[Accuracy of platelet counting by optical and impedance methods in patients with Thrombocytopaenia and Microcytosis]

Objectives: Obtaining accurate platelet counts in microcytic blood samples is challenging, even with the most reliable automated haematology analysers. The CELL-DYN[TM] Sapphire [Abbott Laboratories, Chicago, Illinois, USA] analyser uses both optical density and electronic impedance methods for platelet counting. This study aimed to evaluate the accuracy of optical density and electrical impedance methods in determining true platelet counts in thrombocytopaenic samples with microcytosis as defined by low mean corpuscular volume [MCV] of red blood cells. Additionally, the impact of microcytosis on platelet count accuracy was evaluated

Methods: This study was carried out between February and December 2014 at the Haematology Laboratory of the Sultan Qaboos University Hospital in Muscat, Oman. Blood samples were collected and analysed from 189 patients with thrombocytopaenia and MCV values of <76 femtolitres. Platelet counts were tested using both optical and impedance methods. Stained peripheral blood films for each sample were then reviewed as a reference method to confirm platelet counts. Results: The platelet counts estimated by the impedance method were on average 30% higher than those estimated by the optical method [P <0.001]. The estimated intraclass correlation coefficient was 0.52 [95% confidence interval: 0.41-0.62], indicating moderate reliability between the methods. The degree of agreement between methods ranged from -85.5 to 24.3 with an estimated bias of -30, suggesting that these methods generate different platelet results

Conclusion: The impedance method significantly overestimated platelet counts in microcytic and thrombocytopaenic blood samples. Further attention is therefore needed to improve the accuracy of platelet counts, particularly for patients with conditions associated with microcytosis

Non-invasive haemoglobin estimation in patients with thalassaemia major

This study aimed to validate pulse CO-oximetry-based haemoglobin [Hb] estimation in children and adults with thalassaemia major [TM] and to determine the impact of different baseline variables on the accuracy of the estimation. This observational study was conducted over a five-week period from March to April 2012. A total of 108 patients with TM attending the daycare thalassaemia centre of a tertiary care hospital in Muscat, Oman, were enrolled. Spot [Sp] Hb measurements were estimated using a Pronto-7 [Registered Sign] pulse CO-oximetry device [Masimo Corp., Irvine, California, USA]. These were compared to venous samples of Hb using the CELL-DYN Sapphire Hematology Analyzer [Abbott Diagnostics, Abbott Park, Illinois, USA] to determine the reference [Ref] Hb levels. A multivariable linear regression model was used to assess the impact of baseline variables such as age, gender, weight, height, Ref Hb and blood pressure on the Hb estimations. Of the 108 enrolled patients, there were 54 males and 54 females with a mean age of 21.6 years [standard deviation [SD] = 7.3 years; range: 2.5-38 years]. The mean Ref Hb and Sp Hb were 9.4 g/dL [SD - 0.9 g/dL; range: 7.5-12.3 g/dL] and 11.1 g/dL [SD = 1.2 g/dL; range: 7.5-14.7 g/dL], respectively. The coefficient of determination [R[2]] was 21% with a mean difference of 1.7 g/dL [SD = 1.1 g/dL; range: -0.9-4.3 g/dL]. In the multivariable model, the Ref Hb level [P = 0.001] was the only statistically significant predictor. The Pronto-7 [Registered Sign] pulse CO-oximetry device was found to overestimate Hb levels in patients with TM and therefore cannot be recommended. Further larger studies are needed to confirm these results

smarter SMA technology for the realization of drug delivering endoscopic capsule

Traditional endoscopic and colonoscopic techniques are unable to access the small intestine for the delivery of biomarker probes and/or drugs. This is limiting the ability of medical researchers and practitioners to adequately explore the functional characteristics of the gastrointestinal tract [GIT], as well as the changes in the functional characteristics due to disease. This in turn is obstructing research for the development of newer biomarker probes and drugs for diagnosis and treatment of many conditions related to GIT. The advances in wireless capsule endoscopy have enabled medical researchers to view the inside of the GIT. However, these devices are not capable of delivering biomarker probes and drugs to affected areas of the gastrointestinal tract. The prototype drug delivery mechanism presented in this paper is aimed at delivering a suitable technology for adoption in an endoscopic capsule for the administration of biomarker probes anchor drugs to targeted areas in the GIT. The design proposed in this paper is based on thermally actuated shape memory alloys