Abstract: According to one aspect of the invention, a force measurement system includes a force measurement assembly, a motion base configured to displace the force measurement assembly, and an inertial compensation system configured to determine the inertial forces and/or moments resulting from the displacement of the force measurement assembly by the motion base. According to another aspect of the invention, a method for accurately determining the forces and/or moments applied to a surface of a force measurement device by a subject disposed thereon is disclosed, which includes the step of determining, by using an inertial compensation system, the inertial forces and/or moments resulting from the displacement of a force measurement assembly by a motion base. According to still another aspect of the invention, a force and/or motion measurement system having inertial compensation includes a motion acquisition system having a plurality of motion sensing devices configured to capture a subject's movement.

Abstract: A force measurement system having inertial compensation includes a force measurement assembly with at least one accelerometer configured to measure the acceleration thereof. According to one aspect of the invention, the force measurement system additionally includes at least one angular velocity sensor configured to measure the angular velocity of the force measurement assembly. According to another aspect of the invention, the force measurement system additionally includes a data processing device with a computer-readable medium loaded thereon that is configured to execute a calibration procedure for determining the inertial parameters of the force measurement assembly by utilizing the measured acceleration of the force measurement assembly while the force measurement assembly is subjected to a plurality of applied linear and/or rotational motion profiles. According to still another aspect of the invention, the at least one accelerometer is disposed on the force transducer.

Abstract: A force measurement system having inertial compensation includes a force measurement assembly with at least one accelerometer configured to measure the acceleration thereof. According to one aspect of the invention, the force measurement system additionally includes at least one angular velocity sensor configured to measure the angular velocity of the force measurement assembly. According to another aspect of the invention, the force measurement system additionally includes a data processing device with a computer-readable medium loaded thereon that is configured to execute a calibration procedure for determining the inertial parameters of the force measurement assembly by utilizing the measured acceleration of the force measurement assembly while the force measurement assembly is subjected to a plurality of applied linear and/or rotational motion profiles. According to still another aspect of the invention, the at least one accelerometer is disposed on the force transducer.

Abstract: According to one aspect of the invention, a force measurement system includes a force measurement assembly, a motion base configured to displace the force measurement assembly, and an inertial compensation system configured to determine the inertial forces and/or moments resulting from the displacement of the force measurement assembly by the motion base. According to another aspect of the invention, a method for accurately determining the forces and/or moments applied to a surface of a force measurement device by a subject disposed thereon is disclosed, which includes the step of determining, by using an inertial compensation system, the inertial forces and/or moments resulting from the displacement of a force measurement assembly by a motion base. According to still another aspect of the invention, a force and/or motion measurement system having inertial compensation includes a motion acquisition system having a plurality of motion sensing devices configured to capture a subject's movement.

Abstract: A load transducer for use in an automated control system such as those used in robotic assemblies, and other linkage systems separated by joints. The transducer is capable of measuring force and moments transmitted by the joint of the robotic assembly. This localized sensory data is utilized by a microprocessor to control the motion of the linkages of the system. In addition to being very accurate and reliable, the load transducer has a low profile and small size. This invention is easily manufactured using strain gage technology.

Abstract: A load transducer for use in an automated control system such as those used in robotic assemblies, and other linkage systems separated by joints. The transducer is capable of measuring force and moments transmitted by the joint of the robotic assembly. This localized sensory data is utilized by a microprocessor to control the motion of the linkages of the system. In addition to being very accurate and reliable, the Load transducer has a low profile and small size. This invention is easily manufactured using strain gage technology.

Abstract: A device for balance training and assessing dynamic balance by measuring a subject's ability to react to perturbations. A universal joint assembly is translated at the base of a support plate while a top plate on which the subject stands is fixed against translation. The universal joint permits the attached top plate to rotate about at least one and preferably multiple axes, and the subject must control balance following the translation of the universal joint. All components are housed in a one-piece platform assembly, made up of two plates in which the components are mounted. An existing force plate measurement system is placed on the top plate, and the subject stands thereon during use. A virtual environment, by image-creating devices, may be used to create a realistic sensation of tripping and general postural instability, or shifting of the support surface.

