Blood collection bag weight monitor
First Claim
1. A weight monitor for monitoring the fill of a blood collection bag, said weight monitor comprising in combination:
- (a) a fixed end;
(b) a movable end;
(c) means for suspending the blood collection bag from said movable end; and
(d) spring means for interconnecting said fixed end with said movable end and for repositioning said movable end from a first state to a second state on application upon said movable end of a predetermined force presented by the weight of a filled blood collection bag, said spring means having the characteristic of a buckling beam to abruptly reposition said movable end with a snap action upon application of the predetermined force and to essentially resist repositioning of said movable end in response to any applied force of a lesser magnitude than the predetermined force.
1 Assignment
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Accused Products
Abstract
A weight monitor includes a first part for attachment to a pedestal or other support member and a second part for suspending a blood collection bag to be filled by a flow of blood from a donor. A trough shaped spring interconnects the first and second parts and retains the second part in fixed positional relationship to the first part until the bending force imposed upon the spring by the filling blood collection bag exceeds a predetermined value at which point the spring flexes abruptly and the second part becomes positionally reoriented with respect to the first part. A clamp, associated with the fill tube of the blood collection bag, is actuated by the reorientation of the second part to terminate further flow of blood through the fill tube into the blood collection bag.
16 Citations
22 Claims
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1. A weight monitor for monitoring the fill of a blood collection bag, said weight monitor comprising in combination:
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(a) a fixed end; (b) a movable end; (c) means for suspending the blood collection bag from said movable end; and (d) spring means for interconnecting said fixed end with said movable end and for repositioning said movable end from a first state to a second state on application upon said movable end of a predetermined force presented by the weight of a filled blood collection bag, said spring means having the characteristic of a buckling beam to abruptly reposition said movable end with a snap action upon application of the predetermined force and to essentially resist repositioning of said movable end in response to any applied force of a lesser magnitude than the predetermined force. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A weight monitor for monitoring the fill of a blood collection bag, said weight monitor comprising in combination:
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(a) a fixed end; (b) a movable end; (c) means for suspending the blood collection bag from said movable end; and (d) spring means for interconnecting said fixed end with said movable end and for repositioning said movable end from a first state to a second state on application upon said movable end of a predetermined force presented by the weight of a filled blood collection bag, said spring means comprising a trough shaped spring having a concave surface and a convex surface when said movable end is in the first state. - View Dependent Claims (14, 15, 16, 17)
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18. A weight monitor for terminating the flow of blood through a fill tube into a blood collection bag on fill to a predetermined weight, said weight monitor comprising in combination:
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(a) a fixed end; (b) a movable end for suspending the blood collection bag; (c) spring means interconnecting said fixed end and said movable end for repositioning said movable end from a first state to a second state in response to a force related to a predetermined fill weight of the blood collection bag and exerted upon said movable end by the blood collection bag said spring means being characterized as essentially inflexible to maintain said movable end essentially immobile in response to application of a bending force of a magnitude less than a predetermined force and as subject to buckling in an elastic mode only upon application of a bending force equal to or of a magnitude greater than the predetermined force; (d) means for altering the magnitude of the force exerted upon said spring means by the predetermined fill weight; and (e) means for terminating flow through the fill tube coincident with the change of state of said movable end. - View Dependent Claims (19, 20)
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21. A weight monitor for terminating the flow of blood through a fill tube into a blood collection bag on fill to a predetermined weight, said weight monitor comprising in combination:
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(a) a fixed end; (b) a movable end for suspending the blood collection bag; (c) spring means interconnecting said fixed end and said movable end for repositioning said movable end from a first state to a second state in response to a force related to a predetermined fill weight of the blood collection bag and exerted upon said movable end by the blood collection bag, said spring means including a longitudinal axis extending from said fixed end to said movable end and a concave upwardly opening cross-section transverse to the longitudinal axis; (d) means for altering the force exerted upon said spring means by the predetermined fill weight; and (e) means for terminating flow through the fill tube coincident with the change of state of said movable end.
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22. A weight monitor for terminating the flow of blood through a fill tube into a blood collection bag on fill to a predetermined weight, said weight monitor comprising in combination:
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(a) a fixed end; (b) a movable end for suspending the blood collection bag; (c) spring means interconnecting said fixed end and said movable end for repositioning said movable end from a first state to a second state in response to a force related to a predetermined fill weight of the blood collection bag and exerted upon said movable end by the blood collection bag; (d) means for altering the force exerted upon said spring means by the predetermined fill weight, said altering means including means for adjusting the distance along said movable end between said spring means and the suspended blood collection bag; and (e) means for terminating flow through the fill tube coincident with the change of state of said movable end.
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Specification