But in spite of real market opportunities, two main problems still remain and can explain actual difficulties for a real emergence of technical assistive aids:
the acceptability of the users;
the affordability and economic rationale.
Leaving to specific details, these types of products may be conceived, developed and proposed in a productive sequence as shown following:
Specification of Needs
Determination of Target
Conception and Production of Products and Services
Problem of Acceptability
Problem of Solvency
To satisfy the demand of dependent people (disabled and the elderly), products and services are more and more often conceived according expressed needs, after long and expensive market study. But, in spite of this analysis, a part of the demand is still not satisfied or not concerned by all the products. The phenomenum of acceptability can explain the differences between declared needs and their acceptance by the users.
Many criteria can be integrated:
cultural, sociological an religious environment;
level of social life;
age of the users;
profession of the users;
medical and dependence situation;
the weight of user association;
the level of development;
the rule of the public institutions;
the size of the market etc.
The three following examples can explain the situation:
quadriplegic, living alone at home, need assistive aids to prepare meals, to switch on TV or recorder etc. Some products are adapted to their handicap and can help them, but an individual's way of life, their culture, their personal history can lead them to reject the product.
older people, especially dependent ones with problems of mobility and memory, prefer to stay at home instead of going to special institutions. Special equipment such as alarm and surveillance services exist, but they can be rejected because they symbolise age and dependency.
religious aspects can explain a better acceptance of technologies. Protestants have a different conception of society from Catholics and in general they use technological products more readily.
After the transformation of needs into real demand a last step must be solved before the purchase of products, ie the financial resources of users. Despite public and official promises, most countries have not integrated into their social assurance system the financial contribution to finance for technical assistive aids.
These products and services have a cost, and a limited market does not permit a decrease in the selling ie "ladder economies".
In Europe the analysis of two different countries reveal the importance of the public financial contribution.
In The Netherlands, technical assistive aids such as environment control and robots are supported by the public social assurance system as are medical expenses or pharmaceutical products. Special sites  are implanted to fix these technical assistive aids on the wheelchair for instance. The consequences on the market are extremely positive  and there is a real emergence of technical assistive aids for the benefit of disabled and older people.
But in France, public social assurance is oriented to medical and pharmaceutical expenses. Technical assistive aids do not benefit from public financial support. Users who cannot finance these products and services themselves must find private support eg users associations  . Users are left alone to manage integration of all these products in order to counter discomfort, disruptions, compatibility problems etc.
In spite of a rising number of dependent people all other the world, and the actual tendency of the industrial sectors to resolve problems and to propose products and services not for a local market but for in international one, we can ask the following questions:
Can we speak of an international or local demand?
Is the demand similar everywhere?
How to measure the phenomenum of acceptability?
How to solve the problem of solvency?
 Hetdorp in The Netherlands.
 Sales of Manus are very significant in The Netherlands, more than hundreds.
 AFM (French muscular dystrophy users association) and APF (French association for motor disabled), for instance.