WO2015048908A1

WO2015048908A1 - System and method for measuring structural stability of an object based on impact reaction

Info

Publication number: WO2015048908A1
Application number: PCT/CA2014/050963
Authority: WO
Inventors: Siamak Arzanpour; Hamlet ABNOUSI; Saroush NOROUZI
Original assignee: Denscope Inc.
Priority date: 2013-10-04
Filing date: 2014-10-06
Publication date: 2015-04-09

Abstract

Examples of a system and a method for measuring object stability are disclosed. The system comprises a measuring probe for detecting a response behavior of the object upon an impact. The measuring probe includes a head that comprises a housing having a first end, a second end and a body extending between the first end and the second end. At least one of the first end and the second end of the housing is opened. An impact means is mounted at least partially within the housing. The impact means has a first end connected to a detector and a second end. The detector is configured to detect a reaction behavior of the object upon the impact of the impact means with an impact structure. The detector can generate a voltage or current upon the impact means impacts the impact structure. The probe further comprises a guide configured to determine a position and an orientation of the head of the probe and an impact angle during measurements. The guide can be mechanical guide, such as a sleeve, a suction cup or a T-shaped guide, removably secured to the housing in proximity of the at least one of the open end of the housing. The guide is configured to precisely position and orients the head of the probe to the impacting structure to limit its motion during measurements. In one embodiment the guide can be an electronic guide that comprises a position measuring unit to calculate the position and orientation of the head and an impact angle and to guide a user to position the head of the probe in a desired position and orientation. The signal from the detector is transferred to a processing unit that processes and analyzes the signal calculating a quotient number and producing a report on the stability of the object based on such quotient number.

Description

SYSTEM AND METHOD FOR MEASURING STRUCTURAL STABILITY OF AN OBJECT BASED ON IMPACT

REACTION

Technical Field

The present disclosure generally relates to a method and an apparatus for measuring a

5 stability of an object and more particularly relates to a method and an apparatus for

measuring the stability of an object using an impact method.

Overview

Ability to reliably and repeatedly measure stability of an object and/or its integration within a structure has wide applications in many areas such as construction, civil

10 engineering, dentistry to measure stability of natural tooth or dental implant etc.

Various systems and methods have been used to determine the dental implant stability such as a percussion test, radiography, Periotest®, a resonance frequency analysis (RFA), modal analysis. The decision of the object's stability in some of these known systems and methods is subjective and experience-driven. For example, the

15 percussion test (in its simplest form) is based on a sound heard upon percussion of the

object with a metallic instrument. A clear ringing sound indicates greater stability whereas a "dull" sound can indicate low stability of the object. Various attempts were made to measure the stability of the object quantitatively and/or qualitatively by enhancing the response detection using various sensors such as microphones,

20 accelerometers, a strain gauge and analyzing such signals to objectively determine the

structural stability of the object. However, such attempts lack sensitivity and repeatability since the measurements are highly influenced by excitation conditions, such as a position and orientation of the excitation tool, excitation tool parameters, object's parameters (material, design, dimensions, orientation), environment etc.

25 The present invention overcomes the limitations of the prior art devices and methods

for measuring structural stability of an object. Summary

In one aspect, a device for measuring a structural stability of an object is disclosed. The device is used to measure a structural stability of an object as a stand-alone structure or a system of multiple structures. The device comprises a measuring probe that has a head that includes a housing having a first end, a second end and a body extending between the first end and the second end. At least one of the first end and the second end of the housing is opened. An impact means is mounted at least partially within the housing to impact an object during measurements. The impact means has a first end and a second end. The second end of the impact means protrudes out from the at least one open end of the housing. A detector is connected to the first end of the impact means for detecting a reaction behavior of the object upon an impact of the impact means with an impact structure. The device further comprises a guide that is configured to determine a position and an orientation of the head of the probe and an impact angle during measurements. The impact means is selected from a group of an elongated rod, a ball, a hemi-sphere and a plate.

In one aspect, the guide is a sleeve that has a first end, a second end and a body between the first end and the second end. A passage that penetrates throughout the body from its first end to its second end is configured and sized so that the impact means can be inserted into the passage. The first end of the sleeve is configured to position the guide in a predetermined position and orientation.

The sleeve is inserted into the at least one open end of the housing so that it envelops the second end of the impact means and it moves along the longitudinal axis of the head from an extended position in which the second end of the impact means is enveloped by the sleeve to a retracted position when the second end of the impact means protrudes through the first end of the sleeve.

In another aspect, the sleeve is separate and independent of the measuring probe and is temporarily attached to the impact structure in a predetermined position and orientation. During the measurements the impact means is inserted into the guide to hit the impact structure. In one aspect, the guide is a T-shaped guide with a horizontal guide and a vertical guide. The T-shaped guide is removably secured to the housing in proximity of the at least one open end of the housing.

In yet another aspect, the guide is electronic, composed of but not limited to sensors such as accelerometers, gyroscopes and magnetometers, etc. The electronic guide calculates the position and orientation of the probe and an impact angle and guides a user to position the head of the probe in a desired position and orientation.

In another aspect, a system for measuring a structural stability of an object is disclosed. The system comprises a measuring probe with a head that comprises a housing having a first end, a second end and a body extending between the first end and the second end. At least one of the first end and the second end of the housing is opened. An impact means is mounted at least partially within the housing to impact an object during measurements.. The impact rod has a first end and a second end. The second end of the impact means protrudes out from the at least one of the open end of the housing. A detector is connected to the first end of the impact means for detecting a reaction behavior of the object upon an impact of the impact means with an impact structure. The device further comprises a guide that is configured to determine a position and an orientation of the head of the probe and an impact angle during measurements. A processing unit that is in communication with the detector receives the output signal from the detector, and based on such output signal and data of the position and orientation of the head and the impact angle from the guide it produces a report of the structural stability of the object. The data from the processing unit are displayed on a display positioned on the probe or remotely from the probe.

In one aspect, a method for measuring a stability of an object is disclosed. The method comprises guiding a measuring probe to a desired position and orientation with respect to an impact structure and exciting the object by impacting an impact structure with an impact means. A signal produced by such excitation is detected by a detector which transfers the output signal from the detector to a processing unit which analyzes the signal and calculates a quotient number based on the analyzed signal. The processing unit determines object's stability based on a value of the quotient number.

