I-Corps: Portable Light Scattering Device for Field Diagnosis of Microcytic Anemia

缺铁性贫血(IDA)和地中海贫血(TT)是两种常见的贫血类型，临床表现相似，但治疗方法不同。IDA接受补铁治疗，而TT则不接受治疗。在地中海地区和东南亚等地区，TT的发病率可超过人口的10%。发病率高的原因是TT对疟疾有一定的保护作用。对患有TT的患者进行补铁治疗会显著增加他们感染疟疾的风险，此外还会增加有毒的铁超载和铁过量补充的其他负面后果。许多患者生活在低资源地区，他们获得集中医疗保健的机会有限，导致诊断不足、治疗不足和治疗不当。便携式诊断工具的开发将对社会产生重大影响，因为它增加了贫血诊断的机会，从而改进了铁疗法等靶向治疗。弹性光散射是一种经过充分验证的计量技术，可以以纳米级的精度测量多分散悬浮液中颗粒的尺寸分布。它在生物学中用于研究细胞大小已经有很长的历史了，大多数现代流式细胞仪都提供了前向和侧向散射通道。该装置将一次测量简单制备的红细胞悬浮液的弹性散射图案。通过使用光瞳平面成像系统和双色照明，该设备将同时根据细胞分布确定大小和折射率参数，细胞大小的精度优于15 nm，尽管在其结构中使用了消费级组件，远远超过了便携式显微镜等其他低成本设备所能获得的。

Iron deficiency anemia (IDA) and thalassemia trait (TT) are two common anemia types whose clinical presentation is similar, but with different treatments. IDA is treated with iron supplementation, while TT is left without treatment. In areas such as Mediterranean regions and SE Asia, the incidence of TT can exceed 10% of the population. The reason for this high incidence is because TT offers some protection against malaria. Treating patients suffering from TT with iron supplementation significantly increases their risk of malaria infection19, in addition to toxic iron overload and other negative consequences of iron over supplementation. Many patients live in low-resource regions and their access to centralized healthcare is limited, leading to under-diagnosis, under-treatment, and mis-treatment. The development of a portable diagnostic tool will have significant impact on society by increasing access to anemia diagnosis and, therefore, improve targeted treatments such as iron therapy.Elastic light scattering is a well-validated metrology technique to measure size distributions of particles in a polydisperse suspension with nanometer-scale precision. It has a long history of use in biology to study cell size, with most modern flow cytometers offering forward- and side-scattering channels. The proposed device will measure elastic scattering patterns for a simply prepared suspension of red cells in a single shot. Through the use of a pupil-plane imaging system and two-color illumination, the device will simultaneously determine size and refractive index parameters from cell distributions with better than 15nm accuracy in cell size, despite using consumer-grade components in its construction, well beyond what can be obtained by other low-cost devices such as portable microscopy.