Artificial Neural Networks (ANNs) are playing an increasingly vital role in modern healthcare. From assisting in disease diagnosis to enhancing image analysis and summarising complex medical records, ANNs are transforming clinical workflows and influencing clinical decision-making. Without at least a basic understanding of how these systems operate, clinicians may struggle to keep pace with technological advancements that are rapidly shaping the delivery of patient care. These networks, inspired by the structure of the human brain, are already embedded in algorithms that process and interpret data for conditions such as melanoma and diabetic retinopathy. As such, familiarity with the functioning of ANNs is becoming essential for professionals working across the healthcare ecosystem.
The Biological Inspiration Behind ANNs
The foundational design of artificial neural networks mirrors how the human brain processes visual and sensory information. Groundbreaking research conducted by Nobel Prize winners Torsten Wiesel and David Hubel revealed how simple neurons in the brain can detect the orientation of edges in images, at every degree of rotation. These simple neurons then pass this information to more complex neurons, which are capable of interpreting various shapes. This network of neurons enables the brain to build an abstract concept, such as recognising the image of a cat. This progression from simple to complex processing is echoed in the layered structure of an ANN.
In the case of artificial networks, input data may include thousands of medical images, ranging from radiology scans to retinal photographs or dermatological images. These are used to assist in identifying a range of conditions, such as diabetic retinopathy or melanoma. In this setup, the artificial equivalents of brain neurons are called nodes, which exist within hidden layers of the network. Each node is assigned a numerical weight, corresponding to how strongly a specific feature is expressed in the input data. A higher numerical value might indicate the presence of a feature strongly associated with malignancy, such as an irregularly shaped lesion. Conversely, a smooth and round shape might be assigned a lower weight, suggesting a benign and typical finding, such as a normal mole. This weighted system enables the network to make preliminary assessments based on the data it receives.
How ANNs Learn and Improve Over Time
Although powerful, artificial neural networks do not function perfectly from the outset. When they initially perform calculations or analyses, they often produce numerous errors. However, they include a mechanism designed to correct these inaccuracies over time. This process, known as backpropagation, enables the network to look back at the mistakes it has made in earlier iterations. By doing so, it readjusts its algorithms and alters the numerical weights assigned to particular features. This iterative feedback loop strengthens the network’s ability to interpret new data more accurately and enhances its predictive power.
With repeated cycles of analysis and correction, the ANN becomes more adept at distinguishing relevant features within its data inputs. For instance, after being exposed to a large set of dermatological images, it may gradually improve its accuracy in differentiating between malignant melanomas and benign moles. This capacity for learning and self-correction makes ANNs increasingly valuable in clinical settings, where high volumes of complex data must be interpreted quickly and with growing precision. Over time, their ability to support clinicians with data-informed assessments becomes more refined and reliable.
The Power of Convolutional Neural Networks in Imaging
Among the many types of artificial neural networks developed over the years, convolutional neural networks (CNNs) have proven particularly effective for tasks involving image recognition. CNNs are widely used in medical applications because of their ability to detect intricate patterns in imaging data. The term convolution, while potentially confusing to those without a mathematics background, refers to a specific type of mathematical operation. In everyday language, the word may suggest something complex and hard to follow. In the context of informatics, convolution describes a process where two functions are combined by sliding one over the other. At each point of overlap, the values are multiplied and the results summed, forming a new function.
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This sliding motion is a helpful way to conceptualise how CNNs operate. Acting like stencils, the network’s filters move across the image to detect and highlight features. When the filter detects a matching element in the image, such as a specific shape or letter, the convolution process generates a strong image, which is then mapped to a feature map. This filtering process enables CNNs to detect highly complex visual patterns. As a result, they have become important tools in improving the interpretation of diagnostic imaging, including X-rays and MRI scans.
Once the data has been processed through the convolutional layers, it then passes through three additional steps: activation functions, pooling layers and fully connected layers. These stages contribute further to the processing and interpretation of data.
Artificial Neural Networks are rapidly becoming essential tools within the healthcare landscape, owing to their ability to replicate the brain’s approach to information processing and their capacity to improve accuracy over time. From the abstraction of visual data in layered structures to the precise pattern recognition achieved by convolutional networks, these technologies now play a critical role in supporting accurate diagnosis and enhancing clinical decision-making. As ANNs continue to evolve and become more deeply embedded in healthcare systems, the importance of understanding their mechanisms will only increase. For clinicians and healthcare professionals, staying informed about these technologies is no longer optional—it is necessary for maintaining relevance and effectiveness in a digitally advanced clinical environment.
Source: Mayo Clinic
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