A simple, non-invasive technique to monitor the biomechanical properties of ex vivo cultured blood vessels

2003 ◽  
Author(s):  
R.J. Gusic ◽  
K.J. Gooch
Keyword(s):  
Blood Vessels ◽  
Ex Vivo ◽  
Biomechanical Properties ◽  
Invasive Technique ◽  
Non Invasive

Extracranial Carotid Artery Disease Assessed By Indium-111 Labelled Platelets In Man

1981 ◽  
Author(s):  
M Goldman ◽  
D Simpson ◽  
R J Hawker ◽  
Z Drolc ◽  
C N McCollum
Keyword(s):  
Gamma Camera ◽  
Ex Vivo ◽  
Carotid Artery Disease ◽  
Objective Assessment ◽  
Diagnostic Methods ◽  
Invasive Technique ◽  
Platelet Activity ◽  
Transient Ischaemic Attacks ◽  
Non Invasive

Platelet microemboli have been implicated in the aetiology of transient ischaemic attacks and strokes. Current non-invasive diagnostic methods are restricted to assessing blood flow. Arteriography may demonstrate non-occluding atheromatous ulcers but carries a significant morbidity.111-In labelled platelets and gamma camera imaging of diseased carotid vessels have therefore been evaluated.Eight patients proceeding to unilateral carotid endarterectomy received an injection of autologous platelets labelled with 111-In-oxine 48 hours preoperatively. Gamma camera images were taken at 4 and 24 hours. Operative endarterectomy specimens were collected and gamma emissions were measured.The scintigraphic images were independently assessed by two observers. Nine abnormal vessels were identified by platelet accumulation. In 5 cases the observers combined assessment was in complete accord with previous bilateral angiography. Individually each observer identified the symptomatic side in 6 patients. Activity in the endarterectomy specimens measured ex vivo varied from 1.22-84.5 times greater than background activity. The ratio of specimen activity to 5 ml blood samples simultaneously taken varied from 0.017 to 0.360 (mean 0.089).This non-invasive technique allows localisation of platelet activity in the extracranial cerebral circulation. Objective assessment in vivo is hindered by the relatively small amount of activity on the diseased vessels by comparison with circulating blood activity.

Christian Doppler ist 200 Jahre jung

VASA ◽  
2003 ◽  
Vol 32 (4) ◽  
pp. 225-233 ◽  
Author(s):  
Bollinger ◽  
Partsch
Keyword(s):  
Flow Velocity ◽  
Blood Vessels ◽  
Continuous Wave ◽  
Invasive Technique ◽  
Ultrasound Waves ◽  
Non Invasive ◽  
Double Stars ◽  
The Difference ◽  
Large Vessels ◽  
Valvular Insufficiency

Christian Doppler was born 200 years ago in Salzburg, Austria, on November 29, 1803, worked in Prague and Vienna and died 150 years ago in Venice. In an article of eight pages he described the principle, which made him famous. It appeared in 1842 with the exotic title: “On the Coloured Light of the Double Stars and Certain Other Stars of the Heaven”. The validity of his principle for velocity measurement was confirmed by trumpet sounds produced on a train moving towards and away from the observer. Around 1960 Japanese scientists suggested that flow velocity in blood vessels could be determined by analysing the difference of frequency between emitted and backscattered ultrasound. Rushmer and coworkers built machines suitable for medicine in Seattle, where Eugene Strandness recognized their potential and applied them in first studies. In 1967 the technique jumped to Europe and started to be used worldwide. Already by using continuous wave ultrasound it was possible to diagnose occlusive disease of neck and limb arteries, venous thrombosis and valvular insufficiency with accuracy. Measurements of poststenotic ankle blood pressure were facilitated by Doppler sensing. Over the years more sophisticated instruments were developed. Pulsed emission of ultrasound waves opened a way to study flow velocity profiles across large vessels. By combining the method with A or B mode ultrasound blood flow could be quantified and finally perfused segments of blood vessels visualized. Duplex scanning in its simple and then in its colour coded version is nowadays the standard non-invasive technique that nobody would like to miss. Vascular territories like intracranial, renal and intestinal arteries can also be explored. For the assessment of microvascular flow in skin and mucosae laser Doppler instruments were introduced.

scholarly journals Intramedullary Nail Holes Laser Indicator, a Non-Invasive Technique for Interlocking of Intramedullary Nails

2021 ◽  
Author(s):  
Mohammadreza Maleki ◽  
Alireza Fadaei Tehrani ◽  
Ayda Aray ◽  
Mehdi Ranjbar
Keyword(s):  
Intramedullary Nail ◽  
Ex Vivo ◽  
Trauma Surgery ◽  
Biological Tissues ◽  
Invasive Technique ◽  
X Rays ◽  
Procedure Time ◽  
Intramedullary Nails ◽  
Non Invasive ◽  
Drilling Quality

