Non-Invasive Technique for Assessing Shunt Flow

Technology #ua13-137

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Jesse Skoch
Clinical Assistant VI, Surgery
Rein Anton
Assistant Professor, Surgery
Eniko Enikov
Professor, Aerospace & Mechanical Engineering
Managed By
Robert Sleeper
Licensing Manager (520) 626-4604

Invention: The present invention here captures the latest developments in material science, nanotechnology, and electronics by providing a flow sensor capable of resolving 1 mL/hr with an 24-hr error of not more than 50 mL (approximately 10% of daily discharge). 


Background:  Cerebral spinal fluid (CSF) shunting as a long-term treatment option for hydrocephalus is one of the most common neurosurgical procedures performed with an estimated incidence of approximately 5.5 per 100,000. Implanted cerebrospinal fluid shunts have been in use since 1950s, however approximately 39% of shunts fail within the first year, 53% fail with in the first two years, and about 80% fail at some point after implantation. Even in the modern shunt era up to 10% of hydrocephalus deaths are reportedly related to shunt failure. Measuring slow moving fluid inside the lumen of a catheter is challenging due to the decreased role of inertial forces commonly used in Pitot-type flow meters.  Presently there are no micro-flow sensors capable of resolving 1 mL/hr flow rates in implantable catheters. Such flow rates are common in drug delivery pumps and ventricular peritonieal shunts used to drain CSF fluid in patients suffering from hydrocephalous. Therefore, there exists a need for a non-invasive technique for assessing VP shunt flow, which would both aid understanding of the working shunt and potentially improve proper diagnosis of shunt malfunction.


Application: This device would provide superior monitoring and measurements of the flow rates common in both hydrocephaly shunts and in drug delivery pumps. It’s use can lead to a lower failure rate of hydrocephalic shunts and a higher detection rate of when these shunts fail, lower the current mortality rate associated with hydrocephaly.



This invention has been demonstrated to be superior to the state-of-the-art in (a) theory, and (b) simulations. Our simulation results show orders of magnitude in improvement, as compared to traditional methods. Real results from simulations closely replicate results predicted by theory.

•       Only sensor currently capable of measuring 1 mL/hr;

•       Measurements not obscured by hydrostatic pressure in human body like other sensors;

•       Provides both quantitative and qualitative measurements concerning liquid flow;

•       Sensor is not sensitive to temperature changes, and they will not interfere with flow readings.


Lead Inventor: Eniko T. Enikov


UA ID:  UA13-137



Robert Sleeper

Licensing Manager, College of Engineering

220 W. 6th Street

University Services Annex, 4th floor

PO Box 210300

Tucson, AZ  85721