If you have ever been to the Museum of Science and Industry in Chicago, you might have stood in their elliptically shape room where an individual standing at one focal point can hear an individual whispering at the other focal point even though the room is filled with noisy people, many of which could in fact be between the two individuals at the focal points. This because the distance from one focal point to the body of an ellips and then continuing to the other focal point is a constant. The result of which is all of the sound spreading in all directions from one focal point is reflected back to the other focal point, and the whole wave front gets there at the same time. Using half of an ellipsoid for the listening piece, with the sound sampler at the remaining focal point, the doctor would not have to sift through all of the noise in the body, but would hear mainly the sound at the other focal point. Even though half of the ellipsoid is gone, and much of the sound will be lost, much of the sound produced at the other focal point would be focused at the desired focal point. Enough to overwhelm other sounds. To make it work well, the stethoscope’s elliptical bell should be filled with a medium that has as close to the same sound transmitting properties as the human body. I would also extend this medium outside of the stethoscope’s bell within a balloon like membrane allowing the doctor to press the stethoscope against the patient at different levels allowing for more than a single depth of listening.-- Ozone, Apr 18 2008 Ultrasonic Lithotripter http://www.math.iup...fs/lithotripter.GIFthis idea in reverse, used for breaking up kidney stones [baconbrain, Apr 18 2008] If you filled it with salt water, it'd work great, if your balloon could be managed. The best shape is actually part of an ellipsoid, which is a rotated ellipse. (Take a look at ultrasonic lithotripters, which is this idea in reverse, used for breaking up kidney stones.)-- baconbrain, Apr 18 2008 The two halves of the ellipsoid are sort of like two parabolic dishes - one to transmit and one to collect sounds. One parabolic dish can enhance collection of signal - as used with mircophones, satellite dishes, etc. The ellipsoid talk sort of distracted me from this - what I suspect is the essence of what you propose.
Would a parabolic stethoscope bell work better? It might. Regular stethoscopes have almost no bell. This should be testable using a plastic egg with an ear hole, like those old Legg eggs. Does interposing a plastic egg with an earhole over a patient's heart make the sound crisper or louder than if you place your ear over the heart?-- bungston, Apr 18 2008 As it stands, stethoscopes have two listening levels, and are not pinpoint accurate. However, i'm very used to hearing what i do through a conventional stethoscope and would be nervous using one which sounds different, so it's probably a bit like the QWERTY keyboard or the width of rail tracks in the US in that adjustment would be too difficult for those who are already using the old system.
In other words, technically this is a fine idea but i don't know how it could be adopted. I wouldn't want to miss something important because i wasn't used to how it sounded. On the other hand, i suppose i could try auscultating with both until i was used to it.-- nineteenthly, Apr 20 2008 Through an Idea Adoption Agency, which offers permanent caring homes to orphan Ideas ?-- 8th of 7, Apr 20 2008 A paraboloid is a special case of a half ellipsoid--it's one in which the second focal point is infinitely far away. A parabolic stethoscope wouldn't do what this idea seeks to, which is to gather sound from a specific place inside the body.-- baconbrain, Apr 20 2008 Sorry [baconbrain] but not quite. Circles, ellipses, parabolas, and hyperboles are all conic sections but the have different properties, different equations and are not just "at the limit cases" of each other. An ellipse is the figure made when you slice through a cone at an angle. A parabola is the figure made when you slice a cone parallel to the side of the cone. A parabola has one and only one focal point. Hyperbolas have two. Ellipses have two. A circle has an origin.
You are absolutely correct though that no, a parabolic bell will not do what is being talked about here.-- Ozone, Apr 21 2008 Thank you. I tend to look for progressions and continuities, and sometimes that gets me in trouble with the discrete and dichotomous. But Wikipedia (I know, not the best source) says, "A parabola can also be obtained as the limit of a sequence of ellipses where one focus is kept fixed as the other is allowed to move arbitrarily far away in one direction. In this sense, a parabola may be considered an ellipse that has one focus at infinity."
Another Conics page (not Wikipedia) says, "Parabola can be thought of as a limiting case of ellipse or hyperbola." I might maybe should have spoken of conic sections, but I'll stick with my earlier anno, as I was trying to illustrate that a paraboloid wouldn't have a useful listening spot, as the "other focus" would be ever so far away.
I'm going far away now.-- baconbrain, Apr 21 2008 Please forgive me [baconbrain], I really was not potty trained at gun point. While I understand the difference between black, white, and shades of gray, I like to think in terms of black and white. Makes it easier to make choices.
Parabolic listening devices are good for directional, not pinpoint listening. Bird watching and hearing what is going on in the opposing huddle come to mind.-- Ozone, Apr 22 2008 I like the concept but the things inside the body that make sounds aren't pinpoint sources - wouldn't too tight a focus be a bad thing?
As for what to fill the parabola with to improve the conduction, I recommend ballistics gelatin.-- elhigh, Apr 23 2008 Why not think beyond, much like thinking how can an elipsoid solve our energy crisis? Guess what is in my mind...-- rotary, Apr 23 2008 A frightened squirrel?-- baconbrain, Apr 24 2008 A cyanide suppository?-- james_what, Apr 24 2008 one clue: sequential firing.
Oh, you have unique ideas too. Again, think big.-- rotary, Apr 24 2008 ps Become a "conehead" and hear yourself think. At least that's what the little voices told me.-- james_what, Apr 24 2008 hmmmmmm, how is that, [james_what]?
Anyway, 2nd clue: confinement.-- rotary, Apr 24 2008 3rd clue: inertial
[rotary], I know where you are going, and, as usual, it's something most of us have thought of. Get back to the idea, eh?-- baconbrain, Apr 24 2008 So, what a frightened squirrel got to do with it, [baconbrain]?
Oh, I know now: the implosive-explosive death of one squirrel would kill the adjacent squirrel the same manner, and so on and so forth. Nice! Can we amplify the lights/rays too like how a LASER is done?-- rotary, Apr 24 2008 [rotary] I have no idea how this string got to this point or even where this point is but I need to know, when do the squirrels reach crittical mass?-- Ozone, Apr 25 2008 [Ozone], I would just like to emphasize how to somehow harness the radiated heat of first laser-imploded fusion reaction of heavy isotopes of hydrogen encased in a pellet to aid implosion-explosion of the other pellet beside it so that the overall reaction is self-sustaining - above the break-even point - as long as the pellets are continuously supplied sequentially and timed precisely alternating in the two foci of the ellipsoidal reflective inner chamber surfaces while the chamber is water jacketed with heavy water so to capture the energy of the fusion particles and be converted to steam power that would drive the turbine-generator layout to supply electricity to the grid for the benefit of man and the creation of sustainable future without the dependence of petroleum oil and other energy sources that disrupt the ecological balance of our beloved, beautiful, blue planet we called home.-- rotary, Apr 25 2008 That is really a good idea [Rotary]. A point explosion at the focus of an ellipsoid would approach the other focus, such that the material at the focus would be compressed pushing it into a critical mass. This might be an idea that would work as the triggering device for instruments of mass destruction. You need to rewrite this and present it.-- Ozone, May 01 2008 random, halfbakery