Sensor and method for detecting a patient's movement via position and occlusion
First Claim
1. A patient sensor for use in monitoring a patient who is at risk of developing decubitus ulcers, said patient sensor having at least a first end and a second end, comprising:
- (a) a nonconductive upper member, said upper member having an outer surface and an inner surface, wherein at least a portion of said upper member inner surface is electrically conductive;
(b) a nonconductive lower member, said lower member having an inner surface and an outer surface, said lower member inner surface being positionable to be proximate to said upper member inner surface, wherein at least a portion of said lower member inner surface is electrically conductive, said electrically conductive portion of said lower member inner surface containing at least two electrically isolated circuits thereon, (b1) wherein a first circuit of said at least two electrically isolated circuits contains at least a plurality of spaced apart resistive elements therein, and, (b2) wherein a second circuit of said at least two electrically isolated circuits, when taken in combination with said first circuit, forms a plurality of switches, each of said switches having at least one of said resistive elements associated therewith and each of said switches being located at a predetermined distance from said first end of said patient sensor;
(c) a nonconductive central spacer between said upper member and said lower member, said central spacer electrically separating at least a portion of said upper member and said lower member inner surfaces, and, allowing at least a portion of said conductive portions of said upper member and said lower member to come into electrical contact when a patient is present on said patient sensor, thereby electrically engaging at least one of said plurality of switches and the resistive elements associated therewith; and
, (d) an electrical line in electrical communication with said conductive portions of said upper and lower members, said electrical line having at least three electrically isolated conductors therein, wherein (d1) a first conductor of said at least three conductors is in electrical communication with said first circuit, (d2) a second conductor of said at least three conductors is in electrical communication with said first circuit, such that by measuring the potential between said first and second conductors a total resistance in said first circuit may be determined, and (d3) a third conductor of said at least three conductors is in electrical communication with said second electrically isolated circuit, such that by measuring a total resistance between said first circuit and said second circuit a determination may be made of a location and extent of said at least one point of contact.
1 Assignment
0 Petitions
Accused Products
Abstract
There is provided herein a sensor for use in connection with an electronic patient monitor, wherein the sensor preferably uses a linearly configured resistive ladder with spaced-apart resistors as a means of determining at least approximately a location of the patient on the sensor as well as an approximate length of the sensor which is compressed by the patient. By continuously determining both of these quantities over time it is possible to track the patient'"'"'s movement and determine to what extent the patient needs to be manually turned and/or the extent to which a next-scheduled turn can be skipped.
62 Citations
44 Claims
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1. A patient sensor for use in monitoring a patient who is at risk of developing decubitus ulcers, said patient sensor having at least a first end and a second end, comprising:
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(a) a nonconductive upper member, said upper member having an outer surface and an inner surface, wherein at least a portion of said upper member inner surface is electrically conductive;
(b) a nonconductive lower member, said lower member having an inner surface and an outer surface, said lower member inner surface being positionable to be proximate to said upper member inner surface, wherein at least a portion of said lower member inner surface is electrically conductive, said electrically conductive portion of said lower member inner surface containing at least two electrically isolated circuits thereon, (b1) wherein a first circuit of said at least two electrically isolated circuits contains at least a plurality of spaced apart resistive elements therein, and, (b2) wherein a second circuit of said at least two electrically isolated circuits, when taken in combination with said first circuit, forms a plurality of switches, each of said switches having at least one of said resistive elements associated therewith and each of said switches being located at a predetermined distance from said first end of said patient sensor;
(c) a nonconductive central spacer between said upper member and said lower member, said central spacer electrically separating at least a portion of said upper member and said lower member inner surfaces, and, allowing at least a portion of said conductive portions of said upper member and said lower member to come into electrical contact when a patient is present on said patient sensor, thereby electrically engaging at least one of said plurality of switches and the resistive elements associated therewith; and
,(d) an electrical line in electrical communication with said conductive portions of said upper and lower members, said electrical line having at least three electrically isolated conductors therein, wherein (d1) a first conductor of said at least three conductors is in electrical communication with said first circuit, (d2) a second conductor of said at least three conductors is in electrical communication with said first circuit, such that by measuring the potential between said first and second conductors a total resistance in said first circuit may be determined, and (d3) a third conductor of said at least three conductors is in electrical communication with said second electrically isolated circuit, such that by measuring a total resistance between said first circuit and said second circuit a determination may be made of a location and extent of said at least one point of contact. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A patient sensor for use in monitoring a patient who is at risk of developing decubitus ulcers, said patient sensor having at least a length and a first end and a second end, comprising:
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(a) a nonconductive lower member, said lower member having an inner surface and an outer surface, wherein said lower member inner surface has at least one resistive ladder thereon, said at least one resistive ladder having a plurality of serially connected spaced apart resistive elements spanning at least a portion of said length of said patient sensor, and, wherein said nonconductive lower member inner surface has an electrically isolated contact circuit proximate to said resistive ladder;