Abstract Interlocking of intramedullary nails is a challenging procedure in orthopedic trauma surgery. Numerous methods have been described to facilitate this process. But they are exposed patient and surgical team to X-rays or involves trial and error. An accurate and non-invasive method has been provided to easily interlocking intramedullary nails. By transferring a safe visible light inside the nail, a drilling position appears which use to drilling bone toward the nail hole. The wavelength of this light was obtained from Ex-Vivo spectroscopy on biological tissues which has optimal transmission, reflectance, and absorption properties. Moreover, animal and human experiments were performed to evaluate performance of the proposed system. Ex-Vivo performance experiments were performed successfully on two groups of cow and sheep samples. Output parameters were procedure time and drilling quality which there were significant differences between the two groups in procedure time (P<0.05). But no significant differences were observed in drilling quality (P>0.05). Moreover, an In-Vivo performance experiment was performed successfully on a middle-aged man. Intramedullary nail holes laser indicator is a safe and accurate method that reduced surgical time and simplifies the process. This new technology makes it easier to interlocking the intramedullary nail which can have good clinical applications.

scholarly journals Intramedullary nail holes laser indicator, a non-invasive technique for interlocking of intramedullary nails

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammadreza Maleki ◽  
Alireza Fadaei Tehrani ◽  
Ayda Aray ◽  
Mehdi Ranjbar
Keyword(s):  
Intramedullary Nail ◽  
Ex Vivo ◽  
Biological Tissues ◽  
Invasive Technique ◽  
Procedure Time ◽  
Middle Aged ◽  
Intramedullary Nails ◽  
Non Invasive ◽  
Human Experiments ◽  
Drilling Quality

AbstractInterlocking of intramedullary nails is a challenging procedure in orthopedic trauma surgery. Numerous methods have been described to facilitate this process. But they are exposed patient and surgical team to X-rays or involves trial and error. An accurate and non-invasive method has been provided to easily interlocking intramedullary nails. By transferring a safe visible light inside the nail, a drilling position appears which use to drilling bone toward the nail hole. The wavelength of this light was obtained from ex-vivo spectroscopy on biological tissues which has optimal transmission, reflectance, and absorption properties. Moreover, animal and human experiments were performed to evaluate performance of the proposed system. Ex-vivo performance experiments were performed successfully on two groups of cow and sheep samples. Output parameters were procedure time and drilling quality which there were significant differences between the two groups in procedure time (P < 0.05). But no significant differences were observed in drilling quality (P > 0.05). Moreover, an In-vivo performance experiment was performed successfully on a middle-aged man. To compare the provided method, targeting-arm, and free-hand techniques, two human experiments were performed on a middle-aged and a young man. The results indicate the advantage of the proposed technique in the procedure time (P < 0.05), while the drilling quality is equal to the free-hand technique (P = 0.05). Intramedullary nail holes laser indicator is a safe and accurate method that reduced surgical time and simplifies the process. This new technology makes it easier to interlocking the intramedullary nail which can have good clinical applications.

USING DOPPLER TO ASSESS THE FETAL HEALTH FOR THE PREDICTION OF GESTATIONAL OUTCOME

2014 ◽  
pp. 9-18
Author(s):  
Thi Linh Giang Truong ◽  
Vu Quoc Huy Nguyen
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Umbilical Artery ◽  
Functional Method ◽  
Invasive Technique ◽  
Routine Practice ◽  
Fetal Health ◽  
Uterine Arteries ◽  
Non Invasive ◽  
Key Words Doppler

Background: Assessment of fetal health plays the most important role in prenatal care because of influence of the prediction of gestational outcome. One of the main aims of routine antenatal care is to identify the ‘ at risk ‘ fetus in order to apply clinical interventions which could results in reduced perinatal morbidity and mortality. Doppler ultrasound is a non invasive technique whereby the movement of blood is studied by detecting the change in frequence of reflected sound, Doppler blood flow velocity waves form of fetal side (umbilical artery, middle cerebral artery ...) and maternal side ( uterine arteries) are discussed and monograms for routine practice are presented. Recently this method is important tool for qualifying high risk pregnancies and help early forecasts the health of the babies and mothers disorder. Doppler sonography in obstetrics is a widely accepted functional method of examining the prediction of gestational outcome. Key words: Doppler, umbilical artery, middle cerebral artery, uterine arteries

Review of Various Tasks Performed in the Preprocessing Phase of a Diabetic Retinopathy Diagnosis System

2020 ◽  
Vol 16 (4) ◽  
pp. 397-426
Author(s):  
Muhammad Nadeem Ashraf ◽  
Muhammad Hussain ◽  
Zulfiqar Habib
Keyword(s):  
Diabetic Retinopathy ◽  
Blood Vessels ◽  
Early Stage ◽  
Spherical Shape ◽  
Cost Effective ◽  
Lesion Detection ◽  
Diabetic Patients ◽  
Cad System ◽  
Non Invasive ◽  
Optic Discs

