Multi-frequency sensing system and method
A sensor device may include an electrochemical (EC) gas sensor, a metal-oxide semiconductor (MOS) gas sensor, and control circuitry. The control circuitry may provide EC excitation signals to the EC gas sensor, provide at least two MOS excitation signals to the MOS gas sensor, and detect at least two gases. The control circuitry may detect the gases based on receiving EC response signals from the at least one EC gas sensor based on providing the EC excitation signals, receiving MOS response signals from the MOS gas sensor based on providing the MOS excitation signals, determining a multivariate response pattern based on the EC response signals and the MOS response signals, and differentiating between the at least two gases in contact with the sensor device based on the multivariate response pattern.
1 . A sensor device comprising:
at least one electrochemical (EC) gas sensor;
at least one metal-oxide semiconductor (MOS) gas sensor; and
control circuitry configured to:
provide one or more EC excitation signals to the at least one EC gas sensor;
provide at least two MOS alternating current (AC) excitation signals to the at least one MOS gas sensor; and
detect at least two gases based on:
receiving a plurality of EC response signals from each EC gas sensor of the at least one EC gas sensor in response to each EC excitation signal of the provided one or more EC excitation signals;
receiving at least two or more MOS response signals from each MOS gas sensor of the at least one MOS gas sensor based on providing the at least two MOS AC excitation signals;
determining a multivariate response pattern based on the plurality of EC response signals and the at least two or more MOS response signals; and
differentiating between the at least two gases in contact with the sensor device based on the multivariate response pattern.
2 . The sensor device of claim 1 , wherein the multivariate response pattern comprises the plurality of EC response signals from each EC gas sensor of the at least one EC gas sensor and the at least two or more MOS response signals from each MOS gas sensor of the at least one MOS gas sensor.
3 . The sensor device of claim 1 , wherein the at least one EC gas sensor comprises an EC gas sensing material and the at least one MOS gas sensor comprises a MOS gas sensing material.
4 . The sensor device of claim 1 , wherein the control circuitry comprises:
a controller coupled to the at least one EC gas sensor and the at least one MOS gas sensor configured to generate the one or more EC excitation signals and the at least two MOS AC excitation signals, and
a detector configured to receive the plurality of EC response signals and the at least two or more MOS response signals, wherein the detector comprises an electrical current detector, a resistance detector, an impedance detector, or a combination thereof.
5 . The sensor device of claim 1 , wherein detecting a first gas of the at least two gases is by correcting a baseline drift of the at least two or more MOS response signals based on the plurality of EC response signals.
6 . The sensor device of claim 1 , wherein the control circuitry differentiates between the at least two gases based on the multivariate response pattern by applying one or more supervised multivariate statistical analysis tools, one or more unsupervised multivariate statistical analysis tools, or both.
7 . The sensor device of claim 1 , comprising a memory storing one or more gas classification models to detect a first gas and a second gas based on differentiating the at least two gases.
8 . The sensor device of claim 7 , wherein the memory stores one or more gas quantitation models associated with detecting a concentration of the first gas, the second gas, or both.
9 . The sensor device of claim 1 , wherein the control circuitry receives:
control signals indicative of one or more operation parameters of the at least one MOS gas sensor, the at least one EC gas sensor, or both; and
one or more values for each of the one or more operation parameters before providing the one or more EC excitation signals to the at least one EC gas sensor and providing the at least two MOS AC excitation signals to the at least one MOS gas sensor.
10 . The sensor device of claim 9 , wherein the one or more operation parameters comprise a real part of impedance, an imaginary part of the impedance, frequency, or a combination thereof, of the one or more EC excitation signals, the at least two MOS AC excitation signals, or both.
11 . The sensor device of claim 1 , wherein the control circuitry comprises one or more processors, where the one or more processors are configured to determine one or more gas types and at least one gas concentration of the at least two gases.
12 . The sensor device of claim 11 , wherein the one or more processors are configured to generate control signals indicative of performing at least one responsive action based on determining the one or more gas types and the at least one gas concentration.
13 . The sensor device of claim 12 , wherein the responsive action comprises generating one or more alerts, activation of an emergency response, activation of a particular treatment or decontamination of a subject having the sensor device, optimization of logistics steps after a knowledge about a detected concentration of the at least two gases, minimization of logistics steps after the knowledge about the detected concentration of the at least two gases, or a combination thereof.