Disclosure of Invention
In view of the above-mentioned disadvantages of the prior art, an object of the present invention is to provide a human body sitting station transferring capability measuring apparatus, a measuring method and an electronic device, which are used to solve the problems of the prior art that the apparatus is expensive, the measuring environment requirement is high, the installation of the reflective marker is time-consuming, the requirement for the installation position is high, the apparatus is easily shielded, a dedicated laboratory space is required, and the post-processing time is long.
To achieve the above and other related objects, the present invention provides a human body sitting station transfer capability measuring apparatus, comprising:
the force measuring pedal is arranged on the sole of a human body;
at least three posture measuring devices respectively arranged at the positions of the crus, the thighs and the trunk of the human body;
and the upper computer is respectively connected with the posture measuring devices and the force measuring pedal and is used for acquiring joint angle data and joint moments of ankle joints, knee joints and hip joints according to received plantar force data measured by the force measuring pedal in the human body sitting station transfer movement process and movement posture data of positions of shanks, thighs and trunks of the human body measured by each posture measuring device.
In an alternative embodiment, the load cell comprises a two-dimensional force measuring device or a multi-dimensional force measuring device.
In an alternative embodiment, the attitude measurement device comprises a combination of a two-axis acceleration sensor and a single-axis gyroscope, or a six-axis inertial sensor consisting of a 3-axis gyroscope and a 3-axis acceleration sensor, or a nine-axis attitude sensor consisting of a 3-axis accelerometer, a 3-axis gyroscope and a 3-axis electronic compass.
In order to achieve the above and other related objects, the present invention further provides a method for measuring a transfer capability of a human body sitting station, comprising the steps of:
measuring plantar force data in the human body sitting station transfer movement process by using a force measuring pedal, and measuring movement posture data of positions of shanks, thighs and trunks of the human body in the human body sitting station transfer movement process by using a posture measuring device;
and acquiring joint angle data and joint moments of ankle joints, knee joints and hip joints in the human body sitting, standing and transferring process by using the sole force data and the motion posture data.
In an alternative embodiment, in the step of measuring plantar force data during the human body sitting and standing transfer exercise by using the force measuring pedal, the plantar force data comprises human body plantar horizontal force and normal force and force action positions.
In an alternative embodiment, the Euler angles in the motion posture data of the positions of the lower leg, the upper leg and the trunk of the human body are used for calculating joint angle data of the ankle joint, the knee joint and the hip joint of the human body.
In an optional embodiment, in the human body sitting and standing transfer process, the step of acquiring the joint angle data and the joint moment at the ankle joint, the knee joint and the hip joint in the human body sitting and standing transfer process by using the plantar force data and the motion posture data comprises the following steps:
acquiring ankle joint moment according to the sole force data;
acquiring knee joint moment according to the plantar force data and the motion posture data measured by the posture measuring device at the position of the crus;
and acquiring hip joint moment according to the plantar force data and the motion posture data measured by the posture measuring device at the trunk.
In an optional embodiment, before the hip of the human body leaves the seat, the step of acquiring the joint angle data and the joint moment at the ankle joint, the knee joint and the hip joint in the sitting and standing transfer process of the human body by using the plantar force data and the motion posture data comprises the following steps:
acquiring ankle joint moment according to the sole force data;
acquiring knee joint moment according to the plantar force data and the motion posture data measured by the posture measuring device at the position of the crus;
acquiring hip joint moment according to motion posture data measured by the posture measuring device at the trunk;
obtaining seat supporting force according to the plantar force data and the movement posture data measured by the posture measuring devices at the positions of the crus, the positions of the thighs and the trunk, and judging whether the buttocks of the human body leave the seat or not according to the seat supporting force;
when the hip of the human body leaves the seat, the step of acquiring the joint angle data and the joint moment of the ankle joint, the knee joint and the hip joint in the sitting and standing transfer process of the human body by the motion posture data comprises the following steps:
acquiring the total potential energy and kinetic energy of the human body in the sitting and standing transfer process according to the motion posture data, the coordinates of the mass centers of the human body crus, the thighs and the trunk and the lengths of the human body crus, the thighs and the trunk;
and acquiring joint moments of the ankle joint, the knee joint and the hip joint in the human body sitting and standing transfer process according to the total potential energy and the kinetic energy in the human body sitting and standing transfer process.
