Hyperspectral imaging in perfusion and wound diagnostics – methods and algorithms for the determination of tissue parameters

2018 ◽  
Vol 63 (5) ◽  
pp. 547-556 ◽  
Author(s):  
Amadeus Holmer ◽  
Jörg Marotz ◽  
Philip Wahl ◽  
Michael Dau ◽  
Peer W. Kämmerer
Keyword(s):  
Wound Healing ◽  
Hyperspectral Imaging ◽  
Tissue Oxygenation ◽  
Blood Perfusion ◽  
Objective Evaluation ◽  
Key Factor ◽  
Novel Method ◽  
Reliable Methods ◽  
Insight Into

Abstract Blood perfusion is the supply of tissue with blood, and oxygen is a key factor in the field of minor and major wound healing. Reduced perfusion of a wound bed or transplant often causes various complications. Reliable methods for an objective evaluation of perfusion status are still lacking, and insufficient perfusion may remain undiscovered, resulting in chronic processes and failing transplants. Hyperspectral imaging (HSI) represents a novel method with increasing importance for clinical practice. Therefore, methods, software and algorithms for a new HSI system are presented which can be used to observe tissue oxygenation and other parameters that are of importance in supervising healing processes. This could offer an improved insight into wound perfusion allowing timely intervention.

scholarly journals Hyperspectral imaging of the degradation of meat and comparison with necrotic tissue in human wounds

2019 ◽  
Author(s):  
Amadeus Holmer ◽  
Christoph Homberger ◽  
Thomas Wild ◽  
Frank Siemers
Keyword(s):  
Hyperspectral Imaging ◽  
Near Infrared ◽  
Objective Evaluation ◽  
Infrared Range ◽  
Spectral Features ◽  
Necrotic Tissue ◽  
Tissue Discrimination ◽  
Near Infrared Range ◽  
Imaging Setup

The objective evaluation of scattering tissue and the discrimination of tissue types is an issue that cannot be solved with colour cameras and image processing alone in many cases. Examples can be found in the determination of freshness and ageing of meat, and the discrimination of tissue types in food technology. In medical applications tissue discrimination is also an issue, e.g. in wound diagnostics. A novel hyperspectral imaging setup with powerful signal analysis algorithms is presented which is capable of addressing these topics. The spectral approach allows the chemical analysis of material and tissues and the measurement of their temporal change. We present a method of hyperspectral imaging in the visible-near infrared range which allows both the separation and spatial allocation of different tissue types in a sample, as well as the temporal changes of the tissue as an effect of ageing. To prove the capability of the method, the ageing of meat (slices of pork) was measured and, as a medical example, the application of the hyperspectral imaging setup for the recording of wound tissue is presented. The method shows the ability to discriminate the different tissue components of pork meat, and the ageing of the meat is observable as changes in spectral features. An additional result of our study is the fact that some spectral features, which seem to be typical for the ageing of the meat, are similar to those observed in the necrotic tissue from wound diagnostics in medicine.

scholarly journals Comparison of hyperspectral imaging and fluorescence angiography for the determination of the transection margin in colorectal resections—a comparative study

2020 ◽  
Author(s):  
Boris Jansen-Winkeln ◽  
Isabell Germann ◽  
Hannes Köhler ◽  
Matthias Mehdorn ◽  
Marianne Maktabi ◽  
...  
Keyword(s):  
Indocyanine Green ◽  
Hyperspectral Imaging ◽  
Surgical Resection ◽  
Blood Perfusion ◽  
Border Zone ◽  
Fluorescence Angiography ◽  
Central Position ◽  
Link Type ◽  
Resection Line

Abstract Purpose One relevant aspect for anastomotic leakage in colorectal surgery is blood perfusion of both ends of the anastomosis. The clinical evaluation of this issue is limited, but new methods like fluorescence angiography with indocyanine green or non-invasive and contactless hyperspectral imaging have evolved as objective parameters for perfusion evaluation. Methods In this prospective, non-randomized, open-label and two-arm study, fluorescence angiography and hyperspectral imaging were compared in 32 consecutive patients with each other and with the clinical assessment by the surgeon. After preparation of the bowel and determination of the surgical resection line, the tissue was evaluated with hyperspectral imaging for 5 min before and after cutting the marginal artery and assessed by 6 hyperspectral pictures followed by fluorescence angiography with indocyanine green. Results In 30 of 32 patients, the image data could be evaluated and compared. Both methods provided a comparable borderline between well-perfused and poorly perfused tissue (p = 0.704). In 15 cases, the surgical resection line was shifted to the central position due to the imaging. The border zone was sharper in fluorescence angiography and best assessed 31 s after injection. With hyperspectral imaging, the border zone was visualized wider and with more differences between proximal and distal border. Conclusion Hyperspectral imaging and fluorescence angiography provide similar results in determining the perfusion border. Both methods allow a good and safe visualization of the blood perfusion at the central resection margin to create a well-perfused anastomosis. Trial registration This study was registered at Clinicaltrials.gov (NCT04226781) on January 13, 2020.

