medical device for detecting tissue temperature and pressure

I would be concerned that by the time you're producing microcavitation that you'll be doing tissue damage -- that's certainly not something that you want to do just to measure temperature.

Also, are you sure that inflammation that's entirely within the body actually shows a higher temperature? I think the reason that inflamed tissue on the surface of the body shows a higher temperature is simply from increased blood flow carrying heat from inside the body to the inflamed spot quicker than to the rest of the skin -- if I'm correct then within the body you wouldn't see that.

I can see wanting to know intercranial pressure, although that might be something that's show up in a PET scan or other high-tech scan.

Every inter-cranial pressure method I've seen is invasive. I think if you come up with a non-invasive method, people would be interested.

ChesterW

No, when there is an infection, part of the immune system is to raise the body (core) temperature to fight the infection. Think "fever".

I don't see how?

Save yourself the trouble. Your ideas are only original because nobody else is silly enough to ignore the obvious difficulties.

As has been pointed out, creating microcaviation via ultrasound is inherent ly destructive.

When ultrasound imaging needs small bubbles as a contrast medium, they inje ct them into the body with a hypodermic needle, rather than by creating des tructive foci of high intensity ultrasound.

High resolution MRI doesn't offer that kind of resolution.

Handheld MRI is an interesting idea. Breeding giants with hands the size of a small room might be the most practical way of getting there. For Jamie I probably need to point out that selective breeding wouldn't get us anythin g bigger than an elephant, which wouldn't be big enough to qualify.

Hi,

I already am skeptical of the safety of routine ultrasounds due to the microcavitation issue among other potential problems caused by MHz focused sound waves, especially in sensitive growth of tissue, ie fetal ultrasounds, but since these are accepted procedures, that can cause microcavitation, using them for diagnostic procedures would not be any more of a problem, unless more microcavitation is required.

I don't think PET scan's show pressure, since there are invasive tests done (spinal tap) to detect intercranial pressure etc.

cheers, Jamie

Hi,

Yes I was surprised there is no non-invasive method that I could find, since there are so many second order and higher effects of medical instruments you just gotta hook up the existing equipment in the right way and analyze the data probably to detect pressure. At the worst it might require some marker added to an IV, which has an oscillation proportional to fluid pressure or something that the ultrasound echo will vary based on etc..

cheers, Jamie

Hi,

I don't plan on building or attempting to build one, just looking for non-dull minds (ie not Sloman) to brainstorm to make the difficulty you refer to less.

with a hypodermic needle, rather than by creating destructive foci of high intensity ultrasound.

Many medical diagnostic procedures are destructive one way or another, if there can be limited damage done to sense pressure via micro- cavitation it might be a lot less damaging/invasive and repeatable than current methods, ie for measuring inter-cranial pressure.

Statistical analysis of an area of 1000's of micro-cavitation (or nano-cavitation) bubbles, ie distributed over 1mm^3 volume could be accessible to high tech MRI machines.

way of getting there. For Jamie I probably need to point out that selective breeding wouldn't get us anything bigger than an elephant, which wouldn't be big enough to qualify.

A handheld MRI might just analyze a single point, and not require a sweeping scan of voxels, so it could be made with a pulsed coil for the magnetic field.

cheers, Jamie

Diagnostic ultrasound power is much too low to create microcavitation.

}skipped the usual totally off-topic asinine responses of an uneducated trol.{

I have a better suggestion, and it costs only $8.72:

;-)

joe

If it's the whole body that gets hotter due to the local inflammation, then Tim's argument against local internal measurement would still hold.

joe

Heat in the body comes from within cell's and varies based on their metabolism, each cell produces heat, ie mitochondria burning sugar with oxygen. Tissue or organs that have a higher metabolic rate or inflammation run hotter, circulation distributes the heat, but still there is a temperature differential, and heat path that should be detectable.

Even a handheld IR scope should be able to detect inflammation and metabolic differences, ie hepatitis probably shows a hot spot on the skin around the liver.

cheers, Jamie

I guess you forgot about having an infected finger, or even a local infection in other areas, there can be an easily felt higher temperature in the local area of infection on the skin.

Temperature can be measured by pointing an antenna at the object, and measuring the noise power received by the antenna. This has been used to measure the temperature of tissues. One example I read about was a diathermy machine (basically an inside-out microwave oven pointed at a patient that somebody thinks would benefit from being microwaved and thereby heated). The machine would periodically turn off the magnetron, then connect a receiver to its antenna and measure the temperature of the tissues it had just been heating. This was in order to implement some sort of temperature control or thermostat.

Chris

Actually I didn't. I just followed your "raise the body (core) temperature". I thought you referred to the whole body there.

joe

A fever raises all of a body's isotherms more or less equally. So, the question of whether medial inflammation raises body temperature at the site of the injury or infection remains. Good luck!

I understand what a fever is -- does the immune system raise the temperature of just one spot, or does it indeed raise the temperature of the whole body? "Oh, this here spot has a 2 degree fever just like all the other spots" doesn't seem useful to me.

Sorry -- the _cause_ may show up just as well, not the actual intercranial pressure. My bad for not being clear. A magic scanner that could show intercranial pressure could be a good thing, although that's all it'd be useful for.

That's due to increased blood flow in an area that's normally cooled by the environment.

Is this known medical fact, or are you assuming? If it's really true, then yes, being able to scan for it may be worthwhile.

Actually, being able to scan for _any_ signifier of inflammation would be good, so perhaps the first thing to do is to catalog everything that signifies inflammation and see which ones are easy to scan for.

I used to work for FLIR, and they were constantly -- and unsuccessfully

-- trying to sell the medical community on IR scanning. AFAIK they still are (unsuccessfully trying, that is).

IR scanning does, it turn out, have a useful place in animal husbandry -- horses get hot spots on their legs when there's problems, and horse's legs both fragile and essential to health. So even when an IR camera was $40000 there were high-end horse operations that would use them to quickly check the health of their stock.

I don't know if that reasoning extends to cattle or other animals. It could, but individual cows aren't as valuable as individual race horses, so people may not want to mess with the technology.

Clearly if the infection is limited to one area, the temperature of just that area is raised. We've probably all had that happen with a localized infection. My point was that it's not just about blood flow and getting more blood to the affected area. If that were the case, the entire body temperature couldn't be raised during a generalized infection (fever). The body does burn more fuel to fight the infection. AIUI, it's because the higher temperature tends to the invader.

Sure, if it's a physical and large enough to be seen. Certainly CAT scans are used to find hemmorages.