Implantable sensors for determining bone health that can be utilized in conjunction with orthopedic implants are described. The sensors can include passive strain gauges or passive chemical sensors that can be read by radiographic imaging techniques. Sensors can be affixed to implantable support devices so as to non-invasively monitor the effect of load on the implant; for instance, to provide a quantitative assessment of when a fracture is sufficiently healed to allow safe weight-bearing upon the limb. Alternatively, sensors can monitor the health of a local implant area; for instance, to monitor the implant area of early stage infection or healing of a fusion procedure.

Implantable sensors for determining bone health that can be utilized in conjunction with orthopedic implants are described. The sensors can include passive strain gauges or passive chemical sensors that can be read by radiographic imaging techniques. Sensors can be affixed to implantable support devices so as to non-invasively monitor the effect of load on the implant; for instance, to provide a quantitative assessment of when a fracture is sufficiently healed to allow safe weight-bearing upon the limb. Alternatively, sensors can monitor the health of a local implant area; for instance, to monitor the implant area of early stage infection or healing of a fusion procedure.

In the present disclosure, embodiments including a system, device and methods are disclosed for accurately measuring the strain or extension of a fastener that occurs as the nut on the fastener is tightened and the fastener is put under load. The measurement technique is based on measurement of the time for an ultrasonic wave generated on one end of the fastener to travel a round trip through the fastener. As the fastener is tightened, the applied stress causes an associated increase in length. This length can be determined from a measurement of the increase in transit time. In various embodiments, the disclosed device and method uses laser ultrasonic testing (LUT), in which a pulsed laser generates the ultrasonic wave and a type of laser vibrometer detects the wave when it returns to the position of generation following a combination of longitudinal wave reflections and a mode conversion to a shear wave.

Resistive and capacitive force sensor including an element having first and second electrodes, wherein the element is configured such that, when an external force is applied, intrinsic capacitance of the electrodes and intrinsic resistance between the electrodes change as a function of a magnitude of the external force; a first unit connected to the electrodes and configured to determine an intrinsic electrical capacitance C(t) of the second electrode; a second unit connected to the electrodes and configured to determine an electrical resistance R(t) between the electrodes; an evaluation unit configured to determine magnitude |F(t)| of force F(t) applied externally to the element as a function of a mean value of the determined intrinsic capacitance C(t) in a time interval and as a function of a mean value of the determined resistance R(t) in the time interval; and an output unit configured to output the determined magnitude |F(t)| of force F(t).

A prosthetic component suitable for long-term implantation is provided. The prosthetic component measures a parameter of the muscular-skeletal system is disclosed. The prosthetic component comprises a first structure having at least one support surface, a second structure having at least one feature configured to couple to bone, and at least one sensor. The prosthetic component is a housing for the at least one sensor and electronic circuitry. The electronic circuitry is hermetically sealed from an external environment. The at least one sensor couples to the support surface of the first structure. The support surface of the first structure is compliant. The first and second structure are coupled together housing the at least one sensor and electronic circuitry.

An ultrasonic test device and test method for service stress of a moving mechanical component, where the device comprises an ultrasonic probe, a coupling fluid, a pressure-maintaining cover and universal wheels. The cover is vertically arranged above an inspected position of an inspected component, an interior of the pressure-maintaining cover is filled with coupling fluid, a bottom of the cover is provided with a structure permeable to the coupling fluid to form a coupling fluid film between the inspected position and the bottom of the cover, and a top of the cover is equipped with the ultrasonic probe. A detection part at a lower part of the ultrasonic probe extends into the coupling fluid of the cover and is vertical to the bottom of the cover without contact. The distance between the ultrasonic probe and the inspected component is kept unchanged through the universal wheels.

A device and a method for ultrasonic detecting a rotating member based on magnetic fluid coupling, wherein the device comprises an ultrasonic probe, magnetic field protection rings, magnetic fluid and a magnetic fluid protection cover. The ultrasonic probe is arranged above the rotating member that is horizontally placed. Front ends of a transmitting ultrasonic transducer and a receiving ultrasonic transducer of the ultrasonic probe are provided with the magnetic field protection rings for generating magnetic fields in the magnetic field protection rings. The protective cover is sleeved on a circumferential outer side of the rotating member where a detected position is located, and the front ends of the ultrasonic probe are arranged to penetrate through the magnetic fluid protective cover. A cavity formed between the magnetic fluid protective cover and the rotating member is filled with the magnetic fluid and the magnetic fluid is a liquid mixture solution.

A detection system for identifying deterioration in a structure is provided that has acoustic sensors that receive acoustic emission waves. The acoustic emission wave detected by the acoustic sensor is identified as a hit. An analysis circuit is present that identifies an A state, a B state, and a C state. The B state has increased hit activity from the A state where a rate B is greater than a rate A by a factor of f1. The C state has increased hit activity from the B state where a rate C is greater than the rate A by a factor of f2. An alarm is activated when an amount of time that the C state is identified as being present reaches a value of TM, or alternatively when a threshold value based upon of the number of hits and time in the C state is reached.

A load sensor includes a core having a hollow part provided therein and containing magnetic material and a coil attached to the core. A magnetic path along which a magnetic flux generated by a current flowing in the coil is formed along a circumference direction of the hollow part. The core has a load-receiving portion that receives a load at a surface of the core located in a crossing direction crossing a plane along which the magnetic path is formed.

A displacement detection device includes a piezoelectric sensor. The piezoelectric sensor is provided with a piezoelectric sheet on both principal surfaces of which detection electrodes are formed. When stress is applied to the piezoelectric sensor, charge is generated, and an output voltage in accordance with this generated charge is detected in a DC voltage detector. A controller measures this output voltage at a predetermined time interval. Every time the controller measures the output voltage, the controller makes a short-circuit control of a switch, and causes the charge generated in the piezoelectric sensor to be released. The controller can thereby detect an amount of change in output voltage generated at the predetermined time interval in accordance with an amount of displacement of the piezoelectric sensor. By sequentially integrating this, the controller can accurately detect the amount of displacement of the piezoelectric sensor which changes across measurement timings.