# US 9,459,089 B2 · Method, devices and systems for detecting an attachment of an electronic patch > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,459,089 B2 - Document ID: US9459089B2 - Status: Granted - Kind: B2 - Application number: 14/459,996 - Filed: 2014-08-14 - Published: 2015-10-15 - Granted: 2016-10-04 - Earliest claimed: 2014-04-09 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Robert Bruce Ganton; Robert Scott Ballam - Web page: https://patentgrep.com/patent/US9459089B2 ## CPC - G01B 7/023: {for measuring distance between sensor and object (G01B7/082 and G01B7/102 take precedence)} - A61B 5/6833: {Adhesive patches} - A61B 5/6844: {Monitoring or controlling distance between sensor and tissue} - H03K 17/955: using a capacitive detector - A61B 2560/0209: adapted for power saving - A61B 2560/028: Arrangements to prevent overuse, e.g. by counting the number of uses - A61B 2562/0257: Proximity sensors - H03K 2217/94042: Means for reducing energy consumption - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) ## Abstract An electronic sensor patch includes a capacitive sensor configured to detect when the electronic sensor patch is applied to a patient. A processor may be powered down for a predetermined time interval in response to determining that the electronic patch is not in close proximity to a body. The electronic sensor patch may be activated in response to determining that the electronic patch is in close proximity to the body. The capacitance sensor may be used to determine whether the electronic sensor patch is in close proximity to a body by measuring capacitance of the capacitance sensor, comparing the measured capacitance to a threshold, and determining that the electronic sensor patch is in close proximity to a body in response to the measured capacitance of the capacitance sensor being more than the threshold. ## Claims ### Claim 1 A method of activating an electronic sensor patch configured to be applied to a patient, comprising: using a capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body; powering down a processor of the electronic sensor patch to a low-power mode for a predetermined time interval in response to determining that the electronic sensor patch is not in close proximity to a body; activating the electronic sensor patch in response to determining that the electronic sensor patch is in close proximity to the body; and executing, by the processor, a manufacturing mode in response to connection to a battery power source, wherein while in the manufacturing mode the capacitance sensor is not activated. ### Claim 2 (depends on 1) The method of claim 1, wherein using the capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body comprises: measuring a capacitance of the capacitance sensor; comparing the measured capacitance of the capacitance sensor to a capacitance threshold; and determining that the electronic sensor patch is in close proximity to a body in response to the measured capacitance of the capacitance sensor being more than the capacitance threshold. ### Claim 3 (depends on 1) The method of claim 1, wherein using the capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body comprises: energizing the processor of the electronic sensor patch upon expiration of the predetermined time interval; energizing the capacitance sensor; measuring, by the processor, a capacitance of the capacitance sensor based on energizing the capacitance sensor; comparing, by the processor, the measured capacitance of the capacitance sensor to a capacitance threshold; and determining that the electronic sensor patch is in close proximity to a body in response to the measured capacitance of the capacitance sensor being more than the capacitance threshold. ### Claim 4 (depends on 3) The method of claim 3, wherein energizing the capacitance sensor comprises applying to the capacitance sensor one of a voltage from a voltage source, and a constant current from a constant current source. ### Claim 5 (depends on 3) The method of claim 3, wherein powering down the processor of the electronic sensor patch to the low-power mode for the predetermined time interval in response to determining that the electronic sensor patch is not in close proximity to a body comprises: starting a timer in response determining that the electronic sensor patch is not in close proximity to a body; powering down the processor of the electronic sensor patch to the low-power mode that monitors the timer and reduces a power consumption by the processor and components of the electronic sensor patch; determining based on the timer whether the predetermined time interval has elapsed; and leaving the processor in the low-power mode in response to determining based on the timer that the predetermined time interval has not elapsed, wherein energizing the processor of the electronic sensor patch upon expiration of the predetermined time interval comprises energizing the processor of the electronic sensor patch in response to determining based on the timer that the predetermined time interval has elapsed. ### Claim 6 (depends on 1) The method of claim 1, further comprising: determining whether a time since the connection to the battery power source exceeds a first time threshold, wherein the first time threshold represents an amount of time that the electronic sensor patch may be handled during manufacturing and testing; and