Abstract: A method of timing data sampling includes, in a data acquisition device, generating sampling intervals from a system clock of the data acquisition device, sampling data at the generated sampling intervals, and receiving start of frame (SOF) signals from a port, such as a USB port. For a selected number of SOF signals received, an actual number of system clock cycles is determined for a time interval corresponding to the selected number of SOF signals. The actual number of system clock cycles is compared to a nominal number of system clock cycles and a sampling interval is adjusted based on the comparison. The actual number of system clock cycles may be determined using a count-and-capture counter. The nominal number of system clock cycles may be calculated based on a nominal system clock rate and on a known SOF interval. Generating sampling intervals may include using a divide-by-N counter.

Abstract: A method of processing force signals from plural force platforms includes, in a computer, in an initialization process, receiving data distinguishing the plural platforms, monitoring force data signals from each of the plural platforms, and identifying each of the plural platforms to a force platform data process application by a sequence of received above-threshold force data signals. The method further includes, subsequent to the initialization process, processing subsequent force data signals according to the identification of each of the plural force platforms. The distinguishing data can include data retrieved from nonvolatile memory of each of the plural force platforms, such as a platform serial number, calibration data, and force platform capacity. A force platform system includes one or more force platforms and force platform signal conditioning circuitry connected to the one or more force platforms.

Abstract: A method for providing feedback during ligament insertion in knee joint orthopedic surgeries includes providing an imaging device providing knee joint articular surface geometry data, providing a position measuring device providing distal ligament insertion sites, providing a strain measuring device providing ligament reference strain, providing a drive system providing a prescribed kinematic path for the knee joint and providing an adaptive migration application. The adaptive migration application receives inputs including the knee joint articular surface geometry data, the distal ligament insertion sites, the ligament reference strain and the prescribed kinematic path for the knee joint and generates outputs including sets of isotonic, hypertonic and hypotonic points representing proximal insertion sites of a ligament fiber associated with prescribed distal ligament insertion sites.

Abstract: The present invention relates to joint simulators, and in particular, to methods and systems for controlling joint simulators by using a haptic mapping technique. A joint simulator is used to closely approximate the conditions within the body, particularly with respect to human and animal joints, and can be used to test and evaluate prosthetics for use in various parts of a human or animal body. The haptic mapping technique improves the rate of convergence of the actual testing forces to the prescribed forces during repetitive performance and life testing. The method is used in conjunction with an impedance-mode servo controller.

Abstract: A system for providing feedback during ligament insertion in knee joint orthopedic surgeries includes an imaging device providing knee joint articular surface geometry data, a position measuring device providing distal ligament insertion sites, a strain measuring device providing ligament reference strain, a drive system providing a prescribed kinematic path for the knee joint and an adaptive migration application. The adaptive migration application receives inputs including the knee joint articular surface geometry data, the distal ligament insertion sites, the ligament reference strain and the prescribed kinematic path for the knee joint and generates outputs including sets of isotonic, hypertonic and hypotonic points representing proximal insertion sites of ligament fiber associated with prescribed distal ligament insertion sites.

Abstract: A lens cover for a firearm scope comprises a lens ring configured to mount to a lens, a cover bracket pivotally mounted to the lens ring, and a cover membrane disposed upon a portion of the lens ring and a portion of the cover bracket. When the cover bracket is in a closed position, the cover membrane creates a seal against the lens ring. The lens ring comprises an elastomeric material so as to enable mounting of the lens ring to lenses of differing diameters. The cover bracket includes a plurality of opposing mounting holes for selectively mounting the cover bracket to the adjustable lens ring.

Abstract: A method for calibrating a force platform includes, providing a force platform and applying an n×m grid on a top surface of the force platform via a computing device. Next, applying p known loads on each of the n×m grid points of the top surface along a Z-axis being perpendicular to the X and Y axes and along the X and Y axes. Next, taking multipoint measurements at each grid point and for each applied known load along the X, Y and Z axes and generating six measured output signals, exact position coordinates and applied known load magnitude for each grid point. Next, assembling an array of n×m×p of six equations with six unknown for each grid point and applied known load and then solving the assembled equations and deriving a position and load specific calibration matrix for each grid point.

