Phantom and in-vivo measurements of hemoglobin concentration and oxygen saturation using PCT-S small animal scanner

2007 ◽  
Author(s):  
Bo Liu ◽  
Daniel Reinecke ◽  
Robert A. Kruger ◽  
Keith M. Stantz
Keyword(s):  
Oxygen Saturation ◽  
Small Animal ◽  
Hemoglobin Concentration ◽  
In Vivo Measurements

scholarly journals Oxygen Saturation Imaging Using LED-Based Photoacoustic System

Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 283
Author(s):  
Rianne Bulsink ◽  
Mithun Kuniyil Ajith Singh ◽  
Marvin Xavierselvan ◽  
Srivalleesha Mallidi ◽  
Wiendelt Steenbergen ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Light Propagation ◽  
Structural Information ◽  
Small Animal ◽  
Clinical Applications ◽  
Propagation Model ◽  
Dual Wavelength ◽  
Imaging Method ◽  
Led Array

Oxygen saturation imaging has potential in several preclinical and clinical applications. Dual-wavelength LED array-based photoacoustic oxygen saturation imaging can be an affordable solution in this case. For the translation of this technology, there is a need to improve its accuracy and validate it against ground truth methods. We propose a fluence compensated oxygen saturation imaging method, utilizing structural information from the ultrasound image, and prior knowledge of the optical properties of the tissue with a Monte-Carlo based light propagation model for the dual-wavelength LED array configuration. We then validate the proposed method with oximeter measurements in tissue-mimicking phantoms. Further, we demonstrate in vivo imaging on small animal and a human subject. We conclude that the proposed oxygen saturation imaging can be used to image tissue at a depth of 6–8 mm in both preclinical and clinical applications.

scholarly journals In-Vivo Measurements of Mixed Venous Oxygen Saturation and Hematocrit Using a Novel Implantable Sensor

2007 ◽  
Vol 13 (6) ◽  
pp. S122-S123
Author(s):  
Yelena Nabutovsky ◽  
Kyungmoo Ryu ◽  
Keith Victorine ◽  
Brian Wenzel ◽  
Allen Keel ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Mixed Venous Oxygen Saturation ◽  
In Vivo Measurements ◽  
Venous Oxygen Saturation ◽  
Implantable Sensor ◽  
Mixed Venous

Clinical Application of Tissue Reflectance Spectrophotometry to Periodontal Disease

1988 ◽  
Vol 2 (2) ◽  
pp. 389-394 ◽  
Author(s):  
S. Shizukuishi ◽  
T. Hanioka ◽  
A. Tsunemitsu
Keyword(s):  
Periodontal Disease ◽  
Oxygen Saturation ◽  
Hemoglobin Concentration ◽  
Gingival Tissue ◽  
Reflectance Spectrophotometry ◽  
Oxygen Utilization ◽  
Oxygen Saturation Level ◽  
In Vivo Experiments

Rapid, accurate, and non-invasive measurements of hemodynamics and oxygen utilization in gingiva are clinically important in evaluation of the severity of the inflammatory response in periodontal disease. In the present study, tissue reflectance spectrophotometry was used to examine gingiva in vivo to estimate hemoglobin concentration (Hb index) and the oxygen saturation level of hemoglobin in gingiva (HbSO2 index). Reflectance spectrophotometry was also used to examine these parameters in experimental periodontitis in dogs, and in patients with periodontal disease. Both in vitro and in vivo experiments confirmed that the Hb index was positively correlated with hemoglobin concentration in gingival tissue. The relationship between the HbSO2 index and PO2 in gingiva was a sigmoid curve resembling the hemoglobin-oxygen dissociation curve. In rapidly advancing periodontitis resulting from ligature placement in dogs, the Hb index was significantly enhanced, but the HbSO2 index was reduced. This reduction corresponded to increases in gingival inflammation during the experiments. Furthermore, in humans, the Hb index was significantly higher in inflamed gingiva than in clinically healthy gingiva. A lower HbSO2 index was also found in inflamed gingiva. These findings are consistent with congested blood vessels, impaired venous return, and localized hypoxia in inflamed gingival tissue. Tissue reflectance spectrophotometry is clinically useful in estimating blood volume and oxygen saturation in diseased gingiva.

scholarly journals Simulating a Ground Truth for Transit Time Analysis of Indicator Dilution Curves

2020 ◽  
Vol 6 (3) ◽  
pp. 268-271
Author(s):  
Michael Reiß ◽  
Ady Naber ◽  
Werner Nahm
Keyword(s):  
Transit Time ◽  
Sampling Rate ◽  
Ground Truth ◽  
Indicator Dilution ◽  
Cross Sectional ◽  
In Vivo Measurements ◽  
Multiple Indicator Dilution ◽  
Transit Times ◽  
Dilution Curves

AbstractTransit times of a bolus through an organ can provide valuable information for researchers, technicians and clinicians. Therefore, an indicator is injected and the temporal propagation is monitored at two distinct locations. The transit time extracted from two indicator dilution curves can be used to calculate for example blood flow and thus provide the surgeon with important diagnostic information. However, the performance of methods to determine the transit time Δt cannot be assessed quantitatively due to the lack of a sufficient and trustworthy ground truth derived from in vivo measurements. Therefore, we propose a method to obtain an in silico generated dataset of differently subsampled indicator dilution curves with a ground truth of the transit time. This method allows variations on shape, sampling rate and noise while being accurate and easily configurable. COMSOL Multiphysics is used to simulate a laminar flow through a pipe containing blood analogue. The indicator is modelled as a rectangular function of concentration in a segment of the pipe. Afterwards, a flow is applied and the rectangular function will be diluted. Shape varying dilution curves are obtained by discrete-time measurement of the average dye concentration over different cross-sectional areas of the pipe. One dataset is obtained by duplicating one curve followed by subsampling, delaying and applying noise. Multiple indicator dilution curves were simulated, which are qualitatively matching in vivo measurements. The curves temporal resolution, delay and noise level can be chosen according to the requirements of the field of research. Various datasets, each containing two corresponding dilution curves with an existing ground truth transit time, are now available. With additional knowledge or assumptions regarding the detection-specific transfer function, realistic signal characteristics can be simulated. The accuracy of methods for the assessment of Δt can now be quantitatively compared and their sensitivity to noise evaluated.

In vivo measurements of glenohumeral distraction technique performed in three different joint positions

2021 ◽  
pp. 1-7
Author(s):  
Diego Guerra-Rodríguez ◽  
Liliana Rozo ◽  
Daniel Basilio ◽  
Juan Guerrero-Henriquez
Keyword(s):  
In Vivo Measurements
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