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NK Biotechnical Corporation

 10850 Old County Road 15
Minneapolis, MN 55441

1-763-541-0411

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1-800-462-3751

 

Sensors

This sensor is designed to provide accurate, direct measurements, interoperatively, of the patellofemoral forces acting on the patella implant. The total force vector is decomposed into its three orthogonal components by this sensor. 

The NK Instrumented Tibial Plateau
U.S. Patent No. 5,197,488
 
DESCRIPTION: 

This device is designed to interface with trial knee implant, providing surgeons the ability to obtain interoperative measurement of loads between the tibia and the femur. With this information, dynamic assessment of load balance of the tibiofemoral joint can be made to aid in balancing soft tissue structures, resulting in precise positioning of the implant and greater knee stability. The system is fully automated, with data acquisition and processing capabilities. 

 STATUS: 

Research using a custom version of this device is ongoing at Scripps Clinic, La Jolla, CA, at the present time. The results of this research are the subject of the following paper: 

Kenton R. Kaufman, PhD, Nebosja Kovacevic, MSAE, Steven E, Irby, BS, and Clifford W. Colwell, MD, Instrumented Implant for Measuring Tibiofemoral Forces, Journal of Biomechanics, Vol 29, No. 5, pp 667-671 (1996).
  

The Instrumented Tibial Plateau. The telemetric transmission antenna and is in the non-metallic tip of the shaft. Data acquisition utilizes an inductive power supply, also in the tip of the shaft

The Tibial Plateau installed in a non-metallic calibration fixture. Note the coil for inductive supply of data acquisition power and the telemetric data acquisition antenna .
The NK S-TRANSDUCER
Patella-Ligament Sensor
 
 The NK Patella-Ligament ("S") Sensor is designed to measure the tension of the patella ligament.  

The sensor is small in size and can be interfaced with any knee implant device.
 
WARRANTY 
  • NKB warrants only the functionality of its Tibial Trial Sensor and Software. All mechanical components are warranted for one year in normal use. 

    The NK Patella-Ligament "S" System is currently sold for research purposes only.
The NK "Z" Transducer for Tendons and Ligaments
  • The "Z" Tendon Transducer is a miniature sensing device used for the measurement of torsional forces of tendons and ligaments during surgical procedures. Tendon and ligament studies have been and are being conducted, utilizing this transducer, by researchers at the Mayo Clinic, Rochester MN, The Scripps Clinic, San Diego, CA, Wright State University, Dayton OH, the Shriners Hospital, Philadelphia, PA, and The University of Miami, FL.

    The device is intended for research purposes only and is the subject of several papers, Including:
     

    • Direct 'In Vivo' Tendon Force Measurement System, Journal of Biomechanics, vol. 23, no. 12, 1990. Kai-Nan An, Lawrence Berglund, William P. Cooney, Edmund Y.S. Chao, and Nebosja Kovacevic.
    • Flexor Tendon Forces: In Vivo Measurements, Journal of hand Surgery, vol 17A, No. 2, March 1992. Frederic Schuid, M.D., Marc Garcia, M.D., William P. Cooney, M.D., Kai-Nan An, PhD.
    • Motor Responses to Implantable FES Electrodes in a Growing Limb, Presented at 17th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Montreal, 1995. June M. Akers, Ronald J. Tiolo, Randal R. Betz, Department of Research, Shriners Hospital for Crippled Children, Philadelphia Unit, Department of Orthopedic and Biomedical Engineering, Case Western Reserve University.
     
    FEATURES OPTIONS
    One piece structure with "optimization" inserts Data acquisition unit
    Easily implanted and removed, non-destructive Data acquisition software
    Fully encapsulated for long-term implant
    In Vitro or In Vivo application
    Miniature
    Full static and dynamic applications
    Made of high strength stainless steel material
    Customizable as to size, shape, load envelope
    Calibrations traceable to NIST
    Electrical and mechanical components warranted for one year SPECIFICATIONS
    Sold for research purposes only Length                             1.4 Cm (0.56 In)
    Not approved for use in humans Height                             0.64 Cm (0.25 In)
    Gas autoclavable to 66o C (150o F)  Width                              1.27 Cm (0.5 In)
    Designed for controlled environment applications Weight, including cable     2 Gm (0.07 Oz)
    Can sustain a force of 150% of rated capacity Excitation voltage              5 VDC (Nominal)
    Not intended for submerged applications Electrical Output               1.5 mV/V (Nominal)
    Can be used in environments up to and including 95% relative humidity Cable                                4 conductor, 28 in. long
     
     
     

     

The NK Clip-On Soft Tissue Sensor
U.S. Patent No. 5,289,826
  • The NK Clip-On Soft Tissue Sensor is designed to accurately measure, interoperatively, the forces of the knee extensor mechanism. The Sensor incorporates the following principles:
     
    1. THE LEAST DISTURBANCE OF NORMAL TISSUE DURING APPLICATION OF THE SENSOR. This is accomplished by a unique design which allows for a very thin lower plate, while preserving, in assembly, the necessary structural rigidity.
    2. THE ABILITY TO SENSE SHEAR FORCE. The is accomplished by utilizing a special electromechanical sensing structure.
    3. THE ABILITY TO CONTROL INITIAL LOADING CONDITIONS. Because of very complex boundary conditions in measuring "soft tissue" force, a special mechanism is integrated into the Sensor to preserve initial load for relative measurements of tension force from test ot test.
    4. EASY HANDLING. The Sensor is a fully modular structure, allowing for easy autoclaving and, if necessary, east replacement of components - in particular, the electromechanical component.