Abstract: A prosthesis includes a first plate and a second plate spaced apart from the first plate to form a gap therebetween. The second plate can move independently of the first plate. The prosthesis also includes a lower plate spaced apart from the first plate and the second plate. A plurality of support posts support the first plate and the second plate above the lower plate.

Abstract: A prosthesis is provided having a first plate and a second plate spaced apart from the first plate. A substantially round post separates the first plate and the second plate and a flexure is provided in the second plate proximate the post.

Abstract: A prosthesis includes a first plate and a second plate spaced apart from the first plate to form a gap therebetween. The second plate can move independently of the first plate. The prosthesis also includes a lower plate spaced apart from the first plate and the second plate. A plurality of support posts support the first plate and the second plate above the lower plate.

Abstract: A prosthesis is provided having a first plate and a second plate spaced apart from the first plate. A substantially round post separates the first plate and the second plate and a flexure is provided in the second plate proximate the post.

Abstract: A teletibial implant is provided for measuring forces between a femur having first and second condylar surfaces and a tibia when a joint is articulated. The implant includes a medial tibial insert engaging the first condylar surface and a lateral tibial insert engaging the second condylar surface. A transducer includes a medial plate coupled to the medial tibial insert, a lateral plate coupled to the lateral tibial insert, and a bottom plate supporting the medial and lateral plates. The medial and lateral plates receive forces from the medial and lateral inserts, respectively. The bottom plate also has a plurality of spaced apart force sensors for measuring forces exerted on the medial and lateral plates.

Abstract: A system and method are disclosed for measuring range of motion of a body joint formed between a first body portion and a second body portion. The system includes a range of motion sensor comprising a support linkage having a first link joined to a second link for relative movement therebetween. The first link is adapted to be retained for movement with the first body portion and the second link is adapted to be retained for movement with the second body portion. An angular sensing device senses angular displacement of the second link relative to the first link and provides a representative indication thereof. A force sensing device joined to the support linkage senses the applied force to the first body portion and provides a representative indication thereof. Output signals from the angular sensing device and the force sensing device are provided to a signal processor for recording and analysis.

Abstract: A method and apparatus for measuring the forces acting on a patella includes a patella sensor comprising a sensor, a sensor cover, and a plurality of strain gages. The sensor cover is attached to the sensor and has an outer surface that is in contact with a femoral insert. The sensor cover transmits the forces acting on its outer surface to the sensor. The sensor has a plurality of strain gages mounted thereon to measure the forces acting on the sensor cover. The sensor is mounted to a resected patella. The measured forces are then used to obtain loading and boundary limits for the design of patellofemoral prosthetic components.

Abstract: A skin compliance measurement device for measuring the compliance of human skin. The skin compliance measurement device comprises a housing containing two flexible strips attached to the housing at one end and attached to a probe at an opposite end. The probe extends from the flexible strips, through an opening in the bottom of the housing, and contacts an area of skin. A measurement device measures the flexure of the strips when the probe comes into contact with the skin.

Abstract: A force transducer for a joint prosthesis is disclosed. The transducer includes A f5RUw,V,central body having a plurality of cavities formed therein from a lower surface. Each cavity defines a flexure member. A plate is located on the side opposite the cavities and connect to each flexure member through support posts. The support posts localize three applied to the plate to each flexure member. Force sensing elements attached to each flexure member provide a signal corresponding to the force applied to the flexure member.

Abstract: A digit grip sensor for measuring the grip strength of the human hand. The digit grip sensor comprises a post support having a first and a second sensor therein. A first post extends through the first sensor and a second post extends through the second sensor. A crossbar spaced from the post support extends between the first post and the second post. Each sensor has a plurality of strain gages mounted thereon for measuring the deflection of the sensor. The crossbar can have a plurality of individual digit sensors mounted thereon for measuring the contributions of each finger to the grip force. The crossbar and the individual digit sensors can be adjusted for various hand and finger sizes.

Abstract: A force sensor is used to determine tension forces present in a portion of tissue adjacent a body joint. A support plate is inserted under a tissue portion through two spaced apart incisions. The ends of the support plate are exposed and are mounted to a sensor frame along with a flexure member. A load plate mounted to the flexure member transfers force loads sensed from the tissue portion to the flexure member. A strain gage is mounted to the flexure member to provide an output signal representative of the force on the flexure member and thus forces in the tissue.

Abstract: A system is disclosed for measuring dynamically forces applied to a prosthetic joint. The system comprises a first support member attached to an outer surface of a first bone, a second support member attached to an outer surface of a second bone and a transducer secured to the second support member and engaging the first support member. The transducer measures forces applied to the first and second support member as the prosthetic joint is articulated and provides a representative force output signal. In the preferred embodiment, the transducer comprises a central body having plurality of integrally formed flexure members, each flexure member defined by a corresponding cavity in the body and defining a force responsive flexure section. A plate is secured to the transducer with support posts to localize forces onto the flexure members. Although the assembly forms components for implementation of a knee prosthetic, the present invention can be adapted to any particular joint of the body.

Abstract: An apparatus and method for insuring that the evaluation of forces generated from an injured human limb or hand are accurately determined without malingering factors. The apparatus includes a sensor for determining forces generated by a hand which provides an output signal for input into a scaling circuit of a computer. The scaling circuit has a random scale factor randomly selected by a computer's microprocessor. The random scale factor alters presentation of the sensor output signals on a visual display. The visual display provides an indication to the patient of the amount of force that has been generated, but the scale factor modifies the output signals in a manner and amount that is unknown to the patient. The scale factor for example can be such that at a start of a test sequence a standard force can be displayed in approximately the middle of a scale shown on the visual display.

Abstract: A human hand load sensor is a strain gauge based force measurement instrument that has two platforms or handles that can be moved together with parts of the human hand, for example, a thumb and finger, or the handles can be grasped between the heel of the hand and several fingers. The instrument permits very precise measuring of strength force by supporting a movable handle relative to a base or reference handle through a flexure system which deforms predictably under shear loading as the handles or platforms are moved together. The flexure system is much like a parallel linkages made from a single block of material between a base and a movable block, and having a small deflecting beam sensing element between the base and the movable block that is isolated from influences of bending or rolling movements on the strain level. The strain energy is sensed with strain gauges that provide a signal directly proportional to the shear loading for very accurate measurements.

Abstract: A sensing device for determining the sensory responses of the human skin to evaluate the fiber-receptor nervous system of the human body, primarily in connection with the measurement of the ability to discriminate separate points of touch of the hand. The sensing device includes electronic sensors for determining the displacement, or force, acting on individually mounted prongs or pins which are positioned to engage and apply a load to a human body. The force sensors provide not only the load individually to each of the prongs, but also the average load applied to the surface of the human body by the two prongs.

Abstract: A calibration stand for multiforce component sensors is capable of providing six components of force and moment to such sensors, using support and loading apparatus on the calibration stand. The stand is a compact, portable unit that provides for holding the sensor in a precise position by fully permitting pitch and lateral adjustments of the support assembly, as well as vertical and lateral adjustments for axial and "roll" or moment loading. The adjustability permits accurate applications of normal, lateral, and axial loads on the sensor being calibrated. Load cells are used to measure the application of the loads, and by proper instrumentation the output from the load cells can be used for recording data or providing digital displays. A coupling for carrying loads to the sensor permit determining whether shear loads are being introduced into the sensor and the adjustments permit zeroing out such shear loads so the loads are directed along the desired axes only.