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Yokoyama Y, Tanaka A, Tagawa Y. Droplet impact of blood and blood simulants on a solid surface: Effect of the deformability of red blood cells and the elasticity of plasma. Forensic Sci Int 2021; 331:111138. [PMID: 34906891 DOI: 10.1016/j.forsciint.2021.111138] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 01/25/2023]
Abstract
The impact of blood droplets onto a solid wall is of great importance for bloodstain pattern analysis in forensic science. Previous studies suggest that the behaviour of impacting blood is similar to that of a Newtonian fluid, which has a shear viscosity equivalent to that of blood at high shear rates. To understand this important fact, we conducted comparative experiments of droplet impact on a glass surface using whole blood and three solutions with a shear viscosity similar to that of blood. Specifically, we used dog's whole blood (deformable red blood cells dispersed in plasma, WB), plasma with non-deformable resin particles (PwP), glycerol and water with resin particles (GWwP), and a commercial blood simulant (hard particles dispersed in a water-based Newtonian solution, BS). Ranges of Reynolds and Weber numbers in our experiments were 550<Re<1700 and 120<We<860, respectively. Side and bottom views of droplet impact were simultaneously recorded by two high-speed cameras. The spreading radius of the impacting WB droplet in our experiments agreed well with that of Newtonian fluids with viscosity similar to that of WB at high shear rates. Splashing droplets of WB and Newtonian fluids form finger structures (finger-splashing). Although PwP has a viscosity similar to that of WB at high shear rates, an impacting PwP droplet exhibited typical characteristics of impacting suspension droplets, that is, a reduced spreading radius and splashing with ejection of particles. Such significant differences between impacting droplets of PwP and WB indicates that the high deformability of red blood cells in WB plays a crucial role in the Newtonian-like behaviour of blood droplets on impact. The finger-splashing of PwP and GWwP exhibited no significant difference, indicating that the effect of plasma elasticity on finger-splashing is negligible. Importantly, the impacting BS droplet behaved quite differently from WB in both spreading and splashing. Our results imply that the use of deformable particles rather than hard particles in a BS is essential for mimicking blood droplet impact.
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Affiliation(s)
- Yuto Yokoyama
- Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology, Koganei Campus 6-507, 2-24-16 Nakacho, Koganei, Tokyo, Japan
| | - Akane Tanaka
- Laboratory of Comparative Animal Medicine, Division of Animal Life Science, Tokyo University of Agriculture and Technology, Fuchu Campus, 3-5-8 Saiwaicho, Fuchu, Tokyo, Japan
| | - Yoshiyuki Tagawa
- Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology, Koganei Campus 6-507, 2-24-16 Nakacho, Koganei, Tokyo, Japan.
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Ndabakuranye JP, Rajapaksa AE, Burchall G, Li S, Prawer S, Ahnood A. A novel optical assay system for bilirubin concentration measurement in whole blood. IEEE Trans Biomed Eng 2021; 69:983-990. [PMID: 34516369 DOI: 10.1109/tbme.2021.3111150] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
As a biomarker for liver disease, bilirubin has been utilized in prognostic scoring systems for cirrhosis. While laboratory-based methods are used to determine bilirubin levels in clinical settings, they do not readily lend themselves to applications outside of hospitals. Consequently, bilirubin monitoring for cirrhotic patients is often performed only intermittently; thus, episodes requiring clinical interventions could be missed. This work investigates the feasibility of measuring bilirubin concentration in whole porcine blood samples using dual-wavelength transmission measurement. A compact and low-cost dual-wavelength transmission measurement setup is developed and optimized to measure whole blood bilirubin concentrations. Using small volumes of whole porcine blood (72 L), we measured the bilirubin concentration within a range corresponding to healthy individuals and cirrhotic patients (1.2-30 mg/dL). We demonstrate that bilirubin levels can be estimated with a positive correlation (R-square > 0.95) and an accuracy of 1.7 mg/dL, with higher reliability in cirrhotic bilirubin concentrations (> 4 mg/dL) critical for high-risk patients. The optical and electronic components utilized are economical and can be readily integrated into a miniature, low-cost, and user-friendly system. This could provide a pathway for point-of-care monitoring of blood bilirubin outside of medical facilities (e.g. patients home).
