Embolic material detachment detection system and method and assembly for embolic treatments
First Claim
1. A system for detecting the detachment of an implant from a guiding member coupled thereto, wherein the implant is guided by the guiding member into a target site in a living being, comprising:
- means for generating a current;
means for supplying the generated current via the guiding member to the implant;
means for measuring a voltage and current between the guiding member and the ground for a plurality of cycles, during each of which the voltage and current are measured for a plurality of times;
means for computing the average of the measured voltages and the average of the measured currents in each cycle;
means for determining the detachment of an implant from the guiding member based on a change in impedance between the guiding member and the ground, wherein the change is detected using the average voltage and average current of the latest cycle of voltage and current measurements, and the average voltage of the previous cycle of voltage and current measurements;
means for extracting the minimum of average voltages each of which is taken for a plurality of voltage measurements; and
means for comparing the minimum with the present average, and storing the present average as a new minimum voltage if it is less than the minimum voltage.
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Abstract
A system and method for determining the detachment of an embolic material using a single power supply are disclosed, wherein the determination is made by applying a DC power to an assembly with an embolic material, a sacrificial link and a guiding wire which are serially connected and repeatedly measuring a voltage and current between the assembly and the ground for a plurality of cycles and a plurality of times in each cycle; computing an average of the measured voltages and an average of measured currents; and determining the detachment of the embolic material from the guiding wire based on a change in impedance between the guiding wire and the ground, wherein the change is detected using the present average of the measured voltages, the present average of the measured currents and a previous average voltage which is previously measured for a plurality of times.
130 Citations
14 Claims
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1. A system for detecting the detachment of an implant from a guiding member coupled thereto, wherein the implant is guided by the guiding member into a target site in a living being, comprising:
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means for generating a current;
means for supplying the generated current via the guiding member to the implant;
means for measuring a voltage and current between the guiding member and the ground for a plurality of cycles, during each of which the voltage and current are measured for a plurality of times;
means for computing the average of the measured voltages and the average of the measured currents in each cycle;
means for determining the detachment of an implant from the guiding member based on a change in impedance between the guiding member and the ground, wherein the change is detected using the average voltage and average current of the latest cycle of voltage and current measurements, and the average voltage of the previous cycle of voltage and current measurements;
means for extracting the minimum of average voltages each of which is taken for a plurality of voltage measurements; and
means for comparing the minimum with the present average, and storing the present average as a new minimum voltage if it is less than the minimum voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7)
means for calculating a first fluctuation in impedance for the implant according to;
wherein Vmin, Va and Ia represent the minimum voltage, the present average of the measured voltages and the present average of the measured currents, respectively; and
a first estimation means for comparing the first impedance fluctuation to a first predefined threshold, and determining that the implant has been suddenly detached from the guiding member, if the first impedance fluctuation is larger than the first predefined threshold.
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4. The system of claim 3, wherein the comparing means further includes:
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means for computing a second fluctuation in impedance for the implant according to;
wherein Va, Vp and Ia represent the present average of the measured voltages, the previous average voltage and the present average of the measured currents, respectively; and
a second estimation means for comparing the second impedance fluctuation and a second predefined threshold, and determining that the implant has been gradually detached from the guiding member, if the second impedance fluctuation is larger than the second predefined threshold.
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5. The system of claims 3 or 4, wherein the comparing means further includes means for updating the present average as a new previous average voltage.
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6. The system of claim 1, wherein the implant includes an electrically conducting wire which is passed there through.
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7. The system of claim 6, wherein the distal end of the guiding member has an external diameter smaller slightly than the internal diameter of the implant and is connected to the electrically conducting wire within the implant by welding.
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8. A method for detecting the detachment of an implant from a guiding member coupled thereto, wherein the implant is guided by the guiding member into a target site in a living being, comprising the steps of:
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(a) generating a current;
(b) supplying the generated current via the guiding member to the implant;
(c) repeatedly measuring a voltage and current between the guiding member and the ground for a plurality of cycles, during each of which the voltage and current are measured for a plurality of times;
(d) computing an average of the measured voltages and an average of the measured currents in each cycle;
(e) determining the detachment of an implant from the guiding member based on a change in impedance between the guiding member and the ground, wherein the change is detected using the average voltage and average current of the latest cycle of voltage and current measurements, and the average voltage of the previous cycle of voltage and current measurements;
(f) extracting the minimum of average voltages each of which is taken for a plurality of voltage measurements; and
(g) comparing the minimum and the present average, and storing the present average as a new minimum if it is less than the minimum. - View Dependent Claims (9, 10, 11, 12, 13, 14)
(g1) calculating a first fluctuation in impedance for the implant according to;
wherein Vmin, Va and Ia represent the minimum voltage, the present average of the measured voltages and the present average of the measured currents, respectively; and
(g2) comparing the first impedance fluctuation and a first predefined threshold, and determining that the implant has been suddenly detached from the guiding member, if the first impedance fluctuation is larger than the first predefined threshold.
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11. The method of claim 10, wherein the step (g) further includes the steps of:
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(g3) computing a second fluctuation in impedance for the implant according to;
wherein Va, Vp and Ia represent the present average of the measured voltages, the previous average voltage and the present average of the measured currents, respectively; and
(g4) comparing the second impedance fluctuation and a second predefined threshold, and determining that the implant has been gradually detached from the guiding member, if the second impedance fluctuation. is larger than the second predefined threshold.
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12. The method of claims 10 or 11, wherein the step (g) further includes the step of updating the present average of the measured voltages as a new previous average voltage.
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13. The method of claim 8, wherein the implant includes an electrically conducting wire which is passed there through.
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14. The method of claim 13, wherein the distal end of the guiding member has an external diameter smaller slightly than an internal diameter of the implant and is connected with the electrically conducting wire within the implant by welding.
Specification