The data of the object stability are reported on a display. In addition to the aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and study of the following detailed description.

Brief Description of the Drawings Throughout the drawings, reference numbers may be re-used to indicate correspondence between referenced elements. The drawings are provided to illustrate example embodiments described herein and are not intended to limit the scope of the disclosure. Sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not drawn to scale, and some of these elements are arbitrarily enlarged and positioned to improve drawing legibility.

FIG. 1 is a cross-sectional side view of a device for measuring a structural stability of an object showing a measuring probe with a head comprising an excitation source and a guide enveloping the excitation source. FIG. 2A is a perspective view of a device for measuring a structural stability of an object showing a measuring probe with a curved head.

FIG. 2B is a cross-sectional side view of a device for measuring a structural stability of an object showing a measuring probe with a head perpendicular to a handle.

FIG. 3 is a cross-sectional side view of a device for measuring a structural stability of an object with a two open ended housing and two excitation sources.

FIG. 4A is a cross-sectional side view of a device for measuring a structural stability of an dental implant showing a guide of a measuring device in an extended position.

FIG. 4B is a cross-sectional side view of a device of FIG. 4A with the guide in a retracted position. FIG. 5A is a cross-sectional side view of a device for measuring a structural stability of an dental implant showing another non-limiting embodiment of a guide attached to an impact structure and a measuring probe remote from the guide. FIG. 5B is a cross-sectional side view of a device of FIG. 5A with an impact rod inserted into the guide for impacting the impact structure.

FIG. 6 is a perspective view of a "suction cup" type of guide.

FIG. 7 A is a cross-sectional side view of a "T-Shaped" type of guide with a horizontal guide perpendicular to the vertical guide.

FIG. 7B is a cross-sectional side view of a "T-Shaped" type of guide with a horizontal guide angled in relation to the vertical guide.

FIG. 8A is a perspective view of a housing with a grooved wall and a "T-Shaped" type of guide, the T-shaped guide being separated from the housing. FIG. 8B is a perspective view of the housing with the grooved wall of FIG. 8A and the "T-Shaped" type of guide secured to the housing.

FIG. 9 is a flow chart of a processing unit of the system for measuring a structural stability in an embodiment of the invention.

FIGS. 10A - IOC illustrate graphs of examples a raw voltage signal (in volts) as a function of time (in seconds) obtained from a detecting sensor at various stages of implant integrating process.

FIG. 11 illustrates graphs of examples of raw voltage signals (in volts) as a function of time (in seconds) obtained from a detecting sensor at various stages of implant integrating process after the signals were normalized. FIG. 12 illustrates graphs of examples of multiple curves sine wave output voltage signal (in volts) as a function of time (in seconds) obtained from a detecting sensor.

FIGS. 13 A and 13B show graphs of a signal taken from impacts on an implant (FIG. 13 A) and a crown (FIG. 13B).

Detailed Description of Specific Embodiments For the purpose of the present invention a structural stability measurement can mean condition monitoring of an object throughout its life. An object can be a stand-alone structure (e.g. implant, foundation, pier) or a system of multiple structures (e.g. implant with a crown or bridge, foundation with a building, etc.). The present invention describes a system and method for measuring a structural stability of the object, as a stand-alone structure or a system of multiple structures, throughout the life of such object. For example, the present invention can be used for primary, secondary and/or lifelong monitoring of a structural stability of a loaded implant, an unloaded implant, a single implant based prosthetic, multiple implants based prosthetic, non-prosthetic implants and/or prosthetic implants. In another example, the system of the present invention can be used for assessing the structural stability of foundation of a building before/after its construction or to measure the structural stability of the foundation over the time (e.g. before and after an earthquake). In addition the present invention provides a method for a trending analysis of an object (structural stability of the stand-alone structure or a system of multiple structures throughout its life), a comparison analysis of structural stability of different stand-alone structures, such as a comparison between structural stability of different implants (e.g. different types of implants), a comparison analysis between structural stability of different systems of multiple structures and/or a comparison analysis between structural stability of a stand-alone structure and a system of multiple structures.

The system and the present invention is a simple and easy to use and does not require any special qualifications or training for the user to be able to perform the measurements. An example of a system for measuring a structural stability of an object is schematically illustrated in FIG. 1. The device comprises a measuring probe 10 having a head 2. The head 2 can comprise an elongated housing 3 defining an inner bore of the head 2. The housing 3 can comprise an open end 3a, a close end 3b and a body 3c extending between the open end 3a and the close end 3b. An excitation source, such as an impact rod 6, is mounted within the inner bore of the head 2. The impact rod 6 can extend along a longitudinal axis of the housing 3. The impact rod 6 can have a first end 6a with a base 6a' connected to a detecting sensor 7, and a second end 6b. The second end 6b of the impact rod 6 is a free end and extends out from the open end 3 a of the housing 3. The second end 6b of the impact rod 6 is configured to impact an impact structure (not shown). The impact structure can be the object of the measurement (e.g. a dental implant) or any other structure associated with the object (e.g. a system of a crown with an implant). The impact rod 6 can be made of a metal, a ceramic or any other material suitable to provide an impact force to the object/impact structure. The system can further comprise a handle 4 configured to hold the measuring probe 10. The head 2 can be connected to the handle 4. The head 2 can be directly connected to the handle 4 or by using a joint (not shown). In one implementation the joint can be a pivot to rotate the head changing its orientation in space to help advancing the head 2 of the probe 10 to less approachable areas (e.g. a molar region of an oral cavity). In one embodiment the head 2 can be detached from the handle 4 and/or the joint and re-attached again if needed. In some applications, the housing 3 and the head 2 of the measuring probe 10 can be heat treated (i.e. sterilized). In yet another embodiment, the handle 4 can be omitted and the user can hold the probe 10 by holding the housing 3 of the probe 10.

In the example illustrated in FIG. 1 the head 2 has a straight configuration however in some embodiments the housing 3 of the head 2 can have a curved configuration (see FIG. 2A) so that the open end 3a is facing downwardly or upwardly of the body 3c. In such embodiments the impact rod 6 can have a curved configuration as well.

