Connected injection devices with status sensing systems

A method for determining initiation of a dispensing event, the method comprising:

• providing an injection device assembly, the assembly comprising:
• a housing,
• a syringe assembly at least partially disposed within the housing,
• a drive mechanism configured to drive the syringe assembly from a storage position to an injection position,
• one or more skin-contact sensors, each sensor being configured to detect contact with skin tissue, and
• an accelerometer disposed within the device assembly and configured to output a signal representative of sensed acceleration;
• determining, by at least one processing circuit, whether at least one of the one or more skin-contact sensors detect contact with skin tissue;
• analyzing, by the at least one processing circuit, the signal output by the accelerometer to detect a first acceleration spike;
• determining, by the at least one processing circuit, that the first acceleration spike is caused by initiation of a dispensing event in which the syringe assembly is driven by the drive mechanism from the storage position to the injection position only when at least one of the one or more skin-contact sensors detect contact with skin tissue at a time when the first acceleration spike was detected.

An injection device assembly comprising:

• a housing;
• a syringe assembly at least partially disposed within the housing;
• a drive mechanism configured to drive the syringe assembly from a storage position to an injection position to dispense medication;
• one or more skin-contact sensors, each sensor being configured to detect contact with skin tissue;
• an accelerometer disposed within the housing and configured to output a signal representative of sensed acceleration;
• and
• a processing circuit operably coupled with the one or more skin-contact sensors and the accelerometer configured to:
• analyze the signal output by the accelerometer to detect a first acceleration spike and a second acceleration spike subsequent to the first acceleration spike,
• determine that a dispensing event has been completed when a set of one or more conditions are satisfied, wherein the set of conditions comprises the following condition:
• at least one of the one or more skin-contact sensors detect contact with skin tissue at least once during a time period beginning with the first acceleration spike and ending with the second acceleration spike, and
• determine that the dispensing event has not been completed when at least one condition in the set of conditions is not satisfied,
• wherein the processing circuit is configured to analyze the signal output by the accelerometer to detect acceleration spikes by:
• calculating an integrated signal by integrating at least a portion of the signal, and
• detecting the first acceleration spike or the second acceleration spike when the integrated signal is less than a maximum signal threshold.

A method for determining completion of a dispensing event, the method comprising:

• providing an injection device assembly, the assembly comprising:
• a housing,
• a syringe assembly at least partially disposed within the housing,
• a drive mechanism configured to drive the syringe assembly from a storage position to an injection position to dispense medication,
• one or more skin-contact sensors, each sensor being configured to detect contact with skin tissue, and
• an accelerometer disposed within the device assembly and configured to output a signal representative of sensed acceleration;
• analyzing the signal output by the accelerometer to detect a first acceleration spike and a second acceleration spike subsequent to the first acceleration spike;
• and
• determining whether a dispensing event has been completed by:
• determining that the dispensing event has been completed when a set of one or more conditions are satisfied, wherein the set of conditions comprise the following condition:
• at least one of the one or more skin-contact sensors detect contact with skin tissue at least once during a time period beginning with the first acceleration spike and ending with the second acceleration spike, and
• determining that the dispensing event has not been completed when at least one condition in the set of conditions is not satisfied,
• wherein analyzing the signal output by the accelerometer comprises:
• calculating an integrated signal by integrating at least a portion of the signal output by the accelerometer, and
• detecting an acceleration spike when the integrated signal is less than a maximum signal threshold.