Description:FIELD OF THE INVENTION
The present invention relates to sternal bridge, a device intended to be used in cardiac surgical procedures. More particularly, the device is used in keeping the sternum open after complicated heart surgery in a secure, safe and effective manner.

BACKGROUND OF THE INVENTION
Heart surgery is usually performed through an incision in the midline of the chest (median sternotomy) which gives fair access to the heart and to other organs within the thoracic cavity.

Open heart surgeries are complex surgeries, wherein sternum (breast-bone) is cut longitudinally and retracted during the surgery. Normally the sternum is sutured back with steel wires immediately after the surgery.

In some difficult, long and complicated surgeries, there is excessive tissue swelling (oedema) of the heart and surrounding tissues making it impossible for the sternum to be closed immediately as it would put pressure on the heart and circulation. In such cases, the sternum needs to be left open temporarily for few hours or days depending upon the condition of the patient. This is particularly in case of complex pediatric heart surgeries, especially in newborns and young infants.

Conventionally, in such cases, the sternum is wedged open by inserting the barrel of a syringe or other re-purposed objects between the cut edges of the sternum to keep it open, however, this is not an ideal.

The sternal bridge is also refereed as “Retractors” in this domain and has been so referred to in some of the prior art specifications mentioned below.

There are various patents or non-patent literature which discloses the retractors or such devices which are used in cardiac surgery. Some examples of the same are given below:

WO-2001080725-A1 discloses a device for annular fitting of a mechanical prosthesis of the heart valve, having a body made in the form of a ring, characterized in that it includes clamps equipped with spouts and hooks with sawtooth protrusions for engagement with the spouts of the clamps, while rectangular holes are made in the body for clamps and hooks , the hooks are installed with the possibility of alternately retracting to expand the seat of the mechanical prosthesis of the heart valve, fixation by moving the clamps with spouts towards the sawtooth protrusions of the hooks and loosening after completion of the annular landing.

Another patent application no.: US690501A discloses a retractor with devices that allow a surgeon to control the amount of retractor force. The retractor may include a first blade and a second blade. The second blade can be moved by a gear mechanism. A torque measuring device, force measuring device and/or slip clutch may be coupled to the gear mechanism. The torque measuring device may have a readout that displays the amount of torque being applied by the surgeon to the retractor. The readout provides accurate feedback that allows the surgeon to gauge the amount of force being applied to the patient. Likewise the force measuring device may provide a visual indication of the actual force being applied by the retractor onto the patient. The slip clutch may actuate at a threshold torque to prevent an excessive exertion of force on a patient.

The various retractor or sternal supporter or sternal bridge as disclosed in the existing state of art are bulky and have multiple components which make the process even more cumbersome, whereas the present invention discloses a device which is compact, easy to use and does not possess multiple components handling.

The bulky nature of the existing state of art adds extra expenditure to its manufacturing and processing whereas the present invention is very economical and patient and doctor compliant.

Accordingly, to obviate the drawbacks in the existing state of art, the present invention discloses a sternal bridge which has a simple construction and is easy to handle, clean and sterilize.

OBJECT OF THE INVENTION
In order to obviate the drawbacks in the existing state of the art, the main object of the present invention is to provide a sternal bridge for keeping the sternum open after the complicated heart surgery in a secure, safe and effective manner, which is compact and user friendly.

Yet another object of the invention is to provide a sternum bridge which is easy to clean and sterilize.

Yet another object of the invention is to provide a sternum bridge which grips the cut-edges of the sternum firmly yet non-traumatically.

SUMMARY OF THE INVENTION:
Accordingly, the present invention discloses a device intended to be used for keeping the sternum open after complicated heart surgery in a secure, safe and effective manner. The device comprises of a flat superior surface and a gently concave inferior surface which further extends to elongated dual flanges on either side. The concavity of the inferior surface is designed to provide more room for the underlying swollen tissues and heart. These dual flanges are designed such that they grip the cut edges of the sternum firmly and steadily.

The device is available in different sizes for children.

The present device is manufactured in a wide range of bio-safe materials including stainless-steel, titanium and a range of suitable plastics or similar materials.

The device is manufactured using but not limited to 3D printing, injection molding or even machined. Both resin and plastic, depending on the 3D printing method, are used for manufacturing the device. The plastic material which is used to manufacture the bridge looks like wire coiled on a spool which gets fed into the machine. The plastic material then melts at the printing head and is deposited in a layer by layer fashion to form the device of requisite shape and size.

BRIEF DESCRIPTION OF DRAWINGS
Figure 1 displays the top view, side view and front view of the sternal bridge.
Figure 2 displays the top view, side view and front view of adjustable sternal bridge

DETAILED DESCRIPTION OF THE INVENTION ILLUSTRATIONS AND EXAMPLES
While the invention has been disclosed with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made, and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt to a particular situation or material to the teachings of the invention without departing from its scope.

