Time-of-Sight Liquid Flow Measurements in the Low Nanoliters per Minute Scale.

We describe an affordable and robust measurement technique applicable to nanoscale liquid flow. The approach can provide good precision (<1% RSD) in the 1.5-15 nL/min flow range.

Attenuation Coefficients of Tubular Conduits for Liquid Phase Absorbance Measurement: Shot Noise Limited Optimum Path Length.

We trace the history of liquid core waveguides (LCWs, also called liquid core optical fibers) and the role Teflon AF (TAF) has played in their development. We show that, in any shot noise limited situation, the optimum signal-to-noise ratio (S/N) occurs at a path length of 1/α{ln[1 + 2(α/α)]}, approximately 2/α under most conditions, α and α being the light attenuation coefficient due to the analyte and the background, respectively. The analysis shows that LCW length should be selected depending on the applicable α value.

Inline flow sensor for ventriculoperitoneal shunts: Experimental evaluation in swine.

Shunts are commonly employed to treat hydrocephalus, a severe central nervous disease caused by the buildup of cerebrospinal fluid in the brain. These shunts divert excessive cerebrospinal fluid from brain ventricles to other body cavities, thereby relieving the symptoms. However, these shunts are highly prone to failure due to obstruction from cellular debris, leading to cerebrospinal fluid accumulation in the brain and exacerbation of neurological symptoms.

Inline Shunt Flow Monitor for Hydrocephalus.

In hydrocephalus, cerebrospinal fluid (CSF) builds up in the cranial cavity causing swelling of the head and potentially brain damage. A shunt to drain the fluid into a body cavity is now universally used, but failure is all too common. Techniques for ascertaining shunt failure are time-consuming, expertise-dependent, and often inconclusive.