Effect of vibration on insertion force and deflection of bioinspired needle in tissues

An experimental study on the mechanics and control of SMA-actuated bioinspired needle

Active needles demonstrate improved accuracy and tip deflection compared to their passive needle counterparts, a crucial advantage in percutaneous procedures. However, the ability of these needles to effectively navigate through tissues is governed by needle-tissue interaction, which depends on the tip shape, the cannula surface geometry, and the needle insertion method. In this research, we evaluated the effect of cannula surface modifications and the application of a vibrational insertion technique on the performance of shape memory alloy (SMA)-actuated active needles. These features were inspired by the mosquito proboscis' unique design and skin-piercing technique that decreased the needle tissue interaction force, thus enhancing tip deflection and steering accuracy. The bioinspired features, i.e., mosquito-inspired cannula design and vibrational insertion method, in an active needle reduced the insertion force by 26.24% and increased the tip deflection by 37.11% in prostate-mimicking gel. In addition, trajectory tracking error was reduced by 48%, and control effort was reduced by 23.25%, pointing towards improved needle placement accuracy. The research highlights the promising potential of bioinspired SMA-actuated active needles. Better tracking control and increased tip deflection are anticipated, potentially leading to improved patient outcomes and minimized risk of complications during percutaneous procedures.

Bioinspired medical needles: a review of the scientific literature

Needles are commonly used in medical procedures. However, current needle designs have some disadvantages. Therefore, a new generation of hypodermic needles and microneedle patches drawing inspiration from mechanisms found in nature (i.e. bioinspiration) is being developed. In this systematic review, 80 articles were retrieved from Scopus, Web of Science, and PubMed and classified based on the strategies for needle-tissue interaction and propulsion of the needle. The needle-tissue interaction was modified to reduce grip for smooth needle insertion or enlarge grip to resist needle retraction. The reduction of grip can be achieved passively through form modification and actively through translation and rotation of the needle. To enlarge grip, interlocking with the tissue, sucking the tissue, and adhering to the tissue were identified as strategies. Needle propelling was modified to ensure stable needle insertion, either through external (i.e. applied to the prepuncturing movement of the needle) or internal (i.e. applied to the postpuncturing movement of the needle) strategies. External strategies include free-hand and guided needle insertion, while friction manipulation of the tissue was found to be an internal strategy. Most needles appear to be using friction reduction strategies and are inserted using a free-hand technique. Furthermore, most needle designs were inspired by insects, specifically parasitoid wasps, honeybees, and mosquitoes. The presented overview and description of the different bioinspired interaction and propulsion strategies provide insight into the current state of bioinspired needles and offer opportunities for medical instrument designers to create a new generation of bioinspired needles.

Experimental study of mosquito-inspired needle to minimize insertion force and tissue deformation

The aim of this work is to propose a mosquito-inspired (bioinspired) design of a surgical needle that can decrease the insertion force and the tissue deformation, which are the main causes of target inaccuracy during percutaneous procedures. The bioinspired needle was developed by mimicking the geometrical shapes of mosquito proboscis. Needle prototypes were manufactured and tested to determine optimized needle shapes and geometries. Needle insertion tests on a tissue-mimicking polyvinylchloride (PVC) gel were then performed to emulate the mosquito-proboscis stinging dynamics by applying vibration and insertion velocity during the insertion. An insertion test setup equipped with a sensing system was constructed to measure the insertion force and to assess the deformation of the tissue. It was discovered that using the proposed bioinspired design, the needle insertion force was decreased by 60% and the tissue deformation was reduced by 48%. This finding is significant for improving needle-based medical procedures.