In an optional embodiment, the method for measuring the human body sitting and standing transfer capability further comprises the step of judging the lower limb movement capability, muscle strength and balance capability of the human body in the sitting and standing transfer process according to the acquired joint angle data and joint moments of the ankle joint, the knee joint and the hip joint in the human body sitting and standing transfer process.
To achieve the above and other related objects, the present invention further provides an electronic device, comprising a processor and a memory coupled to each other, wherein the memory stores program instructions, and the program instructions stored in the memory when executed by the processor implement the human body sitting station transferring capability measuring method.
According to the human body sitting and standing transfer capacity measuring device, the measuring method and the electronic equipment, during measurement, the posture measuring devices are installed on the shanks, the thighs and the trunk of a user, the feet stand on the force measuring pedal, the movement posture data of the positions of the shanks, the thighs and the trunk of the human body transmitted by the posture measuring devices in the sitting and standing process and the foot bottom force data transmitted by the force measuring pedal are recorded, the moment of each joint is calculated, and the lower limb movement capacity, the muscle force and the balance capacity of the human body in the sitting and standing transfer process are judged according to the moment of each joint.
The invention provides a sitting and standing transfer measuring device based on an attitude measuring device and a force measuring pedal, which has the characteristics of practicability, simplicity, convenience in installation, unlimited installation position, reasonable wiring and convenience for clinical popularization.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.
It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.
Please refer to fig. 1-4. It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention, and the drawings only show the components related to the present invention rather than the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.
Fig. 1 shows a schematic view of a human body sitting and standing transfer capability measuring apparatus of the present invention worn on a human body. Referring to fig. 1, the human body sitting and standing transfer measuring device may include: a force measuring pedal 1, at least three attitude measuring devices and an upper computer (not shown).
Referring to fig. 1, in the present embodiment, the force measuring pedal 1 is located under the foot of the human body to be measured, and is used for measuring the ground reaction force during the transfer exercise of the human body in the sitting position, and the force measuring pedal 1 may be, for example, a two-dimensional force measuring device, and may be used for measuring the sole horizontal force, the normal force, and the force action position of the human body, and the sole horizontal force is the friction force between the human body and the ground. It is understood that in other embodiments, the force measuring pedal 1 may also employ a multi-dimensional force measuring device, which can measure the joint moments at the ankle joint, the knee joint and the hip joint before the hip leaves the seat and the joint moments at the ankle joint, the knee joint and the hip joint after the hip leaves the seat.
Referring to fig. 1, in the present embodiment, the posture measuring devices include three posture measuring devices, which are respectively located on three body segments of the human body, namely, the shank, the thigh and the trunk, and are used for measuring the movement posture data of the positions of the shank, the thigh and the trunk during the sitting, standing and transferring process of the human body. As an example, the posture measuring device can be located at any position of the human body legs, thighs and trunk, and does not need to limit the position of the center of mass placed at the human body legs, thighs and trunk. It will be appreciated that in other embodiments, attitude measurement devices such as a combination of a two-axis acceleration sensor and a single-axis gyroscope, or a six-axis inertial sensor consisting of a 3-axis gyroscope and a 3-axis acceleration sensor, or a nine-axis attitude sensor consisting of a 3-axis accelerometer, a 3-axis gyroscope, and a 3-axis electronic compass. As an example, the motion attitude data includes motion attitude data such as acceleration, angular velocity, and euler angle. As an example, the three posture measuring devices include a first posture measuring device 2 provided on the calf of the human body, a second posture measuring device 3 provided on the thigh of the human body, and a third posture measuring device 4 provided on the trunk of the human body.
