Real time CSF flow measurement system and method
First Claim
1. An apparatus for determining cerebrospinal fluid (CSF) flow rate in an implanted CSF shunt, said apparatus comprising:
- a pad that is configured to be placed against the skin of a patient over the location of the CSF shunt, said pad comprising;
a first plurality of temperature sensors that are configured to be aligned in a transverse direction with respect to said CSF shunt and wherein one of said first plurality of temperature sensors is configured to be aligned with the CSF shunt; and
a second plurality of temperature sensors that are configured to be aligned in a transverse direction with respect to said CSF shunt, downstream of said first plurality of temperature sensors, and wherein one of said second plurality of temperature sensors is configured to be aligned with the CSF shunt; and
a third plurality of temperature sensors associated with a temperature source that are configured to be positioned over the CSF shunt whenever said pad is placed against the skin; and
a sensor processing device that is electrically coupled to said pad for receiving temperature data from each of said plurality of temperature sensors, said sensor processing device configured to use said temperature data to remove the effects of skin depth of CSF shunt implantation, skin thermal conductivity and skin thermal diffusivity from temperature data collected by said first, second and third pluralities of temperature sensors, and said sensor processing device further configured to determine a flow rate of said CSF through said CSF shunt when a temperature source is applied to said pad.
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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.
29 Citations
26 Claims
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1. An apparatus for determining cerebrospinal fluid (CSF) flow rate in an implanted CSF shunt, said apparatus comprising:
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a pad that is configured to be placed against the skin of a patient over the location of the CSF shunt, said pad comprising; a first plurality of temperature sensors that are configured to be aligned in a transverse direction with respect to said CSF shunt and wherein one of said first plurality of temperature sensors is configured to be aligned with the CSF shunt; and a second plurality of temperature sensors that are configured to be aligned in a transverse direction with respect to said CSF shunt, downstream of said first plurality of temperature sensors, and wherein one of said second plurality of temperature sensors is configured to be aligned with the CSF shunt; and a third plurality of temperature sensors associated with a temperature source that are configured to be positioned over the CSF shunt whenever said pad is placed against the skin; and a sensor processing device that is electrically coupled to said pad for receiving temperature data from each of said plurality of temperature sensors, said sensor processing device configured to use said temperature data to remove the effects of skin depth of CSF shunt implantation, skin thermal conductivity and skin thermal diffusivity from temperature data collected by said first, second and third pluralities of temperature sensors, and said sensor processing device further configured to determine a flow rate of said CSF through said CSF shunt when a temperature source is applied to said pad. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for determining cerebrospinal fluid (CSF) flow rate in an implanted CSF shunt, said method comprising:
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applying a first plurality of temperature sensors against the skin over the location of the CSF shunt and wherein only one of said first plurality of temperature sensors is aligned with the CSF shunt; applying a second plurality of temperature sensors against the skin over the location of the CSF shunt, downstream of said first plurality of temperature sensors, and wherein only one of said second plurality of temperature sensors is aligned with the CSF shunt; associating a third plurality of temperature sensors with a temperature source, said temperature source being applied against the skin aligned with the CSF shunt; collecting temperature data from said first, second and third plurality of temperature sensors after a predetermined period of time has elapsed; removing the effects of skin depth of CSF shunt implantation, skin thermal conductivity and skin thermal diffusivity; and determining a flow rate of the CSF through the CSF shunt from said resultant temperature signal. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification