Transdermal drug delivery and analyte extraction

Claim 3

A device according to claim 1, wherein the power source is adapted to apply the electrical energy such that skin layers beneath the stratum corneum are substantially not ablated.

Claim 4

A device according to claim 1, wherein the power source is adapted to apply the electrical energy such that the ablation of the stratum corneum causes a puncturing thereof.

Claim 5

A device according to claim 1, wherein the power source is adapted to generate an electric field which causes a current to flow through the stratum corneum, and wherein the device is adapted to reduce power dissipated in the stratum corneum responsive to variation of a characteristic of the current.

Claim 6

A device according to claim 4, wherein the characteristic of the current is drawn from a list consisting of: the magnitude of the current; a time-integration of the current; a first time-derivative of the current; and a second time-derivative of the current.

Claim 7

A device according to claim 4, wherein the power source is adapted to modify the electric field so as to reduce current through one of the plurality of electrodes, substantially independently of the current through another one of the plurality of electrodes.

Claim 8

A device according to claim 4, and comprising a limited-conduction unit, wherein at least one of the plurality of electrodes is coupled to receive the current through the limited-conduction unit, which unit allows current below a threshold value to flow therethrough substantially unimpeded, and becomes substantially non-conductive if the current flowing therethrough exceeds a limited-conduction threshold value.

Claim 9

A device according to claim 4, and comprising an electrically-conductive dissolving element, wherein at least one of the plurality of electrodes is coupled to the electrically-conductive dissolving element, wherein the dissolving element is characterized by a dissolving rate generally proportional to the current passing therethrough, and wherein the dissolving element is adapted to become substantially nonconductive responsive to a function of the current.

Claim 10

A device according to claim 8, wherein the dissolving element is adapted such that the function comprises a time-integral of the current having passed through the dissolving element.

Claim 11

A device according to claim 8, wherein the dissolving element comprises: an electrolyte solution within the element; and a first node and a common node immersed in the electrolyte solution, wherein the dissolving element is adapted so that current flows from the first node to the common node through the electrolyte solution, wherein the common node is adapted to be consumed by the current flow at a rate generally proportional to the current passing therethrough, and wherein the dissolving element is adapted to become substantially nonconductive when the total charge having passed through the common node exceeds a common node threshold value.

Claim 12

A device according to claim 10, wherein the dissolving element further comprises a second node, immersed in the electrolyte solution, wherein the power source is adapted to generate alternating current, and wherein the device further comprises: a first diode, coupled in series between the power source and the first node, which is adapted to conduct current from the power source to the first node when the alternating current is in a positive phase thereof; and a second diode, coupled in series between the power source and the second node, which is adapted to conduct current from the second node to the power source when the alternating current is in a negative phase thereof, such that the dissolving element is adapted to become substantially nonconductive when the total charge having passed through the common node exceeds a common node threshold value.

Claim 13

A device according to claim 8, wherein the dissolving element comprises: an electrolyte solution within the element; a large-area anode immersed in the electrolyte solution; and a plurality of cathodes, immersed in the electrolyte solution, each of the cathodes being coupled to a respective one of the plurality of electrodes, wherein the dissolving element is adapted such that current flows from the large-area anode to the plurality of cathodes through the electrolyte solution, wherein at least one of the cathodes is adapted to be consumed by the current flow at a rate generally proportional to the current passing therethrough, and wherein the at least one cathode is adapted to become substantially nonconductive responsive to a function of the current having passed therethrough.

Claim 14

A device according to claim 4, wherein the power source is adapted to modify the electric field such that the current through at least one of the plurality of electrodes is reduced responsive to the variation of the characteristic of the current through another one of the plurality of electrodes.

Claim 15

A device according to claim 4, and comprising a voltage sensing unit coupled to measure a voltage drop across two of the plurality of electrodes, and wherein the power source is adapted to modify the electric field so as to reduce the current responsive to the measurement made by the sensing unit.

