Hollow silicon microneedles, fabricated using combined wet and dry etching techniques, for transdermal delivery and diagnostics.

Microneedle-based technologies are the subject of intense research and commercial interest for applications in transdermal delivery and diagnostics, primarily because of their minimally invasive and painless nature, which in turn could lead to increased patient compliance and self-administration. In this paper, a process for the fabrication of arrays of hollow silicon microneedles is described. This method uses just two bulk silicon etches - a front-side wet etch to define the 500 μm tall octagonal needle structure itself, and a rear-side dry etch to create a 50 μm diameter bore through the needle.

A Comparison of Flow- and Pressure-Controlled Infusion Strategies for Microneedle-based Transdermal Drug Delivery.

Microneedle-based transdermal drug delivery is considered an attractive alternative to conventional injections using hypodermic needles due to its minimally invasive and painless nature; this has the potential to improve patient adherence to medication regimens. Hollow microneedles (MNs) are sharp, sub-millimeter protrusions with a channel that serves as a fluidic interface with the skin. This technology could be coupled with micro-pumps, embedded sensors, actuators and electronics to create Micro Transdermal Interface Platforms - smart, wearable infusion systems capable of delivering precise microdoses over a prolonged period.

Towards Micropump- and Microneedle-based Drug Delivery using Micro Transdermal Interface Platforms (MicroTIPs).

Micro Transdermal Interface Platforms (MicroTIPs) will combine minimally invasive microneedle arrays with highly miniaturized sensors, actuators, control electronics, wireless communications and artificial intelligence. These patch-like devices will be capable of autonomous physiological monitoring and transdermal drug delivery, resulting in increased patient adherence and devolved healthcare. In this paper, we experimentally demonstrate the feasibility of controlled transdermal drug delivery using a combination of 500 μm tall silicon microneedles, a commercial micropump, pressure and flow sensors, and bespoke electronics.

Continuous monitoring of cardiac function by 3-dimensional accelerometers in a closed-chest pig model.

Objectives: Cardiac wall motions reflect systolic and diastolic function. We have previously demonstrated the ability of a miniaturized three-axis (3D) accelerometer to monitor left ventricular function in experimental models and in patients. The main aim of this study was to investigate the clinical utility of the method for monitoring the left and right ventricular function during changes in global and regional cardiac function in a postoperative closed-chest situation.

Fabrication and assembly of MEMS accelerometer-based heart monitoring device with simplified, one step placement.

An accelerometer-based heart monitoring system has been developed for real-time evaluation of heart wall movement. In this paper, assembly and fabrication of an improved device is presented along with system characterization and test data from an animal experiment. The new device is smaller and has simplified the implantation procedure compared to earlier prototypes.