Use of finer needles for venipuncture increases haemolysis despite reducing persistent pain and nerve injury: A retrospective study.

Background: Although venipuncture is minimally invasive, and is the most frequently performed medical procedure, it carries the small risk of causing persistent pain, including nerve damage. Recently, our hospital stopped using 22-gauge needles for venipuncture in outpatients and switched to using only 23- and 25-gauge needles. We investigated the impact of using only the finer needles on the incidence of persistent or neuropathic pain and the prevalence of haemolysis, as well as the impact of haemolysis associated with the needle change on other laboratory data.

Visual information of vehicle velocity acquired by pedestrians involved in road crossing accidents.

This paper describes a geometric optical relationship between the perceived visual information of approaching vehicles by pedestrians who intend to cross the road and the factors underlying pedestrian accidents in Japan. We create a model based on this visual information, wherein the retinal image corresponding to vehicle velocity perception is broken down into tangential components and normal components in a two-dimensional polar coordinate system that employs the nodal point of the eyeball as the origin. Our visual model uses the relationship between the tangential and normal components of the velocity to calculate the distance at which the velocity of the vehicle can be perceived by pedestrians.