(b) a nonconductive upper member, said upper member having an outer surface and an inner surface, wherein at least a portion of said upper member inner surface is electrically conductive, (c) a nonconductive central spacer positionable to be between said upper member and said lower member, said central spacer separating said electrically conductive portions of said upper member and said lower member, and, allowing said electrically conductive portions of said upper member and said lower member to come into contact when pressure is applied to said patient sensor, thereby electrically shorting said first circuit and said second circuit at a point of contact when said contact is made; and
,(d) an electrical line in electrical communication with said conductive portions of said upper and lower members, said electrical line having at least three electrically isolated conductors therein, wherein (d1) a first conductor of said at least three conductors is in electrical communication with said first circuit, (d2) a second conductor of said at least three conductors is in electrical communication with said first circuit such that by measuring the potential between said first and second conductors a total amount of resistance in said first conductor may be determined, and (d3) a third conductor of said at least three conductors is in electrical communication with said second electrically isolated circuit. - View Dependent Claims (12, 13)
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14. A method of monitoring a patient who is at risk of developing decubitus ulcers,
wherein is provided a patient sensor positionable to be proximate to the patient and being operable to provide at least a proportion of the sensor occluded by the patient and a contact point of the patient on the sensor, and, a patient turn interval, comprising the steps of: -
(a) determining whether a patient is present on the sensor;
(b) using said patient sensor to determine an initial contact point of the patient on the sensor;
(c) using said patient sensor to determine an initial occluded region of the patient on the sensor;
(d) waiting a period of time;
(e) using said patient sensor to determine a subsequent contact point of the patient on the sensor;
(f) using said patient sensor to determine a subsequent occluded region of the patient on the sensor;
(g) using at least said initial contact point, said initial occluded region, said subsequent contact point, and said subsequent occluded region to determine whether the patient has moved during said period of time;
(h) if the patient has not moved during said period of time, determining a time since the patient last moved;
(i) if said time since the patient last moved exceeds said patient turn interval, sounding an alarm;
(j) if said time since the patient last moved does not exceed said patient turn interval, continuing to perform steps (d) through (i) until either the patient moves again or until the time since the patient last moved exceeds said patient turn; and
,(k) if the patient has moved during said time period, continuing to perform steps (d) through (j) until either the patient moves again or until the patient turn interval is exceeded. - View Dependent Claims (15)
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16. A patient sensor for use in monitoring a patient who is at risk of developing decubitus ulcers, comprising:
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(a) a nonconductive upper member, said upper member having an outer surface and an inner surface, at least a portion of said upper member inner surface being electrically conductive;
(b) a nonconductive lower member, said lower member having an inner surface and an outer surface, said lower member inner surface being positionable to be proximate to said upper member inner surface, said upper member and said lower member together defining an interior region of said patient sensor when so positioned, (c) a first electrical circuit within said interior region of said patient sensor, said first circuit comprising a plurality of spaced apart resistive elements, (d) a second electrical circuit within said interior region of said patient sensor, wherein, (d1) said second electrical circuit is electrically isolated from said first electrical circuit, and, (d2) said conductive portion of said upper member inner surface causes said second electrical circuit to electrically engage said first electrical circuit when said patient sensor is compressed, (e) a nonconductive central spacer positionable between said upper member and said lower member, said central spacer electrically separating said upper member and said lower member when so positioned, and, allowing said second circuit to engage said first circuit when pressure is applied to said patient sensor, thereby electrically shorting said first circuit and said second circuit at at least one point of contact; and
,(f) an electrical line having at least three electrically isolated conductors therein, wherein (f1) a first conductor of said at least three conductors is in electrical communication with said first circuit, (f2) a second conductor of said at least three conductors is in electrical communication with said first circuit such that by measuring the potential between said first and second conductors a total amount of resistance in said first conductor may be determined, and (f3) a third conductor of said at least three conductors is in electrical communication with said second electrically isolated circuit. - View Dependent Claims (17, 18, 19, 20, 21)
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22. A patient sensor for use in monitoring a patient who is at risk of developing decubitus ulcers, wherein said sensor is configured to be positioned beneath the patient, comprising:
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(a) a nonconducting upper member, said upper member having a perimeter and an inner surface;
(b) a nonconducting lower member, said lower member having a perimeter and an inner surface, and said lower member being sized to be at least approximately commensurate with said upper member, said upper and lower members being joined together along their perimeters, said upper and lower members taken together forming an interior of said patient sensor therebetween;
(c) a nonconducting central spacer, positioned between said upper and lower members and separating at least a portion of upper member inner surface from contact with said lower member inner surface;
(d) a first conductor within said interior of said patient sensor, said first conductor having a first end and a second end, and said first conductor comprising at least a plurality of serially interconnected resistive elements;
