DESC:FIELD OF THE INVENTION:
This invention relates to the field of biomedical engineering.

Particularly, this invention relates to an automatic bone alignment system.

BACKGROUND OF THE INVENTION:
Deformity correction is a procedure to straighten a bone that is bent or twisted in a way that is not normal. After the bone is straightened, the arm, leg, or foot has normal alignment and function.

In the past, patients with fractures which failed to heal (non-union), or healed incorrectly (mal-union) had little treatment available to them, and patients who required surgical removal of infected bone (osteomyelitis) or cancerous bone often had no choice but to have an amputation of the affected limb. The treatment of such orthopedic conditions was revolutionised by Dr Gavril Ilizarov, as will be explained below. The Ilizarov’s frame takes its name from Dr Gavril Abramovich Ilizarov.

The Ilizarov’s apparatus is a set of external fixators consisting of rings, rods and kirschner wires, all made of stainless steel. The purpose of the Ilizarov’s fixator is to stimulate bone growth, and this works by the principle of distraction osteogenesis, which is the pulling apart of bone to stimulate new bone growth.

FIGURE 1 illustrates an Ilizarov External Ring Fixature.

This can be fitted, externally, to two different bones, of which deformity is to be corrected. Based on the sequence of screw motion / turns, two plates (11, 13) are made parallel in the end and it assures correction in deformity.

Due to heavy demand to cure bone fracture, it is, therefore, necessary for many researchers who are involved in developing such alignment set-up, to develop advanced alignment system for bone fractures with the X-ray images and in consultation with an orthopedist / an orthopedic surgeon.

Manual alignment set-up involves deep study of the nature of bone fracture, which is done in post operation stage by surgeon.

Background knowledge on human bone anatomy and details regarding various bone fractures is essentially required before operating a set-up of manual alignment.

A detailed survey of the current practices followed in correcting deformities, can offer more appropriate and more precisely set incremental alignment by using pre-programmed automatic alignment. It is required to develop automation after implementing a spatial frame for deformity correction in post-surgery cases of bone fractures.

A survey of prior art literature reveals that Stewart's platform mechanism is most commonly attributed to D. Stewart's paper published by the Institution of Mechanical Engineers. However it is remarkably similar to at least two other devices: Peterson and Cappel's Hexapod system, which was patented in the United States; and Gough's Universal tyre test machine, designed. The mechanism, however, is referred to as a "Stewart Platform" to maintain consistency with recent papers. The mechanism is a space truss with an upper and lower plate and six links in an octahedral arrangement. The Stewart platform mechanism, mainly referred to as hexapod, is a parallel kinematic structure that can be used as a basis for controlled motion with 6 degrees of freedom (d.o.f.), such as manufacturing processes and precise manipulative tasks. The mechanism itself consists of a stationary platform (base platform, the base) and mobile platform that are connected via six struts mounted on universal joints. The struts have an in-built mechanism that allows changing the length of each individual strut. The desired position and orientation of the mobile platform is achieved by combining the lengths of the six struts, transforming the six transitional d.o.f. into three positional and three orientation ones. The lengths of the struts cannot, of course, be changed independently, but only in such a fashion that the hexapod construction allows.

The more recent, prior art, practices used for deformity correction using Ilizarov frame can be referred for fitting the rings / plates externally to two different bones.

The following lacuna is identified with current practice for deformity correction.
- Unavailability of an interface and a device that will accommodate the current techniques of deformity corrections;
- Lack of automation in the integration of current techniques in Indian medical practices.

OBJECTS OF THE INVENTION:
An object of the invention is to provide automated bone alignment, of straight bone fracture, using biomedical instrumentation.

Another object of the invention is to provide a biomedical system / biomedical instrument that, automatically, adjusts frames attached to ends of a bone, semi-continuously, as per programmed motion with discrete increments for bone deformity correction treatment.

SUMMARY OF THE INVENTION:
According to this invention, there is provided an automatic bone alignment system comprising:
- an operative base plate spaced apart from a co-axial operative top plate, said plates being configured to receive ends of a fractured bone therebetween;
- one or more actuators located on said operative base plate;
- a link extending from a lateral edge of said actuators, each link comprising a first end, which is an operative proximal end, which connects to its corresponding actuator and each link comprising a second end, which is an operative distal end, which connects to its correspondingly paired rod; and
- rods, wherein each rod is connected, at its one end, to said corresponding link and is connected, at its another end, to an outer circumferential end of said operative top plate via struts mounted on universal joints;
said system, thereby, achieving 6 degrees of freedom between said operative top plate and said operative base plate.

