The voice prosthesis is constructed from silicone. It is designed to assist patients to speak when their entire voice box (or larynx), has been removed as a result of surgery designed to treat throat cancer. Throat cancer can mean cancer of the larynx. However, it may also mean other types of cancer, for example cancer of the food pipe (oesophagus) or thyroid cancer.
With cancer of the voice box, the reason speech is lost is because the windpipe and food pipe become separated from each other as a result of the surgical procedure. This makes speech difficult or impossible, without a mechanical aid. These devices are affordable in richer countries, but they are prohibitively expensive to those in poorer countries or areas without developed healthcare systems. More sophisticated devices include the electrolarynx, a hand held medical device which is placed under the mandible where it produces vibrations to allow speech. The produced “voice” comes across as electronic or robotic.
The new device, called an Aum Voice Prosthesis, takes the place of the voice box. The voice box works through vibration.
The voice box hollow tubular structure made of cartilage. The voice box is connected to the top of the windpipe, where it manipulates pitch and volume. Inside the voice box are two bands of tissue that form the vocal cords. When a person speaks or sings, muscles pull the cords together. The air passing through the cords makes them vibrate, creating sound. The scientific term is phonation. Phonation is the process by which the vocal folds produce certain sounds through quasi-periodic vibration.
With the new device, instead of the vocal cord vibrating, the food pipe is made to vibrate with the back end of the prosthesis sitting at the food pipe. When air is directed into the food pipe towards the lungs it vibrates and the vibrations create noise, and this noise can be transformed into intelligible speech patterns via the brain.
More details are outlined in the video below:
The device has a one-way valve, in order to prevent food or water from entering the lungs.
The device was convinced by Dr. Vishal Rao, who is a Bangalore based oncologist. His voice prosthesis costs just a fraction of those available on the market. Dr. Roa’s device is small and lightweight, weighing just 25 grams and being around 2.5 centimeters in length.
The inventor, Dr. Rao, trained as a cancer specialist at the Tata Memorial Hospital at Mumbai. His main research interest is in findings ways to achieve a tobacco free world. As well as a practicing oncologist, Dr. Rao is a Visiting Scholar at the Department of Otolaryngology in the University of Pittsburgh School of Medicine, U.S.
To make the device a reality, 37 year-old Dr. Rao collaborated with a friend of his who was knowledgeable about materials science — Shashank Mahes. Dr. Rao’s device was first tested out as a prototype on a male patient called Ramakrishna, living in Karnataka village, in a remote area of India.
Interviewed by The Better India website, Dr. Rao described how the device only two five minutes to fit. Moving onto some other work, Dr. Rao went back later to check on the patient:
“That day, when I came out from another surgery after about three hours, the Kolkata patient was still standing there, waiting for me. He was so emotionally overwhelmed that he just ran towards me and hugged me saying that he had never imagined getting his voice back would be so easy.”
The name of the device, Aum, is drawn from Hindi scripture. ‘A’ stands for creation, ‘U’ for sustenance and ‘M’ for annihilation. It symbolizes the rebirth of the voice.
Following this success, trials are taking place o 30 patients and plans are afoot to produce the first commercial batches of the prosthesis towards the end of January 2016. Both Vishal Rao and Shashank Mahes have decided not to receive any payment for developing the device. Their mission is to help very poor throat cancer patients speak again after surgery; as Dr. Rao told The Times of India:
“Speaking is a right. When the voice box of patients is removed during surgery, they crave to speak. As if the trauma of the disease is not enough, the shock of having lost their voice takes a toll on them, emotionally.”
This article is part of Digital Journal’s Essential Science series. Other articles in the series are “Space-food for astronauts made from bacteria“; “Health effects of antibiotic use“; “Graphene makes improved night vision tech“; “Personalized medicines, the health innovation”; “Power paper can store electricity”; “Why some rainbows are completely red“; and “Bright white light affects animal reproduction.”
