Uncertainty calculations in optical methods used for micro flow measurement

Batista, Elsa; Furtado, Andreia; Ferreira, Maria do Céu; Godinho, Isabel; Álvares, Miguel; Afonso, Joana; Martins, Rui F.

doi:10.1016/j.measen.2021.100155

Cited by 3 publications

(2 citation statements)

References 3 publications

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“…A general overview of the uncertainty and errors associated with the gravimetric measurement method is presented in other studies [ 23 25 26 27 28 ]. Briefly, these errors are from the balance resolution, balance stability setting, time delay, balance measurement repeatability, buoyancy effect of the immersed needle, evaporation rate, etc.…”

Section: Methodsmentioning

confidence: 99%

Performance evaluation study of a commercially available smart patient-controlled analgesia pump with the microbalance method and an infusion analyzer

Park¹,

Jung

2022

J Dent Anesth Pain Med

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Background Patient-controlled analgesia (PCA) has been widely used as an effective medical treatment for pain and for postoperative analgesia. However, improper dose errors in intravenous (IV) administration of narcotic analgesics from a PCA infusion pump can cause patient harm. Furthermore, opioid overdose is considered one of the highest risk factors for patients receiving pain medications. Therefore, accurate delivery of opioid analgesics is a critical function of PCA infusion pumps. Methods We designed a microbalance method that consisted of a closed acrylic chamber containing a layer and an oil layer with an electronic balance. A commercially available infusion analyzer (IDA-5, Fluke Co., Everett, WA, USA) was used to measure the accuracy of the infusion flow rate from a commercially available smart PCA infusion pump (PS-1000, UNIMEDICS, Co., Ltd., Seoul, Korea) and compared with the results of the microbalance method. We evaluated the uncertainty of the flow rate measurement using the ISO guide (GUM:1995 part3). The battery life, delay time of the occlusion alarm, and bolus function of the PCA pump were also tested. Results The microbalance method was good in the short-term 2 h measurement, and IDA-5 was good in the long-term 24 h measurement. The two measurement systems can complement each other in the case of the measurement time. Regarding battery performance, PS-1000 lasted approximately 5 days in a 1 ml/hr flow rate condition without recharging the battery. The occlusion pressure alarm delays of PS-1000 satisfied the conventional alarm threshold of occlusion pressure (300-800 mmHg). Average accuracy bolus volume was measured as 63%, 95%, and 98.5% with 0.1 ml, 1 ml, and 2 ml bolus volume presets, respectively. A 1 ml/hr flow rate measurement was evaluated as 2.08% of expanded uncertainty, with a 95% confidence level. Conclusion PS-1000 showed a flow accuracy to be within the infusion pump standard, which is ± 5% of flow accuracy. Occlusion alarm of PS-1000 was quickly transmitted, resulting in better safety for patients receiving IV infusion of opioids. PS-1000 is sufficient for a portable smart PCA infusion pump.

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Section: Methodsmentioning

confidence: 99%

Performance evaluation study of a commercially available smart patient-controlled analgesia pump with the microbalance method and an infusion analyzer

Park¹,

Jung

2022

J Dent Anesth Pain Med

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“…More rigorous observations and inspections can be made in microfluidics using a camera and microscopy over a range of wavelengths because of the planar attributes and optical transparency commonly associated with these devices. The overall uncertainty of the measurement is highly dependent on the resolution of the detection apparatus, as well as factors such as liquid evaporation and test duration ( Schroder, 2001 ; Kauffman et al, 2010 ; Ogheard et al, 2020 ; Batista et al, 2021 ). Color dyes ( Shiroma et al, 2016 ) or fluorescent tracers ( Chueh et al, 2007 ; Trietsch et al, 2017 ; Gonzalez-Gallardo et al, 2021 ) are often added to the test fluid to easily monitor the flow pathway and, in turn, any leaks that may occur.…”

Section: Types Of Leakage Testingmentioning

confidence: 99%

Overcoming technological barriers in microfluidics: Leakage testing

Silvério

Guha

Keiser

et al. 2022

Front. Bioeng. Biotechnol.

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The miniaturization of laboratory procedures for Lab-on-Chip (LoC) devices and translation to various platforms such as single cell analysis or Organ-on-Chip (OoC) systems are revolutionizing the life sciences and biomedical fields. As a result, microfluidics is becoming a viable technology for improving the quality and sensitivity of critical processes. Yet, standard test methods have not yet been established to validate basic manufacturing steps, performance, and safety of microfluidic devices. The successful development and widespread use of microfluidic technologies are greatly dependent on the community’s success in establishing widely supported test protocols. A key area that requires consensus guidelines is leakage testing. There are unique challenges in preventing and detecting leaks in microfluidic systems because of their small dimensions, high surface-area to volume ratios, low flow rates, limited volumes, and relatively high-pressure differentials over short distances. Also, microfluidic devices often employ heterogenous components, including unique connectors and fluid-contacting materials, which potentially make them more susceptible to mechanical integrity failures. The differences between microfluidic systems and traditional macroscale technologies can exacerbate the impact of a leak on the performance and safety on the microscale. To support the microfluidics community efforts in product development and commercialization, it is critical to identify common aspects of leakage in microfluidic devices and standardize the corresponding safety and performance metrics. There is a need for quantitative metrics to provide quality assurance during or after the manufacturing process. It is also necessary to implement application-specific test methods to effectively characterize leakage in microfluidic systems. In this review, different methods for assessing microfluidics leaks, the benefits of using different test media and materials, and the utility of leakage testing throughout the product life cycle are discussed. Current leakage testing protocols and standard test methods that can be leveraged for characterizing leaks in microfluidic devices and potential classification strategies are also discussed. We hope that this review article will stimulate more discussions around the development of gas and liquid leakage test standards in academia and industry to facilitate device commercialization in the emerging field of microfluidics.

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