David Qi1, Elsa Olson2, Sven Ivankovic2, Taylor Sommer2, Kalyani Nair3, Martin Morris3, Julian Lin2. 1. Department of Neurosurgery, University of Illinois College of Medicine at Peoria, Peoria, IL, USA. mq3@uic.edu. 2. Department of Neurosurgery, University of Illinois College of Medicine at Peoria, Peoria, IL, USA. 3. Department of Mechanical Engineering, Bradley University, Peoria, IL, USA.
Abstract
PURPOSE: Prove the concept of high-resistance proximal catheters for valve-independent treatment of hydrocephalus. METHODS: A preliminary design process yielded optimal high-resistance proximal ventricular catheters with a "scaled" design and parallel-oriented, U-shaped inlets. Prototypes were manually constructed using carving tools to stamp through silicone tubings. A testing apparatus was developed to simulate cerebrospinal fluid flow through a catheter, and the prototypes were tested against a control catheter for exhibition of an "on/off" phenomenon whereby no flow occurs at low pressures, and flow begins beyond a pressure threshold. Flow distribution was visualized with India ink. Regression analysis was performed to determine linearity. RESULTS: The new designs showed varying amounts of improved flow control with the "scaled" design showing the most practical flow rate control across various pressures, compared to the standard catheter; however, no true "on/off" phenomenon was observed. The "scaled" design showed various degrees of dynamism; its flow rate can be time dependent, and certain maneuvers such as flushing and bending increased flow rate temporarily. Variation in the number of inlets within each "scaled" prototype also affected flow rate. Contrastingly, the flow rate of standard catheters was found to be independent of the number of inlet holes. Ink flow showed even flow distribution in "scaled" prototypes. CONCLUSIONS: This initial feasibility study showed that high-resistance ventricular catheters can be designed to mimic the current/valved system. The "scaled" design demonstrated the best flow control, and its unique features were characterized.
PURPOSE: Prove the concept of high-resistance proximal catheters for valve-independent treatment of hydrocephalus. METHODS: A preliminary design process yielded optimal high-resistance proximal ventricular catheters with a "scaled" design and parallel-oriented, U-shaped inlets. Prototypes were manually constructed using carving tools to stamp through silicone tubings. A testing apparatus was developed to simulate cerebrospinal fluid flow through a catheter, and the prototypes were tested against a control catheter for exhibition of an "on/off" phenomenon whereby no flow occurs at low pressures, and flow begins beyond a pressure threshold. Flow distribution was visualized with India ink. Regression analysis was performed to determine linearity. RESULTS: The new designs showed varying amounts of improved flow control with the "scaled" design showing the most practical flow rate control across various pressures, compared to the standard catheter; however, no true "on/off" phenomenon was observed. The "scaled" design showed various degrees of dynamism; its flow rate can be time dependent, and certain maneuvers such as flushing and bending increased flow rate temporarily. Variation in the number of inlets within each "scaled" prototype also affected flow rate. Contrastingly, the flow rate of standard catheters was found to be independent of the number of inlet holes. Ink flow showed even flow distribution in "scaled" prototypes. CONCLUSIONS: This initial feasibility study showed that high-resistance ventricular catheters can be designed to mimic the current/valved system. The "scaled" design demonstrated the best flow control, and its unique features were characterized.
Authors: Marcelo Galarza; Ángel Giménez; José Valero; Olga Porcar Pellicer; José María Amigó Journal: Childs Nerv Syst Date: 2013-07-24 Impact factor: 1.475
Authors: Marcelo Galarza; Volkan Etus; Fidel Sosa; Romina Argañaraz; Beatriz Mantese; Roberto Gazzeri; Christian Garcia Montoya; Pedro de la Rosa; Antonio López Guerrero; Gerald Chaban; Ángel Giménez; José María Amigó Journal: Childs Nerv Syst Date: 2020-10-29 Impact factor: 1.475
Authors: M Galarza; A Giménez; J M Amigó; M Schuhmann; R Gazzeri; U Thomale; J P McAllister Journal: Childs Nerv Syst Date: 2017-08-15 Impact factor: 1.475