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I do synthetic aperture radar signal processing for a living. I make the SAR pictures you see (or use for your research). I think a big part of the cost is th

I do synthetic aperture radar signal processing for a living. I make the SAR pictures you see (or use for your research). I think a big part of the cost is the signal processing. You need fast A/D converters too. The software though to make a steerable ultrasound beam is not trivial by any means. Also, you have multiple sound speeds to account for in layered media where you dont know the layers occur or what their sound speed is. Another really hard problem.

jostmey 10y ago
Yeah, putting together the software to generate an image is not lot building a database or webservice. It requires engineering and science knowledge well outside the domain of computer science.
- Declanomous 10y ago
  You can't program what you don't know. I actually chose biology over computer science because of problems like this[1]. Now, I don't think I have all the knowledge necessary to build an ultrasound myself, but at least I have the ability to read the literature and make sense of it, and I can understand the language radiologists and doctors use to describe an ultrasound. I don't think the programming would actually be that hard. It's basically sonar for people. There are tons of builds of devices that use time-of-flight to produce images. I think you could actually get something reasonable working pretty quickly if you had access to testing apparatus and a radiologist. I don't have the skills to build the ultrasound machine myself, but I'm not an EE. I don't think the programming is a huge barrier though. Quick edit: I would probably try emulating a system with physical lenses first. It seems like an easier problem. There was an article on Hackaday a while back about a guy who built a phased array radar in his garage, but it seems harder than the physical lens version: http://hackaday.com/2015/04/07/build-a-phased-array-radar-in-your-garage-that-sees-through-walls/ http://hackaday.com/2015/04/07/build-a-phased-array-radar-in... One quote from the article which I think is pretty relevant: "If you are willing to trade acquisition time for cost you could implement a much less expensive near-field array using switching techniques" And here's an article on a DIY Ultrasound development kit: https://hackaday.com/2016/04/12/a-developers-kit-for-medical-ultrasound/ https://hackaday.com/2016/04/12/a-developers-kit-for-medical... [1] I specifically wanted to do bioinformatics, but the field pays poorly, and also requires an advanced education.
  - ipunchghosts 10y ago
    I can assure you it's not sonar for people. The signal processing is way more complicated than traditional sonar. Sonar also has number roughly 10 channels. Ultrasound transducers have 10x more. The array is generally 2d and not planar either where sonar is generally a 1d planar array.
    - Declanomous 10y ago
      You can have a basic ultrasound with only on channel. The following patent is from 1985, and has a pretty good overview of the field at the time. It appears that most if not all untrasound transducers at the time were large single channel instruments. https://patents.google.com/patent/US4446395A https://patents.google.com/patent/US4446395A This patent, from 1989, indicates that most ultrasound transducers are either single element or linear arrays. It was the earliest patent I could find with a cursory look that had a 3 dimentional array. https://patents.google.com/patent/US5027820A/en https://patents.google.com/patent/US5027820A/en Regardless, even Wikipedia suggests that most of the arrays used for medical imaging use either a single element or a phased array: To generate a 2D-image, the ultrasonic beam is swept. A transducer may be swept mechanically by rotating or swinging. Or a 1D phased array transducer may be used to sweep the beam electronically. The received data is processed and used to construct the image. The image is then a 2D representation of the slice into the body. 3D images can be generated by acquiring a series of adjacent 2D images. Commonly a specialised probe that mechanically scans a conventional 2D-image transducer is used. However, since the mechanical scanning is slow, it is difficult to make 3D images of moving tissues. Recently, 2D phased array transducers that can sweep the beam in 3D have been developed. These can image faster and can even be used to make live 3D images of a beating heart. https://en.wikipedia.org/wiki/Medical_ultrasound#Sound_in_the_body https://en.wikipedia.org/wiki/Medical_ultrasound#Sound_in_th... Point being, I think you are wrong. I'm not an EE, so I can't speak towards signal processing, but I am a biologist by training, and I don't see a clear reason why sonar principles wouldn't work. We are basically a bag of salt water. Also, I am familiar enough with ultrasound to be sure that models with only a single transducer are very common. Hospitals and the like might be using the fancy-pants multi-dimensional arrays now, but the units we used to image things in college were definitely not multi-dimension. For one thing, they were older than the patent that demonstrated multi-dimensional arrays.

jostmey 10y ago

Yeah, putting together the software to generate an image is not lot building a database or webservice. It requires engineering and science knowledge well outside the domain of computer science.

