(Fig 1b) Optimization of microneedle length in device prototype development: the effect of microneedle length on blood flow rate and pain sensation.

To determine the optimal microneedle array dimensions for
use in our device, we began by evaluating the effect of microneedle length on
blood flow rate and perceived pain over a range of 750 to 1250 µm. This was
investigated by inserting microneedle arrays into the skin using a snap dome
mechanism and then applying vacuum to the puncture sites to encourage blood
flow. Pain sensation scores were obtained from each participant
immediately after each microneedle array actuation, using the Wong-Baker FACES
pain scale, with '0' corresponding to "no hurt" and '10'
corresponding to "hurts worse."

为确定适配本设备的最优微针阵列（microneedle array）参数，我们首先在750至1250微米的量程范围内，针对微针长度对血流量及受试者主观疼痛感知的影响展开了评估。本研究通过按扣式穹顶机构（snap dome mechanism）将微针阵列刺入皮肤，随后对穿刺部位施加负压以促进血液流出。每次微针阵列穿刺触发后，即刻采用Wong-Baker面部表情疼痛评分量表（Wong-Baker FACES pain scale）收集每位受试者的疼痛评分，其中评分‘0’对应‘无疼痛感’，评分‘10’对应‘剧痛难忍’。