executing, by the processor, a shelf mode in which the capacitance sensor is activated at the predetermined time interval in response to determining that the time since the connection to the battery power source exceeds a first time threshold. ### Claim 7 (depends on 6) The method of claim 6, further comprising: determining a duration that the electronic sensor patch has been in the shelf mode in response to activation of the electronic sensor patch; and transmitting an indication of the determined duration that the electronic sensor patch has been in the shelf mode. ### Claim 8 An electronic sensor patch, comprising: a battery; a capacitance sensor; and a processor coupled to the battery and the capacitance sensor, wherein the processor is configured with processor executable instructions to perform operations comprising: using the capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body; placing the processor in a low-power mode for a predetermined time interval in response to determining that the electronic sensor patch is not in close proximity to a body; activating the electronic sensor patch in response to determining that the electronic sensor patch is in close proximity to the body; and executing, by the processor, a manufacturing mode in response to connection to a battery power source, wherein while in the manufacturing mode the capacitance sensor is not activated. ### Claim 9 (depends on 8) The electronic sensor patch of claim 8, wherein the processor is configured with processor executable instructions to perform operations such that using the capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body comprises: measuring capacitance of the capacitance sensor; comparing the measured capacitance of the capacitance sensor to a capacitance threshold; and determining that the electronic sensor patch is in close proximity to a body in response to the measured capacitance of the capacitance sensor being more than the capacitance threshold. ### Claim 10 (depends on 8) The electronic sensor patch of claim 8, wherein the processor is configured with processor executable instructions to perform operations such that using the capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body comprises: energizing the processor of the electronic sensor patch upon expiration of the predetermined time interval; energizing the capacitance sensor; measuring capacitance of the capacitance sensor based on energizing the capacitance sensor; comparing the measured capacitance of the capacitance sensor to a capacitance threshold; and determining that the electronic sensor patch is in close proximity to a body in response to the measured capacitance of the capacitance sensor being more than the capacitance threshold. ### Claim 11 (depends on 10) The electronic sensor patch of claim 10, wherein the processor is configured with processor-executable instructions such that energizing the capacitance sensor comprises applying to the capacitance sensor one of a voltage from a voltage source, and a constant current from a constant current source. ### Claim 12 (depends on 10) The electronic sensor patch of claim 10, wherein the processor is configured with processor-executable instructions such that powering down the processor of the electronic sensor patch to the low-power mode for the predetermined time interval in response to determining that the electronic sensor patch is not in close proximity to a body comprises: starting a timer in response determining that the electronic sensor patch is not in close proximity to a body; powering down the processor of the electronic sensor patch to the low-power mode that monitors the timer but minimizes power consumption by the processor and components of the electronic sensor patch; determining based on the timer whether the predetermined time interval has elapsed; and leaving the processor in the low-power mode in response to determining based on the timer that the predetermined time interval has not elapsed, wherein energizing the processor of the electronic sensor patch upon expiration of the predetermined time interval comprises energizing the processor of the electronic sensor patch in response to determining based on the timer that the predetermined time interval has elapsed. ### Claim 13 (depends on 8) The electronic sensor patch of claim 8, wherein the processor is configured with processor-executable instructions to perform operations further comprising: determining whether a time since the connection to the battery power source exceeds a first time threshold, wherein the first time threshold represents an amount of time that the electronic sensor patch may be handled during manufacturing and testing; and executing a shelf mode in which the capacitance sensor is activated at the predetermined time interval in response to determining that the time since the connection to the battery power source exceeds a first time threshold. ### Claim 14 (depends on 13) The electronic sensor patch of claim 13, wherein the processor is configured with processor-executable instructions to perform operations further comprising: determining a duration that the electronic sensor patch has been in the shelf mode in response to activation of the electronic sensor patch; and transmitting an indication of the determined duration that the electronic sensor patch has been in the shelf mode. ### Claim 15 An