Medical diagnostic device for applying controlled stress to joints
First Claim
1. A medical diagnostic device for applying a desired stress to a knee joint of a patient, comprisinga frame,a restraint at a first end of the frame for immobilizing the patient'"'"'s thigh,a cradle at a second end of the frame for receiving and supporting the patient'"'"'s leg,a pair of reciprocable pistons between the frame and the cradle for supporting the cradle, the pistons being constrained to move within respective cylinders a distance between a first position in which the cradle is proximal to the frame and a second position in which the cradle is remote from the frame, anda source of pressurized fluid connected to the cylinders for controllably moving the pistons from the first position to the second position, the second position being a position of equilibrium between the weight of the patient'"'"'s leg and a force generated by pressure in the cylinders.
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Accused Products
Abstract
A medical diagnostic device for applying a desired stress to a limb joint has a frame, a limb-restraint at a first end of the frame for immobilizing a first limb portion on one side of the joint, a cradle at a second end of the frame for receiving and supporting a second limb portion on the opposite side of the joint, a reciprocable member connected between the frame and cradle and constrained to move a preselected distance between a first position in which the cradle is proximal to the frame and a second position in which the cradle is remote from the frame, and a driver for controllably moving the reciprocable member from the first position to the second position. Movement of the reciprocable member moves the cradle from a position in which the joint is relaxed to a position in which the joint is subjected to the controlled stress. The invention also covers a method of applying a desired stress to a limb joint, comprising the steps of immobilizing a first limb portion on one side of the joint, receiving a second limb portion on the opposite side of the joint in a movable cradle, and applying a preselected force on the second limb portion by moving the cradle by a preselected amount from a first position in which the joint is relaxed to a second position in which the joint is subjected to the desired stress.
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Citations
18 Claims
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1. A medical diagnostic device for applying a desired stress to a knee joint of a patient, comprising
a frame, a restraint at a first end of the frame for immobilizing the patient'"'"'s thigh, a cradle at a second end of the frame for receiving and supporting the patient'"'"'s leg, a pair of reciprocable pistons between the frame and the cradle for supporting the cradle, the pistons being constrained to move within respective cylinders a distance between a first position in which the cradle is proximal to the frame and a second position in which the cradle is remote from the frame, and a source of pressurized fluid connected to the cylinders for controllably moving the pistons from the first position to the second position, the second position being a position of equilibrium between the weight of the patient'"'"'s leg and a force generated by pressure in the cylinders.
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4. A medical diagnostic device for applying a desired stress to a knee joint of a patient to aid in diagnosis of ligamentous instability in the knee, comprising
a frame made of a material not responsive to diagnostic imaging methods, a restraint at a first end of the frame for immobilizing the patient'"'"'s thigh, a cradle at a second end of the frame for receiving and supporting the patient'"'"'s leg, a pair of reciprocable pistons between the frame and the cradle for supporting the cradle, the pistons being constrained to move within respective cylinders mounted on said frame a distance between a first position in which the cradle is proximal to the frame and a second position in which the cradle is remote from the frame, movement of the cradle resulting in the application of an anteriorly directed force on the patient'"'"'s leg, and a source of pressurized air connected to the cylinders for controllably moving the pistons from the first position to the second position, the second position being a position of equilibrium between the weight of the patient'"'"'s leg and a force generated by pressure in the cylinders, whereby the desired stress is applied to the knee joint when the pistons are in the second position.
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5. A medical diagnostic device for applying a desired stress to a joint of a limb comprising:
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a support frame, a limb restraint at one end of the frame for immobilizing a first limb portion on one side of the joint, a cradle located near the limb restraint for receiving and supporting a second limb portion on the opposite side of the joint, at least one driver attached to the support frame and engageable with the cradle, the driver being movable between a first position in which the cradle is proximal to the support frame and the joint is relaxed and a second position in which the cradle is remote from the support frame whereby the first limb portion is translocated relative to the second limb portion. - View Dependent Claims (6, 7, 8, 9)
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10. A method of conducting magnetic resonance imaging of ACL injuries in a patient'"'"'s knee comprising the steps of:
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anteriorly translocating the patient'"'"'s tibia relative to the patient'"'"'s femur causing the patient'"'"'s ACL to stretch or separate; maintaining the patient'"'"'s ACL in a stretched or separated condition; and taking an MRI scan of the ACL while maintained in the stretched or separated condition. - View Dependent Claims (11, 12, 13)
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14. A method of conducting magnetic resonance imaging of ligament injuries in a patient'"'"'s limb joint comprising the steps of:
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anteriorly translocating a first limb portion on one side of the joint relative to a second limb portion on the opposite side of the joint causing a ligament of the joint to stretch or separate; maintaining the ligament in a stretched or separated condition; and taking an MRI scan of the ligament while maintained in the stretched or separated condition. - View Dependent Claims (15, 16, 17)
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18. A method of conducting magnetic resonance imaging of ligament injuries in a patient'"'"'s limb joint comprising the steps of:
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placing a first limb portion on one side of the joint in restraint; placing a second limb portion on the opposite side of the joint in a movable cradle; moving the cradle to anteriorly translocate the second limb portion relative to the first limb portion causing a ligament of the joint to stretch or separate; taking an MRI scan of the ligament while it is maintained in the stretched or separated condition.
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Specification