approach from mainstream robotics where humans are kept out of the robot's work area.

The combination of robotics and medical imaging may soon provide orthopaedic surgeons with a tool that significantly increases the precision of cementless total hip replacement operations and directly links preoperative planning with surgical execution. Twenty-six successful robot-assisted operations have been performed on dogs and the first clinical trials on human patients have recently taken place.

A special-purpose robot for prostatectomies has been developed. Details of the robot mechanism, control system and human/computer interface (HCI) are discussed with special emphasis on software methods to ensure system safety. The clinical application of the system is described and software requirements for operating-theatre use are indicated. These requirements include safe error recovery, facilitation of reliable surgical procedures, and an effective HCI.

We describe a robot capable of performing all procedures necessary to carry out a complete stereotactic neurosurgical operation under the control and supervision of a surgeon. The operation consists of the introduction of a small probe with diameter 2–3 mm through a hole without trepanation. The robot has been built and is now being tested and evaluated. The accompanying control software as well as various medical probes are either in development or partially tested. The installation will be able to carry out a complete intervention under the surveillance of a computed tomography scanner. In this article we emphasize the design choices required to eliminate gearing backlash in a crucial degree of freedom.