A Position-Adjustable Multi-Point Synchronizing Biopsy Tool for Intratumor Heterogeneity: A Proof-of-Principle Study

A biopsy needle is a tool employed to fetch a portion of tissue at a point in the volume of diseased tissue, i.e., a Single Sample with a Single Spoon (SS-SS). Using this tool, the pathological status of the unhealthy tissue is generally represented by that of the specimen. However, for the tumor growing heterogeneously, like brainstem glioma, its inner constituent is heterogeneous. Therefore, the histological status of the specimen cannot precisely represent that of other points except the sampled point itself. The common principle of the existing solutions to this problem is to design the needle that fulfills biopsy operation by obtaining Multiple Samples with a Single Spoon at different points (MS-SS). The drawback of the designs following this principle is that during one biopsy operation, the latter samples are contaminated by their formers. The reason for the shortcoming is that the same spoon grabs all samples. To solve this problem, we design a novel biopsy tool that implements a single insertion to obtain Multiple Samples in multiple desired points with Multiple Spoons (MS-MS). The detailed system structure design, the motion procedure of the needle spoon, and the critical stress on the crucial mechanical parts are explicitly presented. Experiments using a built prototype is carried out on agar phantom and ex vivo porcine tissue, respectively. The results demonstrate the feasibility of the novel position-adjustable multi-point synchronizing biopsy tool for investigating intratumoral heterogeneity.