Abstract: A method useful for evaluating abnormal body tremors wherein a subject is positioned onto a support surface and one or more components of the load exerted by the subject upon the support surface are measured. Simultaneously, the cardiac activity of the subject is also recorded and the time interval between each consecutive heartbeat is computed. The measured load output is modified to normalize the weight of the subject and then plotted against a modified frequency wherein each time interval between heartbeats represent a unit of time and a selected equal number of force measurement samples are interpolated between each heartbeat. The frequency spectrum analysis of such a modified power spectrum graph yields information about body tremor which can be compared to a prior analysis of the same subject or to the same analysis of a standard.

Abstract: A method useful for evaluating abnormal body tremors wherein a subject is positioned onto a support surface and one or more components of the load exerted by the subject upon the support surface are measured. Simultaneously, the cardiac activity of the subject is also recorded and the time interval between each consecutive heartbeat is computed. The measured load output is modified to normalize the weight of the subject and then plotted against a modified frequency wherein each time interval between heartbeats represent a unit of time and a selected equal number of force measurement samples are interpolated between each heartbeat. The frequency spectrum analysis of such a modified power spectrum graph yields information about body tremor which can be compared to a prior analysis of the same subject or to the same analysis of a standard.

Abstract: This invention is a system to analyze the balance, stability, and tremor of a load or subject by measuring forces and calculating the center of pressure, as well as being capable of measuring all forces and moments. The plate (or platform) component of the system houses the measurement, amplification, and transmission technology. The forces and moments are measured by strain gages which are geometrically attached to specially machined beams inside the plate. The plate has a low profile for ease of stepping on and off, is light weight for portability, and is adjustable to compensate for unlevel surfaces. The data acquisition component of the system allows the user to analyze, interact with, and observe the measurement data. One version of the invention utilizes a compressible pad which can be placed on the plate to perturb the load or subject without interfering with the plate's capabilities.

Abstract: This invention utilizes geometrically positioned strain gages attached to load cells (pylons) where each cell measures all force and moment components (Fx, Fy, Fz, Mx, My, Mz), thereby measuring all six degrees of freedom. The independent measurements eliminate the need for one cell's dependency on another, therefore reducing assumption, calculation, and cross-sensitivity errors. At least two load cells are attached to a top plate, to which the load is applied, and an optional bottom plate and an optional mounting plate. These force plates can be connected together to form an array of plates to measure multiple instances of load application over a greater area. The signals produced can be transmitted via wiring or wireless means either directly to a data collection device, or to a connector board, then through an optional pre-amplifier and a second stage amplifier for signal amplification and conditioning, then, finally, the data is received by a data collection device for interpretation and reading.

Abstract: Disclosed is a particular method of strain gage placement on a cylindrical or tubular device for measuring the three force and three moment components of a load. The prescribed parameters of this method optimize measurement sensitivity of the gages and simplify production. On any calibrated cylindrical or tubular device (e.g., a prosthetic or robotic arm), at least six strain gages shall be attached and wired independently or in an independent bridge configuration. A first set of at least three gages shall be oriented approximately sixty degrees or less from either side of the long axis of the device. Then, a second set of at least three gages shall be oriented between approximately forty-five and one hundred-twenty degrees to the first set of gages, and approximately no greater than sixty degrees from either side of the long axis of the device. Each respective gage shall be equally spaced from each other around the periphery of the device.

Abstract: A device for tracking the translational and rotational displacement of an object having two degrees of freedom using a single point of contact with the object. The device is particularly useful in a catheter simulation device for surgery and interventional radiology applications. A spherical contact member is mounted for free rotation about all axes in force-transmitting contact with the surface of the object and a pair of shafts are mounted in tangential engagement with the spherical member to reflect the displacement imparted to the object relative to a reference position. This arrangement provides simultaneous tracking of the combined translational and rotational displacement of the object. Measuring the displacement of the object and a haptic applicator are included such that a load may be applied to the object to precisely control the degree of force required to cause displacement of the object.