Lancet-free blood sampling and collection for the management of diabetes

In this paper, we report on a system for the management of diabetes using jet injection. Jet injection uses a high-speed liquid jet to break the surface of the skin without requiring a needle. We propose that a single jet injection system may be capable of performing the key steps of insulin therapy including releasing and collecting blood, measuring blood glucose concentration, and administering insulin. We have previously demonstrated that our system can penetrate fingertip skin with a small (~20 µL) jet injection. In this work we present a secondary piston to maintain a partial vacuum pressure of −40 kPa by reversing the injector. The application of this partial vacuum is essential to enhance the volume of blood release to ensure sufficient blood is collected for a glucose measurement. On a silicone model of a hand, we demonstrate that the system can automatically extract and transfer blood into a glucose test strip. This is achieved using a device that retains the ability to then deliver subcutaneous jet injections of up to 300 µL of insulin.