Indicator tool for use with an implantable medical device
The invention is directed toward a magnetic indicator tool used to determine the setting of an implantable medical device. The implantable medical device includes a magnetic indicator device coupled to a valve on the implantable medical device. External magnetic fields, specifically earth's magnetic field, may interfere with a conventional compass and create an incorrect device setting indication. The magnetic indicator tool estimates the external magnetic fields to subtract the estimate from received data to minimize any influence that external magnetic field has on the accuracy of the device setting measurement.
1. An electronic magnetic-based indicator tool comprising:
a housing having an electric connection and removable mounting to a locator tool;
an electronic compass module carried by the housing for measuring an orientation of sensed magnetic fields; and
a locator tool interface module carried by the housing of the indicator tool for electronically communicating sensed magnetic field data to a processing module carried in the locator tool for receiving magnetic data values from the electronic compass module;
wherein the processing module:
receives and stores background magnetic field data;
receives target magnetic field data from the electronic compass module when the indicator tool is connected to the locator tool and is located above an implanted flow control device having a magnetic indicator device coupled to a valve;
electronically determines an orientation of the magnetic indicator device based upon the background magnetic field data and the target magnetic field data; and
electronically determines a setting for the valve from the determined orientation of the magnetic indicator device.
2. The electronic magnetic-based indicator tool according to claim 1 , wherein the processing module further subtracts the background magnetic field data from the target magnetic data to determine the setting of the valve on the implantable flow control device.
3. The electronic magnetic-based indicator tool according to claim 1 , wherein the indicator tool further comprises a mechanical key device about its housing for orientating the indicator tool into a desired position relative to a locator tool placed in a desired orientation relative to the implanted flow control device.
4. The electronic magnetic-based indicator tool according to claim 1 , wherein the indicator tool corresponds to a handheld device.
5. The electronic magnetic-based indicator tool according to claim 4 , wherein the handheld device includes a removable battery.
6. An electronic magnetic-based indicator tool comprising:
an indicator tool housing configured for removable assembly to a housing of a locator tool;
a target compass module within the indicator tool housing for measuring an orientation of sensed magnetic fields;
a background compass module within the locator tool away from the indicator tool for measuring an orientation of sensed magnetic fields; and
a locator tool interface module for electronically communicating sensed magnetic field data to a processing module in the locator tool for receiving magnetic data values from the target compass module;
wherein the processing module:
receives background magnetic field data from the background compass module independent of assembly of the indicator tool housing to the housing of the locator tool;
receives target magnetic field data from the target compass module when the indicator tool is assembled to the housing of the locator tool and the indicator tool is located above an implanted flow control device having a magnetic indicator device coupled to a valve; and
determines a setting for the valve within the implanted flow control device based upon the background magnetic field data and the target magnetic field data.
7. The electronic magnetic-based indicator tool according to claim 6 , wherein the processing module further subtracts the background magnetic field data from the target magnetic field data to determine the setting of the valve on the implantable flow control device.
8. The electronic magnetic-based indicator tool according to claim 6 , wherein the indicator tool further comprises a mechanical key device about its housing for orientating the indicator tool into a desired position relative to a locator tool placed in a desired orientation relative to the implanted flow control device.
9. The electronic magnetic-based indicator tool according to claim 6 , wherein the indicator tool corresponds to a handheld device.
10. The electronic magnetic-based indicator tool according to claim 9 , wherein the handheld device includes a removable battery.