Agglutinated blood transports differently onto paper than stable blood with well dispersed red cells. This difference was investigated to develop instantaneous blood typing tests using specific antibody−antigen interactions to trigger blood agglutination. Two series of experiments were performed. The first related the level of agglutination and the fluidic properties of blood on its transport in paper. Blood samples were mixed at different ratios with specific and nonspecific antibodies; a droplet of each mixture was deposited onto a filter paper strip, and the kinetics of wicking and red cell separation were measured. Agglutinated blood phase separated, with the red blood cells (RBC) forming a distinct spot upon contact with paper while the plasma wicked; in contrast, stable blood suspensions wicked uniformly. The second study analyzed the wicking and the chromatographic separation of droplets of blood deposited onto paper strips pretreated with specific and nonspecific antibodies. Drastic differences in...

Paper Diagnostic for Instantaneous Blood Typing

The behaviors of ferromagnetic nano-particles in and around blood vessels under applied magnetic fields

Nanomedicine is a promising application of nanotechnology in medicine, which can drastically improve drug delivery efficiency through targeted delivery. However, characterization of the nanoparticle targeted delivery process under vascular environment is very challenging due to the small scale of nanoparticles and the complex in vivo vascular system. To understand such complicated system, various computational models are developed to help reveal nanoparticle targeted delivery process and design nanoparticles for optimal delivery. This article discusses a few computational tools to model the nanoparticle delivery process and design nanoparticles for efficient targeted delivery. The modeling approaches span from continuum vascular flow, particle Brownian adhesion dynamics, to molecular level ligand-receptor binding. Computer simulation is envisioned to be able to optimize drug carrier design and predict drug delivery efficiency for patient specific vascular environment.

Computational Modeling of Nanoparticle Targeted Drug Delivery

An apparatus is described which combines laser Doppler velocimetry and optical plethysmography for a rapid, multi‐parameter characterization of blood flow in cutaneous tissues. The Doppler parameter is determined by analog computation of the square root of the normalized second moment of the photodiode detector output during illumination by laser light scattered from the illuminated tissue. Incident and scattered light are transmitted by fiber optics to permit convenient sampling of local tissue regions. The instrument is compact, portable, and inexpensive. Data are presented which illustrate the utility of this device, and potential applications are discussed.

Laser doppler blood flow meter and optical plethysmograph

Analysis of fluid separation in microfluidic T-channels

The paper discusses the structure and composition of blood, its viscous properties and how these affect flow, and also the electrical, optical and thermal properties, which can be used to quantify flow. The development of a flow profile is discussed for steady and pulsatile flow in major vessels. The various types of flowmeter which have been developed to take this profile into account are discussed. These include electromagnetic and ultrasonic flowmeters, indicator-dilution methods (including thermal dilution) and various pressure-sensing devices. In small vessels and in bulk tissue the concept of flow profile has no meaning and the measurement methods include indicator-transport methods using radioactive isotopes various forms of plethysmograph, calorimeters and thermal-conductivity probes. Each type of flow measurement method is discussed, together with its advantages and disadvantages.

https://iopscience.iop.org/article/10.1088/0034-4885/39/1/002/pdf

J P Woodcock

Papers

Physical properties of blood and their influence on blood-flow measurement