Blood collector with capillary structure

A method of determining an amount of an analyte in a blood sample using a cartridge and a blood collector, wherein the cartridge is operable for being spun around a rotational axis,

• the blood collector comprises a mounting surface, and a capillary structure for holding the blood sample,
• the capillary structure comprises a curved portion, a capillary inlet for receiving the blood sample, a capillary channel, and a vent forming a capillary stop at an end of the capillary channel remote from the capillary inlet, wherein the capillary channel is transparent from the capillary inlet to the vent to form a visual indicator which indicates when the capillary structure is filled completely between the capillary inlet and the vent with a precise amount of the blood sample,
• the cartridge comprises a receiving surface for attaching to the mounting surface, a cartridge inlet for receiving the blood sample from the blood collector, the blood collector being configured such that when the mounting surface is attached to the receiving surface the capillary inlet is in fluidic connection with the cartridge inlet, a microfluidic structure for processing the blood sample into a processed sample, the microfluidic structure being fluidically connected to the inlet, and a measurement structure for enabling measurement of the processed sample to determine the amount of the analyte in the blood sample, the method comprising:
• placing the blood sample into the capillary inlet;
• attaching the mounting surface to the receiving surface;
• rotating the cartridge about the rotational axis to transport the blood sample from the capillary structure to the cartridge inlet;
• rotating the cartridge about the rotational axis to transport the blood sample from the cartridge inlet into the microfluidic structure;
• controlling the rotation of the cartridge about the rotational axis to process the blood sample into the processed sample using the microfluidic structure;
• controlling the rotation of the cartridge to transfer the processed sample to the measurement structure;
• controlling the rotation of the cartridge to position the measurement structure relative to a measuring system;
• and
• measuring, via the measurement system, the amount of the analyte in the processed sample transferred to the measurement structure.