Jerk (d(acceleration)/dt) as an operative variable in pneumatic tube transport (PTT).

Background: Jerk, the rate of change of acceleration (d(acceleration)/dt), is a known operative variable in public transportation safety, but this term has never appeared in the literature regarding pneumatic tube transport (PTT) and specimen integrity. We investigated profiles of acceleration and jerk for 2 PTT routes within our hospital system.

Methods: Acceleration data were collected for PTT for 2 routes (A, B) using an accelerometer.

Evaluation of the ARK Diagnostics immunoassay for qualitative detection of xylazine in urine.

Xylazine exposure is common in some US cities, but a commercial assay for routine laboratory testing for xylazine is not currently available. We evaluated a pre-release version of the ARK Diagnostics immunoassay for qualitative detection of xylazine/4-hydroxyxylazine in urine. Studies were conducted using either the semi-quantitative assay application (A.

Characterization by image analysis of the dose vs response curve for a qualitative serum hCG lateral flow immunoassay.

Background: As an adjunct to verification of performance characteristics of a qualitative serum hCG lateral flow immunoassay (LFI), we performed image analysis to characterize the dose vs response curve (visibility of the test line), as a means of understanding the transition from negative to positive as a function of increasing [hCG].

Methods: Using serum samples of known [hCG], device images were obtained using a scanner at the prescribed reading time (5 min). Image analysis (using Python and R) was used to obtain the integral (S) of the test-line color as a function of [hCG].