Apparatus for determining viscoelastic characteristics of an object, and method thereof

Abstract

Disclosed is an apparatus for determining viscoelastic characteristics of at least a portion of an object. The apparatus comprises a fluidly sealable housing, comprising at least one aperture and at least one fluid inlet port and at least one resilient membrane that is operatively coupled to the housing so as to sealingly engage with the at least one aperture. The apparatus further comprises at least one actuator that is operatively coupled to the at least one inlet port and adapted to actuate the at least one resilient membrane via a working fluid that is contained within the housing, so that the at least one resilient membrane is moved towards and into engagement with at least a portion of an object at a predetermined pressure. Furthermore, the apparatus comprises at least one first sensor that is operably coupled to the membrane and that is adapted to determine at least a deformation of the at least one resilient membrane during actuation.

1 . An apparatus for determining viscoelastic characteristics of at least a portion of an object, comprising:
 a fluidly sealable housing, comprising at least one aperture and at least one fluid inlet port;   at least one resilient membrane, operatively coupled to said housing so as to sealingly engage with said at least one aperture;   at least one actuator, operatively coupled to said at least one inlet port and adapted to actuate said at least one resilient membrane via a working fluid contained within said housing, so that said at least one resilient membrane is moved towards and into engagement with said at least a portion of an object at a predetermined pressure, and   at least one first sensor, operably coupled to said membrane and adapted to determine at least a deformation of said at least one resilient membrane during actuation.   
     
     
         2 . An apparatus according to  claim 1 , wherein said at least one actuator is adapted to selectively provide a predetermined static or transient fluid pressure within said working fluid. 
     
     
         3 . An apparatus according to  claim 1 , wherein said actuator is adapted to provide a predetermined pressure wave within said working fluid. 
     
     
         4 . An apparatus according to  claim 3 , wherein any one or all of a time period, frequency and amplitude of said pressure wave is selectively adjustable. 
     
     
         5 . An apparatus according to  claim 4 , wherein said predetermined pressure wave is a periodic wave. 
     
     
         6 . An apparatus according to  claim 5 , wherein said periodic wave is a square wave. 
     
     
         7 . An apparatus according to  claim 1 , wherein said actuator further comprises at least one pressure sensor operably coupled to said at least one inlet port and adapted to determine the fluid pressure generated within said working fluid at said at least one inlet port during actuation. 
     
     
         8 . An apparatus according to  claim 1 , wherein said housing further comprises at least one force sensor operably coupled to a contact surface of said housing and adapted to determine a contact pressure when engaging at least said portion of an object during use. 
     
     
         9 . An apparatus according to  claim 1 , wherein said at least one first sensor is a strain sensor adapted to determine the strain of said at least one resilient membrane during actuation. 
     
     
         10 . An apparatus according to  claim 9 , wherein said strain sensor comprises any one of a resistance strain gauge, an optical strain gauge, a piezoelectric sensor and a resistive pattern sensor operably printed on said at least one resilient membrane. 
     
     
         11 . An apparatus according to  claim 10 , wherein said resistive pattern is made from any one of a graphene or graphite material. 
     
     
         12 . An apparatus according to  claim 1 , wherein said at least one first sensor is a deflection sensor adapted to determine a displacement of said at least one resilient membrane during actuation. 
     
     
         13 . An apparatus according to  claim 12 , wherein said displacement sensor comprises any one of an ultrasonic transducer and an interferometer. 
     
     
         14 . An apparatus according to  claim 1 , wherein said at least one first sensor is operably coupled to said at least one resilient membrane via a cantilever adapted to couple at least said deformation of said at least one resilient membrane with said at least one first sensor. 
     
     
         15 . An apparatus according to  claim 1 , wherein said at least one resilient membrane comprises at least two parallelly arranged and superposed resilient layers that are bonded so as to form said at least one resilient membrane. 
     
     
         16 . An apparatus according to  claim 15 , wherein said at least one first sensor is located and secured in-between said at least two parallelly arranged and superposed resilient layers. 
     
     
         17 . An apparatus according to  claim 1 , wherein said at least one resilient membrane is made from silicone. 
     
     
         18 . An apparatus according to  claim 1 , wherein said housing further comprises at least one perforated support structure operably coupled between said at least one aperture and said at least one resilient membrane so as to form said at least one resilient membrane into a predetermined shape. 
     
     
         19 . An apparatus according to  claim 18 , wherein said predetermined shape is a dome shape. 
     
     
         20 . An apparatus according to  claim 1 , comprising a plurality of first sensors operably coupled to said at least one resilient membrane and arranged in a predetermined pattern. 
     
     
         21 . An apparatus according to  claim 1 , wherein said housing further comprises a plurality of apertures and associated plurality of resilient membranes, and a plurality of first sensors, each operably coupled to a respective one of said associated plurality of resilient membranes. 
     
     
         22 . An apparatus according to  claim 21 , wherein said plurality of apertures and associated plurality of resilient membranes, are arranged in a predetermined pattern adapted to reveal movement of an object during actuation of any one of said plurality of resilient membranes during use. 
     
     
         23 . An apparatus according to  claim 1 , further comprising a data storage adapted to receive and store data. 
     
     
         24 . An apparatus according to  claim 1 , further comprising a wireless transceiver adapted to transmit data from a sensor to a remote data storage. 
     
     
         25 . An apparatus according to  claim 1 , wherein said apparatus is removably mountable to a finger and transductally deployable. 
     
     
         26 . An apparatus according to  claim 1 , wherein said object is a biological tissue. 
     
     
         27 . A method for quantifying viscoelastic properties of at least a portion of an object, comprising the steps of:
 (a) operably and engagingly positioning an apparatus according to  claim 1  to at least a portion of an object;   (b) activating said apparatus by selectively providing a predetermined static or transient actuation pressure to said at least a portion of an object via a resilient membrane of said apparatus;   (c) recording a deformation characteristic of said resilient membrane during engagement with said at least a portion of an object;   (d) recording a contact pressure between said apparatus and said at least a portion of an object during actuation;   (e) determining at least one quantifying parameter from said deformation characteristic of said resilient membrane, utilizing said associated predetermined static or transient activation pressure and said associated contact pressure.   
     
     
         28 . A method according to  claim 27 , wherein said quantifying parameter comprises at least an elastic property of said at least a portion of an object. 
     
     
         29 . A method according to  claim 27 , wherein said quantifying parameter further comprises at least a viscous property of said at least a portion of an object. 
     
     
         30 . A method according to  claim 27 , wherein said deformation characteristic is a strain of said resilient membrane during activation. 
     
     
         31 . A method according to  claim 27 , wherein said deformation characteristic is a deflection of said resilient membrane during activation. 
     
     
         32 . A method according to  claim 27 , wherein said transient actuation pressure comprises a transient pressure wave. 
     
     
         33 . A method according to  claim 32 , wherein any one or all of a time period, frequency and amplitude of said pressure wave is selectively adjustable. 
     
     
         34 . A method according to  claim 27 , wherein said transient actuation pressure comprises a plurality of pressure waves, each one comprising a different predetermined frequency. 
     
     
         35 . A method according to  claim 27 , further comprising a calibration step prior to step (a), wherein a creep-related non-linear material effect of said resilient membrane is minimized by removing the creep-related change in deformation characteristic of said resilient membrane. 
     
     
         36 . A method according to  claim 27 , further comprising step:
 (f) identifying and/or classifying a mechanical characteristic of said at least a portion of an object, utilizing said at least one quantifying parameter.   
     
     
         37 . A method according to  claim 28 , wherein said quantifying parameter further comprises at least a viscous property of said at least a portion of an object.