US4950235A — Container-side occlusion detection system for a m…

Claim 1

Independent Claim 155 words

A container-side occlusion detection system for use in a medication infusion system having a disposable cassette mounted onto a main pump unit, comprising: a reciprocating piston pump located in a disposable cassette, said pump having a fill stroke and a deliver stroke; a motor location in a main pump unit, said motor for driving said pump; means for monitoring motor current during said fill stroke of said pump, said motor current being indicative of the presence or absence of a container-side occlusion in a fluid line, said monitoring means comprising an integrator for taking the first integral of motor current and providing as an output a CSOD value characteristic of said motor current; means for providing an alarm; and means for comparing said CSOD value to a preselected alarm threshold value, said comparing means causing said means for providing an alarm to initiate an alarm when said CSOD value exceeds said preselected alarm threshold value.

Claim 2

Dependent Claim 155 words

A container-side occlusion detection system for use in a medication infusion system having a disposable cassette mounted onto a main pump unit, comprising: a reciprocating piston pump located in a disposable cassette, said pump having a fill stroke and a deliver stroke; a motor location in a main pump unit, said motor for driving said pump; means for monitoring motor current during said fill stroke of said pump, said motor current being indicative of the presence or absence of a container-side occlusion in a fluid line, said monitoring means comprising an integrator for taking the first integral of motor current and providing as an output a CSOD value characteristic of said motor current; means for providing an alarm; and means for comparing said CSOD value to a preselected alarm threshold value, said comparing means causing said means for providing an alarm to initiate an alarm when said CSOD value exceeds said preselected alarm threshold value.

Claim 3

Dependent Claim 20 words

A container-side occlusion detection system as defined in claim 1, wherein said integrator integrates motor current during said fill stroke.

Claim 4

Dependent Claim 30 words

A container-side occlusion detection system as defined in claim 2, wherein said integrator also integrated motor current during a period following said fill stroke but prior to said deliver stroke.

Claim 5

Dependent Claim 29 words

A container-side occlusion detection system as defined in claim 1, wherein said integrator holds said CSOD value during said deliver stroke to allow said CSOD value to be sampled.

Claim 6

Dependent Claim 21 words

A container-side occlusion detection system as defined in claim 4, wherein said integrator is reset prior to the succeeding fill stroke.

Claim 7

Dependent Claim 28 words

A container-side occlusion detection system as defined in claim 1, wherein said monitoring means additionally comprises: an analog-to-digital converter for converting said CSOD value into a digital signal.

Claim 8

Dependent Claim 35 words

A container-side occlusion detection system as defined in claim 1, wherein said monitoring means additionally comprises: a shunt resistor in series with said motor, the input to said integrator being provided across said shunt resistor.

Claim 9

Dependent Claim 29 words

A container-side occlusion detection system as defined in claim 1, additionally comprising: means for calibrating said system, said calibration means providing as an output said preselected alarm threshold value.

Claim 10

Dependent Claim 37 words

A container-side occlusion detection system as defined in claim 8, wherein said preselected threshold value is the measured CSOD value using a test cassette having no cassette friction multiplied by a constant factor between 1.5 and 3.0.

Claim 11

Dependent Claim 17 words

A container-side occlusion detection system as defined in claim 9, wherein said constant value is approximately 2.0.

Claim 12

Dependent Claim 24 words

A container-side occlusion detection system as defined in claim 9, wherein said calibration means provides minimum and maximum limits to said preselected threshold value.

Claim 13

Dependent Claim 22 words

A container-side occlusion detection system as defined in claim 11, wherein said minimum limit is 42 and said maximum limit is 80.

Claim 14

Dependent Claim 58 words

A container-side occlusion detection system as defined in claim 1, additionally comprising: means for driving said motor, wherein said motor is driven by periodic pulses supplied by said driving means, said pulses being either at a lower commanded drive voltage or at a higher commanded drive voltage, said higher commanded drive voltage being used at higher flow rates.

Claim 15

Dependent Claim 40 words

A container-side occlusion detection system as defined in claim 13, wherein said lower commanded drive voltage supplied by said driving means is approximately 5 Volts and said higher commanded drive voltage supplied by said driving means is approximately 13 Volts.

Claim 16

Dependent Claim 74 words

A container-side occlusion detection system as defined in claim 13, wherein said CSOD value is monitored by said monitoring means following each fill stroke when said motor is being driven at said lower commanded drive voltage, and wherein when said motor is being driven at said higher commanded drive voltage said motor is periodically driven through an entire fill stroke at said lower commanded drive voltage to allow said CSOD value to be monitored.

Claim 17

Dependent Claim 50 words

A container-side occlusion detection system as defined in claim 13, wherein said CSOD value is monitored by said monitoring means once during each time a predetermined number of periodic pulses occurs when said motor is being driven at either said higher commanded drive voltage or said lower commanded drive voltage.

Claim 18

Dependent Claim 26 words

A container-side occlusion detection system as defined in claim 16, wherein said CSOD value is monitored by said monitoring means once during each five periodic pulses.

Claim 19

Dependent Claim 29 words

A container-side occlusion detection system as defined in claim 17, wherein in a start-up infusion said CSOD value is monitored by said monitoring means during the second periodic pulse.

