The stethoscope is an electronic device used by the doctors in the medical field or in medical applications. This device is used to listen to the internal sound of a human body or an animal and BP in veins and arteries. Normally, stethoscope includes a round shaped resonator or chest piece and two tubes. Where, the resonator is placed on the chest and tubes are connected to the ears. These devices are also used for monitoring different small scale acoustic tasks and to check the scientific vacuum chambers.
But many researches have been made to upgrade the design of traditional stethoscope. In present days, general types of stethoscopes are available to the consumers are traditional acoustic, amplifying & digitizing. All the electronic stethoscopes fall into two types, namely amplifying & digitizing. The working principle of electronic stethoscopes is similar to acoustic stethoscopes. But, the main difference is, electronic stethoscopes works with a battery and used to amplify human body sound clearly.
The sound level of the traditional stethoscope is extremely low. So, electronic stethoscopes use an advanced technology to overcome this problem by electronically amplifying body sounds.
These stethoscopes require a change of audio sound waves obtained through the chest piece into electronic waves which are then transferred through exclusively designed circuitry and managed for optimal listening. The circuit of the stethoscope comprises of various components that permit the energy to be amplified and enhanced for listening at different frequencies.
In this type of stethoscope, the easy and small effective method of sound detection is attained by placing a microphone in the chest piece. This stethoscope is a recording device, and can provide audio and visual o/p, signal enhancement and noise reduction. These stethoscopes are used by CAA (computer aided auscultation) programs to examine the innocent heart murmurs or recorded heart sounds.The electronic stethoscopes are categorized into two types such as amplifying stethoscopes and digitizing stethoscopes.
The other kind of electronic stethoscope available in the market is digitizing stethoscope. This stethoscope converts the audio signal to the digital signal. These stethoscopes can transfer serialized audio data that can be shared synchronously and forward asynchronously. The working of these units can be done by sensing sound through the sensor in the electronic stethoscope, converts that sound to electricity and runs through the circuit. Finally that can be amplified, filtered and converted from analog to digital data. The digitized data can be sent through RS2323 i/p of the video conferencing unit across a n/w.
The majority of these stethoscopes on the market has an audio o/p signal, uses a stereo and a mono cable connection, can let the audio o/p received by the stethoscope to be transferred real time to an associated software application. The associated software may employ numerous algorithms that are developed for interpretation and diagnosis of the audio o/p attained from the electronic stethoscopes. The process of audio o/p can be done through numerous accompanying software packages, which can be saved as a file and transmitted through email for diagnosis and asynchronous assessment. Some electronic stethoscopes have audio data o/p options, that can be used to hook up to audio i/p of a video conferencing unit, which would allow them to send the sound data real time over a n/w connection to another endpoint of videoconferencing.
The video conferencing units work as encoders and decoders of the sound data, permitting it to be transferred over a n/w. In this kind of setup, the user needs to be aware of the fact that normally the sound data can only be sent between videoconferencing units and models of brands. Some kind of electronic stethoscopes permits transmission of data via through a Bluetooth which interfaces to other devices. Most of the stethoscopes require Bluetooth receivers (dongles) to transfer data wirelessly. These communication strategies use different technologies, but transmission of this form of data may be a limiting factor mismatch with devices other than computers
Electronic Stethoscope Circuit Diagram
The circuit diagram of electronic stethoscope is shown below. The main purpose of the stethoscope is to hear the heartbeat of the human body or animals. The circuit of the electronic stethoscope is built with a piezo sounder or a melody generator. This transducer has an o/p signal on the order of 100mV and its low frequency response is directed by the i/p impedance of the amplifier.
Due to this reason we have preferred to use an emitter follower transistor amplifier. This consumes high i/p impedance and confirms that the transducer will have a low frequency response. At the end of the o/p you just need to connect a set of headphones which has a low impedance to be able to hear your heartbeat. Furthermore, to increase the i/p impedance of the amplifier replaces the emitter follower with a Darlington transistor.
Thus, this is all about electronic stethoscope, circuit diagram and its types. We hope that you have got a better understanding of this concept. Furthermore, any queries regarding this topic or electronic stethoscope project, please give your valuable suggestions by commenting in the comment section below.Here is a question for you, what is the difference between an acoustic stethoscope and electronic stethoscope?