electronic sensor patch, comprising: a battery; a capacitance sensor; means for using the capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body; means for placing the electronic sensor patch in a low-power mode for a predetermined time interval in response to determining that the electronic sensor patch is not in close proximity to a body; means for activating the electronic sensor patch in response to determining that the electronic sensor patch is in close proximity to the body; and means for executing a manufacturing mode in response to connection to a battery power source, wherein while in the manufacturing mode the capacitance sensor is not activated. ### Claim 16 (depends on 15) The electronic sensor patch of claim 15, wherein means for using the capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body comprises: means for measuring a capacitance of the capacitance sensor; means for comparing the measured capacitance of the capacitance sensor to a capacitance threshold; and means for determining that the electronic sensor patch is in close proximity to a body in response to the measured capacitance of the capacitance sensor being more than the capacitance threshold. ### Claim 17 (depends on 15) The electronic sensor patch of claim 15, wherein means for using the capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body comprises: means for energizing the capacitance sensor upon expiration of the predetermined time interval; means for measuring a capacitance of the capacitance sensor based on energizing the capacitance sensor; means for comparing the measured capacitance of the capacitance sensor to a capacitance threshold; and means for determining that the electronic sensor patch is in close proximity to a body in response to the measured capacitance of the capacitance sensor being more than the capacitance threshold. ### Claim 18 (depends on 17) The electronic sensor patch of claim 17, wherein the means for energizing the capacitance sensor comprises means for applying to the capacitance sensor one of a voltage from a voltage source, and a constant current from a constant current source. ### Claim 19 (depends on 17) The electronic sensor patch of claim 17, wherein the means for placing the electronic sensor patch in the low-power mode for the predetermined time interval in response to determining that the electronic sensor patch is not in close proximity to a body comprises: means for starting a timer in response determining that the electronic sensor patch is not in close proximity to a body; means for powering down the electronic sensor patch to the low-power mode that maintains the timer but minimizes power consumption by components of the electronic sensor patch; means for determining based on the timer whether the predetermined time interval has elapsed; and means for leaving the electronic sensor patch in the low-power mode in response to determining based on the timer that the predetermined time interval has not elapsed, wherein the means for energizing the capacitance sensor upon expiration of the predetermined time interval comprises means for energizing the capacitance sensor in response to determining based on the timer that the predetermined time interval has elapsed. ### Claim 20 (depends on 15) The electronic sensor patch of claim 15, further comprising: means for determining whether a time since the connection to the battery power source exceeds a first time threshold, wherein the first time threshold represents an amount of time that the electronic sensor patch may be handled during manufacturing and testing; and means for executing a shelf mode in which the capacitance sensor is activated at the predetermined time interval in response to determining that the time since the connection to the battery power source exceeds a first time threshold. ### Claim 21 (depends on 20) The electronic sensor patch of claim 20, further comprising: means for determining a duration that the electronic sensor patch has been in the shelf mode in response to activation of the electronic sensor patch; and means for transmitting an indication of the determined duration that the electronic sensor patch has been in the shelf mode. ### Claim 22 A non-transitory processor-readable storage medium having stored thereon processor-executable instructions configured to cause a processor of an electronic sensor patch to perform operations comprising: using a capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body; powering down the processor of the electronic sensor patch to a low-power mode for a predetermined time interval in response to determining that the electronic sensor patch is not in close proximity to a body; activating the electronic sensor patch in response to determining that the electronic sensor patch is in close proximity to the body; and executing a manufacturing mode in response to connection to a battery power source, wherein while in the manufacturing mode the capacitance sensor is not activated. ### Claim 23 (depends on 22) The non-transitory processor-readable storage medium of claim 22, wherein the stored processor executable instructions are configured to cause the processor perform operations such that using the capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body comprises: measuring capacitance of the capacitance sensor; comparing the measured capacitance of the capacitance sensor