In at least an embodiment, said operative base plate is a ring and said operative top plate is a ring.

In at least an embodiment, said operative base plate is hexagonal in shape and is made up of the triangular shape cut from the edges.

In at least an embodiment, said one or more actuators being at least three pairs of actuators are located along a circumference formed by a ring that forms said operative base plate, each pair being formed by a first actuators spaced apart from a second actuators and connected to each other by a pair of links such that a first link extends from a lateral edge of said first actuators and connects to a second link extending from a lateral edge of said second actuators.

In at least an embodiment, said upper plate having six pin points through which said rod is attached via spherical joints.

In at least an embodiment, said actuators ensure linear movement and angular movement of said plates with respect to each other in at least the following manner:
- said operative top plate moves, linearly, with respect to said operative base plate, by 1mm per day.
- said operative top plate, angularly displaces, with respect to said operative base plate, by 1mm per day; 3600 rotation, is achieved, in one day with only 1mm movement

In at least an embodiment, for linear movement, in each direction, in order to obtain linear movement in Z-direction in downward direction, actuator is activated in clockwise direction, which moves said link attached to said actuator, in that, as said link is connected to said rod and said rod is connected to said operative top plate via said spherical joint which, in turn, moves said operative top plate in said downward direction.

In at least an embodiment, for angular movement, in each degree of freedom, in order to obtain angular movement in Z-direction in clockwise manner, said actuator is activated in anticlockwise manner, which moves said link attached to said actuator, in that, as said link is connected to said rod and said rod which is connected to said operative top plate via said spherical joint which, in turn, moves said operative top plate in said clockwise manner.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
The invention will now be described in relation to the accompanying drawings, in which:

FIGURE 1a illustrates details of top platform of a customized Stewart platform;
FIGURE 1b illustrates details of rod of a customized Stewart platform;
FIGURE 1c illustrates details of bottom platform of a customized Stewart platform;
FIGURE 1d illustrates details of bush of a customized Stewart platform;
FIGURE 1e illustrates details of link of a customized Stewart platform;
FIGURE 2 illustrates 3-dimesional model of assembly of Customized Stewart platform (CSP);
FIGURE 3 illustrates Customized Stewart platform (CSP); and
FIGURE 4 illustrates Arrangement of proximal & distal ring for alignment of fracture bone.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
According to this invention, there is provided an automatic bone alignment system. Typically, this system is a biomedical instrument developed for automated bone alignment of straight bone fracture to correct bone deformity.

The prior art practices, used for deformity correction, use an Ilizarov frame which is referred for fitting rings / plates, externally, to two different bones for achieving manual alignment of a bone fracture. A sequential automatic movement of screw attached to a mechanism similar to Stewart's platform mechanism, can turn two rings or plates fitted parallel and at the ends of the fractured bone for automatic alignment of bone. It assures easy, safer, and automated incremental correction while aligning the bone towards eliminating the deformity. The alignment of fracture bone can be achieved using a new biomedical instrument which has electronically controlled actuators and scheduled incremental movement towards perfect alignment.

FIGURE 1a illustrates details of top platform of a customized Stewart platform.
FIGURE 1b illustrates details of rod of a customized Stewart platform.
FIGURE 1c illustrates details of bottom platform of a customized Stewart platform.
FIGURE 1d illustrates details of bush of a customized Stewart platform.
FIGURE 1e illustrates details of link of a customized Stewart platform.

FIGURE 2 illustrates 3-dimesional model of assembly of Customized Stewart platform (CSP).
FIGURE 3 illustrates Customized Stewart platform (CSP).
FIGURE 4 illustrates Arrangement of proximal & distal ring for alignment of fracture bone.

In at least an embodiment, the system, of this invention comprises an operative base plate (22) spaced apart from a co-axial operative top plate (24). Preferably, the base plate (22) and the top plate (24) are plates of Chromium Plated Mild Steel. According to preferred embodiments, operative top plate (24) diameter range and bottom plate (22) diameter range is between 90mm and 220mm. Typically, the operative base plate (22) is a ring. Typically, the operative top plate (24) is a ring.

