On the merits of tetrapolar impedance spectroscopy for monitoring lithium concentration variations in human blood plasma

Constantinou, Loukas; Triantis, Iasonas F.; Hickey, Michelle J.; Kyriacou, Panayiotis A.

doi:10.1109/tbme.2016.2570125

Cited by 11 publications

(18 citation statements)

References 36 publications

(35 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Samples of human plasma that have been spiked with lithium were prepared by mixing 1 mL from each reagent of Li2CO3 prepared earlier i.e. 18,24,30,36,42,48,54 and 60 mEq with 29 mL of blood plasma, thus giving 8 samples of 30 mL, with lithium concentrations ranging between 0.4-2.0 mEq. To check for repeatability of measurement, another set of samples were prepared in the same way using a different batch of blood plasma, as well as an additional set of samples spiked with unknown lithium concentrations in plasma.…”

Section: A Preparation Of Blood Samplesmentioning

confidence: 99%

“…Therefore, variations in the recorded voltage can directly translate to blood lithium concentration changes. A more detailed explanation of the method can be found in [24], where the sensitivity of the method to changes in lithium concentration in human blood The new probe features a tenfold increase in the total sensitivity, corresponding to a tenfold increase in the measured impedance change for specific Li concentration variations. Hence, with appropriately designed instrumentation for tetrapolar impedance measurements, the new probe has the potential to measure very small Li concentration variations.…”

Section: Tetrapolar Electrical Impedance Measurements Of Blood Litmentioning

confidence: 99%

“…This work proposes the combination of optical and electrical impedance spectroscopy methods for measuring blood lithium concentrations. Optical spectroscopy techniques can offer a high degree of selectivity, whereas previous experimentation [24] has shown that electrical impedance spectroscopy can offer a high degree of sensitivity to changes in ionic concentrations. Hence, it is hypothesized that the combination of the two methods would provide an enhanced degree of sensitivity and specificity to changes in lithium concentration in blood.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A Method for Rapid, Reliable, and Low-Volume Measurement of Lithium in Blood for Use in Bipolar Disorder Treatment Management

Qassem

Constantinou

Triantis

et al. 2019

IEEE Trans. Biomed. Eng.

Self Cite

View full text Add to dashboard Cite

Abstract-Goal: Lithium preparations are considered the most reliable mood stabilizers for patients with Bipolar Disorder (BD), and are the most effective at reducing the risk of suicide. However, maintaining blood lithium concentration within the narrow therapeutic range of 0.4-1.2 mEq is crucial but extremely difficult. The aim of this work is to develop a personal lithium blood level analyzer using a novel method of combined optical and electrical impedance spectroscopy to test micro volumes of spiked samples of human blood. Results: Impedance measurements alone showed a limit of detection of less than 0.1 mEq within the therapeutic range, whereas optical measurements could verify the presence of lithium and provide a degree of lithium content. Optical specificity to lithium was further verified in qualitative assessment of lithium spiked blood samples with varying concentrations of sodium. Moreover, analysis of multiple linear regression yielded a prediction model of R2 = 0.322716 and RMSEP =0.223602 for optical measurements only using feature wavelengths, which were found to appear at minima 560 and 605 nm. Combined with impedance measurements, prediction of lithium concentration in samples with unknown lithium content was significantly increased to R2 = 0.876438, and RMSEP = 0.513554. Conclusion:The combination of optical and impedance modalities for determinations of blood lithium resulted in significant improvement to the sensitivity and accuracy of measurement. Significance: Results are complementary of the proposed optoimpedance method, and future work will now focus on the technical development of an integrated and miniaturized system for measurement of lithium levels in blood with a high level of accuracy and sensitivity.

show abstract

Section: A Preparation Of Blood Samplesmentioning

confidence: 99%

Section: Tetrapolar Electrical Impedance Measurements Of Blood Litmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Method for Rapid, Reliable, and Low-Volume Measurement of Lithium in Blood for Use in Bipolar Disorder Treatment Management

