Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Sep 7:2020:5734932.
doi: 10.1155/2020/5734932. eCollection 2020.

Multimodal Detection for Cryptogenic Epileptic Seizures Based on Combined Micro Sensors

Zhitian Shen  1   2 , Yang Jiao  2   3 , Yiwen Xu  2 , Wei Shi  1   2 , Chen Yang  1   2 , Dan Li  4 , Hongtao Ma  2   4   5 , Weiwei Shao  2 , Zhangjian Li  1   2 , Yaoyao Cui  2
Affiliations

Multimodal Detection for Cryptogenic Epileptic Seizures Based on Combined Micro Sensors

Zhitian Shen et al. Biomed Res Int. .

Abstract

The cryptogenic epilepsy of the neocortex is a disease in which the seizure is accompanied by intense cerebral nerve electrical activities but the lesions are not observed. It is difficult to locate disease foci. Electrocorticography (ECoG) is one of the gold standards in seizure focus localization. This method detects electrical signals, and its limitations are inadequate resolution which is only 10 mm and lack of depth information. In order to solve these problems, our new method with implantable micro ultrasound transducer (MUT) and photoplethysmogram (PPG) device detects blood changes to achieve higher resolution and provide depth information. The basis of this method is the neurovascular coupling mechanism, which shows that intense neural activity leads to sufficient cerebral blood volume (CBV). The neurovascular coupling mechanism established the relationship between epileptic electrical signals and CBV. The existence of mechanism enables us to apply our new methods on the basis of ECoG. Phantom experiments and in vivo experiments were designed to verify the proposed method. The first phantom experiments designed a phantom with two channels at different depths, and the MUT was used to detect the depth where the blood concentration changed. The results showed that the MUT detected the blood concentration change at the depth of 12 mm, which is the position of the second channel. In the second phantom experiments where a PPG device and MUT were used to monitor the change of blood concentration in a thick tube, the results showed that the trend of superficial blood concentration change provided by the PPG device is the same as that provided by the MUT within the depth of 2.5 mm. Finally, in the verification of in vivo experiments, the blood concentration changes on the surface recorded by the PPG device and the changes at a certain depth recorded by the MUT all matched the seizure status shown by ECoG. These results confirmed the effectiveness of the combined micro sensors.

PubMed Disclaimer

Conflict of interest statement

The authors declare that they have no conflicts of interest.

Figures

Figure 1
Figure 1
The design of phantom with two channels. The combination was placed above the two channels and close to the phantom surface. Water covers the combination for conducting ultrasound. The first channel was injected with 50% blood. The second channel was injected with different concentrations of blood.
Figure 2
Figure 2
(a) The prototype of cerebral blood detection with combination. (b) The model of local cerebral blood detection with combination. (c) The design of phantom for realizing the model. The tube was attached to the phantom surface, and the combination was placed above the tube. The tube was injected with different concentrations of blood. (d) The schematic and the image of the combination.
Figure 3
Figure 3
(a) The schematic of in vivo experiment. (b) The image of in vivo experiment setup.
Figure 4
Figure 4
(a) The injection procedure in the deeper channel. (b) The result of ultrasound intensity ranged from 9 mm to 13 mm away from phantom surface. (c) The normalized ultrasound intensity in different areas: (i) the first channel, (ii) area between two channels, and (iii) the second channel.
Figure 5
Figure 5
The Pearson product-moment correlation coefficient between the injection procedure and normalized ultrasound intensity from 5 mm to 15 mm away from surface in the phantom.
Figure 6
Figure 6
(a) The light signal changes with the injection procedure including 50% and 100% blood. (b) The ultrasound intensity from 1 mm to 4 mm away from the phantom surface. (c) The ultrasound intensity in different areas: (i) tube area and (ii) phantom area.
Figure 7
Figure 7
The in vivo experiment result: (a) the ECoG signal; (b) the light signal; (c) the ultrasound intensity.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Bagshaw A. P., Kobayashi E., Dubeau F., Pike G. B., Gotman J. Correspondence between EEG-fMRI and EEG dipole localisation of interictal discharges in focal epilepsy. NeuroImage. 2006;30(2):417–425. doi: 10.1016/j.neuroimage.2005.09.033. - DOI - PubMed
    1. Goldensohn E. S., Salazar A. M. Temporal and spatial distribution of intracellular potentials during generation and spread of epileptogenic discharges. Advances in Neurology. 1986;44:559–582. - PubMed
    1. Carneiro Filho O., Vilela Filho O., Ragazzo P. C., Fonseca L. M. A new method for intraoperative localization of epilepsy focus by means of a gamma probe. Radiologia Brasileira. 2014;47(1):23–27. doi: 10.1590/S0100-39842014000100010. - DOI
    1. Kuruvilla A., Flink R. Intraoperative electrocorticography in epilepsy surgery: useful or not? Seizure. 2003;12(8):577–584. doi: 10.1016/S1059-1311(03)00095-5. - DOI - PubMed
    1. Zhang Q., Liu Z., Carney P. R., et al. Non-invasive imaging of epileptic seizures in vivo using photoacoustic tomography. Physics in Medicine & Biology. 2008;53(7):1921–1931. doi: 10.1088/0031-9155/53/7/008. - DOI - PubMed