And the upper computer is respectively connected with the posture measuring device and the force measuring pedal 1, and is used for acquiring joint angle data and joint moments of ankle joints, knee joints and hip joints according to the received plantar force data measured by the force measuring pedal 1 and the motion posture data of the positions of shanks, thighs and trunks of the human body measured by each posture measuring device in the process of human body sitting station transfer motion, and sending an operation instruction to the force measuring pedal 1 and the posture measuring devices for measurement.
Fig. 2 is a flow chart showing a method for measuring the transfer capability of the human body sitting station by using the above-mentioned device for measuring the transfer capability of the human body sitting station. Referring to fig. 2, the method for measuring the transfer capacity of the human body sitting station includes:
step S1: measuring foot sole force data in the human body sitting station transfer movement process by using a force measuring pedal 1, and measuring movement posture data of positions of shanks, thighs and trunks of a human body in the human body sitting station transfer movement process by using a posture measuring device;
step S2: acquiring joint angle data and joint moments of ankle joints, knee joints and hip joints in the sitting and standing transfer process of the human body by utilizing the plantar force data and the motion posture data;
step S3: and judging the lower limb movement capability, muscle strength and balance capability of the human body in the human body sitting station transfer process according to the acquired joint angle data and joint torque of the ankle joint, the knee joint and the hip joint in the human body sitting station transfer process.
FIG. 3 shows a schematic diagram of a mathematical model built according to the simplified human rigid body model of the present invention. The following will specifically describe the steps S1-S3 of the method for measuring the transfer ability of a human body sitting and standing in the present embodiment with reference to fig. 2 and 3.
Referring to fig. 2 and 3, in step S1, the force measuring pedal 1 is used to measure the sole force data during the transfer exercise of the human body sitting and standing, wherein the sole force data includes the horizontal force F of the human solexAnd normal force FyAnd force action positions (x, y), and the sole force measuring device can be a two-dimensional force measuring device or a multi-dimensional force measuring device when calculating joint moments at ankle joints, knee joints and hip joints of a human body.
Referring to fig. 2 and 3, in step S1, motion posture data of positions of the human body 'S calf, thigh and torso during a sitting-standing transfer motion of the human body (including two states before and after the hip leaves the seat) are obtained by the posture measuring devices respectively disposed at the positions of the human body' S calf, thigh and torso, wherein the motion posture data includes acceleration and angular velocity. As an example, the attitude measurement device is, for example, a combination of a two-axis acceleration sensor and a single-axis gyroscope, or a six-axis inertial sensor composed of a 3-axis gyroscope and a 3-axis acceleration sensor, or a nine-axis attitude sensor composed of a 3-axis accelerometer, a 3-axis gyroscope, and a 3-axis electronic compass.
Referring to fig. 2 and 3, the step S2 further includes a step S21 of calculating joint angle data of the human body at the ankle, knee and hip joints by using euler angles in the motion posture data of the positions of the lower leg, thigh and trunk of the human body; and step S22, acquiring joint moments of an ankle joint, a knee joint and a hip joint in the human body sitting and standing transfer process by using the sole force data and the joint angle data.
In step S21, joint angle data θ at the ankle joint, knee joint and hip joint during the human body sitting and standing transfer movement (including two states before and after the hip leaves the seat) is calculated by using the euler angles in the movement posture data of the positions of the lower leg, thigh and trunk of the human bodyiAnd i is 1,2,3, which indicates ankle joint, knee joint and hip joint, respectively. As an example, the Euler angles include a roll angle α, a pitch angleBeta, yaw angle gamma.
Referring to fig. 2 and fig. 3, specifically, the step S21 may further include:
step S211: fixing three posture measuring devices at the positions of the shank, the thigh and the trunk through binding bands respectively, defining an inertial coordinate system W of the posture measuring devices, establishing a global coordinate system { OXYZ } at the foot, locating a coordinate origin O at the ankle joint, and establishing a local coordinate system { O } at the shank, the thigh and the trunk respectivelyixiyizi1,2 and 3, the coordinate origins are respectively positioned at the ankle joint, the knee joint and the hip joint, and a joint angle theta is definediIs yiThe angle between the positive direction of the X.