A novel method for the determination of linting propensity of paper

TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD
Keyword(s):  
Ash Content ◽  
The Novel ◽  
Offset Printing ◽  
Excellent Correlation ◽  
End Conditions ◽  
Bottom Side ◽  
Novel Method ◽  
Total Fraction

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.

Analytical Methods for the Determination of Sartans in Pharmaceutical Formulations and Biological Fluids: A Review

2020 ◽  
Vol 16 (3) ◽  
pp. 208-222
Author(s):  
Miglena Smerikarova ◽  
Stanislav Bozhanov ◽  
Vania Maslarska
Keyword(s):  
Biological Fluids ◽  
Pharmaceutical Preparations ◽  
Improve Patient Care ◽  
Pharmaceutical Formulations ◽  
Treatment Of Hypertension ◽  
Therapeutic Doses ◽  
Reliable Methods ◽  
Improve Patient

Background: Sartans are mostly used as a part of combination with additional medicines in the therapy of essencial hypertension. Preferred combinations are ARB and thiazide diuretics (Hydrochlorothiazide (HCT) and Chlorthalidone (CHL)) or ARB and calcium antagonists. The number of sartans mostly prescribed by specialists is only seven - Candesartan (CDS), Eprosartan (EPS), Irbesartan (IBS), Losartan (LOS), Olmesartan (OMS), Telmisartan (TMS) and Valsartan (VLS). Methods: The widespread use of sartans in the treatment of hypertension requires reliable methods of analysis. Bulk drugs and pharmaceutical preparations should be analyzed to ensure the quality of the medicinal products reaching patients. On the other hand, the analysis of drugs in biological fluids aims to trace and improve patient care by adjusting the therapeutic doses of drugs. According to our knowledge, a review devoted to the analysis of sartans was published in 2014. Results: Spectral methods are widely used in the analysis of bulk drugs and pharmaceutical dosage forms due to their relatively simple procedures, low reagent and sample consumption, speed, precision and accuracy combined with accessibility and comparatively low cost of common apparatus. Many papers for determination of sartans in bulk drugs and pharmaceutical preparations based on liquid chromatographic techniques were published in the available literature. Among these methods, HPLC takes the leading place but UPLC and HPTLC are also present. Conclusion: The widespread use of sartans in the treatment of hypertension requires reliable methods of analysis. Bulk drugs and pharmaceutical preparations should be analyzed to ensure the quality of the medicinal products reaching patients. On the other hand, the analysis of drugs in biological fluids aims to trace and improve patient care by adjusting the therapeutic doses of drugs. Since 2014, many articles have been published on the sartans analysis and this provoked our interest to summarize the latest applications in the analysis of sartans in pharmaceutical formulations and biological media. Articles published from 2014 to 2018 are covered.

scholarly journals Pitfalls in the Immunochemical Determination of β‑Lactam Antibiotics in Water

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 298
Author(s):  
Alexander Ecke ◽  
Rudolf J. Schneider
Keyword(s):  
Limit Of Detection ◽  
Cost Effective ◽  
Enzyme Linked Immunosorbent Assay ◽  
Degree Of Hydrolysis ◽  
Site Analysis ◽  
Antibody Recognition ◽  
Immunochemical Determination ◽  
Key Factor ◽  
Lactam Ring

Contamination of waters with pharmaceuticals is an alarming problem as it may support the evolution of antimicrobial resistance. Therefore, fast and cost-effective analytical methods for potential on-site analysis are desired in order to control the water quality and assure the safety of its use as a source of drinking water. Antibody-based methods, such as the enzyme-linked immunosorbent assay (ELISA), can be helpful in this regard but can also have certain pitfalls in store, depending on the analyte. As shown here for the class of β-lactam antibiotics, hydrolysis of the β‑lactam ring is a key factor in the immunochemical analysis as it influences antibody recognition. With the antibody used in this study, the limit of detection (LOD) in the immunoassay could be significantly reduced by hydrolysis for the five tested penicillins, with the lowest LOD for carbenicillin (0.2 nmol/L) and the greatest impact on penicillins G and V (reduction by 85%). In addition to enhanced quantification, our strategy also provides access to information about the degree of hydrolysis in water samples as shown for the most abundant penicillin amoxicillin.

An insight into the determination of size and number concentration of silver nanoparticles in blood using single particle ICP-MS (spICP-MS): Feasibility of application to samples relevant to in vivo toxicology studies

2021 ◽  
Author(s):  
Isabel Abad-Álvaro ◽  
Diego Leite ◽  
Dorota Bartczak ◽  
Susana Cuello ◽  
Beatriz Gomez-Gomez ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Single Particle ◽  
Number Concentration ◽  
Biological Matrices ◽  
Icp Ms ◽  
Toxicological Studies ◽  
Insight Into

Toxicological studies concerning nanomaterials in complex biological matrices usually require a carefully designed workflow that involves handling, transportation and preparation of a large number of samples without affecting the nanoparticle...

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