In the implementation shown in FIG. 2B the head 2 can be perpendicular to the handle 4. The impact rod 6 can be supported by a shoulder 22 formed in the body of the housing 3. The shoulder 22 can be a bearing or a bushing connected to an inner surface of the housing 3 providing a guide for the impact rod 6. The shoulder 22 defines an opening through which the second end 6b of the impact rod 6 passes through. A seal 20 can be provided to provide fluid tight sealing and prevent any fluids entering the inner bore of the housing 3. The seal 20 can be a silicon seal, a rubber, a soft plastic seal or any other suitable material that do not diffuse vibrations and can be heat resistant (heat treatable). In one embodiment, the housing's wall can define an inner bore (passage) through which the impact rod 6 can pass through having its second end 6b to project out of the open end 3 a. The housing 3 can be made of a ceramic, a plastic, metal or any other suitable material. In addition, the housing 3 of the head 2 can be anodized or coated with ceramic coating (e.g. Cerakote™) for electric insulation, to reduce noise in the signal, anticorrosion and cleaning. Alternatively the coating can be also antimicrobial. In some embodiments, the base 6a' can be sized so that a cross-section of its upper surface is the same or bigger than a cross-section of the first end 6a of the impact rod

6 so that signal from the impact rod can be transferred through the base 6a' to the detector 7 avoiding any diffusion of the signal and thus increasing the sensitivity of the probe 10 (see FIG. 2B). In one implementation, the base 6a' can have a tapered configuration so that its lower surface that is in contact with the detector 7 has a smaller cross-section than its upper surface and the signal transferring to the detector

7 can be focused. In addition, the second end 6b of the impact rod 6 can be tapered (not shown) to further avoid any signal diffusion through the rod's edge and to limit the area of impact. In one implementation, illustrated in FIG. 3, the housing 3 can have two open ends, the first open end 3a and a second open end 3a'. A seal can be provided at both open ends 3 a and 3 a' to provide fluid tight sealing and prevent any fluids entering the inner bore of the housing 3. In the example illustrated in FIG. 3 two separate and independent excitation sources can be provided. One or both of the excitation sources can be an impact rod as the one described with respect to the probe 10 of FIG. 1. FIG. 3 shows an example of the probe 10 in which the two excitation sources are different, such as one of the excitation source can be the impact rod 6 with the free end 6b protruding out of the open end 3a and the second excitation source can be a ball 6' with a portion of the ball protruding out of the open end 3a'. In one embodiment the ball 6' can be a hemi-sphere (oval shaped) partially protruding out of one of the open ends of the housing. One of the excitation sources, e.g. the impact rod 6 can be in communication with one detecting sensor 7 while the other excitation source can be in communication with another detection sensor 7'. The sensors 7 and 7' can be the same or different without departing from the scope of the invention. The device of FIG. 3 can act as two separate measuring probes so that one side of the device (e.g. the side with the impact rod 6) can be used for example as a sensor for implants while the other side (e.g. the one with the ball 6') can be used as a sensor for crowns with implants. In one embodiment, only one detector 7 can be provided that is in communication with both excitation sources. Any other type of excitation source can be provided without departing from the scope of the invention. For example, the excitation source can be a plate that is formed at the open end of the housing and which is in communication with the detecting sensor.

FIG. l further shows a guide 8 that is configured to determine the position and orientation of the head with respect to the object/impact structure, as well as a path of the impact rod 6 and an angle of the impact. In the illustrated example of FIG. 1, the guide 8 is an elongated sleeve that can be inserted in the open end 3a of the housing 3. The guide 8 can be configured to slide along the longitudinal axis of the head 2 between its extended position and its retracted position. The guide 8 comprises a first end 8a, a second end 8b and a body extending between the first end 8a and the second end 8b. A passage that penetrates throughout the body of the guide 8 from its first end 8a to its second end 8b is configured and sized so that the impact rod 6 can be inserted and supported by such passage. The guide 8 is configured so that the impact rod 6 is at least partially enclosed by the guide's body. The first end 8a of the guide 8 can protrude out from the open end 3a of the housing 3 when the guide 8 is in its extended position. The second end 8b can be positioned within the housing 3. The second end 6b of the impact rod is inserted into the passage of the guide's body. Biasing means, such as a spring 9, can be used to facilitate the movement of the guide 8 in longitudinal direction along the body 3c of the housing 3. The second end 6b of the impact rod 6 is positioned within the guide 8 so that when the guide 8 is in its extended position the second end 6b of the impact rod 6 is completely enclosed by the guide 8. In the illustrated example, a loading force of the spring 9 can act on the second end 8b of the guide 8 to keep it in its extended position. Bushings 15 mounted in the inner bore of the housing 3 in proximity to its close end 3b can hold the spring 9 and the guide 8 within the inner bore of the housing 3. In one implementation, a stopper (not shown) can be mounted in the inner bore of the housing 3 to engage the guide 8 to prevent it from dislodging from the housing 3, e.g. when the probe 10 is in vertical, downward, position. In order to move the guide 8 to its retracted position, a user can press the first end 8a of the guide 8 to push it against the spring's loading force and thus move it to its retracted position. When the guide 8 is in its retracted position the second end 6b of the impact rod 6 protrudes from the first end 8a. Once the user stops pushing the guide 8, it returns to its extended position due to the loading force of the spring 9. Skilled person in the art would understand that any other means can be used to facilitate the movement of the guide 8 along the longitudinal axis of the housing without departing from the scope of the invention. For example, instead of spring 9, an elastic foam, , air cushion or any other elastic element can be used. In one implementation, the guide 8 can be driven between the extended position and the retracted position by a motor or a magnetic levitation. A profile of the first end 8a of the guide 8 is configured to precisely position the measuring probe 10 in a predetermined position and orientation with respect to the object/impact structure. When the guide 8 moves to its retracted position, the second end 6b of the impact rod 6 gets uncovered (protrudes from the first end 8a of the guide 8) and impacts the object/impact structure at the predetermined impact point (precise position, orientation and impact angle). The object reacts to such impact and a response signal is detected by the detector 7. Positioning the probe 10 so that the impact rod 6 impacts the object at a precise impact point (impact angle) can be controlled by a configuration and a shape of the first end 8a of the guide 8. As illustrated in FIG. 1, the first end 8a forms a mouth opening that comprises at least two arms (lips) 16. When the first end 8a of the guide 8 is in contact with a surface of the object or the impact structure, the at least two arms 16 engage such surface and prevent/minimize the motion of the head 2. One or all of the arms 16 can include curvature to accommodate a better grasp of the surface, for example a tooth circumference. The at least two arms 16 are positioned under an angle a to each other. The angle a between the at least two arms 16 of the first end 8a defines the position and orientation of the head 2 to the object during measurements. Such angled geometry of the first end 8a provides that the head 2 of the probe 10 is tilted off a vertical axis 19 (see FIG. 4A) of the object and thus the probe 10 can be used to measure stability of the object in areas that are harder to approach, such as for example the molar region. This can be seen better in FIGS. 4A and 4B that illustrates the measuring probe 10 positioned to a tooth crown 32 for measuring the structural stability of a dental implant 30. One of the arms 16 engages one surface of the implant or crown 30, 32 (e.g. a top surface) while the other of the arms 16 engages another surface (e.g. vertical surface) of the implant or crown 30, 32. FIG. 4A shows the measuring probe 10 with the guide 8 in extended position while FIG. 4B shows the measuring probe 10 with the guide 8 in the retracted position and the impact rod 6 protruding out of the first end 8a to impact the crown 32. The stability of the implant 30 can be measured by either impacting the implant itself or by impacting the crown 32 enclosing the implant 30.