Step S212: let the lengths of the shank, thigh and trunk be l1、l2And l3The joint rotation centers are A, B, C respectively, and the angle theta of the ankle joint1Knee joint center B in coordinate system { o }1x1y1z1The position vector below is:
step S213: let a coordinate system { o
1x
1y
1z
1The rotation matrix with respect to the inertial frame W is
The rotation matrix of the global coordinate system { OXYZ } with respect to the inertial coordinate system W is
The general formula of the rotation transformation matrix is:
the Euler angle gamma measured by the attitude measuring device
i、β
i、α
iBy bringing into the above formula, the corresponding
Then coordinate system o1x1y1z1Rotation matrix relative to a coordinate system { OXYZ }:
step S214: the position vector of the knee joint center B under the coordinate system { xyz } is:
step S215: the direction vector from point a to point B is denoted as a, so a is:
a=[ox oy oz]T
therefore, the angle between the vector a and the positive direction of the X axis, i.e. the ankle joint angle, is:
step S216: the rotation matrix is an orthogonal matrix, so
Are orthogonal, and therefore
Are also orthogonal, so:
thus:
θ1=cos-1(ox)。
step S217: for the same reason, θ2、θ3Can be obtained by the same method.
Referring to fig. 2 and 3, in step S22, the sole force data and the joint angle data are used to obtain the moment of the ankle, knee joint and hip joint in the sitting and transferring process of the human body, wherein the step S221 of obtaining the moment of the ankle, knee joint and hip joint in the sitting and transferring process of the human body includes the step S222 of obtaining the moment of the ankle, knee joint and hip joint before the hip leaves the seat and the step S222 of obtaining the moment of the ankle, knee joint and hip joint after the hip leaves the seat.
Before calculating the moment of the ankle joint, the moment of the knee joint and the moment of the hip joint, setting I
ci(i ═ 1,2, 3) denotes the distance of the body segment i centroid to its local coordinate system origin, m
iDenotes the mass of a body segment i (
i 1,2, 3), g denotes the acceleration of gravity, a
ij(i-1, 2, 3; J-X, Y) represents the centroid acceleration of the rigid body i in the J-axis direction in the predetermined global coordinate system { xyz }, and J represents the centroid acceleration of the rigid body i in the J-axis direction in the predetermined global coordinate system { xyz }
ci(i-1, 2, 3) represents the moment of inertia of the rigid body i with respect to its center of mass,
is theta
iThe second derivative of (2), i.e. the angular acceleration.
In step S221, when the hip of the human body is separated from the seat, the joint moments at the ankle joint, the knee joint, and the hip joint are measured through steps S2211 to S2215.
Step S2211: calculating to obtain the barycenter coordinates of the human body shanks, thighs and trunk according to the joint angle data of the human body shanks, thighs and trunk and the national standard formulation of human body inertial parameters of Chinese adults, and estimating to obtain the barycenter position according to the national standard formulation of human body inertial parameters of Chinese adults:
shank:
xc1=lc1cosθ1
yc1=lc1sinθ1
thigh:
xc2=l1cosθ1+lc2cosθ2
yc2=l1sinθ1+lc2sinθ2
trunk:
xc3=l1cosθ1+l2cosθ2+lc3cosθ3
xc3=l1cosθ1+l2cosθ2+lc3cosθ3
the mass center acceleration can be calculated by the mass center coordinate derivation data of the human body crus, thighs and trunk and the acceleration data in the motion posture data of the positions of the crus, the thighs and the trunk through the synthetic theorem.
