Patient Screening Tools for Implantable Cardiac Stimulus Systems

Abstract

Tools and devices are provided for determining whether a patient is well suited to receiving an implantable cardiac stimulation device by analyzing cardiac signals captured using external or cutaneous electrodes. Some of the illustrative tools include shapes for visual comparison to printed ECG strips. Kits for use of illustrative tools are also shown. Automatic devices are also disclosed which perform at least some analytical functions electronically for a user. In an example, a printed ECG strip is visually compared to a shape in order to ensure a patient is well suited to receiving a cardiac stimulation device having a particular implant location and/or cardiac signal analysis method implementation.

What is claimed is: 
     
         1 . A patient screening tool for screening patients for receiving a particularly configured implantable cardiac stimulus device (ICSD), the particularly configured ICSD having a dynamic input range for sensing a range of voltages from a minimum voltage to a maximum voltage, the patient screening tool comprising a sheet of material having a stencil including a plurality of individual shapes visible on the transparent sheet, wherein the screening tool is sized such that comparisons may be made to printed ECG data captured from a prospective recipient of the particularly configured ICSD within predetermined printing guidelines including amplitude gain and printing sweep speed. 
     
     
         2 . The patient screening tool of  claim 1  wherein the plurality of individual shapes are sized to allow a determination of whether the printed ECG data from the prospective patient will allow use of the particularly configured ICSD by observation of whether signals from the patient's heart will exceed the dynamic input range of the particularly configured ICSD. 
     
     
         3 . The patient screening tool of  claim 1  wherein the plurality of individual shapes each represent an approximate detection profile that the particularly configured ICSD would use in response to ECG signal amplitudes in a given range. 
     
     
         4 . The patient screening tool of  claim 3  wherein the given range is indicated a given one of the plurality of individual shapes by a visible indicator of minimum and maximum voltages of the printed ECG for which the given one of the plurality of individual shapes should be used. 
     
     
         5 . The patient screening tool of  claim 1  wherein the plurality of individual shapes provide indications of whether overdetection of cardiac signals is likely if the particularly configured ICSD is implanted into the patient. 
     
     
         6 . The patient screening tool of  claim 5  wherein a given one of the plurality of individual shapes is shaped as follows:
 a first region indicates a refractory period that would be applied by the ICSD and includes amplitude indicia showing a range of ECG amplitude for which the given one of the plurality of individual shapes should be used; 
 a second region indicates a detection profile shape that would be applied by the ICSD following a refractory period, such that if the printed ECG amplitude exceeds an outer boundary of the second region, it can be concluded that overdetection of cardiac signals would be likely for a given sensing configuration of the particularly configured ICSD if implanted in the patient. 
 
     
     
         7 . The patient screening tool of  claim 1  further comprising visible indicia indicating placement of electrodes on the skin of the patient to capture electric signals for generating the printed ECG. 
     
     
         8 . The patient screening tool of  claim 1  further comprising a spacing guide for use in determining correct placement of electrodes on the skin of the patient for capturing electrical signals for generating the printed ECG. 
     
     
         9 . A kit for use in pre-operative patient screening for an implantable cardiac stimulus device (ICSD) comprising:
 a first patient screening tool including a stencil having first indicia for comparison to a printed ECG trace, the first indicia corresponding to characteristics of a cardiac signal analysis method incorporated into an ICSD of a first configuration; and   instructions for using the patient screening tool in the following manner:
 placing a plurality of cutaneous electrodes on the skin of the patient at first locations corresponding to planned implantation locations for electrodes of the ICSD of the first configuration; 
 capturing and printing ECG signals using the placed cutaneous electrodes; 
 visually comparing the printed ECG signals to the first patient screening tool to determine whether the printed ECG signals meet a screening criteria represented by the patient screening tool; and 
 if the printed ECG signals meet screening criteria of the first patient screening tool, determining that the patient is well suited to receiving the ICSD of the first configuration; or 
 else determining that the patient should not receive the ICSD of the first configuration. 
   
     
     
         10 . The kit of  claim 9  further comprising at least a second patient screening tool having a stencil with second indicia for comparison to a printed ECG trace, the second visible indicia corresponding to characteristics of a second cardiac signal analysis method incorporated into an ICSD having a second configuration. 
     
     
         11 . The kit of  claim 9  wherein the instructions include second locations for placement of the plurality of cutaneous electrodes if it is determined that the patient should not receive the firstly configured ICSD. 
     
     
         12 . The kit of  claim 9  wherein the first patient screening tool also includes a spacing guide for use in determining correct placement of electrodes on the skin of the patient for capturing electrical signals for generating the printed ECG. 
     
     
         13 . A patient screening tool for use in determining whether a patient is well suited to receiving a implantable cardiac stimulus device (ICSD) of a first configuration comprising first visible indicia tailored for identifying individuals well suited to receiving the ICSD of a first configuration, the first visible indicia shaped and presented to allow comparison to printed ECG signals from the patient to determine whether the printed ECG signals meet screening criteria represented by the patient screening tool. 
     
     
         14 . The patient screening tool of  claim 13  wherein the first visible indicia correspond to characteristics of a cardiac signal analysis method incorporated into the firstly configured ICSD. 
     
     
         15 . The patient screening tool of  claim 14  wherein the ICSD of the first configuration is set to use a detection profile to detect cardiac events, and wherein first visible indicia are shaped to correspond to the detection profile of the ICSD of the first configuration. 
     
     
         16 . The patient screening tool of  claim 13  wherein the first visible indicia is configured to allow a determination of whether the printed ECG data shows that signals from the patient's heart will or will not exceed the dynamic input range of the ICSD of the first configuration. 
     
     
         17 . The patient screening tool of  claim 16  wherein first visible indicia includes visible indicators of minimum and maximum voltages of the printed ECG for which the given one of the plurality of individual shapes should be used, wherein the visible indicators of minimum and maximum voltages are defined relative to predetermined printing guidelines including amplitude gain and printing sweep speed for generating the printed ECG signals. 
     
     
         18 . The patient screening tool of  claim 13  wherein first visible indicia provide indications of whether overdetection of cardiac signals is likely if the ICSD of the first configuration is implanted into the patient. 
     
     
         19 . The patient screening tool of  claim 18  wherein the first visible indicia include a plurality of individual shapes each shaped as follows:
 a first region indicates a refractory period that would be applied by the ICSD of the first configuration and includes amplitude indicia showing a range of ECG amplitude for which the given one of the plurality of individual shapes should be used; 
 a second region indicates a detection profile shape that would be applied by the ICSD of the first configuration following a refractory period, such that if the printed ECG amplitude exceeds an outer boundary of the second region, it can be concluded that overdetection of cardiac signals would be likely if the ICSD of the first configuration was implanted in the patient. 
 
     
     
         20 . The patient screening tool of  claim 13  further comprising visible indicia indicating placement of electrodes on the skin of the patient to capture electric signals for generating the printed ECG.