Analyte-sensing device

Apparatus for detecting a concentration of an analyte in a subject, the apparatus comprising:

• an implantable unit, which is configured to be implanted in a body of the subject, and comprises:
• (a) fluorescent sensor molecules, each of which comprises (i) a binding site for the analyte, (ii) a donor fluorophore, and (iii) an acceptor fluorophore;
• and
• (b) a first implantable-unit light source that is configured to generate light having a first illumination peak wavelength appropriate for excitation of the donor fluorophore;
• a second light source that is configured to generate light having a second illumination peak wavelength appropriate for direct excitation of the acceptor fluorophore;
• and
• an external system, which is physically separate and distinct from the implantable unit, and which comprises:
• (a) an external reading unit, which comprises a light sensor, which is configured to sense fluorescent light emitted from the acceptor fluorophore;
• and
• (b) one or more processors, which are configured to:
• (i) during one or more first time periods:
• (a) drive the first implantable-unit light source to generate the light having the first illumination peak wavelength, and (b) receive, from the light sensor, one or more first measurements of the fluorescent light emitted from the acceptor fluorophore,
• (ii) during one or more second time periods non-overlapping with the first time periods:
• (a) drive the second light source to generate the light having the second illumination peak wavelength, and (b) receive, from the light sensor, one or more second measurements of the fluorescent light emitted from the acceptor fluorophore, and
• (iii) calculate the concentration of the analyte in the subject based on the first and the second measurements.

A method for detecting a concentration of an analyte in a subject, the method comprising:

• implanting, in a body of the subject, an implantable unit, which comprises:
• (a) fluorescent sensor molecules, each of which comprises (i) a binding site for the analyte, (ii) a donor fluorophore, and (iii) an acceptor fluorophore;
• and
• (b) a first implantable-unit light source that is configured to generate light having a first illumination peak wavelength appropriate for excitation of the donor fluorophore;
• placing an external reading unit of an external system above skin of the subject, wherein the external reading unit comprises a light sensor, which is configured to sense fluorescent light emitted from the acceptor fluorophore, and wherein the external system is physically separate and distinct from the implantable unit;
• and
• activating one or more processors of the external system to:
• (a) during one or more first time periods:
• (i) drive the first implantable-unit light source to generate the light having the first illumination peak wavelength, and (ii) receive, from the light sensor, one or more first measurements of the fluorescent light emitted from the acceptor fluorophore,
• (b) during one or more second time periods non-overlapping with the first time periods:
• (i) drive a second light source to generate light having a second illumination peak wavelength appropriate for direct excitation of the acceptor fluorophore, and (ii) receive, from the light sensor, one or more second measurements of the fluorescent light emitted from the acceptor fluorophore, and
• (c) calculate the concentration of the analyte in the subject based on the first and the second measurements.