Patent ID: 11965774
Assignee: COVENTRY UNIVERSITY
Field: Medical technology (Instruments)
Classification: CPC G  A | IPC A  G

Claim 11:
12. A method of monitoring the vibration dose experienced by a machine operator, the method comprising the steps of: providing the operator with a vibration dose measurement apparatus comprising: a sensor assembly; and a support operable, in use, to urge the sensor assembly toward the palm of the operator wherein the sensor assembly comprises an accelerometer operable to detect linear motion; a gyroscope operable to detect rotary motion; and a gripping force sensor operable to detect gripping force applied by the operator; monitoring the vibration dose detected by the apparatus; and outputting a warning if the detected dose exceeds a threshold, wherein the vibration dose the vibration dose is calculated based on a modified A(8) value including an additional term derived from the gripping force sensor output, wherein the modified A(8) value is defined by the formula, A
    ⁡
    (
    8
    )
   
   =
   
    
     
      a
      
       h
       ⁢
       v
      
     
     ⁢
     
      
       T
       
        T
        o
       
      
     
    
    +
    
     
      
       V
       
        E
        ⁢
        T
       
      
      ⁢
      T
     
     
      ρ
      ⁢
      
       A
       s
      
      ⁢
      
       A
       h
      
     
    
   
  
  ,
 

where ahv is the total vibrational vector characterising a particular vibration, T is time that an operator is exposed to the vibration characterised by ahv, To is a reference time value, VET is the vibrational energy transmitted determined from the gripping force sensor output, ρ is the density of the operator's palm skin tissue, As is the area of the operator's skin in contact with the machinery, and Ah is the area of the handle of the machinery.