Hi Folks
I wonder if I can get some advice on microphone selection. I am currently making a combination Esophageal ECG and stethoscope for animals (I work in the animal healthcare field)
Essentially a traditional Esophageal stethoscope is a plastic tube with multiple holes in one end (protected from blocking up by a thin plastic cover) that is passed into an animals esophagus (the food tube) while under anaesthesia (the esophagus passes directly over the heart and you can listen to the heart through the wall of the esophagus) . A regular stethoscope is attached to this simple sealed plastic tube and you can hear the animals heart beat through the stethoscope ear pieces.
We have an amplifier which you can connect to this (so someone does not have to remain listening for the duration of the procedure) but the sound despite being amplified is still quiet, the microphone for the amplifier is place at the exit of the tube and some distance from the heart. I think a lot of the sound is lost in the length of the tube
I am looking to make some custom esophageal stethoscopes that have a microphones placed further down the tube, hopefully to pick up a louder sound for amplification. I am hoping to get some advice on the type of microphone that would be best to pick up these low frequency sounds (somewhere between 50-200Hz ) that are travelling in a plastic tube . It would be a sealed unit , so the microphone would not need to be waterproof , the tubes would be somewhere between 4mm internal diameter and up to 6mm or even 8mm internal diameter (larger units for larger animals) . I hope to combine this with external electrodes that will enable as ECG to be read from the same unit.
I wonder if I get some advice as to the best microphone for such a unit at these frequencies and even the availability. As a youngster I dabbled in electronics but my knowledge of microphones is a little lacking.
Thanking anyone for their advice in advance
Best Regards
Oliver
I wonder if I can get some advice on microphone selection. I am currently making a combination Esophageal ECG and stethoscope for animals (I work in the animal healthcare field)
Essentially a traditional Esophageal stethoscope is a plastic tube with multiple holes in one end (protected from blocking up by a thin plastic cover) that is passed into an animals esophagus (the food tube) while under anaesthesia (the esophagus passes directly over the heart and you can listen to the heart through the wall of the esophagus) . A regular stethoscope is attached to this simple sealed plastic tube and you can hear the animals heart beat through the stethoscope ear pieces.
We have an amplifier which you can connect to this (so someone does not have to remain listening for the duration of the procedure) but the sound despite being amplified is still quiet, the microphone for the amplifier is place at the exit of the tube and some distance from the heart. I think a lot of the sound is lost in the length of the tube
I am looking to make some custom esophageal stethoscopes that have a microphones placed further down the tube, hopefully to pick up a louder sound for amplification. I am hoping to get some advice on the type of microphone that would be best to pick up these low frequency sounds (somewhere between 50-200Hz ) that are travelling in a plastic tube . It would be a sealed unit , so the microphone would not need to be waterproof , the tubes would be somewhere between 4mm internal diameter and up to 6mm or even 8mm internal diameter (larger units for larger animals) . I hope to combine this with external electrodes that will enable as ECG to be read from the same unit.
I wonder if I get some advice as to the best microphone for such a unit at these frequencies and even the availability. As a youngster I dabbled in electronics but my knowledge of microphones is a little lacking.
Thanking anyone for their advice in advance
Best Regards
Oliver
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