Tokyo, June 2, 1998 -- Mitsubishi Electric Corporation (President: Takashi Kitaoka) has developed an exercise system called StrengthErgo. The object of the system is to help rehabilitate patients by restoring effective physical functionality.

Up to now, the absence of an exercise system versatile enough to cater for all levels of disability has prevented partially paralyzed patients from undergoing the sort of positive rehabilitation that would give them the day-to-day independence they need. Patients in need of urgent rehabilitation have been similarly deprived. The new system provides patients of every sort with the opportunity to follow a training program tailored specifically to their needs while at the same time enjoying a video.

During the development of the system, Mitsubishi Electric was provided with clinical advice by Dr. Sumio Yamada, Clerk Examiner of the Department of Rehabilitation Medicine at St. Marianna University School of Medicine in the city of Kawasaki in Kanagawa, Japan.

Development objectives

The progressive aging of Japan's population is making it increasingly important to find ways of helping old people to regain their strength and of preventing them from becoming bedridden. To enhance the quality of old people's lives by enabling them to remain independent on a day-to-day basis, the Public Nursing Care Insurance System, which is due to be introduced in the near future, will be called on to cater not only for the provision of straightforward nursing care but also for the establishment of active rehabilitation programs.

Rehabilitation programs currently tend to focus on training disabled persons to get around, using various means of transport, getting in and out of the bath, and so on. However, they still have a long way to go in helping people to restore and/or maintain their independence through programs of exercise designed to rebuild muscular and overall physical strength. This is because, among other things, most exercise equipment used for rehabilitation purposes is of a sort designed to enable able-bodied persons to enhance their fitness by improving their heart and lung functions rather than to help patients who have suffered partial paralysis as the result of a stroke -- a problem very much on the increase today -- to recover their physical strength.

Mitsubishi Electric undertook the current development program in response to the growing need for exercise equipment for persons undergoing courses of rehabilitation.

Features of the StrengthErgo therapeutic exercise system

1. Training for people with every kind of physical impairment

The system can be used to rehabilitate any patient with functional impairment of his/her legs due, for example, to the partial paralysis that is one of the common after-effects of a stroke. Cycling exercises are used to simultaneously measure patients' left and right leg strength, thereby enabling continuous monitoring of the efficacy of their training. It is thus a simple task to adjust training programs to meet the precise needs of individual patients.

2. Fast rehabilitation achievable by adjustment of the exercise position

The exercise position of the equipment can be adjusted to accommodate patients in various postures from lying face up to occupying a regular sitting position.

3. Training combined with the enjoyment of a video

To promote the continuity that constitutes such an important element of any exercise program, StrengthErgo also includes an enjoyable cycling video as an integral part of the program. Video images of street scenes, mountain scenery, the changing seasons, new discoveries and so on help the patient to achieve the sort of inner fulfillment that can help them relax and enjoy their exercise program.

The System

I Exercise functions to suit specific disabilities

1) Individual left and right drives

Conventional exercise bicycles are fitted with a single crankshaft. This is not suitable for patients whose disability is such that the strength in their left and right legs is not uniform. The present system provides for the pedal crankshaft to respond independently to differences in the force applied by left and right legs. This enables left and right legs each to be exercised at a pace which suits them and enables separate load values to be set for left and right pedals to match the patient's needs.

2) Assisted drives

In addition to the drive load device, each pedal is also fitted with an assist motor to enable the pedals to be switched into a mechanical drive mode. The motor is used to drive the pedals mechanically to help rehabilitate patients who are paralyzed down one side only, for example, or patients with damage to their spinal cord, who may find it difficult to pedal at all. The assist motor function can also be set such that it is activated to help the patient continue pedaling if he/she tires and allows his/her pedaling rate to drop below a specified level.

3) Measurement of leg strength

The system measures muscle strength in situations in which the muscles are actually being used. By putting the equipment into isokinetic mode -- an exercise situation in which the speed is held constant -- leg strength can be evaluated by measuring the load torque applied when the patient presses down on the pedal.

4) Setting the exercise program

By combining the independent left and right drive function and the assisted drive function, the exercise load can be freely and easily set to provide a therapeutic exercise program tailored to the needs of the individual patient. The program can be modified during training to accommodate changes in the patient's condition.

II Adjusting the exercise position

A reclining seat and a pedal height adjustment mechanism enable the exercise bicycle to be set to a position that best suits the patient. As the exercise position of the equipment can be adjusted to accommodate patients in various postures from lying face up to occupying a regular sitting position, it can be used to start rehabilitating patients from the moment they are able to get up out of bed. A revolving saddle also makes it easier for patients to get on and off.

III Cycling video software

The exercise system is also provided with video software to help patients derive greater enjoyment from their exercise sessions. Images of street scenes, mountain scenery, the changing seasons and so on are used to help the patient achieve the sort of inner relaxation that will enable them to enjoy their exercise program. The software also enables the pace and quantity of exercise to be matched with cycling speed, gradient and distance. Patients can use these functions to adjust the pace of their exercise program to suit their physical strength. This makes it possible for them to enjoy the satisfaction of achieving their chosen goal.

By increasing the patient's interest in their health, the system also opens the way to enjoyable daily training sessions for the prevention of obesity, for example.

Possible clinical uses

(1) For patients with impairments of the nervous system such as hemiplegia, ataxia, Parkinson's disease, and (partial) damage to the spinal cord

(2) For patients with inflamed joints, hips, broken vertebrae and the like following orthopedic surgery

(3) For patients with respiratory and circulatory problems who need to improve their heart and lung functions

(4) For patients weakened by long-term confinement to their beds

(5) For patients in need of exercise to combat problems such as diabetes and obesity

Future development goals

Our aim is to improve the system by adding new video software to encourage continuous exercise and by developing and enhancing system functionality to satisfy a wider range of rehabilitation objectives. Furthermore, by combining the system with vital sign monitors such as electrocardiograms and blood pressure readings, a further objective can be to improve load control and enhance the system's safety and scientific validity.