Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
175 words
A device for monitoring the concentration of an analyte in a subject, comprising: a housing having a lower surface for application to the skin of the subject; means for holding the housing in position with the lower surface against the subject's skin; an electrical detection circuit comprising a power source connected across two electrodes mounted on said lower surface and switching means, the circuit being completed upon application of the lower surface to the skin of the subject, one of said electrodes being a sensor needle for penetrating through the epidermis and into the dermis when the lower surface is applied to the skin and having an enzyme associated therewith, said enzyme being specific to the analyte to be detected, and the switching means allowing the current through the circuit to flow intermittently to the sensor needle; and a communication circuit comprising means for measuring the current through said electrical detection circuit, means for calculating the concentration of the analyte from the measured current and communicating means for communicating the calculated concentration to the subject.
Claim 2
Independent Claim
175 words
A device for monitoring the concentration of an analyte in a subject, comprising: a housing having a lower surface for application to the skin of the subject; means for holding the housing in position with the lower surface against the subject's skin; an electrical detection circuit comprising a power source connected across two electrodes mounted on said lower surface and switching means, the circuit being completed upon application of the lower surface to the skin of the subject, one of said electrodes being a sensor needle for penetrating through the epidermis and into the dermis when the lower surface is applied to the skin and having an enzyme associated therewith, said enzyme being specific to the analyte to be detected, and the switching means allowing the current through the circuit to flow intermittently to the sensor needle; and a communication circuit comprising means for measuring the current through said electrical detection circuit, means for calculating the concentration of the analyte from the measured current and communicating means for communicating the calculated concentration to the subject.
Claim 3
Dependent Claim
20 words
A device according to claim 1, wherein the enzyme is glucose oxidase and the analyte to be measured is glucose.
Claim 4
Dependent Claim
38 words
A device according to claim 1, wherein the sensor needle is a working electrode and the other of said two electrodes is a counter electrode in the form of a platinum surface for contact with the subject's skin.
Claim 5
Dependent Claim
56 words
A device according to claim 1, wherein the electrical detection circuit also comprises a reference electrode on the lower surface of the housing, in the form of a silver/silver chloride surface for contact with the subject's skin, and a potentiostat having an operational amplifier which drives a current between the working electrode and the counter electrode.
Claim 6
Dependent Claim
53 words
A device according to claim 4, wherein the power source and the sensor needle are connected in series with the positive input of the amplifier and wherein a resistor and the delivery needle are connected in series with the amplifier output, the reference electrode being connected to the negative input of the amplifier.
Claim 7
Dependent Claim
22 words
A device according to claim 5, wherein the current through the circuit is determined by measuring the voltage drop across said resistor.
Claim 8
Dependent Claim
35 words
A device according to claim 6, wherein a voltmeter connected across said resistor provides a signal determined by the magnitude of the voltage drop and the signal is amplified and supplied to the communicating means.
Claim 9
Dependent Claim
21 words
A device according to claim 1, wherein the switching means comprises means for intermittently applying a voltage to the sensor needle.
Claim 10
Dependent Claim
16 words
A device according to claim 8, further comprising means for comparing the current at different times.
Claim 11
Dependent Claim
28 words
A device according to claim 9, wherein the means for comparing the current at different times is integral with the means for controlling the rate of active discharge.
Claim 12
Dependent Claim
27 words
A device according to claim 1, wherein the sensor needle is provided with a conduit permitting communication between the inner skin-contacting end and a source of oxygen.
Claim 13
Dependent Claim
14 words
A device according to claim 11, wherein the source of oxygen is the atmosphere.
Claim 14
Dependent Claim
39 words
A device according to claim 1, wherein the housing comprises a first part and a second part, the first part comprising the lower surface and the electrodes and the second part comprising the power source and the communication circuit.
Claim 15
Dependent Claim
39 words
A device according to claim 13, wherein the first part is detachably mounted on the second part, such that the first part can be disposed of and replaced and the second part can be reused a number of times.
Claim 16
Dependent Claim
22 words
A device according to claim 1, wherein the communicating means is activated when the calculated analyte concentration falls outside a predetermined range.
Claim 17
Dependent Claim
14 words
A device according to claim 1, wherein the communicating means comprises an audible alarm.
Claim 18
Dependent Claim
22 words
A device according to claim 1, wherein the communicating means operates continuously to provide a constant indication of the subject's analyte concentration.
Claim 19
Dependent Claim
18 words
A device according to claim 1, wherein the communicating means comprises a visible display of the analyte concentration.
Claim 20
Dependent Claim
28 words
A device according to claim 18, wherein the visible display is in the form of a liquid crystal display for indicating the analyte concentration as a numerical value.
Claim 21
Dependent Claim
13 words
The device of claim 1 wherein the concentration is communicated to the subject.
Claim 22
Dependent Claim
13 words
The device of claim 1 wherein the concentration is communicated to a microprocessor.
Claim 23
Dependent Claim
53 words
The device of claim 1 wherein the microprocessor is in communication with a liquid drug delivery device for delivering drug to the subject via the subject's skin, the device containing a liquid drug, whereby the microprocessor controls the rate of discharge of drug via the subject's skin in response to the communication thereto.