Once the probe 10 is in a pre-defined position for taking measurements, the user gently pushes the head 2 of the probe 10 toward the impact surface. Due to the pushing force the guide 8 moves inside the housing 3 exposing the second end 6b of the impact rod 6 so that the impact rod 6 hits the impact surface. The response signal is then detected by the detecting sensor 7. The sensor 7 can comprise a piezo material that can detect a response signal and can generate an output signal such as a corresponding voltage or a current. In one embodiment, the sensor 7 can comprises a magnetostrictive material, such as a terfenol-d, which in presence of an external magnetic field can generate a voltage/current signal.

In one implementation, the guide 8 can be stationary (spring 9 can be omitted). In such embodiment, the sensor 7 can comprise a piezo or a magnetostrictive material which can expand in longitudinal direction due to a magnetic or electric field changes. For example, the material of the sensor 7 can expand when a voltage is applied to it. Expansion of the sensor 7 (expansion of the magnetostrictive material of the sensor 7) in axial direction will result in movement of the impact rod 6 in axial direction as well, so that its second end 6b can protrude out of the first end 8a of the guide 8 and can impact the object/impact structure. So, the guide 8 can be fixed and the movement of the impact rod 6 out of the first end 8a can be facilitated by the properties of the sensor's material.

In one implementation, the guide 8 can be separated and independent from the measuring probe 10. FIGS. 5A and 5B illustrate the guide 8 that is temporarily attached to the impact structure, i.e. crown 32, to guide the impact rod 6 of the measuring probe 10 to hit the impact structure at a predetermined position, orientation and impact angle. So, instead of having a guide 8 that is part of the probe 10, the guide 8 can be a separate unit. The user can position and attach the guide 8 to the impact structure before the measurements, and then the impact rod 6 of the measuring probe 10 can slide inside the passage of the guide 8 to hit the impact structure, such as the crown 30. The guide 8 can be temporarily attached to the impact structure by gluing (e.g. adhesives, tape, wax, pliable polymers), friction (e.g. the at least two arms 16 of the first end 8a can frictionally grasp the impact structure), suction etc. Any other method for temporarily attaching the guide 8 to the impact structure can be used without departing from the scope of the invention. In some embodiments, the guide 8 can be held at the precise position/orientation by the user. In one method of operation, the user first removes the tape and attaches the guide 8 to the right location (precise position and orientation) of the impact structure. By attaching the guide 8 to the impact structure the user provides a precisely positioned and secured guide 8 so that he/she can accurately deliver the impact rod 6 to such guide 8 during the measurements (tapping) by simply inserting the rod 6 into the fixed guide 8 to impact the impact structure (crown/implant). FIG. 5 A shows the guide 8 attached to the crown 32 and the measuring probe 10 with the impact rod 6 remote from the guide 8. FIG. 5B shows the impact rod 6 inserted into the guide 8 to impact the crown 32. By using a precisely placed guide 8, accurate and consistent measurements can be provided. FIG. 6 illustrates the guide 8 configured as a suction cup 8' so that during measurements the guide 8' can be secured at the desired position at the measuring object (e.g. an implant or crown) and the head 2 and the impact rod 6 are stable during the measurements. The guide 8' can comprise a suction cup 50 configured to be bring into contact with the measuring object and a body 52 configured to be placed over the open end 3 a of the housing 3 to secure the guide 8' to the head 2.

FIGS. 7A and 7B show another example of a guide 8" . The illustrated guide 8" is a "T-shaped" guide that is configured to be secured to the housing 3 in proximity to the open end 3a. The T-shaped guide 8" can comprise a horizontal guide 8a" and vertical guide 8b" that is substantially vertical with respect to the horizontal guide 8a". For example, the horizontal guide 8a' ' can be configured to be placed at the top surface of the implant or crown 30, 32. The vertical guide 8b" is adjacent to the side wall of such implant/crown so that the head 2 can be reliably positioned in the desired position every time for taking measurements. The vertical guide 8b" can be configured to be parallel to the face of the open end 3 a and perpendicular to the horizontal guide 8a" (FIG. 7 A) or can be angled in relation to the face of the open end 3a (FIG. 7B). The guide 8" can further comprise an annular body 60 configured to be placed over the housing 3 so that the horizontal and vertical guides 8a", 8b" project ahead from the open end 3a without blocking it. A support bar 61 connected to a wall of the annular body 60 projects forward from the body 60 and is configured as a supporting arm for the vertical and horizontal guides 8b" and 8a". In one implementation, the support bar 61 can be integral with the housing's wall and can comprise a notch or opening (not shown) so that a proximal end 62 of the horizontal guide 8a" can be inserted or secured therein by friction or any other suitable fastening method. In one implementation, the support bar 61 can be inserted or secured to the vertical guide 8b" by friction, clamp, screw, etc. The horizontal guide 8a" is configured to engage the top surface of the implant/crown 30/32. The horizontal guide 8a" can be L-shaped so that does not obstruct the pathway of the impact rod 6 and the viewing field of the user. The vertical guide 8b" is connected to the horizontal guide 8a" and it does not obstruct the open end 3a of the housing 3 or the user's view of the impact rod 6 during measurement. The vertical guide 8b" can be perpendicular to the horizontal guide 8a" (FIG. 7A) or can be positioned under a pre-determined angle in relation to the horizontal guide 8a". Part of the vertical guide 8b" projects downward from the horizontal guide 8a" and is configured to engage a surface of the measuring object, i.e. implant or crown 30, 32 while part of the vertical guide 8b" project upward of the horizontal guide 8a' ' and serves as a visual guidance of the user so that the user can know the angle of impact based on the tilt/angle between the upper part of the vertical guide 8b" and the measuring object. The user can manually record the impact angle and the impact position based on the visual observation of the position of the object in relation to the vertical guide 8b". After the measurement is completed the guide 8, 8' or 8" can be removed and can be disposed or can be sterilized and reused. In one implementation, the housing 3 can comprise an opening or notch formed in its wall at the open end 3a so that the guide 8, 8', 8" can be at least partially inserted therein and secured by either a friction fit, screw or any other fastening method that can allow removably securing the guide. For example, FIGS. 8A and 8B show the housing 3 having a notch (groove) 70 formed in its wall 72 in which the support bar 61 of the T-shaped guide 8" can be inserted and secured. FIG. 8 A shows the guide 8" separated from the housing 3 of the probe 10 while FIG. 8B shows the guide 8" secured in the notch 70 of the housing 3. The guide 8, 8', 8" can further be coated, for example with a teflon coating to reduce friction between the measuring object and the guide, for noise reduction during measurement or to reduce signal noise.