In at least an embodiment, one or more motors / actuators (42) are located on the operative base plate (22). Preferably, at least three pairs of motors / actuators (42) are located along the circumference formed by a ring that forms the base plate (22). Each pair is formed by a first motor (24a, 24c, 24e) spaced apart from a second motor (24b, 24d, 24f) and connected to each other by a pair of links such that a first link (26a, 26c, 26e) extends from a lateral edge of said first motor and connects to a second link (26b, 26d, 26f) extending from a lateral edge of said second motor. Each link, therefore, comprises a first end, which is a proximal end, which connects to its corresponding motor, and a second end, which is a distal end, which connects to its correspondingly paired link.

In at least an embodiment, rods (32) are connected, via bushings (34) [or struts mounted on universal joints], at their one end, to proximal ends of each of the links (26a, 26b, 26c, 26d, 26e, 26f), and at their another end, to an outer circumferential end of the operative top plate (24).

By the means, and mechanism, of this system, 6 degrees of freedom are achieved between the two plates (22, 24).

In other words, desired position and orientation of the mobile platform (and of the bone therebetween) is achieved by combining the lengths of the six struts, transforming the six transitional degrees of freedom into three positional and three orientation ones.

In at least an embodiment, link rod is a connection between the base platform (24) and the upper platform (22). Output of the actuator is given to its correspondingly attached link rod at the base. A crank (which is caused by the links) has an effective radius of 30mm and output of the motor is given as input to the crank and, due to this, the crank is undergoing rotation. The upper plate (22) is having six pin points through which the link rod is attached via spherical joints.

Reference numeral 50a refers to fracture bone attached to top ring.
Reference numeral 50b refers to fracture bone attached to bottom ring.

The motors / actuators (42) ensure linear movement and angular movement of the plates with respect to each other in at least the following manner:
- moving plate moves, linearly, with respect to fixed plate, by 1mm per day.
- moving plate, angularly displaces, with respect to fixed plate, by 1mm per day; 3600 rotation, is achieved, in one day with only 1mm movement
Linear and angular disaplacement is not continuous.

According to a non-limiting exemplary embodiment,
Maximum Displacement, achieved: X=320mm, Y=308mm, Z=158mm
Maximum Angular Displacements, achieved: Roll=43 Roll=43, Pitch=25, Yaw= 65 in degrees, Pitch=25 Roll=43, Pitch=25, Yaw= 65 in degrees, Yaw=65 degrees
Maximum Torque = 6 Nm (12V)

Linear movement i.e., X-direction movement, Y-direction movement, Z-direction movement.
For linear movement, in each direction, in order to obtain linear movement in Z-direction in downward direction, actuator is activated in clockwise direction, which moves crank / link attached to the actuator – as the link is connected to rod and rod is connected to top plate via a spherical joint which in turn moves the top plate in downward direction.

Angular movement i.e., Roll, Yaw, Pitch
For angular movement, in each degree of freedom, in order to obtain angular movement in z-direction in clockwise manner, actuator is activated in anticlockwise manner, which moves crank / link attached to the actuator – as the link is connected to rod and rod which is connected to top plate via a spherical joint which in turn moves the top plate in clockwise manner.

FIGURE 5 illustrates an algorithm flowchart, for deformity correction of fracture bone, by means of fine incremental bone alignment. The steps, to align broken / fractured bones using the system, of this invention, are as follows:
Step 1: Connect customized Stewart platform to monitoring system.
Step 2: Initiate data Acquisition
Step 3: Attach fracture bone to Customized Stewart Platform (CSP) (22, 24)
Step 4: Compute parameters for alignment of straight bone fracture
Step 5: Compute gap identified between fracture bones in terms of linear and angular parameters.
Step 6: Development of a software code using computed parameters for alignment of straight bone fracture.
Step 7: Confirmation / Verification of required alignment in linear parameter: ?x, ?y, ?z, and angular parameter: ?a, ?ß, ?? has properly matched. If not, repeat step 4 to step 7 to achieve desired outcome.

