Low Power Implantable ASIC forBio-Impedance Measurements

Abstract: Electrical bio-impedance can give a lot of insight into the basic physiological parameters of human body and concentration of glucose is one of those vital parameters.In order to control diabetes mellitus, it is critically essential to maintain blood glucose concentrations within the normal physiological range to avoid diabetes related complications.Consequently, accurate in-vivo and in-vitro measurement of glucose concentration in physiological uids has long been a central goal of bio sensor research.The correlation between glucose levels in human body and bio-impedance is more potently described with invasive measurement solutions and implanting the entire system inside human body can be considered one such technique.Any implantable device needs to be miniature in size as well as consume as little power as possible and since these two factors trade-o directly or indirectly with the accuracy, the solution space of dierent presently existing measurement techniques were implored to find an alternative that can meet all the specied constraints .The resultant application specific integrated circuit (ASIC) is capable of doing electrical bio-impedance measurements in implantable equipment and can handle impedance levels residing in a large dynamic range with very low power consumption, having small size and high accuracy. The circuit is based on 150nm technology, consumes around 530W power and has a worst case accuracy of 94%.