A Fully Integrated Multisite Pressure Sensor for Wireless Arterial Flow Characterization

Abstract

This paper presents a fully integrated battery-free sensing system that uses a two-site wireless pressure measurement for the detection of arterial stenosis. The remotely powered system uses a backscatter-modulated passive-telemetry interface and transmits sensor as well as reference information to an external system. The monolithic process used to realize the system integrates a 3 m BiCMOS circuit with silicon-on-glass absolute pressure sensors and an on-chip antenna. The wireless sensor interface consumes 340 W and uses capacitance-to-frequency conversion for readout of the vacuum-sealed pressure transducers. The integrated device has a 200 m profile and a volume of 2 mm 3 . The system can sense a reduction in flow of 13%, corresponding to a differential pressure of 3 mmHg.[1675]Index Terms-Implantable sensor, monolithic integration, on-chip antenna, pressure sensor, wireless telemetry.

Design and simulation of a thermo transfer type MEMS based micro flow sensor for arterial blood flow measurement

“…Numerous research paper published in this area have used various type of heating element in their micro flow sensing device, such as silicon carbide (SiC), platinum (Pt), polysilicon, titanium nitride (TaN) (Chung et al 2009) etc. In the present design model, thin film of Pt has been used as a heating element which is to be deposited on quartz substrate.…”

“…Intra-ocular and Intra-cranial implantable pressure sensor have been used for glaucoma patient and patient suffering from head injury respectively, for continuous pressure measurement using warless system (Receveur et al 2007). Implantable hemodynamic sensor (Ohlsson et al 2001) has been proposed where blood flow is measured by measuring the sensor conductivity (Bolz et al 1997;Chung et al 2009) or heater resistance which changes depending upon blood flow rate. Wireless implantable pressure sensor for arterial flow characterization has been proposed (DeHennis and Wise 2006), which is based on differential pressure measurement using capacitive diaphragms.…”

Complementary Metal Oxide Semiconductors Microelectromechanical Systems Integration

“…Bulk micromachining using wet anisotropic silicon etchants in combination with p ++ etch stop techniques have been used by Wise and his group for fabrication of pressure sensors 77 . The highly p-doped regions are diffused into the silicon substrate wafer after the CMOS p-well implantation.…”

Long term, implantable blood pressure monitoring systems

“…The hermetic enclosure protects the sensitive portion of the system from the body and the biocompatible coating is used to improve the interface of the implant with body. In previous work, the hermetic housing has been formed from a silicon-glass anodic bond (Najafi and Ludomirsky 2004;Park et al 1998;Takahata et al 2004;DeHennis and Wise 2006;Ziaie and Najafi 2001), a glass-glass fusion bond (Allen 2005), chemical vapor deposited oxide (Eggers et al 2000), and ceramic (Fonseca et al 2006).…”