Respiration and heart rate monitoring apparatus
First Claim
1. A respiration sensing apparatus adapted to be held adjacent the chest of a patient and convert movements of the chest during respiration to an electrical signal, comprising:
- a first, rigid pier having a principal surface adapted to be disposed generally parallel to the outer surface of the chest of the patient;
a second, rigid pier having a principal surface adapted to be disposed generally parallel to the outer surface of the chest of the patient, said second pier being separated from the first pier to define a gap therebetween;
a first elongated flexible beam bridging the gap between the first and second piers;
a second, elongated flexible beam bridging the gap between the first and second piers, and lying in spaced, parallel relation to the first beam;
a piezoelectric crystal, located between the first and second beams and bridging the gap between the first and second beams; and
a flexible belt adapted to encircle the chest of the patient, said beams, piers and crystal being attached to said belt, and said belt together with said beams and piers, apply a bending stress to said piezoelectric crystal in response to expansion of the chest during respiration.
1 Assignment
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Accused Products
Abstract
A respiration and heart rate monitoring apparatus includes a mechanical-electric apparatus for detecting chest movements and electrodes for detecting electric impulses associated with heartbeat. A highly sensitive detector includes a transducer crystal mounted in bridge-like configuration on pair of spaced piers connected by at least one flexible beam member. The transducer crystal and electrodes may be connected to circuitry for producing indications of respiration and heart rate. The circuitry blocks detection of chest motion substantially coincident with the impulses associated with heartbeat to inhibit erroneous indications of respiration caused by chest motion due to heartbeat. The circuitry also may block small, single polarity signals to inhibit erroneous indications of respiration caused by muscle noise.
148 Citations
29 Claims
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1. A respiration sensing apparatus adapted to be held adjacent the chest of a patient and convert movements of the chest during respiration to an electrical signal, comprising:
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a first, rigid pier having a principal surface adapted to be disposed generally parallel to the outer surface of the chest of the patient; a second, rigid pier having a principal surface adapted to be disposed generally parallel to the outer surface of the chest of the patient, said second pier being separated from the first pier to define a gap therebetween; a first elongated flexible beam bridging the gap between the first and second piers; a second, elongated flexible beam bridging the gap between the first and second piers, and lying in spaced, parallel relation to the first beam; a piezoelectric crystal, located between the first and second beams and bridging the gap between the first and second beams; and a flexible belt adapted to encircle the chest of the patient, said beams, piers and crystal being attached to said belt, and said belt together with said beams and piers, apply a bending stress to said piezoelectric crystal in response to expansion of the chest during respiration. - View Dependent Claims (2, 3, 4, 5)
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6. A respiration sensing apparatus comprising:
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a crystal which produces an electrical signal responsive to chest wall action of a patient during respiration; and a means for applying bending forces to said crystal responsive to chest wall action of the patient comprising; first and second substantially parallel flexible members disposed in spaced relationship relative to each other adapted to be held so that the longitudinal axes of said first and second substantially parallel flexible members are substantially parallel to the chest wall of the patient, and adapted to be flexed by a chest wall action of the patient during respiration so that a varying curvature is imposed on said longitudinal axes; substantially rigid first and second pier members including proximate edges disposed in spaced relationship relative to each other to cooperatively form a gap therebetween, attached to said first and second substantially parallel flexible members; said crystal being attached to said first and second pier members to span said gap cooperatively formed between said first and second pier members disposed in substantially parallel relationship relative to said first and second substantially parallel flexible members. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14)
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15. A respiration sensing apparatus comprising:
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a base member adapted for location adjacent the chest of a patient and being elastically deformable in response to chest movements; first and second pier members attached to said base member at locations along the longitudinal axis of said base member such that said first and second pier members are spaced apart; a piezoelectric element having opposite ends thereof attached to said first and second pier members so that said piezoelectric element spans said space between said first and second pier members and so that bending stresses developed in said base member due to chest movement are transmitted to the ends of said piezoelectric element to produce an electrical signal; and opposite end portions of each of said first and second pier member being bonded to said base members and portions of said first and second pier members adjacent said space are capable of deflecting away from said base member in response to chest movement during respiration. - View Dependent Claims (16, 17, 18, 19, 20)
