Clinical Authors: David Eyre, Peter Watkinson Reactive Environment: - - PowerPoint PPT Presentation

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Clinical Authors: David Eyre, Peter Watkinson Reactive Environment: - - PowerPoint PPT Presentation

Authors: Rasheed el-Bouri, Tingting Zhu, David Clifton Clinical Authors: David Eyre, Peter Watkinson Reactive Environment: emergency departments (EDs) provide one of the greatest bottlenecks in the hospitalisation process (more acute


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Authors: Rasheed el-Bouri, Tingting Zhu, David Clifton Clinical Authors: David Eyre, Peter Watkinson

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emergency departments (EDs) provide one of the greatest bottlenecks in the hospitalisation process – (more acute since pandemic!)

Can we make this predictive?

Reactive Environment:

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 Increased risk of adverse outcomes for patients. 

Some countries impose financial repercussions on hospitals for long patient waiting times.

 Patients remaining in the ED still need to be cared for. Acts as a closed-

loop and slows the entire process down even further.

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Triage

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Triage Investigation

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Triage Investigation Assessment

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Triage Investigation Assessment

Decision

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Predict what type of ward a patient will be admitted to (seven classes).

The type of ward is used so that any ward in the hospital with that functional capability can be considered

An accurate answer as soon as the patient walks in is the most useful!

Medical Cardiac Neuro Trauma ICU Surgical O&G ED

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Curriculum learning has improved the performance of many algorithms that are trained using gradient descent.

No real consensus on the best type of curriculum for a given problem

Can we tailor-make a curriculum? Not just for a task but for a model too!

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Training a neural network is Markovian

network new network a new network b Train with batch a Train with batch b

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 Some similarity metric, 𝐼, that allows us to sort our training data set from

most complex to least complex, such that

 In this work we use cosine similarity as 𝐼 for images and the

Mahalanobis distance as 𝐼 for categorical and numerical data

𝐶𝑗 𝐶𝑘

𝐼 𝐶𝑗 < 𝐼[𝐶𝑘]

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 Weights 𝑋𝑗𝑘 of size 𝑁𝑗 × 𝑁𝑘  Reference vector of unique

elements, 𝑏

 |𝑋𝑜

𝑗𝑘. 𝑏| and ∠ (𝑋𝑜 𝑗𝑘 . 𝑏)

𝑋𝑜

𝑗𝑘. 𝑏

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 Representation of layer 𝑗 is and all the layers are concatenated together.  The full representation of a student with k hidden layers is

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r Student state 2 1

DDPG or DQN

r = ∇𝑢𝑠𝑏𝑗𝑜𝑗𝑜𝑕 ∗ ∇𝑤𝑏𝑚𝑗𝑒𝑏𝑢𝑗𝑝𝑜

The actor (teacher) has two

  • utputs :
  • 1. Curriculum index
  • 2. Batchwidth
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 Teacher learns how to degrade

performance in order to start again and achieve a better performance after training again

 Bottom plot: orange is first output

index of teacher (index in curriculum), blue is second (width)

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 Plot shows performance on MIMIC-III

mortality prediction task

 The teacher uses the same strategy

as on the ward admission dataset and achieves a strong performance for the student

 Some metric of task similarity will

allow teacher transfer for training

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Discussion of curricula learned for all tasks Constrained teacher Policy calibration Policy Transfer between Tasks Convergence of teacher selection

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Feel free to contact me at rasheed.el-bouri@eng.ox.ac.uk with any questions

  • r ideas