Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Noise-Immune Stethoscope Helps Medics Hear Vital Signs in Loud Environments

30.11.2006
Ultrasound-Based Design Benefits Wounded Soldiers Transported in Helicopters

A new type of stethoscope enables doctors to hear the sounds of the body in extremely loud situations, such as during the transportation of wounded soldiers in Blackhawk helicopters. Using ultrasound technology, the kind used to generate images of internal organs, muscles and unborn fetuses, the new stethoscope design will be presented later this week at the Fourth Joint Meeting of the Acoustical Society of American and the Acoustical Society of Japan, which will be held at the Sheraton Waikiki and Royal Hawaiian Hotels in Honolulu, Hawaii.

Researchers at Active Signal Technologies, Inc., of Linthicum Heights, Md., in collaboration with the U.S. Army Aeromedical Research Laboratory (USAARL) in Fort Rucker, Ala., have developed an ultrasound stethoscope that is nearly impervious to loud noise and is capable of making accurate readings at noise levels up to 120 decibels, similar to the volume experienced at the front row of a rock concert.

Current acoustic stethoscope technology picks up and amplifies vibrations that let doctors hear the heart and lungs. These models become difficult to use effectively around 80 decibels, a noise level comparable to an alarm clock or a busy city street. When noise levels reach 90 decibels, these types of stethoscopes are rendered useless. Modern electronic stethoscopes have raised the maximum tolerable noise level to 90 decibels to 95 decibels by replacing the ear pieces with loudspeaker inserts that provide a better seal with the ear canal and replacing the tubing with electrical cables that do not pick up acoustic noise.

The challenge to build a better stethoscope originated from the Army's Small Business Innovation Research program. For soldiers wounded in combat, the first hour after sustaining an injury is known as the "critical hour," when diagnoses and emergency treatment must take place to give them the best chance of recovery. These soldiers are often transported by helicopter, where noise levels prohibit the use of traditional stethoscopes. Auscultation, the act of listening to sounds within the body as a method of diagnosis, is an important tool for assessing the integrity of the heart muscle, valves and major arteries. Auscultation of the lungs can be essential when confirming the placement of endotracheal tubes to restore or protect the airway or when diagnosing conditions such as a collapsed lung, asthma or pulmonary edema.

Houtsma said he is proud of what the research teams were able to accomplish.

"Having heard so much about the first critical hour that may mean life or death for a seriously injured person, I feel fortunate to have been in a position to lead a great team of dedicated researchers in enabling medical auscultation in very noisy environments," Houtsma said. "I expect this invention to save many lives that otherwise might have been lost."

Active Signal Technologies was awarded grants from the Army totaling $900,000 and another $50,000 from the state of Maryland to develop a new type of stethoscope that could be used in high-noise situations. After several unsuccessful attempts to reach the goal of effectiveness at 110 decibels, the idea of using ultrasound technology was implemented.

Traditional stethoscopes transmit and amplify sound that is within the range of human hearing, from about 20 hertz to 20,000 hertz. Most audible sound, including that of the heart and lungs, takes place at around 100 hertz to 200 hertz. The ultrasound models transmit a sound signal at 2.3 megahertz into the patient's body, according to USAARL stethoscope project team leader Adrian Houtsma. This sound is reflected back to the stethoscope at a slightly different frequency because of the velocity of the internal organs. This is called the Doppler effect. The difference in frequencies between the sound wave that is transmitted and the sound wave that is received can be computed to determine the motion of the internal organs. This difference frequency is then converted into audible sound. Because they are based on different physical principles than conventional stethoscopes, ultrasound models produce a markedly different sound. Where an acoustic stethoscope yields a "lub-dub" sound from a heartbeat, with the first beat being the strongest, an ultrasound stethoscope will yield a "ta-da-ta" pattern, with the second beat being the strongest.

The ultrasound stethoscopes are almost ready to begin the process of FDA approval, which is likely to take two to three months. Then Active Signal Technologies will begin manufacturing the devices to sell to the armed forces. The company's chief executive officer, Arthur Cooke, said the commercial release of the stethoscopes will likely be very small at first, since the cost could be anywhere between $250 and $700. He said he hopes positive feedback from the armed forces will generate widespread interest.

"Once these are seen and implemented," Cooke said, "there will be more commercial interest."

Turner Brinton | EurekAlert!
Further information:
http://www.aip.org
http://www.acoustics.org/press/152nd/houtsma.html

More articles from Medical Engineering:

nachricht Virtual Reality in Medicine: New Opportunities for Diagnostics and Surgical Planning
07.12.2016 | Universität Basel

nachricht 3-D printed kidney phantoms aid nuclear medicine dosing calibration
06.12.2016 | Society of Nuclear Medicine

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>