Systems and methods for the identification of compounds in medical fluids using admittance spectroscopy

A method of determining the identity, concentration, or identity and concentration of one or more compounds in an aqueous solution, the method comprising the steps of:

• placing a pair of electrodes in contact with the aqueous solution so that a boundary layer of aqueous solution is formed on a first surface of one of the electrodes;
• applying electrical excitation between the pair of electrodes to determine a complex admittance at the first surface, wherein the applied electrical excitation results in a voltage that is below the threshold level for electrochemical reactions at the first surface;
• and
• determining the identity, concentration, or identity and concentration of one or more compounds in the aqueous solution based on the complex admittance measured between the electrodes.

A system for determining the identity, concentration or identity and concentration of an intravenous drug solution by admittance spectroscopy, the system comprising:

• a sensor comprising a plurality of electrodes having fluid-contacting surfaces;
• a signal generator configured to provide current at a plurality of frequencies for application from one or more fluid-contacting surfaces of the sensor;
• a signal receiver configured to receive complex admittance data from one or more fluid-contacting surfaces of the sensor;
• a controller configured to coordinate the application of signals from the signal generator and the acquisition of complex admittance data from the sensor to create an admittance spectrographic fingerprint of the intravenous drug solution;
• and
• a processor configured to receive the admittance spectrographic fingerprint and to determine the identity, concentration or identity and concentration of the intravenous drug solution by comparing the admittance spectrographic fingerprint to a library of admittance spectrographic data comprising complex admittance data measured from a plurality of known compounds and mixtures of compounds in a carrier solution at a plurality of frequencies and known concentrations.

A benchtop drug solution analyzer for determining the identity, concentration or identity and concentration of a drug solution by admittance spectroscopy, the analyzer comprising:

• a measurement cell comprising a plurality of electrodes having fluid-contacting surfaces, the measurement cell configured to receive a sample of the drug solution;
• a signal generator configured to provide electrical excitation at a plurality of frequencies for application from one or more pairs of electrodes of the measurement cell;
• a signal receiver configured to receive complex admittance data from one or more pairs of electrodes of the measurement cell;
• a controller configured to coordinate the application of signals from the signal generator, and the acquisition of complex admittance data from the signal receiver, to create an admittance spectrographic fingerprint of the drug solution;
• and
• a processor configured to receive the admittance spectrographic fingerprint and to determine the identity, concentration or identity and concentration of one or more compounds in the drug solution by comparing the admittance spectrographic fingerprint to a library of admittance spectrographic data comprising complex admittance data measured from a plurality of known compounds and mixtures of compounds in a carrier solution at a plurality of frequencies and known concentrations.

A system for controlling the delivery of an intravenous fluid by determining the identity, concentration or identity and concentration of one or more components of the intravenous fluid using admittance spectroscopy, the system comprising:

• a sensor having a plurality of complex admittance electrodes configured to contact an intravenous fluid;
• a signal generator configured to provide electrical excitation at a plurality of frequencies for application across the plurality of complex admittance electrodes;
• a processor configured to receive complex admittance data from the sensor at the plurality of frequencies and to determine the identity, concentration or the identity and the concentration of one or more compounds in the intravenous fluid by comparing the complex admittance data to a library of predetermined complex admittance data;
• and
• a control output configured to regulate the operation of an intravenous drug delivery device based on the determined identity, concentration or concentration and identity of one or more compounds in the intravenous fluid.

A method of determining the identity and concentrations of one or more compounds in a solution by admittance spectroscopy, the method comprising:

• applying electrical excitation at a plurality of frequencies between at least one pair of fluid-contacting surfaces in contact with the solution;
• determining the complex admittance between at least one pair of fluid-contacting surfaces at the plurality of frequencies;
• creating an admittance spectrographic fingerprint of the solution comprising the complex admittance from the at least one pair of fluid-contacting surfaces at the plurality of frequencies;
• and
• determining both the identity and the concentration one or more compounds in the solution by comparing the admittance spectrographic fingerprint to a library of admittance spectrographic data comprising complex admittance data measured from a plurality of known compounds and mixtures of compounds in a carrier solution at a plurality of frequencies and known concentrations.

A method of determining the identity and concentrations of one or more compounds in a solution by admittance spectroscopy, the method comprising:

• applying electrical excitation at a plurality of frequencies between two or more pairs of fluid-contacting surfaces in contact with the solution, wherein at least one of the fluid contacting surfaces is formed of a different material, different size, or different material and size than the other fluid contacting surfaces;
• determining the complex admittance from the two or more pairs of fluid-contacting surfaces at the plurality of frequencies;
• creating an admittance spectrographic fingerprint of the solution comprising the complex admittance from the two or more pairs of fluid-contacting surfaces at the plurality of frequencies;
• and
• determining both the identity and the concentration one or more compounds in the solution by comparing the admittance spectrographic fingerprint to a library of admittance spectrographic data comprising complex admittance data measured from a plurality of known compounds and mixtures of compounds in a carrier solution at a plurality of frequencies and known concentrations.