Abstract: Method and apparatus for determining the direction of the mechanical axis of the femur of a patient in relation to the corresponding knee of the patient in connection with resecting the distal femur for the reception of a femoral knee prothesis include at least partially suspending the patient's leg to locate the knee at a suspended position wherein external forces on the knee, such as the weight of the leg, are balanced and the knee remains essentially stationary at the suspended position, applying a force to the femur at a predetermined location relative to the mechanical axis of the femur, directing the applied force in a direction such that the knee remains undeflected from the suspended position while the force is applied to the femur in that direction, and employing that direction of the applied force to indicate the direction of the mechanical axis of the femur.

Abstract: Method and apparatus for locating functional structures of the lower leg during knee implant surgery by determining the location of the weight-bearing axis. The functional center of the hip is located by fixing the acetabulum of the patient, rotating the femur about its head to several locations, measuring changes of position of a reference point on the femur and computing an imaginary sphere having a center corresponding to the location of the functional center of the hip.

Abstract: Method and apparatus for determining the direction of the mechanical axis of the femur of a patient in relation to the corresponding knee of the patient in connection with resecting the distal femur for the reception of a femoral knee prothesis include at least partially suspending the patient's leg to locate the knee at a suspended position wherein external forces on the knee, such as the weight of the leg, are balanced and the knee remains essentially stationary at the suspended position, applying a force to the femur at a predetermined location relative to the mechanical axis of the femur, directing the applied force in a direction such that the knee remains undeflected from the suspended position while the force is applied to the femur in that direction, and employing that direction of the applied force to indicate the direction of the mechanical axis of the femur.

Abstract: An apparatus for aligning a surgical instrument having a connection device attached to the femur in the vicinity of the knee joint at a point chosen to be on the mechanical axis. An adjustable vertical suspension device attached to the femur for counteracting the moment about the hip joint created by the weight of the femur. A vertical tension indicating device attached to the adjustable vertical suspension device.

Abstract: Apparatus useful in surgery for holding surgical instruments such as retractor blades in a number of different positions required by a surgeon for the performance of a surgical procedure, including an actuation means responsive to a control signal, a signal generating means which enables an operator to generate the control signal and which transmits the control signal to the actuation means, for causing the actuation means to move the surgical instrument.

Abstract: Apparatus for partitioning a pre-selected phase of a sample of liquid, such as blood, having a plurality of phases of differing densities. Disclosed is an apparatus for separating a pre-selected phase of a sample contained in an enclosed chamber, wherein said apparatus can be used with a separating means which rotates the chamber about either a longitudinal axis of the chamber, or about an axis perpendicular to the longitudinal axis of the chamber and not passing through the chamber. In addition, separating means in which such an enclosed chamber is rotated about a longitudinal axis is described. Also disclosed is an apparatus for dispensing fluid from said enclosed chamber.

Abstract: Apparatus for collecting a sample of liquid, such as blood, having a plurality of phases of differing densities. Disclosed is an apparatus for collecting a sample in an enclosed chamber, wherein said apparatus can be used with a separating means which rotates the chamber about either a longitudinal axis of the chamber, or about an axis perpendicular to the longitudinal axis of the chamber and not passing through the chamber. In addition, said apparatus facilitates automated manipulation of the sample by providing formed features for: decreasing the gas permeability of said apparatus; clot activation of a blood sample contained within said apparatus; interconnection of a multiplicity of said apparatus; automated manipulation of said apparatus; protecting markings upon said apparatus; layering the construction of said apparatus; and, encoding of information upon said apparatus in both a tactile and visual manner. Also disclosed is an apparatus for dispensing fluid from said enclosed chamber.

Abstract: Method and apparatus for partitioning a pre-selected phase of a sample of liquid, such as blood, having a plurality of phases of differing densities the method comprising the steps of introducing a sample into a chamber of constant cross-sectional shape and a volume greater than that of the sample, ordering the phases of the sample concentrically by rotating the chamber about its longitudinal axis, reducing the volume of the chamber in response to a separation control signal, removing a portion of the separated sample in order of phase, deriving information about the portion of the sample being removed from the chamber and modifying the separation control signal in response to the derived information.