Abstract: A compact multi-axis load cell with opposing rigid mounting elements includes annular flanges at the perimeter of the elements. A sensing region is formed between the rigid mounting elements by bonding, as by welding or brazing, opposing annular flanges at their end surfaces. To increase the mass and rigidity of the opposing mounting elements, the annular flanges may be partially formed by a peripheral groove, the groove defining a portion of an inside surface of the annular flange. The peripheral groove provides sufficient flange length for affixing strain gauges while positioning internal surfaces of the mounting elements close together in order to reduce the overall length of the load cell. Sensing circuits affixed to the outside surface of the sensing region provide output signals responsive to forces and moments exerted between the rigid mounting elements in at least two substantially perpendicular directions.

Abstract: A joint motion simulator to simulate biomechanical motion includes a mount to which a prosthetic device is mounted, actuators coupled to the mount to drive the mount, and a programmable controller to drive the actuators to translate the mount and to rotate the mount with a center of rotation controllable independent of translation. The simulator can include a linear actuator to translate the mount in a linear direction substantially parallel to the axis of rotation. The linear actuator can include a piston within a sleeve, the piston being coupled to the mount and being hydraulically driven to translate the mount, and the actuators can be coupled to the sleeve. The controller may be programmed to vary the center of rotation with linear translation and rotation of the mount. Sensors may be included that measure displacement of the actuators. The controller may drive the actuators based on the measured displacement.

Abstract: A method of processing force signals from plural force platforms includes, in a computer, in an initialization process, receiving data distinguishing the plural platforms, monitoring force data signals from each of the plural platforms, and identifying each of the plural platforms to a force platform data process application by a sequence of received above-threshold force data signals. The method further includes, subsequent to the initialization process, processing subsequent force data signals according to the identification of each of the plural force platforms. The distinguishing data can include data retrieved from nonvolatile memory of each of the plural force platforms, such as a platform serial number, calibration data, and platform capacity. A force platform system includes one or more force platforms and force platform signal conditioning circuitry connected to the one or more force platforms.

Abstract: A lens cover for a firearm scope comprises a lens ring configured to mount to a lens, a cover bracket pivotally mounted to the lens ring, and a cover membrane disposed upon a portion of the lens ring and a portion of the cover bracket. When the cover bracket is in a closed position, the cover membrane creates a seal against the lens ring. The lens ring comprises an elastomeric material so as to enable mounting of the lens ring to lenses of differing diameters. The cover bracket includes a plurality of opposing mounting holes for selectively mounting the cover bracket to the adjustable lens ring.

Abstract: A simulator for driving a prosthetic element includes a prosthetic drive mechanism that drive the prosthetic element during an accelerated wear test of the prosthetic element. A simulation input represents the action of the simulator and a sensor mechanism is used to measure the force and torque applied to the prosthetic element. Position and orientation control sensors are further used to measure displacement of the prosthetic element. A closed loop feedback control system, responsive to the sensors, is used to determine a drive signal for the drive mechanism. The control system advantageously adds a computational model that incorporates mechanical representations of ligament fibers. The computational model is a non-human approximation to situations that would be encountered by the prosthesis within the human body and includes dimensional geometry of insertion sites and mechanical properties of ligament fibers.

Abstract: A method of processing force signals from plural force platforms includes, in a computer, in an initialization process, receiving data distinguishing the plural platforms, monitoring force data signals from each of the plural platforms, and identifying each of the plural platforms to a force platform data process application by a sequence of received above-threshold force data signals. The method further includes, subsequent to the initialization process, processing subsequent force data signals according to the identification of each of the plural force platforms. The distinguishing data can include data retrieved from nonvolatile memory of each of the plural force platforms, such as a platform serial number, calibration data, and platform capacity. A force platform system includes one or more force platforms and force platform signal conditioning circuitry connected to the one or more force platforms.

