Biophotonic sensors
Printed biophotonic sensors for blood and tissue oximetry
Oximetry, the technique for determining oxygen saturation, optically measures the light absorption of oxygenated and deoxygenated blood and tissue at two different wavelengths. In 2014, we demonstrated the first all-organic optoelectronic oximeter sensor composed of organic light-emitting diodes (OLEDs) and an organic photodiode (OPD) to accurately measure pulse rate and oxygenation with errors of 1% and 2%, respectively [1]. This transmission-mode probe demonstrated that oximetry can be performed with organic optoelectronics. However, to realize the true potential of organic optoelectronics for oximetry, a reflection-mode operation is essential that allows sensor placement on different parts of the body. After optimizing the sensor design and the printing process, in 2017, we reported a reflection-mode organic oximeter probe and performed blood oxygenation measurements on the wrist [2].
Relevant publications:
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All-organic optoelectronic sensor for pulse oximetry Nature communications, 2014 5, *Equal contribution. Media coverage: UC Berkeley Grad News, NSF Science 360 News, UC Berkeley News Center, Phys.Org, ScienceDaily, MSN News, Yahoo News, and many more.
Pulse oximetry is a ubiquitous non-invasive medical sensing method for measuring pulse rate and arterial blood oxygenation. Conventional pulse oximeters use expensive optoelectronic components that restrict sensing locations to finger tips or ear lobes due to their rigid form and area-scaling complexity. In this work, we report a pulse oximeter sensor based on organic materials, which are compatible with flexible substrates. Green (532 nm) and red (626 nm) organic light-emitting diodes (OLEDs) are used with an organic photodiode (OPD) sensitive at the aforementioned wavelengths. The sensor’s active layers are deposited from solution-processed materials via spin-coating and printing techniques. The all-organic optoelectronic oximeter sensor is interfaced with conventional electronics at 1 kHz and the acquired pulse rate and oxygenation are calibrated and compared with a commercially available oximeter. The organic sensor accurately measures pulse rate and oxygenation with errors of 1% and 2%, respectively.
@article{lochner2014all, title = {All-organic optoelectronic sensor for pulse oximetry}, author = {Lochner*, Claire M and Khan*, Yasser and Pierre*, Adrien and Arias, Ana C}, journal = {Nature communications}, volume = {5}, pages = {5745}, year = {2014}, publisher = {Nature Publishing Group}, url = {http://dx.doi.org/10.1038/ncomms6745}, doi = {10.1038/ncomms6745}, thumbnail = {lochner2014all.png}, pdf = {lochner2014all.pdf}, note = {*Equal contribution. Media coverage: }, media_1 = {UC Berkeley Grad News, }, media_1_link = {http://grad.berkeley.edu/news/headlines/engineering-team-invents-medical-sensor/}, media_2 = {NSF Science 360 News, }, media_2_link = {http://news.science360.gov/obj/story/d8f7fa4c-4e41-4bcb-8ccd-1939dc4af3da/organic-electronics-lead-cheap-wearable-medical-sensors}, media_3 = {UC Berkeley News Center, }, media_3_link = {http://newscenter.berkeley.edu/2014/12/10/organic-electronics-cheap-wearable-medical-sensors/}, media_4 = {Phys.Org, }, media_4_link = {http://phys.org/news/2014-12-electronics-cheap-wearable-medical-sensors.html}, media_5 = {ScienceDaily, }, media_5_link = {https://www.sciencedaily.com/releases/2014/12/141210131356.htm}, media_6 = {MSN News, }, media_6_link = {https://www.msn.com/en-us/news/technology/is-the-next-fitbit-a-tattoo/ar-BBHIYih}, media_7 = {Yahoo News, }, media_7_link = {https://in.news.yahoo.com/device-cheap-wearable-fitness-sensors-081008659.html}, media_8 = {and many more.}, media_8_link = {https://www.altmetric.com/details/2972740} }
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Flexible blade-coated multicolor polymer light-emitting diodes for optoelectronic sensors Advanced Materials, 2017 29, 22.
A method to print two materials of different functionality during the same printing step is presented. In printed electronics, devices are built layer by layer and conventionally only one type of material is deposited in one pass. Here, the challenges involving printing of two emissive materials to form polymer light-emitting diodes (PLEDs) that emit light of different wavelengths without any significant changes in the device characteristics are described. The surface-energy-patterning technique is utilized to print materials in regions of interest. This technique proves beneficial in reducing the amount of ink used during blade coating and improving the reproducibility of printed films. A variety of colors (green, red, and near-infrared) are demonstrated and characterized. This is the first known attempt to print multiple materials by blade coating. These devices are further used in conjunction with a commercially available photodiode to perform blood oxygenation measurements on the wrist, where common accessories are worn. Prior to actual application, the threshold conditions for each color are discussed, in order to acquire a stable and reproducible photoplethysmogram (PPG) signal. Finally, based on the conditions, retrieved PPG and oxygenation measurements are successfully performed on the wrist with green and red PLEDs.
@article{han2017flexible, title = {Flexible blade-coated multicolor polymer light-emitting diodes for optoelectronic sensors}, author = {Han, Donggeon and Khan, Yasser and Ting, Jonathan and King, Simon M and Yaacobi-Gross, Nir and Humphries, Martin J and Newsome, Christopher J and Arias, Ana C}, journal = {Advanced Materials}, volume = {29}, number = {22}, pages = {1606206}, year = {2017}, publisher = {Wiley Online Library}, url = {http://dx.doi.org/10.1002/adma.201606206}, doi = {10.1002/adma.201606206}, thumbnail = {han2017flexible.png}, pdf = {han2017flexible.pdf} }
Last modified: 2023-06-25