to a capacitance threshold; and determining that the electronic sensor patch is in close proximity to a body in response to the measured capacitance of the capacitance sensor being more than the capacitance threshold. ### Claim 24 (depends on 22) The non-transitory processor-readable storage medium of claim 22, wherein the stored processor executable instructions are configured to cause the processor perform operations such that using the capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body comprises: energizing the processor of the electronic sensor patch upon expiration of the predetermined time interval; energizing the capacitance sensor; measuring capacitance of the capacitance sensor based on energizing the capacitance sensor; comparing the measured capacitance of the capacitance sensor to a capacitance threshold; and determining that the electronic sensor patch is in close proximity to a body in response to the measured capacitance of the capacitance sensor being more than the capacitance threshold. ### Claim 25 (depends on 24) The non-transitory processor-readable storage medium of claim 24, wherein the stored processor-executable instructions are configured to cause the processor to perform operations such that energizing the capacitance sensor comprises applying to the capacitance sensor one of a voltage from a voltage source, and a constant current from a constant current source. ### Claim 26 (depends on 24) The non-transitory processor-readable storage medium of claim 24, wherein the stored processor-executable instructions are configured to cause the processor to perform operations such that powering down the processor of the electronic sensor patch to the low-power mode for the predetermined time interval in response to determining that the electronic sensor patch is not in close proximity to a body comprises: starting a timer in response determining that the electronic sensor patch is not in close proximity to a body; powering down the processor of the electronic sensor patch to the low-power mode that monitors the timer and reduces a power consumption by the processor and components of the electronic sensor patch; determining based on the timer whether the predetermined time interval has elapsed; and leaving the processor in the low-power mode in response to determining based on the timer that the predetermined time interval has not elapsed, wherein energizing the processor of the electronic sensor patch upon expiration of the predetermined time interval comprises energizing the processor of the electronic sensor patch in response to determining based on the timer that the predetermined time interval has elapsed. ### Claim 27 (depends on 22) The non-transitory processor-readable storage medium of claim 22, wherein the stored processor-executable instructions are configured to cause the processor to perform operations further comprising: determining whether a time since the connection to the battery power source exceeds a first time threshold, wherein the first time threshold represents an amount of time that the electronic sensor patch may be handled during manufacturing and testing; and executing a shelf mode in which the capacitance sensor is activated at the predetermined time interval in response to determining that the time since the connection to the battery power source exceeds a first time threshold. ### Claim 28 (depends on 27) The non-transitory processor-readable storage medium of claim 27, wherein the stored processor-executable instructions are configured to cause the electronic sensor patch to perform operations further comprising: determining a duration that the processor has been in the shelf mode in response to activation of the electronic sensor patch; and transmitting an indication of the determined duration that the electronic sensor patch has been in the shelf mode. ### Claim 29 A method of deactivating an electronic sensor patch configured to be applied to a patient, comprising: activating an timer in response to activation of the electronic sensor patch; determining, by a processor of the electronic sensor patch, whether the timer has expired; and deactivating, by the processor, the electronic sensor patch in response to determining that the timer has expired, wherein deactivating the electronic sensor patch includes purging data stored in memory of the electronic sensor patch. ### Claim 30 (depends on 29) The method of claim 29, further comprising: using a capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body; and activating the electronic sensor patch in response to determining that the electronic sensor patch is in close proximity to the body. ### Claim 31 (depends on 30) The method of claim 30, further comprising executing an on-body operations mode to perform one or more on-body operations in response to activating the electronic sensor patch. ### Claim 32 (depends on 31) The method of claim 31, wherein the one or more on-body operations include at least one member of the group consisting of: a sensing operation; and a communication operation. ### Claim 33 (depends on 30) The method of claim 30, further comprising powering down the processor of the electronic sensor patch to a low-power mode for a predetermined time interval in response to determining that the electronic sensor patch is not in close proximity to a body. ### Claim 34 (depends on 29) The method of