Ultrasonically actuated silicon-microprobe-based testicular tubule metrology.

We report on a microfabricated silicon microprobe integrated with an ultrasonic actuator and polysilicon strain gauges for Microdissection Testicular Sperm Extraction (TESE) surgery. Multiple microprobe insertion experiments were performed on rat testis tissue and, by monitoring the tubule puncture artifacts in the force signal sensed by the microprobe, we were able to estimate the average diameter of the sperm-carrying tubules in the sample. We have demonstrated the ability to sense the existence of larger tubules embedded in a mass of thinner tubules, by means of an Area-Ratio based metric using an analytically calculated expression for the distribution of sizes measured by the microprobe.

Wireless transmission of cardiac action potentials with ultrasonically guided insertion of silicon probes.

This paper reports on the coupling of ultrasonically guided cardiac probes with wireless transmission of cardiac action potentials for applications in monitoring the 3D electrical onset of ventricular fibrillation. An application specific integrated circuit has been designed with a 40 dB amplifying stage and a frequency modulating oscillator to wirelessly transmit the recorded action potentials. Combined with the ultrasonically inserted cardiac probe that reduces penetration force, this system demonstrates the initial results in wireless monitoring of 3D action potential propagation.

An ultrasonically actuated silicon-microprobe-based testicular tubule assay.

Microdissection testicular sperm extraction (TESE) is an invasive surgical procedure in which sparsely located healthy larger diameter tubules carrying viable spermatazoa are identified by visual examination of the seminiferous tubules of the infertile testis under a microscope, and biopsies of regions of interest are performed. In this paper, we report on microfabricated silicon microprobes integrated with an ultrasonic horn actuator and strain gauges for microdissection probe-TESE (MP-TESE) surgery. The microprobes, with axial-force-sensitive polysilicon strain gauges, have high force sensitivity (-0.

Silica nanoparticle tags for capacitive affinity sensors.

Capacitive affinity sensors have shown great promise for disposable biosensors but have poor sensitivity as a direct sensor if the analyte molecule is small. In this paper, we report an indirect capacitive affinity sensor with silica nanoparticle tags to enhance the sensitivity for sandwich type of immunoassays. In these experiments, the antibody—antigen—antibody complex (as in the standard indirect sandwich immunoassay) is simulated by a human—IgG-antihuman-IgG complex.