Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(Section 10 and Rule 13)

1. TITLE OF THE INVENTION:
CARDIAC ASSIST DEVICE

2. APPLICANT:
Meril Life Sciences Pvt. Ltd., an Indian company, of the address Survey No. 135/139 Bilakhia House, Muktanand Marg, Chala, Vapi-Gujarat 396191, India.

3. The following specification particularly describes the invention and the manner in which it is to be performed:

FIELD OF INVENTION
[1] The present disclosure relates to a cardiac assist device. More particularly, the present disclosure relates to a left ventricular assist device.
BACKGROUND OF INVENTION
[2] In certain conditions, when a patient reaches end-stage heart failure, the functions of the ailing heart may be artificially supported by a cardiac device/implant. Left ventricular assist device (or LVAD) is one such device that helps a diseased left ventricular chamber of the heart to pump blood through the Aorta to the rest of the body.
[3] Conventionally, LVAD is surgically implanted into the human heart. LVAD includes an inlet for receiving blood flow from the left ventricle and an outlet for pumping out blood through the Aorta. Inside the LVAD, a rotating impeller pushes the incoming blood out of the outlet with an increase in the pressure of the blood flow. The LVAD is further coupled to a control unit and battery pack disposed outside the body. The battery pack provides power to the control unit which further gives necessary signals and power to the LVAD for its reliable operation.
[4] However, conventional LVADs suffer from a number of drawbacks. Firstly, the conventional LVADs have a very high hemolysis index, i.e., the operation of the LVAD results in lysis of the blood cells of the patient. The operation itself is noisy and the device tends to be on the bulkier side. These drawbacks affect the quality of life of the user of the LVAD.
[5] Furthermore, in some cases, the conventional LVAD induces allergic reaction that may adversely affect the patient.
[6] Thus, there arises a need for a device that overcomes the problems associated with the conventional LVAD devices.
SUMMARY OF INVENTION
[7] Particular embodiments of the present disclosure are described herein below with reference to the accompanying drawings; however, it is to be understood that the disclosed embodiments are mere examples of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.
[8] In an embodiment, the present disclosure relates to a device including a first housing, a second housing, a plate, and an impeller. The first housing defines a lumen to house a motor. The second housing is removably coupled to the first housing. The second housing includes an inflow port, an outflow port and a rotor. The second housing defines a lumen to rotatably house the rotor. The plate is disposed between the lumens of the first housing and the second housing. The rotor magnetically levitates inside the lumen of the second housing such that the rotor defines a pre-defined gap with the plate. The impeller is disposed within the lumen of the second housing. The impeller is coupled to the rotor such that the impeller magnetically levitates and rotates along with the rotor to pump blood out of the outflow port. The impeller includes a body coupled to a roof. The roof includes a hole aligned with the inflow port. One or more blades are at least partially disposed within the body and partially outside the body. The blades are concave-spade shaped. The rotor is coupled to the body.
[9] In an embodiment, the present disclosure relates to a device including a first housing, a second housing, a plate, and an impeller. The first housing defines a lumen to house a motor. The second housing is removably coupled to the first housing. The second housing includes an inflow port, an outflow port and a rotor. The second housing defines a lumen to rotatably house the rotor. The plate is disposed between the lumens of the first housing and the second housing. The rotor magnetically levitates inside the lumen of the second housing such that the rotor defines a pre-defined gap with the plate. The impeller is disposed within the lumen of the second housing. The impeller is coupled to the rotor such that the impeller magnetically levitates and rotates along with the rotor to pump blood out of the outflow port. The impeller includes a first plate coupled to a second plate via one or more blades. The blades are concave shaped. The first plate includes a hole aligned with the inflow port. The rotor is coupled to the second plate.
[10] In an embodiment, the present disclosure relates to a device including a first housing, a second housing, a plate, and an impeller. The first housing defines a lumen to house a motor. The second housing is removably coupled to the first housing. The second housing includes an inflow port, an outflow port and a rotor. The second housing defines a lumen to rotatably house the rotor. The plate is disposed between the lumens of the first housing and the second housing. The rotor magnetically levitates inside the lumen of the second housing such that the rotor defines a pre-defined gap with the plate. The impeller is disposed within the lumen of the second housing. The impeller is coupled to the rotor such that the impeller magnetically levitates and rotates along with the rotor to pump blood out of the outflow port. The impeller includes a base plate having a hole aligned with the inflow port. One or more vanes are disposed over the base plate. The vanes are comma shaped. A height of the vanes increases from a periphery of the base plate to the center of the base plate. The rotor is coupled to the base plate.
