BIOMEDICAL ENGINEERING 15
Patterns and Measurements in Biomedical Engineering by Associate Professor Dr. Ibrahima Faye
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iomedical engineering is a multidisciplinary field with special focus in improving human health. Biomedical engineers construct diagnostic tools and devices used by medical practitioners. For this reason, biomedical engineering incorporates approaches from different research fields (e.g., engineering, mathematics, physics, computer sciences) to come up with practical solutions with minimal constraints from high cost as well as ethical and pain complications. Pattern recognition and objective measurements are two expressions that can be used to illustrate how biomedical engineering could be applied in medicine. Differentiating between normal and abnormal situations is a fundamental step in medicine. For instance, various pattern recognition techniques are used to detect cancer in breast, lung, skin, etc.
FEATURES FOR CLASSIFICATION OF PATTERNS Fruit Pattern Consider a bag containing apples and oranges, and one fruit is to be removed from the bag. For each fruit selected from the bag, without seeing it, we need to determine whether it is an orange or an apple based on a given criteria or feature. From the shape and the skin texture, we are able to classify the fruit as apple or orange. Thus, we would say the shape and the skin texture are good features, i.e., features that can be used to differentiate between apples and oranges in the bag. If the weights of oranges and apples are in the same range, however, then we may not be able to classify the fruits correctly. In this case, we would say that the weight is not an optimal feature to distinguish between oranges and apples.
In the same vein, an objective measurement that statistically explains pattern differences helps medical doctors to assess severity of disease and decide appropriate treatments. An effective objective measurement could solve the problem of assessment difference from different doctors (inter-variability), and from a doctor at different times (intra-variability).
As fruit weight may not be a good identifying feature, we can further use a transformed feature of the fruits as part of the identification process. If each selected fruit is pressed (i.e., ‘transformed’) into juice, the taste of the juice and the texture of the pulp allow us to differentiate between oranges and apples. Pattern recognition is an important technique in detection
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ISSUE 9 / NOVEMBER 2014
