Operating to cure snoring has become a common, and usually effective, procedure, which can be carried out in only half an hour. This suggests there would be a significant international market for a technology that both simplifies diagnosis and tells surgeons how successful an operation has been.
Half of all Norwegians snore, (as one assumes, do half of people everywhere) and there are long queues for operations to cure the condition. Now, a little bit of Norwegian defence technology may shorten the waiting lists.
Scientists and doctors in Trondheim have adapted a technology that was originally developed for military use, consisting of an earplug that acts both as hearing protector and communication system. The plug, called Quiet Pro, consists of a built-in computer, a mini-loudspeaker, and internal and external microphones.
“The aim of our studies is to develop a better tool for measuring snoring both during the diagnostic process and following a snoring operation,” says Tone Berg, an acoustics specialist at Sintef, the largest independent research organisation in Scandinavia.
To do this, the researchers connected recording equipment to the earplug’s microphones. “Although we make use of only part of Quiet Pro here, it is still a unique tool that is capable of revealing the details of a patient’s snoring and breathing patterns, by recording and analysing the sounds they make,” says Berg.
The equipment measures how much the patient snores and the sound level of the snoring. Another aim is to show where the snores arise, a factor of great importance for determining where the surgical intervention should take place.
The project involves cross-disciplinary collaboration between Sintef’s ICT and health research arms and the Ear, Nose and Throat Department at St. Olav’s Hospital, Trondheim.
Doctors distinguish between two types of snoring. Social snoring that is capable of disturbing both snorers themselves and anyone sleeping near them can be cured by stiffening the soft palate, either by means of an implant, or by diathermy, which uses a laser to stiffen the tissue. For some people losing weight is sufficient, since obesity is a common cause of snoring.
Snoring may also be indicative of a more serious condition known as obstructive sleep apnoea syndrome, which can interrupt breathing, make sufferers abnormally tired and at increasing the risk of cardiovascular disease. A breathing machine is usually required to cure this disease, but in some cases more advanced surgery may be required.
The researchers hope that the new measurement method will make examination and diagnosis simpler and more reliable, and give doctors better answers about what sort of surgery they should perform on each patient. The method will also reveal cases in which simple surgery would not help the patient.
“The technology will also give us an objective post hoc measure of the results of an operation. Today, some 15 to 30 per cent of operations to cure snoring are failures,” says Ståle Nordgård, senior medical officer at St Olav’s Hospital.
Currently, many of the patients who are to be examined for snoring problems have to spend the night at St. Olav’s with a tube inserted in their nose and down the oesophagus fitted with different types of sensors. This measures pressure differences in the patient’s pattern of respiration, revealing just where in the throat the snoring problem arises. There are several potential locations.
Obviously, this is unpleasant and may well disturb the patient’s sleep. The sensors also tend to move when the patients turns over in bed, which makes the measurements unreliable.
“What is unique about the new recording method is that the microphone stays in the same place, no matter how much a patient moves about in his sleep. Futhermore, the acoustics of the room do not affect the sound recordings,” says Berg
No other systems on the market at present are capable of measuring sound in this way.
To date, the earplug has been tested on 22 people. “What we found was that Quiet Pro gives us more information about patients’ snoring patterns than the old equipment. Now we know how much patients snore, how frequently and what level of sound they produce,” explains Berg,
The technique is so simple that it opens up the possibility of carrying out large-scale epidemiological studies of snoring.