Mansour Ahmadian

Miniature transmitter for implantable micro systems

This paper considers design of a miniature transmitter operating with near-field inductive coupling, in the context of embedded electronic systems in medical diagnosis, environmental monitoring, and other industrial applications. Recent developments in system-on-chip and lab-on-a-chip technologies made the implementation of such miniaturized systems feasible, and pose an interesting set of problems with respect to low-power, short-range wireless communications. The design of a compact transmitter with a magnetic antenna is discussed and some early results are presented.

Toward a miniature wireless integrated multisensor microsystem for industrial and biomedical applications

This paper presents our work toward the integration of a multisensor microsystem with wireless communication, using system-on-chip (SoC) methodology. Four different forms of microelectronic sensors have been fabricated on two separate 5/spl times/5 mm/sup 2/ silicon chips measuring pH, conductivity, dissolved oxygen concentration, and temperature. The sensors are integrated with a sensor fusion chip comprising analog circuitry for sensor operation and signal amplification prior to digital decoding and transmission. The microsystem prototype will be packaged in a miniature capsule, which measures 16 mm /spl times/55 mm including batteries and dissipates 6.3 mW for a minimal life cycle of 12 h.

The molecular structure of tetra-tert-butyldiphosphine: an extremely distorted, sterically crowded molecule

The molecular structure of tetra-tert-butyldiphosphine has been determined in the gas phase by electron diffraction using the new DYNAMITE method and in the crystalline phase by X-ray diffraction. Ab initio methods were employed to gain a greater understanding of the structural preferences of this molecule in the gas phase, and to determine the intrinsic P-P bond energy, using recently described methods. Although the P-P bond is relatively long [GED 226.4(8) pm; X-ray 223.4(1) pm] and the dissociation energy is computed to be correspondingly small (150.6 kJ mol(-1)), the intrinsic energy of this bond (258.2 kJ mol(-1)) is normal for a diphosphine. The gaseous data were refined using the new Edinburgh structure refinement program ed@ed, which is described in detail. The molecular structure of gaseous P(2)Bu(t)(4) is compared to that of the isoelectronic 1,1,2,2-tetra-tert-butyldisilane. The molecules adopt a conformation with C(2) symmetry. The P-P-C angles returned from the gas electron diffraction refinement are 118.8(6) and 98.9(6) degrees, a difference of 20 degrees, whilst the C-P-C angle is 110.3(8) degrees. The corresponding parameters in the crystal are 120.9(1), 99.5(1) and 109.5(1) degrees. There are also large deformations within the tert-butyl groups, making the DYNAMITE analysis for this molecule extremely important.

Integrated micro-instrumentation for dynamic monitoring of the gastro-intestinal tract

The introduction of microsystem technology into diagnostic devices is a rapidly growing field where low form-factor can significantly improve device access or patient comfort. In this paper we present our results on a lab-in-a-pill device that uses laboratory-on-a-chip and system-on-chip technology to deliver analytical data from a range of sensors, and the methodology employed to build the device.

An Ingestible Electronic Pill for Real Time Analytical Measurements of the Gastro-Intestinal Tract

A state-of-the-art electronic “pill” has been developed for in situ studies of the gastrointestinal (GI) tract using integrated circuit and system level integration technologies. The measurement parameters include real time analysis of temperature, pH, conductivity and dissolved oxygen.

A sensor system on chip for wireless microsystems

Recent years have seen the rapid development of microsensor technology, system on chip design, wireless technology and ubiquitous computing. When assembled into a complex microsystem the technologies become powerful tools in medical diagnostics, environmental monitoring and personal connectivity. In this paper we describe the demonstration of a silicon chip that has all the attributes required of a microsystem for use in these applications. The design methodology we have employed is a variant of the system on chip approach whereby many intellectual property blocks are integrated at a high level in the design flow. Our intellectual property blocks include the analogue sensor instrumentation for temperature and pH, a data multiplexing and conversion module, a digital platform based around an 8-bit microcontroller, data encoding for spread-spectrum wireless transmission and a RF section requiring very few off-chip components. The chip has been fully evaluated and tested by connection to external sensors. Each block has well defined interfaces so that they can be easily reused in future designs targeted to different applications