Related Terminologies

The following terminologies will be commonly used throughout the blog:

Biometric - Recent studies of methods for recognizing distinct human intrinsic physical or behavioral characteristics.
Fingerprint - Commonly used physical trait in biometric identification
Pruney Fingers - The wrinkles occur in skin after a drawn-out (15-20 min) exposure to water.
TPR - True positive rate (benefits)
FPR - False positive rate (costs)
ROC Curves - Relative Operating Characteristic curve is used as a graphical representation to illustrate a comparison of two operating characteristics (TPR & FPR) as the criterion changes. An example of this curve is illustrated below:

An Introduction to ROC Analysis

Stratum corneum (or horny layer) - The outermost layer of the epidermis, composed of large, flat, polyhedral, plate-like envelopes filled with keratin which are the dead cells that have migrated up from the stratum granulosum.

Stratum corneum

Pruning - Wrinkling of the skin as immersed in water for prolonged period. A protein, keratin, in stratum corneum which is responsible for skin hydration, absorbs water. So, as toes or fingers are exposed to water for a prolonged time, this layer of skin will develop wrinkles due to its stretchy properties of skin. However, this condition is temporary and it wears off within minutes.

Research

In order to start our experimental trial, we need to understand the process result in pruney fingers . The duration and temperature are the two parameters that make a difference in our result. So we chose the following paper to complete our understanding of the effect of water aging on fingerprints. 

Effects of water temperature on skin wrinkling

According to this study, the pruning using 40 degree Celsius water will occur in about 5 minutes. For the purpose of our study, we would like to keep the temperature constant to the room temperature. So it will be around 20 degree Celsius. Thus, the duration will increase accordingly.



A similar study shows that the average time to wrinkling in distilled water is 11.5 minutes. The following is a link to this study:

Fingertip Skin Wrinkling the Effect of Varying Tonicity

Experimental Procedure

1. Register fingerprints of volunteer participants
2. Make pruney fingers (i.e. leave the same finger in water for 15 min)
3. Take samples of a wet-wrinkled finger
   
4. Test to see if the wet-wrinkled sample matches the normal sample
   
5. Then take samples of dried- wrinkled finger
6. Test for a match
7. Create a database for indexing and labeling
8. Use ROC curves for further analyses

*Next class period, we will ask our fellow classmates who are willing to participate in our experimental procedure to register their fingerprints and sign a consent form.
* A consent form will be passed out today