In one implementation, an electronic guide can be used instead. The electronic guide can comprise electronics (electronic components, circuits) that can calculate the position and orientation of the head, and the impact angle and/or orientation of the impact rod 6 during stability measurements. In one embodiment, the electronic guide can calculate the path of the impact rod 6 to the impact of the impact structure. Such electronic guide can perform the calculations in real-time and can guide the user to position the head 2 to a right position and orientation to take the measurements. By using an electronic guide the head 2 of the probe 10 does not need to be motionless or the user does not need to bring the head in a predetermined position and/or orientation during the measurements. The position and orientation of the head as well as the impact angle and orientation of the impact rod 6 can be calculated by the electronic guide and can be accounted for during analysis. For example, the electronic guide can calculate the position and orientation of the head and the impact angle and/or impact path of the impact rod and can send such data to a processing unit for analysis. If there are any deviations from the desired position and orientation the processing unit can account for such deviations during the analysis without compromising the accuracy of the measurement results. This provides the user with more flexibility during the measurements. For example, the electronic guide can be an inertial measurement unit (IMU) that can include 3D Gyro, 3D accelerometer, 3D magnetometer and/or any other suitable sensor or combination of sensors that can calculate the position and orientation of the head 2 with respect to the object/impact surface as well as the impact angle, orientation and/or impact path of the second end 6b of the impact rod 6.

The IMU can be placed within the handle 4 of the probe 10 or can be placed outside the probe 10 as a separate unit and can be connected or in communication with the probe 10 either wirelessly or with wire.

In one implementation, the electronic guide can be used in addition to the mechanical guide 8, 8', 8". The guide 8, 8', 8" can be used as a mechanical guide as described above and the electronic guide can be used to measure the position, orientation and impact angle of the measuring probe 10 during the measurements and can alert the user if the probe 10 is in the right position and/or orientation. The user can adjust probe's position and/or orientation before the measurements are taken. The user can be notified/alerted of the probe's position/orientation by either sound signal or a visual signal (using a display 18) or both. An alert system (visual or sound or both) can be also used to inform the user of any error in the measurements and if the measurements need to be repeated.

During the impact, when the impact rod 6 contacts the impact structure (i.e. crown 32 or implant 30) it decelerates and then recoils. Higher deceleration of the impact rod 6 (faster it recoils) indicates a greater stability of the object. For example, when the implant 30 is soft due to its soft integration, upon the impact rod 6 impacts the object (e.g. the implant 30 or the system of the implant 30 and the crown 32), it will move slightly in a direction of the impact force. As a result the impact rod 6 will follow the forward move of the object and will take time to get to its maximum impact level (maximum voltage/current). Thus the recoil of the impact rod 6 is slower resulting in a voltage/current signal curve with gentler ascending/descending angle. When the impact rod 6 comes to a stop (maximum impact level) and it starts to recoil, the voltage/current signal generated by the sensor 7 will slowly start discharging (small descending slope). When the implant is integrated, it is more rigid, so that the impact rod 6 recoils much faster resulting in voltage/current signal curve that has sharper ascending and descending angles. Sharper ascending/descending angle of the voltage/current signal curve indicates a more stable implant whereas a gentler slope indicates less structural stability of the implant or implant's failure in some instances.

In one implementation, the system for measuring the structural stability of the present invention can further comprise at least one sensor in addition to the detector 7, 7' to provide additional information on the object's structural stability. Such additional sensor can be a microphone, an accelerometer or any other suitable sensor used to detect acoustic waves, pressure waves, acceleration or vibrations reflecting from the object upon impact of the impact rod 6 with the impact structure. For example, such additional sensor can be one or all of the sensors of the electronic guide such as the 3D accelerometer, 3D magnetometer, 3D Gyro etc. Such sensors can be used to provide complementary information of the structural stability of the object in addition to the output signal of the sensor 7, 7'. In one embodiment, the output signal(s) from the detector 7, T and/or any other additional sensors can be improved by employing signal amplifier and/or one or more signal filters. For example, one or more digital and/or analog filters can be used to subtract the background noise (e.g. noise from the vibration of the probe 10). In addition, any interference between the output signal from the sensor 7, 7' and the signal/noise from any other sensors (electronic guide) or any other electric circuit and/or mechanical components can be canceled by using one or more analog or digital filters. The system can also comprise a protection circuit e.g. an overvoltage protection circuit to protect the electronics from being damaged by voltage transient, for example to prevent too big output signal from the sensor (high voltage/current) damaging the electronics. For example, such protection circuit can comprise a breaker, a fuse, a voltage divider etc.

