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Challenges

We are attempting to classify and count the different subspecies of WBC in multi-cell images using morphological features. This is a challenging and ongoing problem explored by many independent researchers, and there is no standard solution. While shape and feature recognition is easy to humans, it is one of the most researched topics in machine learning. Most methods divide the process into two subsystems, segmentation and classification.

Past methods

Segmentation

We must segment each cell image into the nucleus and cell body in order to extract features. The first problem is cell isolation. Most researchers cropped the individual cells manually due to the difficulty in isolating overlapping circles (WBCs and red blood cells) which can be seen in Figure 1. Several methods for segmentation have been explored in the literature.

Overlapping Blood Smear.

Figure 1. Overlapping can be seen between RBCs and WBCs.

Green channel filtering is a common way to isolate WBCs in colored blood smear images. Red blood cells (RBCs) and white blood cells separate into two distinct peaks in this space (with number of pixels on the y axis and color value, 0 to 255 on the x axis). The white blood cells have more green content. Furthermore, the WBC nuclei also differ slightly from the cytoplasm in green content. [1] However, this method requires extremely consistent and high quality images due to the subtleties associated with the different cells’ green channel content.

Grayscale images and thresholding can also be used to separate the RBCs, WBCs, and WBC nuclei. WBC cell bodies appear much darker than RBCs, and WBC nuclei appear darker than cell bodies. Several thresholds can be used to differentiate between the cells. [2] For example, in “White Blood Cell Segmentation Using Morphological Operators and Scale-Space Analysis,” a hard-coded threshold was used to isolate the first seed. Then, another equation was used to improve the gradient extracted. This was repeated for 10 iterations. [3]This method requires the images to be high resolution, because blur and graininess can cause individual areas of darker or lighter spots.

Some researchers use a combination of both common methods in order to obtain the best results. They first localize the nuclei using color analysis, and then threshold for finer boundaries. [1]

Past classification methods

We found that many research articles used both morphological and texture features for classification. These are based mostly on nucleus shape. Recall that the subtypes of WBCs have lobed nuclei which differ between the types. In the literature, monocytes are the most difficult to classify, often mistaken lymphocytes and neutrophils.

Most research papers implement at least ten features. These features must differ significantly between the cell types. They include a variety of area, perimeter, and color characteristics. The papers that used colored images have more features than grayscale due to the differences in color content as mentioned above. Below are example categories that have been explored.

    Intensity and color based features

  • Mean and variance of color distances for cell, cytoplasm, and nucleus

    Texture based features

  • Contrast of cytoplasm and nucleus
  • Homogenicity of cytoplasm and nucleus
  • Entropy of cytoplasm and nucleus

    Shape based features

  • Area of cell and nucleus
  • Ratio of nucleus area over cell area and perimeter length
  • Nucleus shape features
  • Number of nuclei

Common classification methods include k-nearest neighbors, learning vector quantization, Multi-layer perceptrons, and support vector machine (SVM). These are pattern recognition algorithms, which makes sense for this application. We found that the most successful paper, which used 57 features in total from all three categories above, had an accuracy of 91% for SVM. [3]

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Introduction. OpenStax CNX. Dec 13, 2015 Download for free at http://legacy.cnx.org/content/col11930/1.1
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