Abstract: A simulator for driving a prosthetic element includes a prosthetic drive mechanism that drive the prosthetic element during an accelerated wear test of the prosthetic element. A simulation input represents the action of the simulator and a sensor mechanism is used to measure the force and torque applied to the prosthetic element. Position and orientation control sensors are further used to measure displacement of the prosthetic element. A closed loop feedback control system, responsive to the sensors, is used to determine a drive signal for the drive mechanism. The control system advantageously adds a computational model that incorporates mechanical representations of ligament fibers. The computational model is a non-human approximation to situations that would be encountered by the prosthesis within the human body and includes dimensional geometry of insertion sites and mechanical properties of ligament fibers.

Abstract: A virtual soft tissue control system that provides enhanced motion control to a prosthetic simulator machine. The control system advantageously adds a “virtual soft tissue” control scheme to a conventional control system, such as a digital proportional integral derivative (PID) controller, to algorithmically model the soft tissue constraints that would be encountered by the prosthesis within the human body, and account for these forces in driving the simulator. In another aspect, a prosthetic simulator comprises a prosthetic drive mechanism; a feedback control system that drives the prosthetic drive mechanism; and an iterative learning control system that determines an error from a previous iteration of motion of the drive mechanism and uses the error to determine a drive signal for a subsequent iteration of motion. In certain embodiments, the prosthetic simulator uses both a soft tissue model and an iterative learning control system.

Abstract: A heat exchanger/heater comprising a tubular member having a fluid inlet end, a fluid outlet end and plurality of pins secured to the interior wall of the tube. Various embodiments additionally comprise a blocking member disposed concentrically inside the pins, such as a core plug or a baffle array. Also disclosed is a vapor generator employing an internally pinned tube, and a fluid-heater/heat-exchanger utilizing an outer jacket tube and fluid-side baffle elements, as well as methods for heating a fluid using an internally pinned tube.

Abstract: Corrosion of steel surfaces in a heat pump is inhibited by adding a rare earth metal salt to the heat pump's ammonia/water working fluid. In preferred embodiments, the rare earth metal salt includes cerium, and the steel surfaces are cerated to enhance the corrosion-inhibiting effects.

Abstract: A heat exchanger/heater comprising a tubular member having a fluid inlet end, a fluid outlet end and plurality of pins secured to the interior wall of the tube. Various embodiments additionally comprise a blocking member disposed concentrically inside the pins, such as a core plug or a baffle array. Also disclosed is a vapor generator employing an internally pinned tube, and a fluid-heater/heat-exchanger utilizing an outer jacket tube and fluid-side baffle elements, as well as methods for heating a fluid using an internally pinned tube.

Abstract: A tubing/pipe cleaning attachment is provided which can be attached to a conventional tubing cutter. The cleaning attachment can be pivotally affixed to the tubing cutter and cleans round pipe or tubing while such tubing or pipe is being cut by the cutter, and thus, within a single operation. The cleaning attachment preferably comprises a substantially V-shaped body member to which an abrasive pad member is attached. The cleaner attachment cleans the pipe when attached to the tubing cutter when it is rotated about the tubing by the abrasive pad member.

Abstract: A rotary torque-to-axial force energy conversion apparatus employs a rotatable member, a translatable member, and a magnetic coupling therebetween. The magnetic coupling converts a rotary torque on the rotatable member to an axial force on the translatable member, and includes a first permanent magnet comprising part of the rotatable member and a second permanent magnet comprising part of the translatable member. By way of example, the first permanent magnet and the second permanent magnet may each comprise interleaved, helical magnet sections of alternating polarities. A significant application of the energy conversion apparatus comprises an actuator apparatus for a ventricle assist device (VAD) or a total artificial heart (TAH). By oscillating the drive motor energizing the rotatable member, an oscillating rotary torque is achieved that is converted by the magnetic coupling to a reciprocating axial motion on the translatable member.