Claim 16

A device according to claim 14, wherein the power source comprises a current source, which is adapted to reduce the current responsive to a measurement made by the sensing unit which indicates that the electrical potential between the two electrodes is below a voltage-threshold value.

Claim 17

A device according to claim 14, and comprising a resistive element coupled to one of the two electrodes and to the power source, wherein the voltage sensing unit is further coupled to measure a voltage drop across the resistive element in order to determine a current passing therethrough, wherein the power source comprises an alternating current source, such that the measurements of the voltage drop across the two electrodes and the current through the resistive element determine a phase shift, and wherein the alternating current source is adapted to reduce the current through the stratum corneum responsive to the phase shift being below a threshold value.

Claim 18

A device according to claim 4, and comprising: a resistive element coupled to one of the plurality of electrodes and to the power source; and a voltage sensing unit coupled to measure a voltage drop across the resistive element in order to determine a current passing therethrough, wherein the power source comprises a voltage source, and wherein the voltage source is adapted to reduce a voltage thereof responsive to a measurement made by the sensing unit which indicates that the current through the resistive element is above a current-threshold value.

Claim 19

A device according to claim 4, wherein at least one of the plurality of electrodes is adapted to be printed directly on the skin and is adapted to become substantially electrically nonconductive responsive to the value of the current passing therethrough being greater than a threshold value.

Claim 20

A device according to claim 4, and comprising: a capacitor, coupled to two of the plurality of electrodes; and a switch, coupled to the power source and the capacitor, such that the switch, in a closed phase thereof, is adapted to allow current to flow from the power source to the capacitor and to the two electrodes, and such that the switch, in an open phase thereof, is adapted to substantially terminate current flow from the power source to the capacitor and to the two electrodes, wherein the power source is adapted to charge the capacitor during the closed phase, and wherein the capacitor is adapted to discharge current through the electrodes during the open phase.

Claim 21

A device according to claim 1, wherein the distance between two of the plurality of electrodes is less than about 0.3 mm.

Claim 22

A device according to claim 20, wherein the distance between the two electrodes is between about 0.01 mm and about 0.1 mm.

Claim 23

A device according to claim 1, wherein the plurality of electrodes comprise: a common electrode, which has a plurality of perforations therethrough; and a plurality of positive electrodes, each positive electrode passing through a respective perforation of the common electrode, wherein the power source is adapted such that current from the power source flows from each positive electrode through the skin to the common electrode.

Claim 24

A device according to claim 1, wherein the power source is adapted to generate alternating current, a frequency thereof being above about 100 Hz.

Claim 25

A device according to claim 23, wherein the power source is adapted to generate the alternating current such that the frequency is between about 1 kHz and about 300 kHz.

Claim 26

A device according to claim 1, wherein the power source is adapted to generate alternating current and to modulate a frequency thereof between a first frequency value and a second frequency value.

Claim 27

A device according to claim 1, wherein the power source is adapted to apply the electrical energy for less than about 1 second.

Claim 28

A device according to claim 26, wherein the power source is adapted to apply the electrical energy for less than about 200 milliseconds.

Claim 33

A device according to claim 29, wherein the power source is adapted to apply the alternating current at a frequency above about 100 Hz.

Claim 34

A device according to claim 30, wherein the power source is adapted to apply the alternating current at a frequency between about 1 kHz and about 300 kHz.

Claim 37

A device according to claim 32, wherein the two points are spaced about 0.01-0.1 mm apart.

Claim 38

A device according to claim 32, wherein the device is adapted to ablate the area of the stratum corneum in order to allow a substance to pass therethrough.

Claim 39

A device according to claim 34, wherein the device is adapted to ablate the area of the stratum corneum so as to allow the substance to pass through the skin into the body of the subject.

Claim 40

A device according to claim 34, wherein the device is adapted to ablate the area of the stratum corneum so as to allow the substance to pass through the skin from within the body.