Csf shunt flow evaluation apparatus and method using a conformable expanded dynamic range thermosensor

An apparatus for evaluating cerebrospinal fluid (CSF) flow rate or flow status in a CSF shunt within a patient, said apparatus comprising:

• a sensor pad having a body comprising a plurality of temperature sensors that are positioned transversely across said body at predetermined positions, said plurality of temperature sensors being aligned such that when said sensor pad is applied to the skin over the CSF shunt, one of said plurality of temperature sensors is positioned over the CSF shunt while the remaining plurality of temperature sensors are equally positioned on opposite sides of the CSF shunt;
• each of said temperature sensors configured to generate respective temperature data related to movement of a temperature pulse introduced into the CSF from a cold source applied to the skin for a predetermined period;
• said body further comprising an alignment member that protrudes from an edge of said pad, said alignment member acting as a guide for a user in positioning said cold source against the skin of the patient to maintain said cold source at a predetermined upstream position away from said plurality of temperature sensors over the CSF shunt, said sensor pad being disposable;
• and
• a sensor processing device that is electrically coupled to said sensor pad for receiving temperature data from each of said temperature sensors, said sensor processing device using said temperature data to determine a flow rate or flow status of said CSF through said shunt when said cold source is applied at said predetermined upstream position.

A method for evaluating cerebrospinal fluid (CSF) flow rate or flow status in a subcutaneous CSF shunt, said method comprising:

• applying a disposable pad having a body including a plurality of temperature sensors that are positioned transversely across said body at predetermined positions, said plurality of temperature sensors being aligned such that when said sensor pad is applied to the patient's skin over the CSF shunt, one of said plurality of temperature sensors is positioned over the CSF shunt while the remaining plurality of temperature sensors are equally positioned on opposite sides of the CSF shunt;
• applying a cold source over the CSF shunt and upstream of said plurality of temperature sensors for a predetermined period, said step of applying said cold source comprising positioning said cold source above an alignment member that protrudes from an edge of said pad for maintaining said cold source at a predetermined upstream position away from said plurality of temperature sensors over the CSF shunt;
• collecting temperature data from said plurality of temperature sensors;
• generating a resultant temperature signal from said temperature data;
• and
• determining a flow rate or flow status of the CSF through the shunt from said resultant temperature signal.

An apparatus for measuring changes in skin temperature above a subcutaneous CSF shunt, said apparatus comprising:

• a sensor pad having a body comprising a plurality of temperature sensors that are positioned transversely across said body at predetermined positions, said plurality of temperature sensors being aligned such that when said sensor pad is applied to the skin over the CSF shunt, one of said plurality of temperature sensors is positioned over the CSF shunt while the remaining plurality of temperature sensors are equally positioned on opposite sides of the CSF shunt;
• each of said temperature sensors configured to generate respective temperature data related to movement of a temperature pulse introduced into the CSF from a cold source applied to the skin for a predetermined period;
• said body further comprising an alignment member that protrudes from an edge of said pad, said alignment member acting as a guide for a user in positioning said cold source against the skin of the patient to maintain said cold source at a predetermined upstream position away from said plurality of temperature sensors over the CSF shunt, said sensor pad being disposable;
• and
• a sensor processing device that is electrically coupled to said sensor pad for receiving temperature data from each of said temperature sensors, said sensor processing device comprising an algorithm for taking the difference between said temperature data of said one of said plurality of temperature sensors that is positioned over the CSF shunt and an average of said temperature data of said remaining plurality of temperature sensors positioned on opposite sides of the CSF shunt, said algorithm adjusting said difference between said temperature data based on the location of the CSF shunt below the skin surface by multiplying said temperature difference by a ratio of actual skin thickness to average skin thickness.