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Orr A, Gualdieri R, Cossette ML, Shafer ABA, Stotesbury T. Whole bovine blood use in forensic research: Sample preparation and storage considerations. Sci Justice 2021; 61:214-220. [PMID: 33985669 DOI: 10.1016/j.scijus.2021.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 02/18/2021] [Accepted: 02/21/2021] [Indexed: 10/22/2022]
Abstract
Mammalian whole blood sources are often used for forensic research and training when human samples cannot be sourced. While porcine, ovine and equine blood have been shown to be viable alternatives to whole human blood for forensic purposes, procurement can still pose a problem, especially for smaller and remote institutions. This work explores the use of whole bovine blood for basic bloodstain simulation. Sample preparation through the addition of ACD-A anticoagulant was optimized and storability was explored. Viscosity, surface tension, density, and packed cell volume, four fluid properties relevant to bloodstain pattern analysis, were monitored over four days and in two temperature conditions. Linear mixed models accounting for variation in the donor demonstrated that these fluid properties of the bovine blood changed predictably over time and with temperature. Whole bovine blood with 12.5% v/v ACD-A was found to be viable for use in basic bloodstain simulation at ambient and physiological temperature.
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Affiliation(s)
- Amanda Orr
- Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON K9L 0G2, Canada
| | - Rebecca Gualdieri
- Forensic Science Undergraduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON K9L 0G2, Canada
| | - Marie-Laurence Cossette
- Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON K9L 0G2, Canada; Forensic Science Undergraduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON K9L 0G2, Canada
| | - Aaron B A Shafer
- Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON K9L 0G2, Canada; Forensic Science Undergraduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON K9L 0G2, Canada
| | - Theresa Stotesbury
- Forensic Science Undergraduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON K9L 0G2, Canada; Faculty of Science, Forensic Science, Ontario Tech University, 2000 Simcoe St N, Oshawa, ON L1G 0C5, Canada.
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Sparer A, Serp B, Schwarz L, Windberger U. Storability of porcine blood in forensics: How far should we go? Forensic Sci Int 2020; 311:110268. [PMID: 32283501 DOI: 10.1016/j.forsciint.2020.110268] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/21/2020] [Accepted: 03/23/2020] [Indexed: 12/13/2022]
Abstract
Previous studies on the storability of porcine blood for bloodstain pattern analysis (BPA) focused on abattoir blood only and did not include measurements of viscoelasticity. Although known to provoke echinocyte formation, EDTA is widely used for BPA issues. We compared ageing samples taken from live pigs with abattoir blood and detected considerable differences in hematocrit (HCT), total protein and shear viscosity that even worsened with time. Upon storage, high shear viscosity continuously increased, resulting in a partial loss of the typical shear thinning property of blood. Furthermore, we explored CPDA-1, the gold standard in preserving red blood cells (RBCs), for storage of forensic samples. We found it to be a superior choice for anticoagulation, as the rise of high shear viscosity was attenuated compared to EDTA. When performing oscillation measurements, we found a sudden change of viscoelasticity of blood after 22 days, providing a cut-off for storage time. To highlight the importance of hematological and hemorheological changes upon cold storage, we performed simple drip pattern experiments. These tests revealed a tendency to smaller stain diameters and higher numbers of satellite spatter. While this contradicts expectations from elevated viscosity values, we associate this trend to microscopic inhomogeneities due to storage. We recommend CPDA-1 for prolonged storage of BPA samples and suggest the use of comprehensive test protocols including viscoelasticity for determination of the maximum shelf life of pig blood.
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Affiliation(s)
- Andreas Sparer
- Center for Biomedical Research, Medical University of Vienna, Austria
| | - Bianca Serp
- Center for Biomedical Research, Medical University of Vienna, Austria
| | - Lukas Schwarz
- University Clinic for Swine, University of Veterinary Medicine Vienna, Austria
| | - Ursula Windberger
- Center for Biomedical Research, Medical University of Vienna, Austria.
