Diagnosis
Engineers develop AI system to detect often-missed cancer tumors
Doctors may soon have help in the fight against cancer thanks to the University of Central Florida's Computer Vision Research Center. Engineers at the center have taught a computer how to detect tiny specks of lung cancer in CT scans, which radiologists often have a difficult time identifying. The artificial intelligence system is about 95 percent accurate, compared to 65 percent when done by human eyes, the team said. "We used the brain as a model to create our system," said Rodney LaLonde, a doctoral candidate and captain of UCF's hockey team. "You know how connections between neurons in the brain strengthen during development and learn? We used that blueprint, if you will, to help our system understand how to look for patterns in the CT scans and teach itself how to find these tiny tumors."
how_decision_trees_work.html
Decision trees are one of my favorite models. They are simple, and they are powerful. In fact most high performing Kaggle entries are a combination of XGBoost, which is variant of decision tree, and some very clever feature engineering. The concept behind decision trees is refreshingly straightforward. Imagine creating a data set by recording the time you left your house, and noting whether you arrived at work on time.
Learn ML Algorithms by coding: Decision Trees – Lethal Brains
Let us build a crude decision tree which predicts the outcome in probabilities (In Scikit learn, predict method returns the predicted classes while the predict_proba method returns the predicted probabilities. What do you think would be most simple and easy way to predict the probabilities? I have touched it up a little bit. The fit method accepts a dataframe(data) and a string for the target attribute(target). Both of the them are then assigned to the object.
Data is the lifeblood of AI, but how do you collect it?
When it comes to artificial intelligence (AI), there is no such thing as data overload. Because AI systems have the ability to process enormous amounts of data, and their accuracy increases along with data volume, the demand for data continues to grow. Consider, for example, an AI program designed to identify the cause of defective medical devices produced during the manufacturing process. As with any AI application, the software looks for patterns in the data using algorithms developed by data scientists. To try to solve this problem, suppose that the AI program receives and sorts through production data from different days of the week, times of day, machines and operators.
Theoretical Aspects of Cyclic Structural Causal Models
Bongers, Stephan, Peters, Jonas, Schölkopf, Bernhard, Mooij, Joris M.
Structural causal models (SCMs), also known as (non-parametric) structural equation models (SEMs), are widely used for causal modeling purposes. A large body of theoretical results is available for the special case in which cycles are absent (i.e., acyclic SCMs, also known as recursive SEMs). However, in many application domains cycles are abundantly present, for example in the form of feedback loops. In this paper, we provide a general and rigorous theory of cyclic SCMs. The paper consists of two parts: the first part gives a rigorous treatment of structural causal models, dealing with measure-theoretic and other complications that arise in the presence of cycles. In contrast with the acyclic case, in cyclic SCMs solutions may no longer exist, or if they exist, they may no longer be unique, or even measurable in general. We give several sufficient and necessary conditions for the existence of (unique) measurable solutions. We show how causal reasoning proceeds in these models and how this differs from the acyclic case. Moreover, we give an overview of the Markov properties that hold for cyclic SCMs. In the second part, we address the question of how one can marginalize an SCM (possibly with cycles) to a subset of the endogenous variables. We show that under a certain condition, one can effectively remove a subset of the endogenous variables from the model, leading to a more parsimonious marginal SCM that preserves the causal and counterfactual semantics of the original SCM on the remaining variables. Moreover, we show how the marginalization relates to the latent projection and to latent confounders, i.e. latent common causes.
New UCI center seeks to empower patients, providers through use of AI in healthcare
Physicians at the University of California, Irvine and UCI Health System have launched the UCI Center for Artificial Intelligence in Diagnostic Medicine, which seeks to advance patient care, improve health outcomes and lower costs by leveraging machine learning technology in all areas of healthcare. Led by Peter D. Chang, MD, and Daniel S. Chow, MD, neuroradiologists in the Department of Radiological Sciences, UCI School of Medicine, the center is a cross-specialty initiative with a specific focus on developing and applying deep learning neural networks to healthcare applications, such as diagnostics, disease prediction and therapy planning. "Our goal is to empower health care providers, researchers and patients through the use of artificial intelligence in healthcare," said Chang. The Center for Artificial Intelligence in Diagnostic Medicine will provide a central research core that enables all UCI faculty, physicians and researchers, to collaborate on translating AI-based concepts into clinical tools to improve individual and population health. "The center will develop machine learning tools that can be implemented for routine clinical use today," said Chow.
The Marriage of Artificial Intelligence and Patient Care - IEEE Transmitter
When something is wrong we go to the doctor and we begin what is ideally a two-step process: diagnosis and therapy. Artificial intelligence (AI) will transform both aspects of health care by adding powerful new tools to the doctor's bag. A range of diverse, compelling research projects around AI-driven diagnoses are underway. For example, an international community (including Google's Brain project) competes in an annual challenge to correctly diagnose breast cancer in 400 expert-labeled microscopic images of biopsy samples. About 99 percent of the slides were identified correctly by a project from Harvard and Massachusetts Institute of Technology.
From Deterministic ODEs to Dynamic Structural Causal Models
Rubenstein, Paul K., Bongers, Stephan, Schoelkopf, Bernhard, Mooij, Joris M.
Structural Causal Models are widely used in causal modelling, but how they relate to other modelling tools is poorly understood. In this paper we provide a novel perspective on the relationship between Ordinary Differential Equations and Structural Causal Models. We show how, under certain conditions, the asymptotic behaviour of an Ordinary Differential Equation under non-constant interventions can be modelled using Dynamic Structural Causal Models. In contrast to earlier work, we study not only the effect of interventions on equilibrium states; rather, we model asymptotic behaviour that is dynamic under interventions that vary in time, and include as a special case the study of static equilibria.
Evaluating Active Learning Heuristics for Sequential Diagnosis
Rodler, Patrick, Schmid, Wolfgang
Given a malfunctioning system, sequential diagnosis aims at identifying the root cause of the failure in terms of abnormally behaving system components. As initial system observations usually do not suffice to deterministically pin down just one explanation of the system's misbehavior, additional system measurements can help to differentiate between possible explanations. The goal is to restrict the space of explanations until there is only one (highly probable) explanation left. To achieve this with a minimal-cost set of measurements, various (active learning) heuristics for selecting the best next measurement have been proposed. We report preliminary results of extensive ongoing experiments with a set of selection heuristics on real-world diagnosis cases. In particular, we try to answer questions such as "Is some heuristic always superior to all others?", "On which factors does the (relative) performance of the particular heuristics depend?" or "Under which circumstances should I use which heuristic?"
Constraint-based Causal Discovery for Non-Linear Structural Causal Models with Cycles and Latent Confounders
Forré, Patrick, Mooij, Joris M.
We address the problem of causal discovery from data, making use of the recently proposed causal modeling framework of modular structural causal models (mSCM) to handle cycles, latent confounders and non-linearities. We introduce {\sigma}-connection graphs ({\sigma}-CG), a new class of mixed graphs (containing undirected, bidirected and directed edges) with additional structure, and extend the concept of {\sigma}-separation, the appropriate generalization of the well-known notion of d-separation in this setting, to apply to {\sigma}-CGs. We prove the closedness of {\sigma}-separation under marginalisation and conditioning and exploit this to implement a test of {\sigma}-separation on a {\sigma}-CG. This then leads us to the first causal discovery algorithm that can handle non-linear functional relations, latent confounders, cyclic causal relationships, and data from different (stochastic) perfect interventions. As a proof of concept, we show on synthetic data how well the algorithm recovers features of the causal graph of modular structural causal models.