Throughout the specification and claims, the following terms take the meanings explicitly associated herein unless the context clearly dictates otherwise. The meaning of “a”, “an”, and “the” include plural references. Additionally, a reference to the singular includes a reference to the plural unless otherwise stated or inconsistent with the disclosure herein.

Following is the non-limiting design and development of the sternal bridge of the present invention.

The device comprises of a flat superior surface and a gently concave inferior surface which further extends to elongated dual flanges on either side. The concavity of the inferior surface is designed to provide more room for the underlying swollen tissues and heart.

These dual flanges are designed such that they grip the cut edges of the sternum firmly and steadily. The different sizes of the device are designed for adults and children.

DESIGN & FORM FACTOR:
The Sternal Bridge device has a form-factor that fulfils the intended purpose of keeping the sternum wedged open. Dual flanges of the device at either end are designed to grip the cut-edges of the sternum firmly yet non-traumatically, with precisely placed hole on the flanges to allow it to be sutured onto the chest wall on either side. The central part of the device creates and bridges the gap between the two sides of the sternum. This central bridging part of the device has a flat superior surface and a gently concave inferior surface. The flat superior surface is to allow unhindered wound dressing/covering. The concavity of the inferior surface is designed to provide more room for the underlying swollen tissues and heart.

Sternal bridges come in different sizes. Size depends on the distance that the surgeons want to cleave the resected sternum. Based on this distance, the varying sizes of sternal bridge can part the resected sternum from 15mm to 40mm range.
In one of the embodiments, the length, breadth and height of the sternal bridge which can part the resected sternum by 30mm is 55mm, 6mm and 12mm (lxbxh) respectively.

In the preferred embodiment, the device is approximately 55mm long, and has a radius of curvature of 20mm. The curvature of the sternal bridge may be regular, that is, with a single radius of curvature or it may have multiple radii of curvature along its length to provide variation in the angle of the flanges with respect to each other. The dual flanges of the sternal bridge are 10.5mm long (for the above mentioned variant which parts sternum by 30mm) or slightly angled to provide the desired secure opening of the sternum.

The device is designed in different sizes for use in different age groups and body sizes.

The device can be manufactured in either ‘single use’ (use and throw) formats, or for multiple use after sterilization.

The device is also available in two options, adjustable sternal bridge and non-adjustable sternal bridge.

ADJUSTABLE-STERNALBRIDGE
The sternum bridge is available with an option of adjustment, if required. The device is meticulously designed to adjust the distance between the two edges of the sternum while safely and securely keeping sternum open with provision to adjust the distance between the two edges of the sternum.

This adjusting feature of the device gives surgeons the flexibility to decide the distance of separation required between the cut-edges of the sternum depending upon the specific case requirement. This also allows surgeon the choice of re-adjusting and fine-tuning the separation distance (either reduction or increase) during the course of the care, using the same device instead of having to change to next fixed-size device.

FORM FACTOR:
The adjustable sternal bridge is made in two parts. Part One is hollow and is designed to allow Part Two that is solid to be pushed into position within it. The length of Part Two inserted into Part One will determine the final distance of separation. Holes are provided in both parts that can be precisely aligned according to the intended length, and then the two parts can be “locked” in position using a locking mechanism. The locking-mechanism in the current design is by insertion of a precisely-designed cylinder into it from the upper surface of the device. The ‘locking cylinder’ is T-shaped - while the vertical cylinder passes through Part One and Part Two to lock the length, the horizontal superior part will be secured on superior surface of the device when in position. This superior part will also be used to hold the lock, position it across the correct hole and to insert the locking cylinder in alignment.

Dual flanges of the device at either end are designed to “grip” the cut-edges of the sternum firmly yet non-traumatically, with precisely placed hole on the flanges to allow it to be sutured onto the chest wall on either side.
, Claims:We claim:
1. A sternal bridge (SB) for keeping the sternum open after complicated heart surgery, said sternal bridge comprising of
· a central bridging part having flat superior surface and a gently concave inferior surface
· dual flanges at either end of sternal bridge to grip the cut-edges of the sternum during surgery
· at least a pair of holes on either side of said sternal bridge for adjusting the length of the sternal bridge as required during surgery
such that sternum is kept open for the desired time in a secure, safe and effective manner.

2. A device as claimed in claim 1 wherein said device is manufactured from bio-safe materials including stainless-steel, titanium and a range of suitable plastics or similar materials.

3. A device as claimed in claim 1 wherein said device has dimensions in the range of 15mm to 40mm.

4. A device as claimed in claim 1 wherein said device having dimensions is 55mm, 6mm and 12mm (lxbxh).

5. A device as claimed in claim 1 wherein the device is available as adjustable sternum bridge and non-adjustable sternum bridge.

6. A sternal bridge as claimed in claim 1 wherein said sternal bridge has a flat superior surface to allow unhindered wound dressing/covering and a gently concave inferior surface to provide more room for the underlying swollen tissues and heart.