Media playback is unsupported on your device Media caption Nalini uses one of Dr Rao's voice boxes and she helps support other throat cancer patients

Dr Vishal Rao is changing the lives of throat cancer patients in India.

Across the country around 30,000 patients a year are diagnosed with cancer of the larynx. For those in the latter stages of the disease the only option can be to have the voice box removed, leaving the patient without a voice.

Replacement prosthetic voice boxes can cost up to $1,000 (£750) which for many patients is unaffordable.

"The majority of our healthcare is private and cost prohibitive. That was the reason that I felt that there was a dire need to actually help these patients speak again, because speech is a right and not a privilege," says Dr Rao who is a surgical oncologist at Health Care Global in Bangalore.

Feeling useless

Naryan Swami had his voice box removed as a result of cancer, and not being able to speak had a huge impact on his life.

"I was a union leader in the company I worked for. I used to help other workers. Without my voice I was useless for them," he says.

"Losing my voice was losing my life, I wanted to kill myself. I couldn't do anything that I enjoyed."

After consultations with patients like Mr Swami, Dr Rao started to wonder if there was something more he could do to help.

When a friend asked him why he didn't design his own affordable voice box, it was the push he needed, and along with a friend, Shashank Mahes who is an industrial engineer, they set to work researching and developing.

Two years later, the result was the Aum voice box - costing one dollar (75p). It's a small device measuring roughly one centimetre that is inserted into the throat of patients who have had their voice box removed.

Image caption The voice box shown with the device used to insert it in to a patient's throat

It has given patients like Nalini Satyanarayana a new lease of life. She is now able to speak and spends her time supporting and counselling other patients who have undergone throat surgery.

"So I bounced back and I'm a living and smiling example of life after cancer," she says.

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"Throat cancer patients, especially in Stage 4, end up losing their voice box because by that time [it] is completely destroyed," explains Dr Rao.

"Now in this set of patients, they can speak again if the windpipe is connected to the food pipe and the air supply from the lungs are able to vibrate the food pipe. And it is here that the brain trains the food pipe to vibrate again and help the patient speak."

The Aum voice box is able to be sold for such a low price - because those who worked on the project gave their time and expertise for free.

The group were driven by wanting to make a social change and offer patients the opportunity to have access to affordable healthcare, says Dr Rao.

The device is also manufactured in India; most other available prosthetic voice boxes had been expensive partly because they were imported.

Image caption Dr Rao believes top quality healthcare should be available to all

Dr Alok Thakar, a specialist in head and neck surgery from the All India Institute of Medical Sciences, believes the Aum voice box can be life changing for patients.

"This is a simple device. Oftentimes it is the only ticket they have to getting back to employment and to having a fulfilling and economically sufficient life," he says.

However, he warns Dr Rao and his team that their challenge will be to expand the availability of their voice box. He says a similar, previous project failed to have a wide impact because of the difficulty of producing it in sufficient quantities.

Dr Rao is working to make his innovation available to regional cancer healthcare centres across India, so that all throat cancer patients, regardless of their income, can have his device.

"This was a simple innovation, that has touched many lives in a very simple way."