Step S2212: calculating ankle joint moment M according to the plantar force data1:
The sole forces measured by the force measuring plate of the force measuring pedal 1 are respectively Fx、FyThe action point is (x, y), and the position of the action point is the action position of the force measured by the force measuring pedal 1, so that the action force of the ankle joint is as follows:
F1y=Fy
F1x=Fx
moment of action of ankle joint:
M1=yFx+xFy。
step S2213: calculating knee joint moment M according to the plantar force data and the motion attitude data measured by the attitude measuring device at the lower legz:
According to the principle of force balance, the force of the knee joint is:
F2y=F1y-m1g-m1a1y
F2x=F1x-m1a1y
moment of action of the knee joint:
step S2214: calculating hip joint moment M according to motion attitude data measured by the attitude measuring device at the trunk3:
For the trunk, hip forces:
F3y=m3g+m3a3y
F3x=m3a3x
F3Xrepresenting the friction force between the person and the chair surface;
moment of force acting on hip joint:
step S2215: obtaining seat supporting force F according to the plantar force data and the motion posture data measured by the posture measuring devices at the crus, the thighs and the trunkSeat with a detachable cover:
FSeat with a detachable cover-m2g-F′3y+F2y=m2a2y
Wherein, F'3yIs F3yThe reaction force of the seat back cushion is opposite in sign and equal in magnitude, and whether the buttocks of the human body leave the seat or not can be judged by calculating the seat supporting force.
In step S222, when the hip of the human body leaves the seat, the movement posture data is used to obtain the joint angle data and the joint torque at the ankle joint, the knee joint and the hip joint during the sitting and standing transfer of the human body. When the buttocks of the human body are separated from the seat, the seat supporting force is 0, that is, F in step S2215Seat with a detachable coverThe joint moments at the ankle, knee and hip joints are measured by steps S2221-S2222, 0.
Step S2221: acquiring the total potential energy E of the human body in the sitting, standing and transferring process of the human body according to the motion posture data, the coordinates of the mass centers of the legs, the thighs and the trunk of the human body and the lengths of the legs, the thighs and the trunk of the human bodypAnd kinetic energy Ek:
Ep=m1glc1sinθ1+m2g(l1sinθ1+lc2sinθ1)+m3g(l1sinθ1+l2sinθ2+lc3sinθ3)
Step S2222: acquiring joint moments tau at ankle joints, knee joints and hip joints in the sitting and standing transfer process of the human body according to the total potential energy and the kinetic energy in the sitting and standing transfer process of the human bodyi;
L=Ek-Ep
Wherein, i is 1,2,3, which corresponds to ankle joint, knee joint and hip joint of human body respectively.
It should be noted that, the calculation of the joint moments at the ankle joint, the knee joint and the hip joint of the human body by the calculation methods defined in the steps S221 and S222 is performed before the hip leaves the seat and after the hip leaves the seat, so as to reduce the calculation amount, because the calculation method defined in the step S222 requires relatively less known amount, which can reduce the calculation amount. It is understood that in some embodiments, the steps in step S221 may be applied to the whole human body sitting and standing transfer process (including two sub-processes before the human body buttocks leave the seat and after the human body buttocks leave the seat).
Referring to fig. 2, in step S3, the lower limb exercise ability, the muscle strength and the balance ability of the human body during the sitting and transferring process of the human body are determined according to the acquired joint angle data and joint moments of the ankle joint, the knee joint and the hip joint during the sitting and transferring process of the human body. For example, joint angle data, joint torque and human lower limb health data of ankle joints, knee joints and hip joints are obtained through analysis of a preset program of an upper computer, human sitting and standing transfer capacity assessment is carried out through a cloud database of the upper computer, and the lower limb movement capacity, muscle strength and balance capacity health level of a measurer are divided.
It should be noted that, as shown in fig. 4, the method for measuring the transfer capability of the human body sitting station of the present invention can be implemented by an electronic device 4, and the electronic device 4 can be, for example, the upper computer in the foregoing or be disposed in the upper computer. The electronic device 4 comprises a memory 43 and a processor 41 which are connected with each other, wherein the memory 43 stores program instructions which when executed by the processor 41 realize the human body sitting station transferring capability measuring method. When communication with the outside is required, the electronic device 4 further includes a communicator 42, and the communicator 42 is connected to the processor 41.
