Auto-injector and drive unit therefor

A drive unit for an auto-injector comprising:

• a drive unit housing arranged for receipt of a syringe, wherein said syringe is movable from a rest position, in which a needle tip of the syringe is within the drive unit housing, to a use position, in which said needle tip protrudes from a needle delivery aperture of the drive unit housing;
• and
• a drive arrangement comprising an electrically powered source of axial drive for advancing the syringe to said use position and ejecting at least part of a volume of liquid drug formulation,
• wherein the drive unit housing is provided with a skin sensor arrangement comprising an array of at least three skin sensor electrodes located peripherally around the needle delivery aperture,
• wherein a forward end cover is provided to the drive unit housing wherein said forward end cover defines an end cover needle delivery aperture, and
• wherein the forward end cover mates with a forward end of the drive unit housing such that the end cover needle cover delivery aperture is in registration with the needle delivery aperture of the drive unit housing.

A drive unit for an auto-injector comprising:

• a drive unit housing arranged for receipt of a syringe, wherein said syringe is movable from a rest position, in which a needle tip of the syringe is within the drive unit housing, to a use position, in which said needle tip protrudes from a needle delivery aperture of the drive unit housing;
• and
• a drive arrangement comprising an electrically powered source of axial drive for advancing the syringe to said use position and ejecting at least part of a volume of liquid drug formulation,
• wherein the drive unit housing is provided with a skin sensor arrangement comprising an array of at least three skin sensor electrodes located peripherally around the needle delivery aperture,
• wherein a forward end cover is provided to the drive unit housing wherein said forward end cover defines an end cover needle delivery aperture, and
• wherein the forward end cover defines an inner circumferential trough and the array of at least three skin sensor electrodes are received within said circumferential trough.

A drive unit for an auto-injector comprising:

• a drive unit housing arranged for receipt of a syringe, wherein said syringe is movable from a rest position, in which a needle tip of the syringe is within the drive unit housing, to a use position, in which said needle tip protrudes from a needle delivery aperture of the drive unit housing;
• and
• a drive arrangement comprising an electrically powered source of axial drive for advancing the syringe to said use position and ejecting at least part of a volume of liquid drug formulation,
• wherein the drive unit housing is provided with a skin sensor arrangement comprising an array of at least three skin sensor electrodes located peripherally around the needle delivery aperture,
• wherein a forward end cover is provided to the drive unit housing wherein said forward end cover defines an end cover needle delivery aperture, and
• wherein the forward end cover is comprised of a resilient plastic polymer material.

A drive unit for an auto-injector comprising:

• a drive unit housing arranged for receipt of a syringe, wherein said syringe is movable from a rest position, in which a needle tip of the syringe is within the drive unit housing, to a use position, in which said needle tip protrudes from a needle delivery aperture of the drive unit housing;
• and
• a drive arrangement comprising an electrically powered source of axial drive for advancing the syringe to said use position and ejecting at least part of a volume of liquid drug formulation,
• wherein the drive unit housing is provided with a skin sensor arrangement comprising an array of at least three skin sensor electrodes located peripherally around the needle delivery aperture,
• wherein the array of at least three skin sensor electrodes are on a flexible printed circuit board,
• wherein the flexible printed circuit board is elongate in form, and
• wherein the array of at least three skin sensor electrodes are on a forward part of said elongate flexible printed circuit board and remainder of the elongate flexible printed circuit board is arranged for receipt within the drive unit housing alongside the drive arrangement.

A drive unit for an auto-injector comprising:

• a drive unit housing arranged for receipt of a syringe, wherein said syringe is movable from a rest position, in which a needle tip of the syringe is within the drive unit housing, to a use position, in which said needle tip protrudes from a needle delivery aperture of the drive unit housing;
• a drive arrangement comprising an electrically powered source of axial drive for advancing the syringe to said use position and ejecting at least part of a volume of liquid drug formulation;
• an electronic control unit, wherein each of the at least three skin sensor electrodes is capable of sending an individual skin sensing signal to said electronic control unit;
• and
• a display unit, wherein the electronic control unit is capable of sending a command to the display unit to display a message when a particular skin sensing state is determined, said message being relevant to said particular skin sensing state,
• wherein the drive unit housing is provided with a skin sensor arrangement comprising an array of at least three skin sensor electrodes located peripherally around the needle delivery aperture.

A drive unit for an auto-injector comprising:

• a drive unit housing arranged for receipt of a syringe, wherein said syringe is movable from a rest position, in which a needle tip of the syringe is within the drive unit housing, to a use position, in which said needle tip protrudes from a needle delivery aperture of the drive unit housing;
• a drive arrangement comprising an electrically powered source of axial drive for advancing the syringe to said use position and ejecting at least part of a volume of liquid drug formulation;
• an electronic control unit, wherein each of the at least three skin sensor electrodes is capable of sending an individual skin sensing signal to said electronic control unit;
• and
• a timer unit wherein the electronic control unit is capable of sending a commence timing command to said timer unit when a skin sensing state corresponding to borderline unacceptable skin contact is determined;
• wherein said timer unit is arranged to either stop counting if acceptable skin contact is determined within a pre-set time period or otherwise to send a persistent borderline unacceptable skin contact signal to the electronic control unit,
• wherein the drive unit housing is provided with a skin sensor arrangement comprising an array of at least three skin sensor electrodes located peripherally around the needle delivery aperture,
• wherein the electronic control unit is capable of collating said individual skin sensing signals for all or a subset of the at least three skin sensor electrodes to determine a skin sensing state for all or a subset of the array of at least three skin sensor electrodes, and
• wherein the electronic control unit is capable of sending an emergency stop command to the drive arrangement on receiving said persistent borderline unacceptable skin contact signal.