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21. A respiration and heart rate monitoring apparatus for a patient comprising:
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a respiration transducer including a piezoelectric crystal and first and second flexible beams disposed in substantially parallel spaced relationship relative to each other, each of said first and second flexible beams having a principal plane adapted to be held substantially parallel to a surface of the chest wall of a patient and a pair of substantially rigid members each attached to one opposite end portion of said substantially parallel first and second flexible beams and one opposite end portion of said piezoelectric crystal, said piezoelectric crystal being disposed between said substantially parallel first and second flexible beams, said substantially rigid members being adapted to transmit bending stress to said piezoelectric crystal thereby producing electric signals responsive to motion of the chest; electrodes adapted to be in electrical communication with the chest wall of the patient which produce signals responsive to the heartbeat of the patient; belt means for holding said respiration transducer and said electrodes against the chest of the patient; and circuit means connected to said respiration transducer and said electrodes for producing an indication of heart rate and respiration rate, said circuit means including filter circuit means for inhibiting detection of signals produced by said piezoelectric crystal occurring substantially simultaneous with the signals from the electrodes, to thereby inhibit erroneous indications of respiration caused by chest motion due to heartbeat. - View Dependent Claims (22, 23, 24, 25, 26)
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27. A respiration sensing apparatus comprising:
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a crystal which produces an electrical signal responsive to chest wall action of a patient during respiration; and a means for applying bending forces to said crystal responsive to chest wall action of the patient comprising; a flexible element including first and second substantially parallel flexible members disposed in spaced relationship relative to each other adapted to be held so that the longitudinal axes of said first and second substantially parallel flexible members are substantially parallel to the chest wall of the patient, and adapted to be flexed by chest wall action of the patient during respiration so that a varying curvature is imposed on said longitudinal axes; substantially rigid first and second pier members disposed in spaced relationship relative to each other to cooperatively form a gap therebetween, attached to said first and second substantially parallel flexible members; said crystal being attached to said first and second pier members to span said gap cooperatively formed between said first and second pier members disposed in substantially parallel relationship relative to said first and second substantially parallel flexible members.
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28. A respiration sensing apparatus comprising:
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an elongated crystal which produces an electrical signal responsive to chest wall action of a patient during respiration; and a means for applying bending forces to said crystal responsive to chest wall action of the patient comprising; an elongated flexible member adapted to be held so that the longitudinal axis of said elongated flexible member is substantially parallel to the longitudinal axis of said elongated crystal and the chest wall of the patient, and adapted to be flexed by the chest wall action of the patient during respiration so that a varying curvature is imposed on said longitudinal axis of said elongated flexible member; substantially rigid first and second pier members disposed in spaced relationship relative to each other to cooperatively form a gap therebetween, attached to said elongated flexible member; opposite end portions of said first and second pier members being bonded to said elongated flexible member and the portions of said first and second pier members adjacent said gap are capable of deflecting away from said elongated flexible member in response to chest movement during respiration; said elongated crystal being attached to said first and second pier members to span said gap cooperatively formed therebetween.
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29. A respiration sensing apparatus comprising:
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a crystal which produces an electrical signal responsive to chest wall action of a patient during respiration; and a means for applying bending forces to said crystal responsive to chest wall action of the patient comprising; a flexible member adapted to be held so that the longitudinal axis of said flexible member is substantially parallel to a chest wall of the patient, and adapted to be flexed by chest wall action of the patient during respiration so that a varying curvature is imposed on said longitudinal axis; substantially rigid first and second pier members disposed in spaced relationship relative to each other to cooperatively form a gap therebetween, attached to said flexible member; said crystal and said flexible member being attached to said first and second pier members to span said gap cooperatively formed therebetween; the longitudinal axis of said crystal being substantially parallel to the longitudinal axis of said flexible member; said crystal and said flexible member being disposed in the same plane when said respiration sensing apparatus is unstressed.
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Specification