Claim 20

Dependent Claim 90 words

A container-side occlusion detection system as defined in claim 16, wherein when said CSOD value is to be monitored by said monitoring means during a periodic pulse, the drive voltage supplied by said driving means is reduced to said lower commanded drive voltage until said pump is driven through one complete fill stroke, after which the drive voltage is returned to said higher commanded drive voltage, a periodic pulse including both said lower commanded drive voltage and said higher commanded drive voltage being referred to as a hybrid voltage pulse.

Claim 21

Dependent Claim 100 words

A container-side occlusion detection system as defined in claim 19, wherein the width of a hybrid voltage pulse supplied by said driving means is calculated according to the formula: ##EQU2## where N p is the calculated position in the delivery cycle (between 0 and 160 encoder counts, where 0 is the beginning of the delivery cycle and 160 is the end), N c is the command to the rate control expressed as encoder counts (i.e. converted from ml/h), U 13 is the pulse width calculated by the closed loop controller at the present sampling period, and g is the gain.

Claim 22

Dependent Claim 159 words

A container-side occlusion detection system for use in a medication infusion system having a disposable cassette mounted onto a main pump unit, comprising: a reciprocating piston pump located in a disposable cassette, said pump having a fill stroke and a deliver stroke; a motor located in a main pump unit, said motor for driving said pump; means for monitoring motor current during said fill stroke of said pump, motor current being indicative of the presence or absence of a container-side occlusion in a fluid line, said monitoring means providing as an output a CSOD value characteristic of said motor current; an integrator for taking the first integral of motor current to produce said CSOD value; means for providing an alarm; and means for comparing the output of said integrator to a preselected alarm threshold value, said comparing means causing said means for providing an alarm to initiate an alarm when said CSOD value exceeds said preselected alarm threshold value.

Claim 23

Dependent Claim 159 words

A container-side occlusion detection system for use in a medication infusion system having a disposable cassette mounted onto a main pump unit, comprising: a reciprocating piston pump located in a disposable cassette, said pump having a fill stroke and a deliver stroke; a motor located in a main pump unit, said motor for driving said pump; means for monitoring motor current during said fill stroke of said pump, motor current being indicative of the presence or absence of a container-side occlusion in a fluid line, said monitoring means providing as an output a CSOD value characteristic of said motor current; an integrator for taking the first integral of motor current to produce said CSOD value; means for providing an alarm; and means for comparing the output of said integrator to a preselected alarm threshold value, said comparing means causing said means for providing an alarm to initiate an alarm when said CSOD value exceeds said preselected alarm threshold value.

Claim 24

Dependent Claim 139 words

A container-side occlusion detection system for use in a medication infusion system comprising a disposable cassette including a reciprocating piston pump mounted onto a main pump unit including a motor for driving the pump, said container-side occlusion detection system comprising: means for monitoring motor current during a fill stroke of said pump, said motor current being indicative of the present or absence of a container-side occlusion in a fluid line, said monitoring means comprising an integrator for taking the first integral of motor current and providing as an output a CSOD value characteristic of said motor current; means for providing an alarm; and means for comparing said CSOD value to a preselected alarm threshold value, said comparing means causing said means for providing an alarm to initiate an alarm when said CSOD value exceeds said preselected alarm threshold value.

Claim 25

Dependent Claim 139 words

A container-side occlusion detection system for use in a medication infusion system comprising a disposable cassette including a reciprocating piston pump mounted onto a main pump unit including a motor for driving the pump, said container-side occlusion detection system comprising: means for monitoring motor current during a fill stroke of said pump, said motor current being indicative of the present or absence of a container-side occlusion in a fluid line, said monitoring means comprising an integrator for taking the first integral of motor current and providing as an output a CSOD value characteristic of said motor current; means for providing an alarm; and means for comparing said CSOD value to a preselected alarm threshold value, said comparing means causing said means for providing an alarm to initiate an alarm when said CSOD value exceeds said preselected alarm threshold value.

Claim 26

Independent Claim 136 words

A method of detecting a container-side occlusion in a medication infusion system having a disposable cassette mounted onto a main pump unit, comprising: providing a reciprocating piston pump in said disposable cassette, said pump having a fill stroke and a deliver stroke; driving said pump with a motor located in said main pump unit; monitoring motor current during said fill stroke of said pump, said motor current being indicative of the presence or absence of a container-side occlusion in a fluid line, said monitoring means comprising an integrator for taking the first integral of motor current and providing as an output a CSOD value characteristic of said motor current; and comparing said CSOD value to a preselected alarm threshold value, said comparing means initiating an alarm when said CSOD value exceeds said preselected alarm threshold value.

Claim 27

Independent Claim 136 words

A method of detecting a container-side occlusion in a medication infusion system having a disposable cassette mounted onto a main pump unit, comprising: providing a reciprocating piston pump in said disposable cassette, said pump having a fill stroke and a deliver stroke; driving said pump with a motor located in said main pump unit; monitoring motor current during said fill stroke of said pump, said motor current being indicative of the presence or absence of a container-side occlusion in a fluid line, said monitoring means comprising an integrator for taking the first integral of motor current and providing as an output a CSOD value characteristic of said motor current; and comparing said CSOD value to a preselected alarm threshold value, said comparing means initiating an alarm when said CSOD value exceeds said preselected alarm threshold value.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1993-08-20	1994-02-19	1994-08-21	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1997-08-20	1998-02-19	1998-08-21	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2001-08-20	2002-02-19	2002-08-21	$7700.00	Window Closed / Lapsed

Container-side occlusion detection system for a medication infusion system

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