Declanomous 10y ago
You can't program what you don't know. I actually chose biology over computer science because of problems like this[1]. Now, I don't think I have all the knowledge necessary to build an ultrasound myself, but at least I have the ability to read the literature and make sense of it, and I can understand the language radiologists and doctors use to describe an ultrasound. I don't think the programming would actually be that hard. It's basically sonar for people. There are tons of builds of devices that use time-of-flight to produce images. I think you could actually get something reasonable working pretty quickly if you had access to testing apparatus and a radiologist. I don't have the skills to build the ultrasound machine myself, but I'm not an EE. I don't think the programming is a huge barrier though. Quick edit: I would probably try emulating a system with physical lenses first. It seems like an easier problem. There was an article on Hackaday a while back about a guy who built a phased array radar in his garage, but it seems harder than the physical lens version: http://hackaday.com/2015/04/07/build-a-phased-array-radar-in-your-garage-that-sees-through-walls/ http://hackaday.com/2015/04/07/build-a-phased-array-radar-in... One quote from the article which I think is pretty relevant: "If you are willing to trade acquisition time for cost you could implement a much less expensive near-field array using switching techniques" And here's an article on a DIY Ultrasound development kit: https://hackaday.com/2016/04/12/a-developers-kit-for-medical-ultrasound/ https://hackaday.com/2016/04/12/a-developers-kit-for-medical... [1] I specifically wanted to do bioinformatics, but the field pays poorly, and also requires an advanced education.
- ipunchghosts 10y ago
  I can assure you it's not sonar for people. The signal processing is way more complicated than traditional sonar. Sonar also has number roughly 10 channels. Ultrasound transducers have 10x more. The array is generally 2d and not planar either where sonar is generally a 1d planar array.
  - Declanomous 10y ago
    You can have a basic ultrasound with only on channel. The following patent is from 1985, and has a pretty good overview of the field at the time. It appears that most if not all untrasound transducers at the time were large single channel instruments. https://patents.google.com/patent/US4446395A https://patents.google.com/patent/US4446395A This patent, from 1989, indicates that most ultrasound transducers are either single element or linear arrays. It was the earliest patent I could find with a cursory look that had a 3 dimentional array. https://patents.google.com/patent/US5027820A/en https://patents.google.com/patent/US5027820A/en Regardless, even Wikipedia suggests that most of the arrays used for medical imaging use either a single element or a phased array: To generate a 2D-image, the ultrasonic beam is swept. A transducer may be swept mechanically by rotating or swinging. Or a 1D phased array transducer may be used to sweep the beam electronically. The received data is processed and used to construct the image. The image is then a 2D representation of the slice into the body. 3D images can be generated by acquiring a series of adjacent 2D images. Commonly a specialised probe that mechanically scans a conventional 2D-image transducer is used. However, since the mechanical scanning is slow, it is difficult to make 3D images of moving tissues. Recently, 2D phased array transducers that can sweep the beam in 3D have been developed. These can image faster and can even be used to make live 3D images of a beating heart. https://en.wikipedia.org/wiki/Medical_ultrasound#Sound_in_the_body https://en.wikipedia.org/wiki/Medical_ultrasound#Sound_in_th... Point being, I think you are wrong. I'm not an EE, so I can't speak towards signal processing, but I am a biologist by training, and I don't see a clear reason why sonar principles wouldn't work. We are basically a bag of salt water. Also, I am familiar enough with ultrasound to be sure that models with only a single transducer are very common. Hospitals and the like might be using the fancy-pants multi-dimensional arrays now, but the units we used to image things in college were definitely not multi-dimension. For one thing, they were older than the patent that demonstrated multi-dimensional arrays.