Diabetic Retinopathy (DR) is a major cause of blindness in diabetic patients. The increasing population of diabetic patients and difficulty to diagnose it at an early stage are limiting the screening capabilities of manual diagnosis by ophthalmologists. Color fundus images are widely used to detect DR lesions due to their comfortable, cost-effective and non-invasive acquisition procedure. Computer Aided Diagnosis (CAD) of DR based on these images can assist ophthalmologists and help in saving many sight years of diabetic patients. In a CAD system, preprocessing is a crucial phase, which significantly affects its performance. Commonly used preprocessing operations are the enhancement of poor contrast, balancing the illumination imbalance due to the spherical shape of a retina, noise reduction, image resizing to support multi-resolution, color normalization, extraction of a field of view (FOV), etc. Also, the presence of blood vessels and optic discs makes the lesion detection more challenging because these two artifacts exhibit specific attributes, which are similar to those of DR lesions. Preprocessing operations can be broadly divided into three categories: 1) fixing the native defects, 2) segmentation of blood vessels, and 3) localization and segmentation of optic discs. This paper presents a review of the state-of-the-art preprocessing techniques related to three categories of operations, highlighting their significant aspects and limitations. The survey is concluded with the most effective preprocessing methods, which have been shown to improve the accuracy and efficiency of the CAD systems.

scholarly journals Histological, Biomechanical, and Biological Properties of Genipin-Crosslinked Decellularized Peripheral Nerves

2021 ◽  
Vol 22 (2) ◽  
pp. 674
Author(s):  
Óscar Darío García-García ◽  
Marwa El Soury ◽  
David González-Quevedo ◽  
David Sánchez-Porras ◽  
Jesús Chato-Astrain ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Nerve Repair ◽  
Wistar Rat ◽  
Biomechanical Properties ◽  
Biological Properties ◽  
Suitable Alternative ◽  
Promising Alternative ◽  
Histological Pattern ◽  
The Impact

Acellular nerve allografts (ANGs) represent a promising alternative in nerve repair. Our aim is to improve the structural and biomechanical properties of biocompatible Sondell (SD) and Roosens (RS) based ANGs using genipin (GP) as a crosslinker agent ex vivo. The impact of two concentrations of GP (0.10% and 0.25%) on Wistar rat sciatic nerve-derived ANGs was assessed at the histological, biomechanical, and biocompatibility levels. Histology confirmed the differences between SD and RS procedures, but not remarkable changes were induced by GP, which helped to preserve the nerve histological pattern. Tensile test revealed that GP enhanced the biomechanical properties of SD and RS ANGs, being the crosslinked RS ANGs more comparable to the native nerves used as control. The evaluation of the ANGs biocompatibility conducted with adipose-derived mesenchymal stem cells cultured within the ANGs confirmed a high degree of biocompatibility in all ANGs, especially in RS and RS-GP 0.10% ANGs. Finally, this study demonstrates that the use of GP could be an efficient alternative to improve the biomechanical properties of ANGs with a slight impact on the biocompatibility and histological pattern. For these reasons, we hypothesize that our novel crosslinked ANGs could be a suitable alternative for future in vivo preclinical studies.

A NOVEL EXTENSIVE EX-VIVO OCT DATABASE FROM MURINE MODELS OF COLORECTAL CANCER

2021 ◽  
Vol 108 (Supplement_3) ◽  
Author(s):  
J Bote ◽  
J F Ortega-Morán ◽  
C L Saratxaga ◽  
B Pagador ◽  
A Picón ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Machine Learning ◽  
Structural Information ◽  
Ex Vivo ◽  
Ground Truth ◽  
Colon Polyps ◽  
Learning Methods ◽  
Non Invasive ◽  
Machine Learning Methods ◽  
In Situ Methods

Abstract INTRODUCTION New non-invasive technologies for improving early diagnosis of colorectal cancer (CRC) are demanded by clinicians. Optical Coherence Tomography (OCT) provides sub-surface structural information and offers diagnosis capabilities of colon polyps, further improved by machine learning methods. Databases of OCT images are necessary to facilitate algorithms development and testing. MATERIALS AND METHODS A database has been acquired from rat colonic samples with a Thorlabs OCT system with 930nm centre wavelength that provides 1.2KHz A-scan rate, 7μm axial resolution in air, 4μm lateral resolution, 1.7mm imaging depth in air, 6mm x 6mm FOV, and 107dB sensitivity. The colon from anaesthetised animals has been excised and samples have been extracted and preserved for ex-vivo analysis with the OCT equipment. RESULTS This database consists of OCT 3D volumes (C-scans) and 2D images (B-scans) of murine samples from: 1) healthy tissue, for ground-truth comparison (18 samples; 66 C-scans; 17,478 B-scans); 2) hyperplastic polyps, obtained from an induced colorectal hyperplastic murine model (47 samples; 153 C-scans; 42,450 B-scans); 3) neoplastic polyps (adenomatous and adenocarcinomatous), obtained from clinically validated Pirc F344/NTac-Apcam1137 rat model (232 samples; 564 C-scans; 158,557 B-scans); and 4) unknown tissue (polyp adjacent, presumably healthy) (98 samples; 157 C-scans; 42,070 B-scans). CONCLUSIONS A novel extensive ex-vivo OCT database of murine CRC model has been obtained and will be openly published for the research community. It can be used for classification/segmentation machine learning methods, for correlation between OCT features and histopathological structures, and for developing new non-invasive in-situ methods of diagnosis of colorectal cancer.

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