The response signal (e.g. a voltage/current signal) generated by the detecting sensor 7, 7' and output signals from any other additional sensors (if any) are then transferred to the processing unit for analysis. The processing unit can be placed inside the handle 4 of the measuring probe 10 or can be remote from the measuring probe 10 as a separate unit, such as a computer that is in communication with the head 2 of the probe 10. Details of the processing unit are illustrated in FIG. 9. The signal from the sensor 7, 7' or any other sensors can be transferred to the processing unit either wirelessly or through a suitable wire connection. The output signal generated by the sensor (e.g. detector 7, 7') can be first pre-processed to assess a quality of the impact (e.g. signal's amplitude, wavelength, frequency, noise, angle of impact) and acceptability of the signal for further analysis. If the signal obtained from the detector 7, 7' is unacceptable the user will be notified (visually or by sound) that the status of the tap (impact) is not good and that the measurement needs to be repeated. The processing unit can also receive the data from the electronic guide (e.g. IMU) or can be manually input by the user and can perform all the calculations and analysis to guide the user to position the head 2 of the probe or to reposition the probe 10 if any errors in the position/orientati on/impact angle were identified.

In one implementation, the raw signal obtained from the detector 7, 7' can be pre- processed to account for an effect of the impact force and to provide a normalized signal. For example, the signal (analog and/or digital) can be pre-processed and in some implementations post-processed by filtering using any or all of a high pass filter, a low pass filter, a wavelet filter, a Butterworth filter, a Chebyshev filter, an elliptical filter, a Bessel filter, a Kalman filter, etc.

FIGS. 10A to IOC show examples of raw voltage signal (in volts) as a function of time (in seconds) obtained from a detecting sensor 7, 7' at various stages of implant integration process before the signals were normalized. FIGS. 10A and 10B illustrate only a first wave of the obtained signal for clarity purposes only, however person skilled in the art would understand that the processing unit processes and analyzes the entire signal obtained from the detector 7, 7'. FIG. 10A shows a raw signal 81 obtained at early stage of implant integration. As can be noticed the curve 81 has a gentle ascending angle (inclining angle/gradient of the voltage curve) indicating a soft implant. FIG. 10B illustrates implant's response signal 82 during the integration process with a sharper ascending angle then the curve 81 of FIG. 10A, while FIG. IOC illustrates implant's response signal 83 when the integration of the implant is almost completed (fully integrated implant interface). As can be noticed, the ascending angle of the curve 83 is very sharp (close to 90°). Although the shape of the signals 81, 82 and 83 for each state is preserved, the amplitudes vary depending on the level of the pushing force (impact force) applied by the user during measurements. FIG. 11 illustrates curve 81, 82, and 83 of FIGS. 10A - IOC after the processing unit processes the raw signals (81, 82 and 83) and provides corresponding normalized signals (81 ', 82' and 83'). The raw signal can be normalized by identifying a maximum amplitude (maximum voltage/current) and dividing the raw signal by the maximum value. As can be noticed in FIG. 11, the maximum amplitude of all three signals (curves 81 ', 8' and 83') is similar. Person skilled in art would understand that any other method can be used to normalize the output signals of the sensor 7, 7' without departing from the scope of the invention. In some implementations, un- normalized curves can be used to analyze and make a decision on the stability of the object.

If the signal obtained from the detector 7, 7' is acceptable for further analysis, the obtained signal will be further analyzed by the processing unit and a quotient number will be calculated. In one implementation, the normalization of the raw signals can be omitted and the raw signals can be used to calculate the quotient number. The quotient number can indicate the level of the structural stability of the object. The quotient number can be a scale indicating a high structural stability, low structural stability and gradient between the high and the low values. For example, a higher quotient number can indicate greater structural stability while a lower quotient number can indicate lower structural stability. In one implementation, the quotient number can be calculated using the ascending and/or the descending angles of the voltage/current curve. A higher inclining angle, sharper ascending/descending angle of the voltage/current curve, provides a quotient number that indicates higher structural stability of the object while slow raising voltage/current curve (gentle ascending/descending angle) indicates lower structural stability of the object. The incline of the ascending/descending angle determines the rate of object's structural stability. The sharper angles (closer to 90°) indicate more stable structures while smaller ascending/descending angles correspond to softer structures.

In one implementation, the quotient number can be calculated by calculating the area under the curve after the signals were normalized. As can be noticed in FIG. 11 the area under curve 83' is much smaller than the area under the curve 82' or 83' meaning that the smaller area under curve indicates higher quotient number and greater object stability.

In another implementation the quotient number can be calculated by curve fitting the voltage/current data. For example the curve fitting can be based but not limited to a Weibull, Gaussian, polynomial, exponential or any other curve fitting function. As can be noticed from FIGS. 10, 11 and 12 the bells of the signals' curves are not perfectly symmetric and are very much like Weibull distribution function. An algorithm has been developed to curve fit the results from the experiments with the Weibull function and identify the fitting parameters. Each of the curves has a shape parameter "k" and a scale parameter "λ" which are the fitting parameters. Once the fitting parameters are identified one or all can be used as a quotient number or to calculate a quotient number. For example, lower values of λ can indicate a higher structural stability of the object.

In addition to calculating the quotient number, the various factors that helped determine the quotient number (e.g. signal's amplitude, wavelength, frequency, quantified measurement of signal noise, angle of impact), can be also used to calculate a quality number. The purpose of the quality number is to show how reliable is the measured quotient number. To do this, the quality number can be a number from a scale (e.g. -10 - +10), and is determined by using the quality factor of parameters that determined the original quotient number (e.g. signal's amplitude, wavelength, frequency, quantified measurement of signal noise, angle of impact). Each of these parameters will have its own quality factor and their quality factor is determined by certain limits.

For one example, if the original signal amplitude was above a certain voltage, for example 3V, a quality factor for the amplitude can be assigned a positive number of e.g. +0.5, and if it was below a certain voltage of e.g. 3V , a negative number (e.g - 0.5) can be assigned. The scoring around the voltage is based on the strength of the tap, thus a weak tap will result in a poor quality factor.

In case of the wavelength parameter, if the original signal wavelength was less than a certain period (e.g 2ms) a quality factor for the wavelength can be for example a positive number and if it was above the certain period (e.g. 2.ms ) a negative number (e.g -0.5) can be assigned. The scoring around the wavelength is based on how quick the contact of the impact was made, a quick impact is most similar to an impulse and thus results in a better quality factor. The frequency parameter can for example share a similar scoring characteristic as wavelength parameter.