claim 29, further comprising sending a deactivation signal in response to determining that the timer has expired. ### Claim 35 (depends on 34) The method of claim 34, wherein the deactivation signal indicates that the electronic sensor patch will be deactivated. ### Claim 36 (depends on 29) The method of claim 29, wherein purging the data stored in the memory of the electronic sensor patch comprises at least one member of the group consisting of: disconnecting power to the memory; and overwriting the data stored in the memory. ### Claim 37 (depends on 29) The method of claim 29, wherein determining whether the timer has expired comprises determining that the active life timer has expired when the value of the timer is one of: zero; equal to an active life time value; and less than the active life time value. ### Claim 38 An electronic sensor patch, comprising: a battery; a timer; a capacitance sensor; and a processor coupled to the battery, the timer, and the capacitance sensor, wherein the processor is configured with processor-executable instructions to perform operations comprising: activating the timer in response to activation of the electronic sensor patch; determining whether the timer has expired; and deactivating the electronic sensor patch in response to determining that the timer has expired, wherein deactivating the electronic sensor patch includes purging data stored in memory of the electronic sensor patch. ### Claim 39 (depends on 38) The electronic sensor patch of claim 38, wherein the processor is configured with processor executable-instructions to perform operations further comprising: using the capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body; and activating the electronic sensor patch in response to determining that the electronic sensor patch is in close proximity to the body. ### Claim 40 (depends on 39) The electronic sensor patch of claim 39, wherein the processor is configured with processor-executable instructions to perform operations further comprising: executing an on-body operations mode to perform one or more on-body operations in response to activating the electronic sensor patch. ### Claim 41 (depends on 40) The electronic sensor patch of claim 40, further comprising: a radio module coupled to the processor; and one or more sensors coupled to the processor, wherein the processor is configured with processor executable instructions to perform operations such that the one or more on-body operations include at least one member of the group consisting of: sensing operations using the one or more sensors; and a communication operation using the radio module. ### Claim 42 (depends on 39) The electronic sensor patch of claim 39, wherein the processor is configured with processor executable instructions to perform operations further comprising: powering down the processor to a low-power mode for a predetermined time interval in response to determining that the electronic sensor patch is not in close proximity to a body. ### Claim 43 (depends on 38) The electronic sensor patch of claim 38, further comprising a radio module coupled to the processor, wherein the processor is configured with processor executable instructions to perform operations further comprising sending a deactivation signal using the radio module in response to determining that the timer has expired. ### Claim 44 (depends on 43) The electronic sensor patch of claim 43, wherein the processor is configured with processor executable instructions to perform operations such the deactivation signal indicates that the electronic sensor patch will be deactivated. ### Claim 45 (depends on 38) The electronic sensor patch of claim 38, wherein the processor is configured with processor executable instructions to perform operations such that purging the data stored in the memory comprises at least one member of the group consisting of: disconnecting power to the memory; and overwriting the data stored in the memory. ### Claim 46 (depends on 38) The electronic sensor patch of claim 38, wherein the processor is configured with processor executable instructions to perform operations such that determining whether the timer has expired comprises determining that the timer has expired when the value of the timer is one of: zero; equal to an active life time value; and less than the time value. ### Claim 47 An electronic sensor patch, comprising: a battery; an timer; a capacitance sensor; and means for activating the timer in response to activation of the electronic sensor patch; means for determining whether the timer has expired; and means for deactivating the electronic sensor patch in response to a determination that the timer has expired, wherein deactivating the electronic sensor patch includes purging data stored in memory of the electronic sensor patch. ### Claim 48 (depends on 47) The electronic sensor patch of claim 47, further comprising: means for using the capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body; and means for activating the electronic sensor patch in response to determining that the electronic sensor patch is in close proximity to the body. ### Claim 49 (depends on 48) The electronic sensor patch of claim 48, further comprising: means for executing an on-body operations mode to perform one or more on-body operations in response to activation of the electronic sensor patch. ### Claim 50 (depends on 48) The