Abstract: An apparatus and method that utilizes thermal dilution to detect a wide range of flow rates and/or flow status in cerebrospinal fluid (CSF) shunt systems. The use of a large cold source in combination with thermosensor pad of a particular construction provide a fluid flow analyzer with the ability to detect very low levels of CSF flow. In addition, a method for adjusting thermal dilution readings to compensate for varying shunt catheter depth is shown and for determining a steady state of the thermal dilution readings. The thermosensor pad is conformable to a patient's skin contour thereby making the apparatus and method less sensitive to ambient temperature errors and, as a result, more accurate in assessing CSF flow. Furthermore, a software error check is provided for identifying poor sensor-to-skin contact for alerting an operator to re-apply the thermosensor pad to correct, as well as a post-test check to determine if temperature data is reasonable before determining flow status or flow rate.

Abstract: An apparatus capable of generating flow in cerebrospinal fluid (CSF) shunt systems by vibrating the shunt, tubing or shunt valve dome, or applying cyclical pressure to the various parts of the shunt system. A method of generating flow and method of using the apparatus in shunt patency assessment, for example, hydraulic resistance assessment, is also disclosed. The apparatus allows, in conjunction with a thermal dilution method or radionuclide method, a quick CSF shunt patency assessment based upon CSF shunt resistance and not upon CSF flow or intracranial pressure (ICP) separately. This provides a more objective measure of shunt obstruction compared to other methods. Furthermore, the apparatus can be used to enhance flow in shunts, identify partial occlusion before symptoms occur, differentiate between patent, partially-occluded and occluded shunts. The apparatus can be used to generate flow in shunts if there is a need to lower ICP or move drugs administered via an injection chamber or a shunt dome.

Abstract: A system for measuring quantitative CSF flow in shunt tubing implanted under the skin. The system includes an array of thermosensors clustered in three sections, cooling device, placed on the skin surface and an associated data acquisition and analysis device. Two sensor sections are placed over the shunt on the skin and measure real time temperature responses related to CSF movement. One array placed adjacent the cooling device collects data on thermal properties of skin including skin thermal condictivity, specific heat, diffusivity, perfusion, and thermal inertia. The method involves assessing thermal properties of skin and measuring CSF flow in shunt tubing. The method is useful for shunt patency assessment, CSF valve adjustment procedures and CSF flow measurements related to CSF over drainage. Alternatively, only one section of sensors need be used when determining relative CSF flow, without the need to determine thermal skin properties and by applying the cooling device continuously.

Abstract: A system for measuring quantitative CSF flow in shunt tubing implanted under the skin. The system includes an array of thermosensors clustered in three sections, cooling device, placed on the skin surface and an associated data acquisition and analysis device. Two sensor sections are placed over the shunt on the skin and measure real time temperature responses related to CSF movement. One array placed adjacent the cooling device collects data on thermal properties of skin including skin thermal condictivity, specific heat, diffusivity, perfusion, and thermal inertia. The method involves assessing thermal properties of skin and measuring CSF flow in shunt tubing. The method is useful for shunt patency assessment, CSF valve adjustment procedures and CSF flow measurements related to CSF over drainage. Alternatively, only one section of sensors need be used when determining relative CSF flow, without the need to determine thermal skin properties and by applying the cooling device continuously.

Abstract: An apparatus capable of generating flow in cerebrospinal fluid (CSF) shunt systems by vibrating the shunt, tubing or shunt valve dome, or applying cyclical pressure to the various parts of the shunt system. A method of generating flow and method of using the apparatus in shunt patency assessment, for example, hydraulic resistance assessment, is also disclosed. The apparatus allows, in conjunction with a thermal dilution method or radionuclide method, a quick CSF shunt patency assessment based upon CSF shunt resistance and not upon CSF flow or intracranial pressure (ICP) separately. This provides a more objective measure of shunt obstruction compared to other methods. Furthermore, the apparatus can be used to enhance flow in shunts, identify partial occlusion before symptoms occur, differentiate between patent, partially-occluded and occluded shunts. The apparatus can be used to generate flow in shunts if there is a need to lower ICP or move drugs administered via an injection chamber or a shunt dome.