Margaret Walker, creator of Makaton, has just retired from day-to-day involvement with the language that helps people with communication difficulties all over the world. She feels justifiably proud of progress so far - and excited that there is still lots more to do.
Most exciting of all, she says, is that the language she developed in a hospital more than 30 years ago to help people with severe mental problems is now turning out to be useful for many children, in special and mainstream settings, particularly in the early years.
Today, there is Makaton for Babies and Maths and Makaton. And, just last month, it emerged that Damien Jordan, head of Fairlight School in Brighton, was using it as a form of latter-day Esperanto to communicate with multi-lingual pupils.
The woman whose work has been of such therapeutic and educational benefit was originally neither a therapist nor a teacher; she was an accountant. But she was that rare thing: an accountant interested in communication.
As Margaret toured around Cornwall working for the family firm it was the interviews rather than the figures she enjoyed. After she had moved to London and married, she decided to train as a speech and language therapist and qualified in 1968.
Her first job involved working in the outpatients' department of Botleys Park Hospital in Chertsey, a large mental hospital catering for 1,300 patients from children to geriatrics. Many had severe learning and communication difficulties. Margaret quickly realised that conventional speech therapy, taking patients out of their setting for one-to-one sessions, was often of little help.
"I began to recognise the need for some means of helping patients to communicate about their everyday difficulties," she says. "It was so frustrating for them and just as frustrating for their carers. There was a communication breakdown."
On the basis of simple observation of patients' daily lives, she drew up a list of the terms that would be most useful to them. Having worked with deaf people during her training as a therapist, she decided to run trials using sign language for simple things, such as food.
The results were amazing. "People who had not been paying attention and had been posing serious behaviour problems suddenly started to pay attention," she says. "For many years, these people had experienced nothing but failure; they just had to be motivated." Margaret drew up a vocabulary of "heavy-duty" words that was to become the core of the Makaton language. The name Makaton is taken from the first syllable of her name and of Kathy and Tony, two former colleagues from the Royal Association of Deaf People. She matched them to signs based on British Sign Language, and also used facial expressions and signing techniques such as indications of movement.
She always spoke the words as she signed them. "Makaton is not a sign language," Margaret says. "The signs are there to support speech. So we always use the words in the order of English speech. If people are not competent to speak back, they sign back."
After that, she started working in schools and was soon inundated with requests for information and training in the new language. Her first workshop took place in the summer of 1976.
In the mid Eighties, graphic symbols (such as a stick man for a person) were introduced for each concept, as an extra aid to understanding. Symbols are often the preferred mode of communication for children with autism, at least initially.
Today, Makaton is used by millions of people in more than 50 countries, ranging from Europe to Japan, India and the Middle East. Key to its success is flexibility. The Core Vocabulary, now numbering about 450 concepts, is divided into stages, starting with immediate needs, such as eat and drink, and moving on to more complex and abstract vocabulary, such as time and emotions. Then there is a huge resource vocabulary: more than 7,000 concepts and still growing, to reflect the needs and experiences of individuals leading different lives.
Now aged 70, Margaret is quitting as joint managing director of the charity she originally set up in her Surrey home. But it is hard to avoid the impression that she will still be its most active consultant.