Endoscopic sensing of alveolar pH

Choudhury, Debaditya; Tanner, Michael G.; McAughtrie, Sarah; Yu, Fei; Mills, Bethany; Choudhary, Tushar R.; Seth, Sohan; Craven, Tom; Stone, Jamie A.; Mati, Ioulia K.; Campbell, Colin J.; Bradley, Mark; Williams, Chris; Dhaliwal, Kevin; Birks, T. A.; Thomson, Robert R.

doi:10.1364/boe.8.000243

Cited by 32 publications

(21 citation statements)

References 38 publications

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“…The optrode was applied in a ventilated and perfused ex vivo ovine lung model, 15 with the fibre optrode passed trans-bronchially into the distal alveolar space. The perfusate was monitored for pH or O2 using commercial meters while simultaneous measurements of these two analytes were measured with the optrode in the alveolar space throughout the duration of the experiment, with the pH or oxygen level of the circulating perfusate readily tuneable by the addition of base or altering the O2/N2 ratio in the ventilation circuit (see Figure 7).…”

Section: Application In a Perfused And Ventilated Ex Vivo Ovine Lung mentioning

confidence: 99%

High fidelity fibre-based physiological sensing deep in tissue

Choudhary

Tanner

Megia‐Fernandez

et al. 2019

Sci Rep

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Physiological sensing deep in tissue remains a clinical challenge. Here a flexible miniaturised sensing optrode providing a platform to perform minimally invasive in vivo in situ measurements is reported. Silica microspheres covalently coupled with a high density of ratiometrically configured fluorophores were deposited into etched pits on the distal end of a 150 µm diameter multicore optical fibre. With this platform, photonic measurements of pH and oxygen concentration with high precision in the distal alveolar space of the lung are reported. We demonstrated the phenomenon that high-density deposition of carboxyfluorescein covalently coupled to silica microspheres shows an inverse shift in fluorescence in response to varying pH. This platform delivered fast and accurate measurements (±0.02 pH units and ±0.6 mg/L of oxygen), near instantaneous response time and a flexible architecture for addition of multiple sensors.

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Section: Application In a Perfused And Ventilated Ex Vivo Ovine Lung mentioning

confidence: 99%

High fidelity fibre-based physiological sensing deep in tissue

Choudhary

Tanner

Megia‐Fernandez

et al. 2019

Sci Rep

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“…Following the same methodology as described before Ref. 27, ovine lungs were obtained from ewes destined for cull and ventilated. Gram-negative Pseudomonas aeruginosa 3284 were cultured overnight in LB, adjusted to an OD 595 1 in PBS and labeled with Syto60 (1 μM, ThermoFisher Scientific), followed by washing three times in PBS providing a red counterstain.…”

Section: Sheep Lung Imagingmentioning

confidence: 99%

Low-cost high sensitivity pulsed endomicroscopy to visualize tricolor optical signatures

et al. 2018

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A highly sensitive, modular three-color fluorescence endomicroscopy imaging platform spanning the visible to near-infrared (NIR) range is demonstrated. Light-emitting diodes (LEDs) were sequentially pulsed along with the camera acquisition to provide up to 20 frames per second (fps) three-color imaging performance or 60 fps single color imaging. The system was characterized for bacterial and cellular molecular imaging in ex vivo human lung tissue and for bacterial and indocyanine green imaging in ex vivo perfused sheep lungs. A practical method to reduce background tissue autofluorescence is also proposed. The platform was clinically translated into six patients with pulmonary disease to delineate healthy, cancerous, and fibrotic tissue autofluorescent structures. The instrument is the most broadband clinical endomicroscopy system developed to date (covering visible to the NIR, 500 to 900 nm) and demonstrates significant potential for future clinical utility due to its low cost and modular capability to suit a wide variety of molecular imaging applications.

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“…A whole ovine lung (without ribcage, ~15 to 20 cm thickness) was ventilated and perfused, as has been described elsewhere [6]. An optical fibre probe was introduced into the lung through the working channel of the bronchoscope and into specific targeted segments.…”

Section: Bronchoscopy Of Ventilated Ovine Lungsmentioning

confidence: 99%

“…6 had a 30 cm field of view with the camera mounted on a standard tripod. The ventilated perfused lung model described elsewhere [6] was navigated by an experienced bronchoscope user to position the fibre probe in controlled lung segments. The lungs were retrieved from ewes destined for cull and were euthanized under Schedule 1 of Animals (Scientific Procedures) Act 1986.…”

Section: Modelsmentioning

confidence: 99%

Ballistic and snake photon imaging for locating optical endomicroscopy fibres

Tanner¹,

Choudhary²,

Craven³

et al. 2017

Biomed. Opt. Express

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We demonstrate determination of the location of the distal-end of a fibre-optic device deep in tissue through the imaging of ballistic and snake photons using a time resolved single-photon detector array. The fibre was imaged with centimetre resolution, within clinically relevant settings and models. This technique can overcome the limitations imposed by tissue scattering in optically determining the in vivo location of fibre-optic medical instruments.

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Endoscopic sensing of alveolar pH

Cited by 32 publications

References 38 publications

High fidelity fibre-based physiological sensing deep in tissue

High fidelity fibre-based physiological sensing deep in tissue

Low-cost high sensitivity pulsed endomicroscopy to visualize tricolor optical signatures

Ballistic and snake photon imaging for locating optical endomicroscopy fibres

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