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Attinger D. Charts based on millions of fluid dynamics simulations provide a simple tool to estimate how far from its source a specific blood stain can be found. Forensic Sci Int 2019; 298:97-105. [PMID: 30889539 DOI: 10.1016/j.forsciint.2019.02.052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 02/26/2019] [Accepted: 02/26/2019] [Indexed: 01/25/2023]
Abstract
The bloodstain pattern analyst sometimes has to judge if a given stain could originate from a specific location. A wide range of values of the maximum distance that a blood drop can travel have been reported from experiments, ranging from less than one meter to more than 10 m. Here we formulate the problem in a fluid dynamics and data mining framework. The fluid dynamics is solved with Newton's classical equation of motion coupled with well-established models for the gravity and drag forces that bend the trajectories of drops. The parameters screened are the drop size, initial velocity and launch angle, as well as the height of a blood source and the ceiling height. Combining a wide range of values of those five parameters commended the performance of more than 5 million fluid dynamic simulations. Results of these simulations have been searched and mined for parameters directly measurable on a crime scene, such as the stain size and stain ellipticity. The results are presented in simple, easy to use charts, which do not require any knowledge of fluid dynamics from the analyst.
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Affiliation(s)
- Daniel Attinger
- Iowa State University, Mechanical Engineering Department, Ames, IA 50010, USA.
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A data set of bloodstain patterns for teaching and research in bloodstain pattern analysis: Gunshot backspatters. Data Brief 2019; 22:269-278. [PMID: 30815519 PMCID: PMC6305896 DOI: 10.1016/j.dib.2018.11.075] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 11/09/2018] [Accepted: 11/12/2018] [Indexed: 01/25/2023] Open
Abstract
This is a data set of blood spatter patterns scanned at high resolution, generated in controlled experiments. The spatter patterns were generated with a rifle or a handgun with varying ammunition. The resulting atomized blood droplets travelled opposite to the bullet direction, generating a gunshot backspatter on a poster board target sheet. Fresh blood with anticoagulants was used; its hematocrit and temperature were measured. The main parameters of the study were the bullet shape, size and speed, and the distance between the blood source and target sheet. Several other parameters were explored in a less systematic way. This new and original data set is suitable for training or research purposes in the forensic discipline of bloodstain pattern analysis.
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Flight C, Jones M, Ballantyne KN. Determination of the maximum distance blood spatter travels from a vertical impact. Forensic Sci Int 2018; 293:27-36. [PMID: 30391666 DOI: 10.1016/j.forsciint.2018.10.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 10/10/2018] [Accepted: 10/17/2018] [Indexed: 01/25/2023]
Abstract
Bloodstain evidence can be very powerful evidence in assault related crimes. Determination of the distance that blood droplets may travel as a result of an impact into liquid blood may be of significance to corroborate or disprove a version of events, provide likely scenarios, or help determine the culpability of a person in determining their proximity to the blood shedding event. It was the aim of this research to determine the potential maximum distance blood droplets travel horizontally following a vertical impact into liquid blood. A custom apparatus was designed and constructed to replicate a vertical impact of a timber weapon, rotating on a fixed axis at one end, striking a pool of liquid blood. The device was positioned at three different levels of elevation to replicate an impact to the head of a person near ground level, a seated or kneeling height and standing height. Overall, the results indicated that the application of kinetic energy of between 1 and 5J at a height of 1780mm led to the blood droplets travelling a maximum horizontal distance of 5361mm (and average maximum distance of 4981mm). The horizontal distance blood droplets may travel upon impact does not appear to follow a linear trend with differing kinetic energy, but is affected by the applied force and release height in a curvilinear relationship. The results provide a valuable tool to bloodstain pattern analysts and investigators in determining search zones within a scene, as well as providing information about the proximity of an individual to an impact event.
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Affiliation(s)
- Chris Flight
- Office of the Chief Forensic Scientist, Victoria Police Forensic Services Department, Australia.
| | - Max Jones
- Biological Services Group, Victoria Police Forensic Services Department, Australia
| | - Kaye N Ballantyne
- Office of the Chief Forensic Scientist, Victoria Police Forensic Services Department, Australia
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Drip bloodstain appearance on inclined apparel fabrics: Effect of prior-laundering, fibre content and fabric structure. Forensic Sci Int 2016; 266:488-501. [DOI: 10.1016/j.forsciint.2016.07.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 06/19/2016] [Accepted: 07/09/2016] [Indexed: 01/25/2023]
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