According to a non-limiting exemplary embodiment, alignment of a straight bone fracture (of a pig bone which has similar properties to a human bone) was successfully carried out using PYTHON based programming while operating it on the automatic alignment set-up.

A kinematic analysis of a spatial frame with detailed synthesis of a biomedical instrument required essentially for establishing the precise and pre-planned incremental motions of this set-up. This analysis can support authenticity of using the device.

The TECHNICAL ADVANCMENT, of this invention, lies in providing a system which provides sequential automatic movement (linear displacement + angular displacement) of screw can turn two rings or plates, fitted parallel to each other, and at the ends of the fractured bone. It assures easy, safer, and automated correction while aligning the bone towards eliminating the deformity.

The ECONOMIC SIGNIFICANCE, of this invention, lies in providing a low-cost solution for orthopedic surgeries for correcting bone deformity occurred due to straight bone fracture related problems. Automatic alignment system allows a surgeon complete flexibility in frame placement and configuration, which improves upon accuracy of the correction during the process of alignment. An incremental movement of spatial frame for straight bone fracture correction can be achieved with automated / programmed alignment with better accuracy. This reduces treatment time from 6 to 8 month to 3 to 4 month which can further reduce treatment cost.

While this detailed description has disclosed certain specific embodiments for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.
,CLAIMS:WE CLAIM,

1. An automatic bone alignment system comprising:
- an operative base plate (22) spaced apart from a co-axial operative top plate (24), said plates (22, 24) being configured to receive ends of a fractured bone (50a, 50b) therebetween;
- one or more actuators (42) located on said operative base plate (22);
- a link (26a, 26b, 26c, 26d, 26e, 26f) extending from a lateral edge of said actuators (42), each link comprising a first end, which is an operative proximal end, which connects to its corresponding actuator and each link comprising a second end, which is an operative distal end, which connects to its correspondingly paired rod (32); and
- rods (32), wherein each rod (32) is connected, at its one end, to said corresponding link (26a, 26b, 26c, 26d, 26e, 26f) and is connected, at its another end, to an outer circumferential end of said operative top plate (24) via struts mounted on universal joints;
said system, thereby, achieving 6 degrees of freedom between said operative top plate (24) and said operative base plate (22).

2. The system as claimed in claim 1 wherein, said operative base plate (22) is a ring and said operative top plate (24) is a ring.

3. The system as claimed in claim 1 wherein, said operative base plate (22) is hexagonal in shape and is made up of the triangular shape cut from the edges.

4. The system as claimed in claim 1 wherein, said one or more actuators (42) being at least three pairs of actuators (42) are located along a circumference formed by a ring that forms said operative base plate (22), each pair being formed by a first actuators (24a, 24c, 24e) spaced apart from a second actuators (24b, 24d, 24f) and connected to each other by a pair of links such that a first link (26a, 26c, 26e) extends from a lateral edge of said first actuators and connects to a second link (26b, 26d, 26f) extending from a lateral edge of said second actuators.

5. The system as claimed in claim 1 wherein, said upper plate (22) having six pin points through which said rod is attached via spherical joints.

6. The system as claimed in claim 1 wherein, said actuators (42) ensure linear movement and angular movement of said plates (22, 24) with respect to each other in at least the following manner:
- said operative top plate moves, linearly, with respect to said operative base plate, by 1mm per day.
- said operative top plate, angularly displaces, with respect to said operative base plate, by 1mm per day; 3600 rotation, is achieved, in one day with only 1mm movement

7. The system as claimed in claim 1 wherein, for linear movement, in each direction, in order to obtain linear movement in Z-direction in downward direction, actuator is activated in clockwise direction, which moves said link attached to said actuator, in that, as said link is connected to said rod and said rod is connected to said operative top plate via said spherical joint which, in turn, moves said operative top plate in said downward direction.

8. The system as claimed in claim 1 wherein, for angular movement, in each degree of freedom, in order to obtain angular movement in Z-direction in clockwise manner, said actuator is activated in anticlockwise manner, which moves said link attached to said actuator, in that, as said link is connected to said rod and said rod which is connected to said operative top plate via said spherical joint which, in turn, moves said operative top plate in said clockwise manner.

Dated this 18th day of October, 2022

CHIRAG TANNA
of INK IDÉE
APPLICANT’S PATENT AGENT
REGN. NO. IN/PA – 1785