On Finding a Subset of Healthy Individuals from a Large Population

TL;DR

This paper establishes information-theoretic bounds on the number of nonadaptive group tests needed to identify non-defective individuals in large populations, improving efficiency over traditional methods and applicable to sparse signal recovery.

Contribution

It derives mutual information bounds for group testing, showing reduced test requirements and extending results to noisy models and sparse signal applications.

Findings

Reduced number of tests compared to traditional methods

Bounds applicable to noisy and noiseless scenarios

Extension to sparse signal recovery applications

Abstract

In this paper, we derive mutual information based upper and lower bounds on the number of nonadaptive group tests required to identify a given number of "non defective" items from a large population containing a small number of "defective" items. We show that a reduction in the number of tests is achievable compared to the approach of first identifying all the defective items and then picking the required number of non-defective items from the complement set. In the asymptotic regime with the population size $N \rightarrow \infty$, to identify $L$ non-defective items out of a population containing $K$ defective items, when the tests are reliable, our results show that $\frac{C_s K}{1-o(1)} (\Phi(\alpha_0, \beta_0) + o(1))$ measurements are sufficient, where $C_s$ is a constant independent of $N, K$ and $L$, and $\Phi(\alpha_0, \beta_0)$ is a bounded function of $\alpha_0 \triangleq \lim_{N\rightarrow \infty} \frac{L}{N-K}$ and $\beta_0 \triangleq \lim_{N\rightarrow \infty} \frac{K} {N-K}$. Further, in the nonadaptive group testing setup, we obtain rigorous upper and lower bounds on the number of tests under both dilution and additive noise models. Our results are derived using a general sparse signal model, by virtue of which, they are also applicable to other important sparse signal based applications such as compressive sensing.