A method for measuring changes in skin temperature above a subcutaneous CSF shunt, said method comprising:

• applying a disposable pad having a body including a plurality of temperature sensors that are positioned transversely across said body at predetermined positions, said plurality of temperature sensors being aligned such that when said sensor pad is applied to the patient's skin over the CSF shunt, one of said plurality of temperature sensors is positioned over the CSF shunt while the remaining plurality of temperature sensors are equally positioned on opposite sides of the CSF shunt;
• applying a cold source over the CSF shunt and upstream of said plurality of temperature sensors for a predetermined period, said step of applying said cold source comprising positioning said cold source above an alignment member that protrudes from an edge of said pad for maintaining said cold source at a predetermined upstream position away from said plurality of temperature sensors over the CSF shunt;
• collecting temperature data from said plurality of temperature sensors;
• generating a resultant temperature signal from said temperature data by taking a difference between said temperature data of said one of said plurality of temperature sensors that is positioned over the CSF shunt and an average of said temperature data of said remaining plurality of temperature sensors positioned on opposite sides of the CSF shunt;
• and
• correcting said temperature data based on the location of the CSF shunt below the skin surface by multiplying said temperature difference by a ratio of actual skin thickness to average skin thickness.

An apparatus for quantifying temperature sensor signal noise generated by poor contact of a plurality of temperature sensors applied to the skin of the patient, said apparatus comprising:

• a sensor pad having a body comprising a plurality of temperature sensors that are positioned transversely across said body at predetermined positions, said plurality of temperature sensors being aligned such that when said sensor pad is applied to the skin over the CSF shunt, one of said plurality of temperature sensors is positioned over the CSF shunt while the remaining plurality of temperature sensors are equally positioned on opposite sides of the CSF shunt;
• each of said temperature sensors configured to generate respective temperature data related to movement of a temperature pulse introduced into the CSF from a cold source applied to the skin for a predetermined period;
• said body further comprising an alignment member that protrudes from an edge of said pad, said alignment member acting as a guide for a user in positioning said cold source against the skin of the patient to maintain said cold source at a predetermined upstream position away from said plurality of temperature sensors over the CSF shunt, said sensor pad being disposable;
• and
• a sensor processing device that is electrically coupled to said sensor pad for receiving temperature data from each of said temperature sensors, said sensor processing device comprising an algorithm for quantifying signal noise generated by poor contact of said sensor pad to the skin of the patient, said algorithm comprising:
• measuring each rise and fall in temperature detected by each one of said plurality of sensors;
• converting each fall in temperature, comprising a negative number, into a positive number for each one of said plurality of sensors;
• totaling all temperature changes for each one of plurality of sensors to form a total error for each sensor;
• and
• comparing said total error of each sensor to a predetermined threshold to determine if said total error exceeds said predetermined threshold or not and re-applying said sensor pad to the skin and obtaining a new set of temperature data for all of said plurality of temperature sensors with said cold source applied if said predetermined threshold is exceeded.

A method for quantifying temperature sensor signal noise generated by poor contact of a plurality of temperature sensors applied to the skin of the patient, said method comprising:

• applying a disposable pad having a body including a plurality of temperature sensors that are positioned transversely across said body at predetermined positions, said plurality of temperature sensors being aligned such that when said sensor pad is applied to the patient's skin over the CSF shunt, one of said plurality of temperature sensors is positioned over the CSF shunt while the remaining plurality of temperature sensors are equally positioned on opposite sides of the CSF shunt;
• applying a cold source over the CSF shunt and upstream of said plurality of temperature sensors for a predetermined period, said step of applying said cold source comprising positioning said cold source above an alignment member that protrudes from an edge of said pad for maintaining said cold source at a predetermined upstream position away from said plurality of temperature sensors over the CSF shunt;
• collecting temperature data from said plurality of temperature sensors;
• and
• quantifying signal noise generated by poor contact of said sensor pad to the skin of the patient, said step for quantifying comprising:
• measuring each rise and fall in temperature detected by each one of said plurality of sensors;
• converting each fall in temperature, comprising a negative number, into a positive number for each one of said plurality of sensors;
• totaling all temperature changes for each one of said plurality of sensors to form a total error for each sensor;
• and
• comparing said total error of each sensor to a predetermined threshold to determine if said total error exceeds said predetermined threshold or not and re-applying said sensor pad to the skin and obtaining a new set of temperature data for all of said plurality of temperature sensors with said cold source applied if said predetermined threshold is exceeded.