UltraStethoscope

UltraStethoscope is a unique stethoscope developed by HIC, capable of operating through many layers of clothing. Conventional stethoscopes must usually be placed directly on the skin. The UltraStethoscope is a non-invasive device which simply collects sound emanating through a surface.

plastic UltraStethoscope device
Plastic version of UltraStethoscope showing variable filter switch, data outlet, volume control and charger.
aluminium UltraStethoscope device
Aluminium version of UltraStethoscope also showing indicator light.

This advantage gives the device practical uses in many situations, including those where clothing cannot be removed, such as in the high cold mountain regions where undressing an injured climber or skier is very undesirable. Another possible use is to listen to the heart sounds of patients covered by bandages. The stethoscope has been identified to assist in Search & Rescue, where it would not be possible to remove patients' clothing.

UltraStethoscope in mountain rescue
The device is used in the mountains where it is important not to undress accident victims.
UltraStethoscope works through thick clothing

Recent feedback also suggests the device can prove useful when dealing with morbidly obese patients, as in such patients breath, upper airway and heart sounds are attenuated by the overabundance of fatty tissue resident in the auscultation pathway.

The UltraStethoscope has been used by a member of the British Antarctic Survey to detect and monitor the heart beat of seals through their thick sound-attenuating layers of fat. Cambridge University Disability Resources Centre was an early customer for the UltraStethoscope.

Because the device has variable gain giving an amplified acoustic output, doctors with various degrees of deafness have also purchased these units.

Analysis Of UltraStethoscope Data

The device also works as a normal stethoscope but provides additional functions, including the ability to output data to a computer - useful for serial comparison of data. This feature makes the device suitable for applications in teaching laboratories of colleges and universities.

The device has high mechanical and electronic signal gain and variable volume, allowing sounds to be heard through conventional headphones. One effect of using high amplification is that environmental sounds are also amplified. HIC has incorporated various features to minimise unwanted sound being heard by the user. For example, the device has built in filtration which can be switched between 100Hz, 200Hz and 1kHz. These blocking filters curtail unwanted environmental noise reaching the headphones.

The UltraStethoscope has a long running time thanks to the inclusion of built in high power rechargeable batteries.

HIC have also developed a system whereby heart sounds can be transmitted to a receiver and heard through a loudspeaker.

Another version already developed is an optosonic stethoscope, where a bright LED light flashes in synchrony with the detected periodic acoustic signals. We would like to hear from those who have an application where this version of the device might be employed.

Software has been developed to record, analyse and display sounds captured by the UltraStethoscope:

UltraStethoscope software graph of heart sounds
Analysis of heart sounds by tailored software developed by HIC.
UltraStethoscope software graph of pulmonary edema
Trace caused by pulmonary edema.

The same software is so versatile that it can be used to analyse ultrasonic Doppler signals from the clinical version of Breastchecker. Versions designed for PC and Apple computers are available.

Apart from this major advantage of PC compatibility and replay there is another important feature, namely that the UltraStethoscope does not require skin contact but works well through clothing. We believe this should obviate the risk of patient-to-patient infections known to be carried by conventional devices.

Recommendations

“I have been using Highland Innovation's UltraStethoscope on the ski slopes of Cairngorm Mountain for several years now. Snow sports casualties in Scotland, rather like those of mountain rescue teams, tend to be injured in cold and windy environments. This presents unique challenges to rescuers, as we have to be able to adequate assess the casualty's injuries quickly and effectively without placing either ourselves or the casualty at further risk.

One of the main risks in this sort of environment is over-exposure to the prevailing elements. Casualties are often wearing multiple layers of clothing and in order adequately examine the chest (in particular) we previously had to balance the risks of undoing layers of clothing in order to access the chest wall against the risks of the cold. The introduction of the UltraStethoscope has revolutionised our management of these individuals.

The ability to listen through multiple layers of clothing allows us to make a rapid and safe assessment of the vital parameters - breath and heart sounds – without the need to open the casualty's protective clothing at all. Respiratory rate can also be assessed in this way. This allows us to exclude potentially serious traumatic injuries such as a tension pneumothorax with confidence on the mountain slopes.

The UltraStethoscope also allows for easy monitoring of the patient during their transfer off the slopes. I have tested it in ambient temperatures as low as -20°C and wind speeds of up to 50mph. Its performance has remained good in all conditions. Battery life is excellent and the unit has proven to be robust and reliable.

I would recommend this unit to anyone who regularly needs to assess for serious injuries in an outdoor environment. Just today, I used the UltraStethoscope on two casualties - both high speed incidents with chest injuries as a result. So good to be able to listen in on the hillside without exposure. A member of a mountain rescue team was involved in one case and he was mightily impressed too, as were the ambulance crew who both had a listen once we got to the base station.

It's a great device that makes a real difference when assessing and managing casualties at the ski area…”

Use Of The UltraStethoscope In Ski Patrol Medicine - Dr Mike Langran, GP at Aviemore Medical Practice and Doctor with Cairngorm Mountain Ski Patrol

“Heart murmurs are the sounds of the heart that can be indicative of deformities of the heart valves and also possible early indicators of heart disease in some instances. One problem is that it is very difficult to hear certain abnormal sounds using a standard stethoscope. Certain studies, including Mangione 2001, suggest that many common abnormal heart murmurs are very difficult to hear.

With its large gain, the heart sounds recorded with the UltraStethoscope can be heard very clearly. From consultations with heart specialists, one improvement that could be made is that the size of the device would ideally be as small as possible. However this aside, the device is an excellent tool for recording heart sounds onto a PC, and the internal battery lasts for many hours following its initial charge…”

Richard Boyle RSE/SE - Enterprise Fellow, Bioengineering Unit & Electronic & Electrical Engineering (CeSIP), University of Strathclyde