Kimiyasu Takoh

Wearable and low-stress ambulatory blood pressure monitoring technology for hypertension diagnosis

We propose a highly wearable, upper-arm type, oscillometric-based blood pressure monitoring technology with low-stress. The low-stress is realized by new developments in the hardware and software design. In the hardware design, conventional armband; cuff, is almost halved in volume thanks to a flexible plastic core and a liquid bag which enhances the fitness and pressure uniformity over the arm. Reduced air bag volume enables smaller motor pump size and battery leading to a thinner, more compact and more wearable unified device. In the software design, a new prediction algorithm enabled to apply less stress (and less pain) on arm of the patient. Proof-of-concept experiments on volunteers show a high accuracy on both technologies. This paper mainly introduces hardware developments. The system is promising for less-painful and less-stressful 24-hour blood pressure monitoring in hypertension managements and related healthcare solutions.

Label-free immunosensor using a gold electrode covered with conductive self-assembled monolayer

This paper describes an electrochemical immunosensor for the detection of target molecules without the use of labeled antibodies. The sensor is based on the combination of a gold electrode covered with a conductive self-assembled monolayer (SAM) of mixed thiols and a permeability measurement of an antibody layer anchored on the SAM. The permeability was measured by the square wave voltammetry (SWV) of ferrocyanide added in a measurement solution. The conductive SAM allows constant electron transfer between the electrode and ferrocyanide, providing a stable signal during repeated SWV measurements in contrast to immunosensors using conventional SAM techniques. We demonstrate that our sensor using the Anti-human chorionic gonadotropin (hCG) antibody selectively detects hCG in a minute without any washing process. The presented label-free immunosensor technology is fundamentally suited for easy-to-use assays for biological molecules such as hormones and drugs.