Abstract:
A dual-mode closed-loop measurement system (100) for capturing a transit time, phase, or frequency of energy waves propagating through a medium (122) is disclosed. A first device comprises an inductor drive circuit (102), an inductor (104), a transducer (106), and a filter (110). A second circuit comprises an inductor (114) and a transducer (116). A parameter to be measured is applied to the medium (122). The medium (122) is coupled between the first device and the second device. The first device initiates the transmit inductor (104) to query via inductive coupling to a receive inductor (114) on the second device via a first path. The inductor (114) triggers a transducer (116) on the second device to emit an energy wave that is propagated in the medium (122) and detected by the first device. The transit time of energy waves is affected by the parameter by known relationship.
Abstract:
A dual-mode closed-loop measurement system for capturing a transit time, phase, or frequency of energy waves propagating through a medium is disclosed. A first module comprises an inductor drive circuit, an inductor, a transducer, and a filter. A second module housed in a screw comprises an inductor and a transducer. The screw is bio-compatible and allows an accurate delivery of the circuit into the muscular-skeletal system. The inductor can be attached and interconnected on a flexible substrate that fits into a cavity in the screw. The first and second modules are operatively coupled together. The first module provides energy to power the second module. The second module emits an energy wave into the medium that propagates to the first module. The transit time of energy waves is measured and correlated to the parameter by known relationship.
Abstract:
An orthopedic implant having a three-axis accelerometer is disclosed. The three-axis accelerometer is used to detect micro-motion in the implant. The micro-motion can be due to loosening of the implant. The implant is configured to couple to the muscular-skeletal system. In one embodiment, the implant is configured to couple to bone. An impact force is imparted to the bone or implant. The impact force can be provided via a transducer coupled to the implant. In the example, the impact force is imparted along a single axis. The three-axis accelerometer measures the impact force along each axis. Resultant peaks of the quantitative measurement and the frequencies at which they occur are measured. The peaks and frequencies of the measurements correspond to micro-motion. Typically, the frequency of interest is less than 1 KHz to determine if micro-motion is occurring.
Abstract:
A system and method for is provided for operation of an orthopedic system. The system includes a load sensor for converting an applied pressure associated with a force load on an anatomical joint, and an inertial sensing device configured to measure alignment. The inertial sensing device provides alignment measurement data to measure alignment. An ultrasonic transducer, MEMs microphone, electromagnets, optical elements, metallic objects or other transducers can be configured to convert or convey a physical movement to an electrical signal and support measurement of muscular-skeletal alignment. The load sensor can be used to measure load magnitude and position of load of an applied load by the muscular-skeletal system.
Abstract:
At least one embodiment is directed to an insert for measuring a parameter of the muscular-skeletal system. The insert can be temporary or permanent. In one embodiment, the insert is prosthetic component for a single compartment of the knee. The insert comprises a support structure and a support structure respectively having an articular surface and a load bearing surface. The height of the insert can be less than 10 millimeters. At least one internal cavity is formed when support structures are coupled together for housing electronic circuitry, sensors, and the power source. The insert includes a flexible articular surface. Flexible articular surface transfers loading to sensors internal to the insert.
Abstract:
An orthopedic implant having an energy-harvesting device is disclosed. In one embodiment the orthopedic implant is a prosthetic component of a joint of the muscular-skeletal system. The orthopedic implant can include electronic circuitry, a power source, and one or more sensors for measuring a parameter of the muscular-skeletal system or a parameter of in proximity to the implant. The energy-harvesting device generates charge for powering the electronic circuitry using movement of the muscular-skeletal system. The energy-harvesting device comprises a piezo-electric element that converts changes in force into charge that is stored onto a storage device. The energy-harvesting device is coupled to the patella of a knee joint. Movement of the knee joint changes a force applied to the energy-harvesting device thereby generating charge that is coupled to circuitry in a prosthetic component of the knee joint.
Abstract:
An orthopedic implant having an energy-harvesting device is disclosed. In one embodiment the orthopedic implant is a prosthetic component of a joint of the muscular-skeletal system. The orthopedic implant can include electronic circuitry, a power source, and one or more sensors for measuring a parameter of the muscular-skeletal system or a parameter of in proximity to the implant. The energy-harvesting device generates charge for powering the electronic circuitry using movement of the muscular-skeletal system. The energy-harvesting device comprises a piezo-electric element that converts changes in force into charge that is stored onto a storage device. The energy-harvesting device is coupled to the patella of a knee joint. Movement of the knee joint changes a force applied to the energy-harvesting device thereby generating charge that is coupled to circuitry in a prosthetic component of the knee joint.
Abstract:
A bone cutting system is disclosed that supports one or more bone cuts that are aligned relative to a mechanical axis. The system comprises a first bone cutting jig, a second bone cutting jig, a sensored insert, a bone jig adapter shim, and a device having at least two reference surfaces. The sensored insert includes a three-axis accelerometer to measure position, rotation, and tilt and includes a plurality of sensors to measure a parameter of the muscular-skeletal system. The reference surface device can be an operating table having a first reference surface and a second reference surface that is perpendicular to the first reference surface for referencing the three-axis accelerometer. The bone jig adapter shim can include a tab that fits into a slot of the first or second bone cutting jigs. A remote system receives accelerometer data to calculate offset relative to a mechanical axis.
Abstract:
A system and method is disclosed herein for measuring anterior-posterior slope of a bone to set a cutting jig coupled to the muscular-skeletal system. The system comprises a sensored module that can be placed within a prosthetic component to measure anterior-posterior slope. The system further includes a remote system for receiving, processing, and displaying quantitative measurements from the sensors. A first bone and a second bone are placed in extension. A sensored module is referenced to a bone landmark of the first bone. The sensored module includes a three-axis accelerometer that is configured to measure position, tilt, and rotation. A bone cutting jig is coupled to the first bone. The sensored insert is coupled to the bone cutting jig. The accelerometer in the sensored insert is used to measure the anterior-posterior slope. The bone cutting jig is then adjusted to a predetermined anterior-posterior slope as measured by the sensored insert.
Abstract:
A system and method for measuring medial-lateral tilt of a bone is disclosed. The bone is coupled to a joint of the muscular-skeletal system. The method comprises coupling a three-axis accelerometer to a prepared bone surface of a bone. The three-axis accelerometer is configured to measure position, rotation, and tilt. The joint is rotated between two points. The rotation between the two points traverses an arc having a maximum therebetween. The joint pivots off of a surface to which the bone is coupled. In one embodiment, a pivot point and joint rotation relates to a mechanical axis of the joint and bone. The three-axis accelerometer measures data points along the arc as it is rotated between the two points. Multiple passes along the arc generates sufficient data points to determine the maximum. The position of the maximum is used to calculate the medial-lateral tilt of the bone.