With respect to the quantified measurement of a signal noise parameter, if the original signal was determined to be extremely noisy, a quality factor for the noise parameter can be assigned a negative number (e.g -0.5) and a signal that was determined to have less noise can be assigned a positive quality factor of number (e.g. +0.5). An extremely noise signal can have some effect to the measurement of the quotient number, thus a noisy signal will result in poor quality factor. In case of the angle of impact parameter, if the original impact was made normal to the impact structure surface, a quality factor for the angle of impact parameter can be assigned a positive number, (e.g +0.5), and if the angle of impact is angled from the surface of impact, a negative quality factor can be assigned (e.g -0.5). An angled impact to the surface of a structure results in a poorer quality factor. Using these various quality factors, a quality number can determine of the overall quality of the quotient number. The quality number can also be used to determine a quotient correction factor number. This quotient correction factor can be combined with the quotient number and can adjust for the overall quality of the quotient number. In addition to calculating a quotient number the processing unit can further conduct a frequency response analysis. The time domain signal (voltage/current over time signal) obtained from the sensor 7, 7' is converted to a frequency domain signal using fast Fourier transform (FFT) to find frequency response. Then the processing unit searches for the amplitude peak and use that for a quotient number. In one implementation, the frequency response analysis can be also used to calculate a dampening energy of the object.

In one implementation, the quotient number can be calculated by looking at the slopes of multiple curves in a sine wave output signal and the output trend (see FIG. 12), e.g. a first peak has a sharp ascending/descending angles while the following peaks have much gentler ascending/descending angles may indicate less stable object than multiple sharp peaks in a row; or based of the number of peaks in one output signal and the consistency of their ascending/descending angles; or the relationship of the ascending angle versus descending angle to the wave length of the signal (first wave and/or multiple waves). In addition, the algorithm for calculating the quotient number can analyze data as: areas under tangent lines from the various points on the curve to x-axis; wave length of the start of the wave to the peak, from the peak back to the x- axis, from the x-axis to the valley, from the valley to the x-axis along with the slopes connecting these points; rate of change of the various tangents and slopes as well; comparison between the highest and lowest rate of change of the slopes on each peak; change in amplitude of each subsequent wave until signal dissipation; line between peak and valley of one wave and relationship to the same line of the subsequent waves in the signal; using a straight line that best fits the peaks and a line that best fits the troughs/valleys and the formed angle; using a curved line that best fits all the peaks and a curved line that best fits all the troughs (see dotted lines of FIG. 12) to find a damping coefficient; etc. In addition, in case of a signal with a wave with more than two inflection points (two peaks in one wave) the algorithm can take this into account in addition to the slopes angle, wavelength and area. The calculated quotient is displayed on the display 18. The display 18 can be a LCD display located at the handle 4 of the probe 10. Apart from displaying the quotient number, the display 18 can be also used to communicate to the user the information of probe position/orientation and impact angle, connectivity of the system, the number of the successful impacts, etc. In one implementation, the display 18 can be remote from the probe, for example can be a monitor such as a computer monitor. Data can be transferred to the monitor wirelessly or by a wire. The data from each measurement and the results are stored in a computer (block "Server" of FIG. 9) designed as a storage unit and can be accessed later for further analysis or comparison (block "APP" of FIG. 9). For example, APP can be a computer application or a tablet application. It can be responsible for taking the signal from the processing unit and relaying it to the server or it can receive the quotient from the processing unit or the server and can display it on the display 18. Furthermore, the APP can be used for data input such as for example, where the user can record the angle and location of the impact and a measuring object identification (i.e. what tooth was impacted).

FIGS. 13 A and 13B show output signals taken with a probe 10 with only electronic guide (no mechanical guide used). FIG. 13A shows a signal taken from taps on an implant while FIG. 13B shows a signal taken from a crown. The analog to digital conversion towards this data acquisition is done at 192 kHz at a 12-bit resolution. When measurement is being done on an implant, the tip (second end 6b of the impact rod 6) of the probe 10 is in direct contact with the implant 30 and the resulting signal is a representation of that contact only. For the case of the signal from the crown 32 (FIG. 13B), the impact signal would have to travel through the crown material and the cement and/or screw that fasten the crown to the implant. The added layers would affect the signal. In order to cancel these effects on the signal, the signal obtained from the crown (FIG. 13B) is filtered through a Wavelet denoising operation. Once the noise from the signal obtained from the crown 32 is removed, the processing is common for both signals of FIGS. 13A and 13B respectively.

In one implementation, the stored data can be used to train the processing unit to learn a difference between stable vs. unstable object or acceptable vs. unacceptable impact.

For example, signals from a number of measurements taken during stability measurements of different objects (e.g. signals taken during osseointegration process of a number of implants) are stored and used as a training set. Each of the signals in the training set is analyzed to find the unique features of such signals and use such unique features as "identifiers". For example, in frequency domain signals (signals converted from time domain to a frequency domain) the highest peaks are identified and used as "identifiers". Then using an algorithm called "artificial intelligence" the system relates the identifiers to a particular status of the object (e.g. peak 1 relates to 30% integration, peak 2 to 40% integration etc.). An artificial intelligence unit/algorithm of the system is then trained and once trained such system can be used to recognize status of the object's stability during real-time measurements. The system can be train in real-time or offline.

The system for measuring structural stability of the present invention can be powered by direct connection to a power outlet or by a battery. The charging of the system can be wired, inductive or using any other suitable charging mechanism. The system can be charged when it is or it isn't in use. A calibration unit (not shown) can be used for calibrating the system of the present invention. The system can be calibrated before it is delivered to the user or can be calibrated from time to time (i.e. every few months, daily or when the user doubts the measurements, or prior to measurement). The calibration unit comprises an object with known structural stability and therefore known quotient number. During calibration, the impact rod impacts the calibration unit and the quotient number is calculated according to the methods described above and any discrepancy in the obtained quotient number and the known quotient number is adjusted.

While particular elements, embodiments and applications of the present disclosure have been shown and described, it will be understood, that the scope of the disclosure is not limited thereto, since modifications can be made by those skilled in the art without departing from the scope of the present disclosure, particularly in light of the foregoing teachings. Thus, for example, in any method or process disclosed herein, the acts or operations making up the method/process may be performed in any suitable sequence and are not necessarily limited to any particular disclosed sequence. Elements and components can be configured or arranged differently, combined, and/or eliminated in various embodiments. The various features and processes described above may be used independently of one another, or may be combined in various ways. All possible combinations and subcombinations are intended to fall within the scope of this disclosure. Reference throughout this disclosure to "some embodiments," "an embodiment," or the like, means that a particular feature, structure, step, process, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in some embodiments," "in an embodiment," or the like, throughout this disclosure are not necessarily all referring to the same embodiment and may refer to one or more of the same or different embodiments. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, additions, substitutions, equivalents, rearrangements, and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions described herein.

