On-chip biofluorescence imaging inside a brain tissue phantom using a CMOS image sensor for in vivo brain imaging verification

Implantable CMOS biomedical devices

“…It is noted that our sensor can detect fluorescence through diffused light. We have already confirmed that the device can detect the diffused light in the depth of about 500 µm [35].…”

Real time in vivo imaging and measurement of serine protease activity in the mouse hippocampus using a dedicated complementary metal-oxide semiconductor imaging device

“…This filter offers high selectivity for the fluorescence emission of 7-amino-4-methylcoumarin (AMC). We achieved a transmittance of −44 dB, which is comparable to discrete filters used in fluorescence microscopes (Ng et al, 2006a).…”

“…As the fluorescence emission light falls in the longer wavelength region, it is less likely to be scattered and therefore the fluorescence image are likely to remain sharp. Although super-positioning of fluorescent images leads to image blurring, we have shown that images that extend beyond 500 m from the sensor surface is likely to be scattered and diffused, thus forming the background signal (Ng et al, 2006a). This signal can easily be removed by image processing.…”

“…Each photosensor pixel output is connected to a column bus line. The details of the image sensor have been described previously (Ng et al, 2006a). The analog output is connected to an off-chip interface circuit board, which is shown in Fig.…”

“…It was used to image internally inside the mouse brain (Ng et al, 2006b). Also, using a model reaction inside a brain tissue phantom, we have demonstrated the possibility of biofluorescence measurement in vivo (Ng et al, 2006a). In this work, we describe the use of the device to study serine protease activity in the mouse brain due to the importance of understanding the events that lead to seizures.…”