(e) a plurality of spaced apart serially connected switches, wherein (e1) each of said switches engages said first conductor at a predetermined location when activated, (e2) at least a portion of each of said switches is located on said upper member inner surface and another portion of each of said switches is located on said lower member inner surface, and, (e3) each of said switches can be separately activated by the patient when said sensor is positioned underneath the patient, each switch being so activated only when it is at least approximately directly beneath the patient; and
,(f) a second conductor in electrical communication with said serially connected switches, said second conductor coming into electrical communication with said first conductor if at least one of said switches is activated in response to a patient'"'"'s presence on said sensor, whereby (f1) measuring an electrical property between said second conductor and said first end of said first conductor provides a value representative of an activated switch nearest said first end of said first conductor, and, (f2) measuring an electrical property between said second conductor and said second end of said first conductor provides a value representative of an activated switch nearest said second end of said first conductor. - View Dependent Claims (23, 24, 25, 26, 27, 28)
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29. A patient sensor for use in monitoring a patient who is at risk of developing decubitus ulcers, said sensor at least for providing a patient'"'"'s position and an amount of said sensor occluded by the patient'"'"'s presence thereon, said patient sensor being positionable to be placed beneath the patient, comprising:
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(a) a nonconductive upper member, said upper member having an outer surface and an inner surface, (b) a nonconductive lower member, said lower member having an inner surface and an outer surface, said lower member inner surface being positionable to be proximate to said upper member inner surface, said upper member and lower member together forming an interior of said sensor, wherein at least a portion of said lower member inner surface is electrically conductive, said electrically conductive portion of said lower member inner surface comprising at least a plurality of resistive elements connected in parallel by at least one conductor, said plurality of resistive elements and said at least one conductor comprising a resistive circuit;
(c) a plurality of spaced apart switches within said interior of said sensor, (c1) wherein each of said switches is positioned at a predetermined location within the sensor, (c2) wherein at least a portion of each switch is on said upper member inner surface;
(c3) wherein at least a portion of said switches engage a matching number of said resistive elements when the sensor is positioned beneath the patient, and, (c4) wherein each of said plurality of switches is separately readable to determine which of said switches is engaged, thereby providing information related to said position of the patient and said amount of said sensor occluded by the patient; and
,(c) a nonconductive central spacer between said upper member and said lower member, said central spacer electrically separating at least a portion of said upper member and said lower member inner surfaces when said sensor is not beneath the patient, and, allowing at least a portion of said conductive portions of said upper member and said lower member to come into electrical contact when a patient is present on said patient sensor, thereby electrically engaging at least one of said plurality of switches and the resistive elements associated therewith, and, (d) a plurality of electrical lines in electrical communication with said plurality of switches, wherein, (d1) each of said electrical lines is electrically isolated from the other, (d2) each of said electrical lines is in electrical communication with a different one of said plurality of switches, and, (d2) measuring an electrical property between any of said electrical lines and said resistive circuit provides a signal indicative of whether said associated switch is engaged. - View Dependent Claims (30, 31, 32, 33, 34, 35)
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36. A method of calibrating patient sensor, said patient sensor at least for use in sensing an amount of said sensor occluded by a patient and said patient sensor at least containing a resistive ladder therein, said resistive ladder being comprised of at least two resistive elements, each of said at least two resistive elements having a nominal resistive value associated therewith, and wherein is further provided a calibration resistive element within said patient sensor, said calibration resistive element having a nominal resistive value representative of said resistive values of said at least two resistive elements, said method comprising the steps of:
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(a) measuring a total resistance of all of said at least two resistive elements;
(b) measuring a resistance of said calibration resistive element;
(c) adjusting said measured total resistance based on said measured resistance of said calibration resistive element;
(d) using at least said adjusted measured total resistance to determine an amount of said sensor occluded by the patient. - View Dependent Claims (37, 38)
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39. A patient sensor for use in monitoring a patient, said sensor at least for providing a patient'"'"'s position and an amount of said sensor occluded by the patient'"'"'s presence thereon, said patient sensor being positionable to be placed beneath the patient, said patient sensor having an interior, comprising:
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(a) a resistive ladder within said patient sensor, said resistive ladder containing a plurality of resistive elements therein, each of said resistive elements having a nominal resistive value associated therewith;
(b) a plurality of switches, each of said switches engaging one of said resistive elements when said switch is placed beneath the patient, each of said switches being located at a predetermined location within said sensor interior; and
,(c) first, second, and third leads in communication with said resistive ladder, whereby, (c1) said first and second leads taken together provide a signal at least representative of a distance of the patient from an end of said sensor, and, (c2) said first and third leads taken together provide a signal at least representative of an amount of said sensor occluded by the patient'"'"'s presence thereon. - View Dependent Claims (40, 41, 42, 43, 44)
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Specification