Methods and systems for predicting occurrence of an event
View Patent ↗Embodiments of the present invention are directed to methods and systems for training a neural network having weighted connections for classification of data, as well as embodiments corresponding to the use of such a neural network for the classification of data, including, for example, prediction of an event (e.g., disease). The method may include inputting input training data into the neural network, processing, by the neural network, the input training data to produce an output, determining an error between the output and a desired output corresponding to the input training data, rating the performance neural network using an objective function, wherein the objective function comprises a function C substantially in accordance with an approximation of the concordance index and adapting the weighted connections of the neural network based upon results of the objective function.
1. A method for predicting recurrence of cancer in a patient comprising:
estimating the probability that cancer will recur within a shorter period of time in a patient with a higher prognostic score than a patient with a lower prognostic score, wherein estimating comprises conducting pair-wise comparisons between prognostic scores for patients i and j, using a neural network trained using an objective function comprising a function C substantially in accordance with an approximation of the concordance index.
2. The method according to claim 1 , wherein using a neural network trained using an objective function comprises using a neural network trained using an objective function comprising a function C substantially in accordance with a derivative of the concordance index.
3. The method according to claim 1 , wherein using a neural network trained using an objective function comprises using a neural network trained using an objective function comprising a function C that allows for the use of censored data in the training.
4. The method according to claim 1 , wherein the function C comprises
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wherein Ω comprises pairs of patients {i, j}meeting one or more predetermined conditions.
5. The method according to claim 1 , wherein the function C comprises
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is a normalization factor, and Ω comprises pairs of data (i, j) meeting one or more predetermined conditions.
6. The method according to claim 4 , wherein the predetermined conditions comprise at least:
both patients i and j have experienced recurrence and the recurrence time t i of patient i is shorter than the recurrence time t j of patient j; and
patient i has experienced recurrence and t i is shorter than patient j's follow-up visit time t j .
7. The method according to claim 5 , wherein the predetermined conditions comprise at least:
both patients i and j have experienced recurrence and the recurrence time t i of patient i is shorter than the recurrence time t j of patient j; and
patient i has experienced recurrence and t i is shorter than patient j's follow-up visit time t j .
8. Computer readable media comprising computer instructions for allowing a computer system to perform a method for predicting recurrence of cancer in a patient, the method comprising estimating the probability that cancer will recur within a shorter period of time in a patient with a higher prognostic score than a patient with a lower prognostic score, wherein estimating comprises conducting pair-wise comparisons between prognostic scores for patients i and j, using a neural network trained using an objective function comprising a function C substantially in accordance with an approximation of the concordance index.
9. The computer readable media of claim 8 , wherein using a neural network comprises using a neural network trained using an objective function comprising a function C substantially in accordance with a derivative of the concordance index.
10. The computer readable media of claim 8 , wherein using a neural network comprises using a neural network trained using an objective function comprising a function C that allows for the use of censored data in the training.
11. The computer readable media according to claim 8 , wherein the function C comprises
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wherein Ω comprises pairs of patients {i, j} meeting one or more predetermined conditions.
12. The computer readable media according to claim 8 , wherein the function C comprises
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is a normalization factor, and Ω comprises pairs of data (i, j) meeting one or more predetermined conditions.
13. The computer readable media according to claim 11 , wherein the predetermined conditions comprise at least:
both patients i and j have experienced recurrence and the recurrence time t i of patient i is shorter than the recurrence time t j of patient j; and
patient i has experienced recurrence and t i is shorter than patient j's follow-up visit time t j .
14. The computer readable media according to claim 12 , wherein the predetermined conditions comprise at least:
both patients i and j have experienced recurrence and the recurrence time t i of patient i is shorter than the recurrence time t j of patient j; and
patient i has experienced recurrence and t i is shorter than patient j's follow-up visit time t j .