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:
A sensor system uses positive closed-loop feedback to provide energy waves into a medium. It comprises a transducer (604), a propagating structure (602), and a transducer (606). A parameter is applied to the propagating structure that affects the medium. A sensor is coupled to a propagation tuned oscillator (416) that forms a positive closed-loop feedback path. The propagation tuned oscillator (416) includes a zero-crossing receiver (200) that generates a pulse upon sensing a transition of an energy wave from the propagating structure (602). The zero-crossing receiver (200) is in the feedback path that maintains the emission of energy waves into the propagating structure (602). The zero-crossing receiver (200) comprises a preamplifier (206), a filter (208), an offset adjustment circuit (210), a comparator (212) and a pulse circuit (218). The transit time, phase, or frequency is measured of the propagating energy waves and correlated to the parameter being measured.
Abstract:
A prosthetic component suitable for long-term implantation is provided. The prosthetic component includes electronic circuitry and sensors to measure a parameter of the muscular-skeletal system. 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. The electronic circuitry and sensors are hermetically sealed within the prosthetic component. Sensors can be used to monitor synovial fluid in proximity to the joint to determine joint health. The prosthetic component can include a temperature sensor or a pH sensor. The temperature or pH of the synovial fluid can be correlated to a variety of joint conditions. Measurements over time can be analyzed for trends. The temperature or pH can be calibrated for the patient. For example, calibration can be for temperature or pH of a patient healthy joint. The measurements are compared against this patient reference.
Abstract:
A measurement system for measuring a parameter of the muscular-skeletal system is disclosed. The measurement system comprises a capacitor, a signal generator, a digital counter, counter register, a digital clock, a digital timer, and a data register. The sensor of the measurement system is the capacitor. The measurement system generates a repeating signal having a measurement cycle that corresponds to the capacitance of the capacitor. The capacitor comprises more than one capacitor mechanically in series. Electrically, the capacitor comprises more than one capacitor in parallel. In one embodiment, the capacitor includes a dielectric layer comprising polyimide. A force, pressure, or load is applied to the capacitor that elastically compresses the device. The capacitor is shielded from parasitic coupling and parasitic capacitance.
Abstract:
A sensing insert device (100) is disclosed for measuring a parameter of the muscular-skeletal system. The sensing insert device (100) can be temporary or permanent. Used intra-operatively, the sensing insert device (100) comprises an insert dock (202) and a sensing module (200). The sensing module (200) is a self-contained encapsulated measurement device having at least one contacting surface that couples to the muscular-skeletal system. The sensing module (200) comprises one or more sensing assemblages (1802), electronic circuitry (307), and communication circuitry (320). An interconnect stack within the sensing module (1700) couples at least one circuit board (1612 and 1616) to one or more sensing assemblages (1802). The interconnect stack includes at least one flexible interconnect (1506) that couples to the circuit board (1612 and 1616). The flexible interconnect (1506) can be in a path for conducting an energy wave through the sensing assemblage (1802).
Abstract:
A sensing insert device (100) is disclosed for measuring a parameter of the muscular-skeletal system. The sensing insert device (100) can be temporary or permanent. Used intra-operatively, the sensing insert device (100) comprises an insert dock (202) and a sensing module (200). The sensing module (200) is a self-contained encapsulated measurement device having at least one contacting surface that couples to the muscular-skeletal system. The insert dock (202) is a passive component made for different prosthetic component manufacturers as well as for different size prosthetic components. The sensing module (200) fits in an opening or cavity of the insert dock (202). The intra-operative insert device is substantially equal in dimension to an implanted final insert. The sensing insert device (100) is also a permanent prosthetic component. The sensing module (200) residing within the sensing insert device and coupling to a bearing surface of the insert.
Abstract:
A measurement system for capturing a transit time, phase, or frequency of energy waves propagating through a propagation medium is disclosed. The measurement system comprises two different closed-loop feedback paths. The first path includes a driver circuit (628), a transducer (604), a propagation medium (602), a transducer (606), and a zero-crossing receiver (640). The zero-crossing receiver (640) detects transition states of propagated energy waves in the propagation medium including the transition of each energy wave through a mid-point of a symmetrical or cyclical waveform. A second path includes the driver circuit (1228), a transducer (1204), a propagation medium (1202), a reflecting surface (1206), and an edge-detect receiver (1240). Energy waves in the propagating medium (1202) are reflected at least once. The edge-detect receiver (1240) detects a wave front of an energy wave. Each positive closed-loop path maintains the emission, propagation, and detection of energy waves in the propagation medium.
Abstract:
A measurement system for capturing a transit time, phase, or frequency of energy waves propagating through a propagation medium is disclosed. The measurement system comprises two different closed-loop feedback paths. The first path includes a transducer driver (726), a transducer (704), a propagation structure (702), a transducer (706), and a zero-crossing receiver (740). The transducer driver (726) efficiently drives the transducer (704) and comprises a digital driver (106), a level shifter (112), and a matching network (114). A second path includes a transducer driver (1126), a transducer (1104), a propagation medium (1102), a reflecting surface (1106), and an edge-detect receiver (1140). Energy waves in the propagating medium (1102) are reflected at least once. The edge-detect receiver (1140) detects a wave front of an energy wave. Each positive closed-loop path maintains the emission, propagation, and detection of energy waves in the propagation medium.
Abstract:
A sensing insert device (100) is disclosed for measuring a parameter of the muscular-skeletal system. The sensing insert device (100) can be temporary or permanent. Used intra-operatively, the sensing insert device (100) comprises an insert dock (202) and a sensing module (200). The sensing module (200) is a self-contained encapsulated measurement device having at least one contacting surface that couples to the muscular-skeletal system. The sensing module (200) comprises one or more sensors (303), electronic circuitry (307), a capacitor (1410), and communication circuitry (320). The capacitor (1410) powers the sensing module during a measurement process. An application specific integrated circuit (ASIC) increases power efficiency while reducing a form factor of the sensing module (200). The ASIC comprises power management circuitry (1412) and operational circuitry (1414). The power management circuitry (1412) couples a low-power energy source (1400) and operational circuitry (1414) to operate in one or more power conservation modes.
Abstract:
A measurement system for capturing a transit time, phase, or frequency of energy waves propagating through a propagation medium is disclosed. The measurement system comprises a compressible waveguide (403), ultrasonic transducers (405, 406), and circuitry to sustain energy wave propagation in the waveguide (403). The circuitry includes a propagation tuned oscillator (404), a digital counter (409), a pulse generator (410), a phase detector (414), a counter (420), a digital timer (422), and a data register (424). The measurement system employs a continuous mode (CM), pulse mode, or pulse-echo mode of operation to evaluate propagation characteristics of continuous ultrasonic waves in the waveguide by way of closed-loop feedback to determine levels of applied forces on the waveguide.