The Processor 41 may be a general-purpose Processor, and includes a Central Processing Unit (CPU), a Network Processor (NP), and the like; or a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, a discrete Gate or transistor logic device, or a discrete hardware component; the Memory 43 may include a Random Access Memory (RAM), and may further include a Non-volatile Memory (Non-volatile Memory), such as at least one disk Memory.
It should be noted that the program instructions in the memory 43 may be implemented in the form of software functional units and stored in a computer readable storage medium when the program instructions are sold or used as independent products. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, an electronic device 4, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention.
The present invention may also provide a storage medium storing a program that, when executed by the processor 41, implements the path planning method for an automatic lawnmower described above; the storage medium includes all forms of non-volatile memory, media and memory devices, including, for example: semiconductor memory devices such as EPROM, EEPROM, and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks.
In summary, according to the device, the method and the electronic device for measuring the transfer capability of the human body when sitting and standing, the posture measuring devices are installed on the crus, the thighs and the trunk of the user during measurement, the feet stand on the force measuring pedal, the motion posture data of the positions of the crus, the thighs and the trunk of the human body transmitted by the posture measuring devices during the sitting and standing process and the foot bottom force data transmitted by the force measuring pedal are recorded, the moment of each joint is calculated, and the lower limb motion capability, the muscle force and the balance capability of the human body during the sitting and standing transfer process are judged according to the moment of each joint. The posture measuring device of the human body sitting and standing transfer capability measuring device can be arranged at any position of the corresponding body section, and the installation position is not limited. The invention has the characteristics of practicality, simplicity, convenient installation, reasonable wiring and convenient clinical popularization, and effectively overcomes various defects in the prior art.
In the description herein, numerous specific details are provided, such as examples of components and/or methods, to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that an embodiment of the invention can be practiced without one or more of the specific details, or with other apparatus, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of embodiments of the invention.
Reference throughout this specification to "one embodiment," "an embodiment," or "a specific embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment, and not necessarily in all embodiments, of the present invention. Thus, appearances of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics of any specific embodiment of the present invention may be combined in any suitable manner with one or more other embodiments. It is to be understood that other variations and modifications of the embodiments of the invention described and illustrated herein are possible in light of the teachings herein and are to be considered as part of the spirit and scope of the present invention.
It will also be appreciated that one or more of the elements shown in the figures can also be implemented in a more separated or integrated manner, or even removed for inoperability in some circumstances or provided for usefulness in accordance with a particular application.
Additionally, any reference arrows in the drawings/figures should be considered only as exemplary, and not limiting, unless otherwise expressly specified. Further, as used herein, the term "or" is generally intended to mean "and/or" unless otherwise indicated. Combinations of components or steps will also be considered as being noted where terminology is foreseen as rendering the ability to separate or combine is unclear.
The above description of illustrated embodiments of the invention, including what is described in the abstract of the specification, is not intended to be exhaustive or to limit the invention to the precise forms disclosed herein. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the present invention, as those skilled in the relevant art will recognize and appreciate. As indicated, these modifications may be made to the present invention in light of the foregoing description of illustrated embodiments of the present invention and are to be included within the spirit and scope of the present invention.
The systems and methods have been described herein in general terms as the details aid in understanding the invention. Furthermore, various specific details have been given to provide a general understanding of the embodiments of the invention. One skilled in the relevant art will recognize, however, that an embodiment of the invention can be practiced without one or more of the specific details, or with other apparatus, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, materials, and/or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the invention.
Thus, although the present invention has been described herein with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosures, and it will be appreciated that in some instances some features of the invention will be employed without a corresponding use of other features without departing from the scope and spirit of the invention as set forth. Thus, many modifications may be made to adapt a particular situation or material to the essential scope and spirit of the present invention. It is intended that the invention not be limited to the particular terms used in following claims and/or to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Accordingly, the scope of the invention is to be determined solely by the appended claims.