US 12,478,741 B2
Drug delivery system with multipolar magnet and sensor system
Laurits Hoejgaard Olesen, Copenhagen (DK); Henrik Bengtsson, Taastrup (DK); Leif Johannsen, Odder (DK); Keld Baden-Kristensen, Hoersholm (DK); and John Aasted Soerensen, Virum (DK)
Assigned to Novo Nordisk A/S, Bagsvaerd (DK)
Filed by Novo Nordisk A/S, Bagsvaerd (DK)
Filed on May 9, 2023, as Appl. No. 18/195,191.
Application 18/195,191 is a continuation of application No. 16/769,643, granted, now 11,684,722, previously published as PCT/EP2018/083324, filed on Dec. 3, 2018.
Claims priority of application No. 17205062 (EP), filed on Dec. 4, 2017; and application No. 17205063 (EP), filed on Dec. 4, 2017.
Prior Publication US 2023/0270949 A1, Aug. 31, 2023
Int. Cl. A61M 5/315 (2006.01); A61M 5/31 (2006.01)
CPC A61M 5/31553 (2013.01) [A61M 5/31525 (2013.01); A61M 5/31556 (2013.01); A61M 5/3158 (2013.01); A61M 2005/3126 (2013.01); A61M 2205/3317 (2013.01); A61M 2205/52 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A drug delivery system, comprising:
a housing forming a reference component,
a drug reservoir or structure for receiving a drug reservoir,
drug expelling structure comprising a rotatable dose setting member allowing a user to set a dose amount of drug to be expelled,
a release member actuatable between a proximal position and a distal position, the proximal position allowing a dose amount to be set, the distal position allowing the drug expelling structure to expel a set dose,
a drive spring arranged to be strained during dose setting and released by the release member to thereby drive expelling of an amount of drug from the drug reservoir, the drive spring being formed from a magnetisable material, and
an indicator element comprising a plurality of dipole magnets and being coupled to the reference component, wherein the number of dipole magnets comprises 2, 3 or 4,
a sensor system comprising:
at least one magnetometer coupled to the dose setting member and adapted to determine continuous magnetic field values from the plurality of dipole magnets,
processor structure configured to determine on the basis of measured values from the at least one magnetometer a rotational movement of the at least one magnetometer relative to the indicator element, and
the processor structure is configured to determine, on the basis of measured values from the at least one magnetometer, a rotational position between the indicator element and the at least one magnetometer with a resolution of at least 18 degrees,
wherein the determined rotational movement of the at least one magnetometer correspond to the set dose amount.