Qassem

Constantinou

Triantis

et al. 2019

IEEE Trans. Biomed. Eng.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Lithium carbonate was selected as the analyte since it is a very interesting and challenging PoC application. Multiple approaches have been used to try and detect it in blood due to its use as a therapeutic means for multiple psychiatric disorders [21][22][23]. The lithium carbonate solutions are made using distilled water and have a very low concentration.…”

Section: Phononic Crystal Sensormentioning

confidence: 99%

Use of Transient Time Response as a Measure to Characterize Phononic Crystal Sensors

Arango¹,

Sánchez²,

Torres³

et al. 2018

Preprint

View full text Add to dashboard Cite

Phononic crystals are periodic composite structures with specific resonant features that are gaining strength in the field as liquid sensors. The introduction of a structural defect in an otherwise periodic regular arrangement can generate a resonant mode, also called defect mode, inside the characteristic band gaps of phononic crystals. The morphology, as well as the frequency in which these defect modes appear, can give useful information on the composition and properties of an analyte. Currently, only gain, and frequency measurements are performed using phononic crystal sensors. Other measurements like the transient response have been implemented in resonant sensors such as quartz microbalances showing great results and proving to be a great complimentary measure to the gain and frequency measurements. In the present paper, a study of the feasibility of using the transient response as a measure to acquire additional information about the analyte is presented. Theoretical studies using the transmission line model were realized to show the impact of variations in the concentration of an analyte, in this case, lithium carbonate solutions, in the transient time of the system. Experimental realizations were also performed showing that the proposed measurement scheme presents significant changes in the resulting data, indicating the potential use of this measure in phononic crystal sensors. This proposed measure could be implemented as a stand-alone measure or as a compliment to current sensing modalities.

show abstract

“…Saline was used as a test reagent because its concentration has a very linear relationship with the measured impedance. (6,28) In general, it is cost effective to achieve accuracy using calibration instead of making sensors infinitely precise. Calibration types can be categorized as individual calibration, in which parameters are applied to individual sensors, and lot calibration, in which the same parameters are applied to the entire production lot.…”

Section: Introductionmentioning

confidence: 99%

Electrode Structure and Stimulation Frequency to Reduce the Estimation Error of Reagent Concentration Determined using Measured Impedance

Kim¹,

Park²,

Park³

et al. 2019

Sensors and Materials

View full text Add to dashboard Cite

We present the structure of an electrode and the excitation frequency that reduces the estimation error when the concentration of a reagent is measured using impedance. To compare the performance characteristics of interdigitated electrodes with one to five fingers, five electrodes of the same type were fabricated independently on printed circuit board (PCB) substrates. A fluidic channel was created on each substrate using double-sided tape and a polycarbonate (PC) cover so that the solution was equally distributed over all electrodes. The impedance was measured with stimulation signals of various frequencies for various concentrations. The measured impedance was used to calculate a linear parameter between the concentration and the impedance, and this parameter was used to calculate the error between the estimated value obtained from the impedance and the original concentration. Using this estimation error as a measure, we investigated the electrode and stimulus frequency suitable for each application requiring either lot or individual calibration. Experimental results show that measuring impedance at high frequencies with a single-finger electrode is advantageous for applications requiring lot calibration, while multiple-finger electrodes are suitable for individual calibration applications at low frequencies.

show abstract

On the merits of tetrapolar impedance spectroscopy for monitoring lithium concentration variations in human blood plasma

Cited by 11 publications

References 36 publications

A Method for Rapid, Reliable, and Low-Volume Measurement of Lithium in Blood for Use in Bipolar Disorder Treatment Management

A Method for Rapid, Reliable, and Low-Volume Measurement of Lithium in Blood for Use in Bipolar Disorder Treatment Management

Use of Transient Time Response as a Measure to Characterize Phononic Crystal Sensors

Electrode Structure and Stimulation Frequency to Reduce the Estimation Error of Reagent Concentration Determined using Measured Impedance

Contact Info

Product

Resources

About