electronic sensor patch of claim 48, wherein means for executing one or more on-body operations comprises at least one member of the group consisting of: means for executing a sensing operation; and means for executing a communication operation. ### Claim 51 (depends on 48) The electronic sensor patch of claim 48, further comprising: means for powering down the electronic sensor patch to a low-power mode for a predetermined time interval in response to a determination that the electronic sensor patch is not in close proximity to a body. ### Claim 52 (depends on 47) The electronic sensor patch of claim 47, further comprising means for sending a deactivation signal in response to a determination that the timer has expired. ### Claim 53 (depends on 52) The electronic sensor patch of claim 52, wherein the deactivation signal indicates that the electronic sensor patch will be deactivated. ### Claim 54 (depends on 47) The electronic sensor patch of claim 47, wherein the purging of the data stored in the memory of the electronic sensor patch comprises at least one member of the group consisting of: means for disconnecting power to the memory; and means for overwriting data stored in the memory. ### Claim 55 (depends on 47) The electronic sensor patch of claim 47, wherein means for determining whether the timer has expired comprises means for determining that the timer has expired when the value of the timer is one of: zero; equal to an active life time value; and less than the active life time value. ### Claim 56 A non-transitory processor-readable storage medium having stored thereon processor-executable instructions configured to cause a processor of an electronic sensor patch to perform operations comprising: activating an timer in response to activation of the electronic sensor patch; determining whether the timer has expired; and deactivating the electronic sensor patch in response to determining that the timer has expired, wherein deactivating the electronic sensor patch includes purging data stored in memory of the electronic sensor patch. ### Claim 57 (depends on 56) The non-transitory processor-readable storage medium of claim 56, wherein the stored processor-executable instructions are configured to cause the processor of the electronic sensor patch to perform operations further comprising: using a capacitance sensor to determine whether the electronic sensor patch is in close proximity to a body; and activating the electronic sensor patch in response to determining that the electronic sensor patch is in close proximity to the body. ### Claim 58 (depends on 57) The non-transitory processor-readable storage medium of claim 57, wherein the stored processor-executable instructions are configured to cause the processor of the electronic sensor patch to perform operations further comprising: executing an on-body operations mode to perform one or more on-body operations in response to activating the electronic sensor patch. ### Claim 59 (depends on 58) The non-transitory processor-readable storage medium of claim 58, wherein the stored processor-executable instructions are configured to cause the processor of the electronic sensor patch to perform operations such that the one or more on-body operations include at least one member of the group consisting of: one or more sensing operations; and a communication operation. ### Claim 60 (depends on 57) The non-transitory processor-readable storage medium of claim 57, wherein the stored processor-executable instructions are configured to cause the processor of the electronic sensor patch to perform operations further comprising: powering down the processor to a low-power mode for a predetermined time interval in response to determining that the electronic sensor patch is not in close proximity to a body. ### Claim 61 (depends on 56) The non-transitory processor-readable storage medium of claim 56, wherein the stored processor-executable instructions are configured to cause the processor of the electronic sensor patch to perform operations further comprising sending a deactivation signal in response to determining that the timer has expired. ### Claim 62 (depends on 61) The non-transitory processor-readable storage medium of claim 61, wherein the stored processor-executable instructions are configured to cause the processor of the electronic sensor patch to perform operations such that sending the deactivation signal indicates that the electronic sensor patch will be deactivated. ### Claim 63 (depends on 56) The non-transitory processor-readable storage medium of claim 56, wherein the stored processor-executable instructions are configured to cause the processor of the electronic sensor patch to perform operations such that purging the data stored in the memory of the electronic sensor patch comprises at least one member of the group consisting of: disconnecting power to the memory; and overwriting the data stored in the memory. ### Claim 64 (depends on 56) The non-transitory processor-readable storage medium of claim 56, wherein the stored processor-executable instructions are configured to cause the processor of the electronic sensor patch to perform operations such that determining whether the timer has expired comprises determining that the timer has expired when the value of the timer is one of: zero; equal to an active life time value; and less than the active life time value.