The stethoscope was invented for medical practice in the 1800s. Although it has been refined, it differs only slightly in use today, considering the purpose remains to listen to internal organs and circulatory systems. It is completely reliant on sound as a diagnostic tool. This means that the better the amplification, the better the device.
Humans cannot hear sounds below 20 Hz. Heartbeat and lung sounds range just barely above this level but are two systems that diagnosticians must check during an exam. Thus the stethoscope is probably the most valuable tool in a medical professional’s clinic.
Stethoscope in Common Practice
The stethoscope is used for diagnosis involving lung and heart but can also be readily used for circulatory systems, bowel issues and in conjunction with a blood pressure cuff. It is a standard tool in a medical office and there are both acoustic and electronic types available.
Since this is a primary tool in any medical practice or diagnostic setting, it is always made to be lightweight enough to carry and can also vary by patient need. Some stethoscopes are made to be more sensitive to fetal heartbeat, for example, or heart murmurs.
With the advent of the digital age, amplifying stethoscopes are becoming more prevalent in practices. Electronic components aid diagnosis by specifically magnifying sound and can provide further additional tools. Some even allow for shared data.
The acoustic stethoscope is reliant on a diaphragm and bell while electronic stethoscopes use an amplifier to magnify fainter body system sounds. The acoustic model is reliant on the practitioners’ hearing and strength of the sound of the body system. The electronic model amplifies sound significantly but can create sound artifacts so care is required in choosing one.
Electronic Amplified Stethoscopes
Traditional acoustic stethoscopes vary in weight, ear tips and length as well as diaphragm type and variation in chest piece. They have been used in diagnosis for almost two centuries and are a common and necessary medical tool. But they are entirely reliant on sound, with all the variations that can be found in the listener, the patient’s system, and the quality of the tool itself.
Electronic amplification stethoscopes can magnify sound eighteen to twenty percent. There is always the consideration that at that great increase, sound artifacts can be produced. At a higher volume, the noise of surface area could be sharp and disturb an exam. Overall, that is a learning curve similar to training on an acoustic model for the first time.
Electronic stethoscope are also sometimes called digital and can use digital systems for advanced diagnostic assistance. They can be made to record as well as be worn with headphones. They are more expensive than the original models but prices have dropped in the past years and they often pay for themselves rapidly.
Electronic Stethoscope Options
Since acoustic stethoscopes rely on hollow tubing to amplify sound, the sound capture is traditionally low. A digital stethoscope amplifies sound significantly by translating acoustic sounds to electronic signals. The circuitry used for the amplification and translation can vary widely. Manufacturers have taken advantage of this and provide multiple model types.
Electronic stethoscopes can provide sound amplification and also digitization. The digitization allows for recording and uploading to computer applications that can assist with diagnosis. The software packs they come with can even offer visual cues and in later models, Bluetooth enabled devices can be used in telemedicine.
Basic electronic models of stethoscope come with the ability to amplify sound and cancel ambient noise. The earliest and simplest models come with a speaker to amplify sound and are not commonly used.
Higher end models are more complex. They convert audible sound to electronic signals which are amplified and then recreated as sound. Since the acoustic sound is converted, the digital reproduction is sometimes noticeably electronic but easily overcome with experience. Some models provide down-loadable software and data sharing, provided the person on the other end has their own model, to receive the digital information.
Features of Electronic Stethoscopes
All of the electronic models require some form of power input. Most often these are in the form of batteries. To save battery life, most are equipped with an auto-off switch or detector and a low power indicator. Choose a model with a button or switch rather than a timer since it could shut off during a patient exam. Digitized stethoscopes are also available and use a power cord. These do not usually have a warning light since they are always connected to a power source.
Volume and amplification are sometimes the same control on electronic models. Volume is sound level but amplification is the process that digitizes sound so it can be amplified artificially. Many models use one control for both processes and some consider volume and amplification to be separate. Keep in mind, the more controls involved in the model create additional variables during an exam.
Volume control indicators vary. They are almost always available and can be found on the chest piece or tubing and are sometimes dial or switch. They also might come with a visual display to identify the current volume level.
Chest Piece, Diaphragm and Bell
Many electronic stethoscopes offer an option to change from bell, diaphragm and extended range sounds with a switch. This changes the frequency sound or listening mode. Some do come with detachable chest pieces for different diagnosis.
Frequency selection on the models allow for a specific Hz level to be selected and cancel out the rest of the sound range or else amplify a specific sound range, such as when listening to organs.
The ear tubes on stethoscopes are crucial in sound relay. The electronic tubes are very similar to the acoustic models. Variations in tubing from traditional stethoscopes may include wiring or other components that transmit the electronic signal. There are some models that are entirely without tubing, using electronic components to relay data.
Some electronic models come with ear tips that are remarkably the same as the acoustic tips. Others come fitted with headphones which can significantly aid in the cancellation of ambient noise. Headphones are a great asset since the purpose of the electronic models is clarity and strength of sound. They can also be used over hearing aids or for any other issues with the ear canal.
Ear tips can vary from plastic to silicone and provide a seal, further enhancing sound and noise cancellation. Better ear tips can cancel ambient noise by better ear seal. In some models of electronic stethoscopes, ambient noise is canceled electronically as well. When the frequency of ambient noise is detected, the stethoscope produces opposing frequencies and cancels the sound.
Amplified stethoscopes are appropriate for anyone looking to increase diagnostic efficiency. The basic models, looking to amplify volume, are an excellent choice for hard of hearing doctors and nurses. Headphones can go over hearing aid devices and cancel out ambient sound. They are also good for any practitioner who wants to have better data in an exam or faces a noisy practice setting.
An interesting aspect of the electronic stethoscope is its use in telemedicine and data sharing. Electronic models can record and share data. They often do this by the use of software packages that come with the stethoscope. The audio data is saved similar to saving any music download and can be sent by email to other practitioners.
There are a few models that come equipped to data share in a live setting. Audio data can be heard in a simple call to another practitioner. It can also be directly connected so that the remote practitioner can hear sound directly, as if in the room with the patient.
The potential for use of electronic stethoscopes is enormous. At one time, with the portable ultrasound devices exploding on the market, it seemed possible the stethoscope could die out in use. But most patients not only recognize a medical practitioner by the ubiquitous stethoscope but also feel comforted by it.
It’s likely that doctors and nurses will also feel more comfortable knowing they still have the first and most enduring of their medical devices hanging around their neck. Now those devices will simply be almost as smart as they are.