Various aspects and advantages of the embodiments have been described where appropriate. It is to be understood that not necessarily all such aspects or advantages may be achieved in accordance with any particular embodiment. Thus, for example, it should be recognized that the various embodiments may be carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other aspects or advantages as may be taught or suggested herein. Conditional language used herein, such as, among others, "can," "could," "might," "may," "e.g.," and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without operator input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment. No single feature or group of features is required for or indispensable to any particular embodiment. The terms "comprising," "including," "having," and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term "or" is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term "or" means one, some, or all of the elements in the list.

The example calculations, simulations, results, graphs, values, and parameters of the embodiments described herein are intended to illustrate and not to limit the disclosed embodiments. Other embodiments can be configured and/or operated differently than the illustrative examples described herein.

Claims

A device for measuring a stability of an object comprising: a measuring probe having a head that includes a housing having a first end, a second end and a body extending between the first end and the second end, at least one of the housing's ends being open, an impact means positioned at least partially within the housing and configured to impact an object, the impact means having a first end and a second end, the second end of the impact means projecting out from the at least one open end of the housing, and a detector connected to the first end of the impact means for detecting a reaction behavior of the object upon the impact of the impact means with an impact structure, the detector producing an output signal based on the reaction behavior of the object; and a guide configured to determine a position and an orientation of the head of the probe and an impact angle during measurements.

The device of claim 1, wherein both of the housing's ends are open, the device further comprising an additional impact means so that its second end projects out from the other open end of the housing.

The device of claim 2, further comprising an additional detector in communication with the additional impact means.

The device of claims 1 to 3, wherein the impact means is selected from a group comprising an elongated rod, a ball, a hemi-sphere and a plate.

The device of claim 1, wherein the guide is a sleeve having a first end, a second end and a body between the first end and the second end, a passage formed in the body extending from the first end to the second end, the passage being configured and sized so that the impact means can be inserted into the passage, the first end of the guide being configured to position the guide in a predetermined position and orientation with respect to the object.

The device of claim 5, wherein the sleeve is inserted into the at least one open end of the housing to envelop the second end of the impact means and being configured to slide along the longitudinal axis of the head from an extended position in which the second end of the impact means is enveloped by the sleeve to an retracted position when the second end of the impact means protrudes through the first end of the sleeve.

The device of claim 5, wherein the sleeve is separate and independent of the measuring probe, the sleeve being temporarily attached to the impact structure in a predetermined position and orientation.

The device of claim 1, wherein the guide comprises a suction cup removably secured to the housing in proximity to the least one open end of the housing and configured to engage the object during measurements.

The device of claim 1, wherein the guide is T-shaped guide having a horizontal guide and vertical guide that is vertical in relation to the horizontal guide, the T-shaped guide being removably secured to the housing in proximity to the at least one open end of the housing.

The device of claim 1, wherein the guide is an electronic guide comprising a position measuring unit to calculate the position and orientation of the head and an impact angle of the impact means guiding a user to position the head of the probe in a desired position and orientation.

The device of claim 1, further comprising at least one additional sensor to detect at least one of acoustic waves, pressure waves, acceleration or vibrations reflecting from the object upon impact of the impact means with the impacting structure.

A system for measuring a stability of an object, comprising: a measuring probe having: a head that comprises a housing having a first end, a second end and a body extending between the first end and the second end, at least one of the housing's ends being open end, an impact means positioned at least partially within the housing and configured to impact an object, the impact means having a first end and a second end, the second end of the impact means projecting out from the at least one open end of the housing, the second end of the impact means projecting out from the at least one of the open end of the housing, and a detector connected to the first end of the impact means for detecting a reaction behavior of the object upon an impact of the impact means with an impact structure, the detector producing an output signal of the reaction behavior of the object; a guide configured to determine a position and an orientation of the head of the probe and an impact angle during measurements; and a processing unit in communication with the detector to receive the output signal from the detector and based on the output signal from the detector and data of the position and orientation of the head and the impact angle produces a data of the structural stability of the object.

The system of claim 12, wherein the guide is a sleeve with a first end, a second end and a body between the first end and the second end, a passage formed in the body extending from the first end to the second end, the passage being configured and sized so that the impact means can be inserted into the passage, the first end of the sleeve being configured to position the guide in a predetermined position and orientation in relation to the object.

The system of claim 13, wherein the sleeve is inserted into the at least one open end of the housing to envelop the second end of the impact means and being configured to slide along the longitudinal axis of the head from an extended position in which the second end of the impact means is enveloped by the sleeve to an retracted position when the second end of the impact means protrudes through the first end of the sleeve.

The system of claim 13, wherein the sleeve is separate and independent of the measuring probe, the sleeve being temporarily attached to the impact structure in a predetermined position and orientation.

The system of claim 12, wherein the guide comprises a suction cup removably secured to the housing in proximity to the least one open end of the housing and configured to engage the object during measurements.

The system of claim 12, wherein the guide is T-shaped guide having a horizontal guide and vertical guide that is vertical in relation to the horizontal guide, the T-shaped guide being removably secured to the housing in proximity to the least one open end of the housing.

The system of claim 12, wherein the guide is an electronic guide comprising a position measuring unit to calculate the position and orientation of the head and the impact angle guiding a user to position the head of the probe in a desired position and orientation.

The system claim 12, wherein the processing unit calculates a quotient number based on the output signal of the sensor, the quotient number providing a scale of a grade of the structural stability of the object.

A method for measuring a stability of an object, comprising:

- guiding a measuring probe in a desired position and orientation with respect to an object;

exciting the object by impacting it with an impact means;

detecting a signal from the object in response to the impact;

- transferring the signal to a processing unit;

analyzing the signal to calculate a quotient number based on the analyzed signal;

determining object's stability based on a value of the quotient number; and displaying the data of the object stability to a user.

A method of claim 20 used in a trending analysis of the object's structural stability throughout its life.

A method of claim 20 used for comparison analysis between structural stability of different objects.