LDC1000 - Measuring shape of human tissue

Hello Ioannis,

Let me see if I understand correctly - you need to measure the curvature of the living tissue, in the end of the day, correct?

What if the shape is not perfectly spherical, i.e. curvatures in x and y directions are not the same?

Hello Evgeny,

The tissue is a round thing but not a perfect circle - i.e. a separation wall of two somehow cylindrical compartments.

I can enter one compartment with the endoscope camera and measure the smoothness of the wall. Imagine that you look at a birthday cake (whose surface is not flat) from above (bird's-eye view) and need to scan the surface and reproduce it on a 3D model. The raw surface of the model depicts the highest and the lowest point on the surface, together with all peaks in between.

What I need is a map of the raw surface, in order to extract it's highs and lows. They can occur as a difference from a fixed point on the surface.

I hope that I described it as good as possible. Please let know if it's still blurry.

Best

Ioannis

Thank you, Ioannis, for your explanation, it gets much clearer now.

Could you please answer two more questions:

How close can endoscope head get to the surface under study?

What is the typical features size (diameter) and height on this map we need to create?

I have to thank you, Evgeny, for your quick reply!

The endoscope head can get as close as possible.

The diameter of the tissue is approximately 1,5 cm - 2 cm and the height differences about 1 mm.

The idea is to measure the height differences according to a reference point (not necessarily the 0 meters height) and since this would be done inductively, also determine which kind of fluid lies behind that tissue (different kind of fluids := different conductivity levels).

Can we accomplish those two tasks with this kind of sensor?

I read that the sensor can sense the shape of a metal, so I thought anything that is conductive could work in the same way.

Best

Ioannis

Hello Ioannis,

It is possible to measure relative height difference between the substrate spots under the sensor and the reference point, if we know reference point height above the substrate.

The sensor size will have to be substantially smaller than required spatial resolution.

To profile the surface features the sensor will have to scan across the surface with the reference point height kept constant by a feedback loop.

Hello Evgeny,

Just to make sure that I get it right:

>> It is possible to measure relative height difference between the substrate spots under the sensor and the reference point, if we know reference point height above the substrate.

With "substrate spots" you mean points (peaks) on the semiconductor base of the sensor coil or some other biological surface?

>> The sensor size will have to be substantially smaller than required spatial resolution.

How small would that be in order to distinguish 1mm of height difference (resolution effectively within 1mm)? Submilli or another power of ten?

>> To profile the surface features the sensor will have to scan across the surface with the reference point height kept constant by a feedback loop.

Do you have any example for that?

I appreciate your help!

Best

Ioannis

By substrate I mean bio matter that you need to profile.

The sensor will need to be of 1mm size then.

Please google for operational principle of Scanning Tunneling Microscope, or Atomic Force Microscope to get a better idea how to control the fixed distance.

Thanks Evgeny!

1mm? So not substantially smaller than the spatial resolution? How did you calculate it?

Now I get what you mean by saying feedback loop.

So, to summarize:

1. It is possible to measure relative height difference between the substrate spots (bio matter that you need to profile) under the sensor and the reference point, if we know reference point height above the substrate.
2. The sensor will need to be of 1mm size in order to distinguish 1mm of height difference (resolution effectively within 1mm).
3. To profile the surface features the sensor will have to scan across the surface with the reference point height kept constant by a feedback loop (google for operational principle of Scanning Tunneling Microscope, or Atomic Force Microscope to get a better idea how to control the fixed distance).

Great! Everything correct?

One last (old) question:

Can we determine which kind of fluid lies behind the tissue (different kind of fluids := different conductivity levels)?

In other words: can we profile materials, if there is another material between sensor and DUT? How do we determine the size of sensor in this case? How deep can we go (in terms of distance between sensor and DUT / how thick could be the layer in between?

I will need more info to answer  this question:

What are the conductivities of the liquid?

What material is blocking, its properties?

Thank you for sharing such great information. This is all very interesting.

_________________

human tissue bank