BRIEF DESCRIPTION OF DRAWINGS
[11] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the apportioned drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the disclosure is not limited to specific methods and instrumentality disclosed herein. Moreover, those in the art will understand that the drawings are not to scale.
[12] Fig. 1 depicts an exploded view of a device 100 in accordance with one or more embodiment of the present disclosure.
[13] Fig. 1a depicts a locking cuff 121f coupled to a second housing 120 of the device 100 in accordance with one or more embodiment of the present disclosure.
[14] Fig. 1a1 depicts a perspective-top view of the locking cuff 121f in accordance with one or more embodiment of the present disclosure.
[15] Fig. 1a2 depicts a side view of the locking cuff 121f in accordance with one or more embodiment of the present disclosure.
[16] Fig. 1a3 depicts a perspective-bottom view of the locking cuff 121f in accordance with one or more embodiment of the present disclosure.
[17] Fig. 1b depicts a lumen 120a of the second housing 120 of the device 100 in accordance with one or more embodiment of the present disclosure.
[18] Fig. 2 depicts an impeller 127a of the device 100 in accordance with one or more embodiment of the present disclosure.
[19] Fig. 2a depicts an exploded view of the device 100 with the impeller 127a and the locking cuff 121f in accordance with one or more embodiment of the present disclosure.
[20] Fig. 3 depicts an impeller 127b of the device 100 in accordance with one or more embodiment of the present disclosure.
[21] Fig. 3a depicts an exploded view of the device 100 with the impeller 127b and the locking cuff 121f in accordance with one or more embodiment of the present disclosure.
[22] Fig. 4 depicts an impeller 127c of the device 100 in accordance with one or more embodiment of the present disclosure.
[23] Fig. 4a depicts an exploded view of the device 100 with the impeller 127c and the locking cuff 121f in accordance with one or more embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[24] Prior to describing the disclosure in detail, definitions of certain words or phrases used throughout this patent document will be defined: the terms "include" and "comprise", as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "coupled with" and "associated therewith", as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have a property of, or the like. Definitions of certain words and phrases are provided throughout this patent document, and those of ordinary skill in the art will understand that such definitions apply in many, if not most, instances to prior as well as future uses of such defined words and phrases.
[25] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.
[26] Although the operations of exemplary embodiments of the disclosed method may be described in a particular, sequential order for convenient presentation, it should be understood that the disclosed embodiments can encompass an order of operations other than the particular, sequential order disclosed. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular embodiment are not limited to that embodiment, and may be applied to any embodiment disclosed herein. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed system, method, and apparatus can be used in combination with other systems, methods, and apparatuses.
[27] Furthermore, the described features, advantages, and characteristics of the embodiments may be combined in any suitable manner. One skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. These features and advantages of the embodiments will become more fully apparent from the following description and apportioned claims, or may be learned by the practice of embodiments as set forth hereinafter.
[28] The present disclosure discloses a cardiac assist device (or device). The device may be implanted to the left ventricle of a heart. This device is used when a patient is unfit for a heart replacement surgery and/or a heart for replacement is not available to the patient.
[29] The device aids the ailing heart by pumping out blood to the rest of the body, thus restoring/supplementing the functions of the ailing heart. In an exemplary embodiment, the device receives the blood from the left ventricle and pumps out the blood to the whole body via the Aorta.
[30] The device includes a very light weight magnetically levitating impeller that has a very low hemolysis index, i.e., the impeller of the device does not cause hemolysis of the blood cells. The device is at least partially provided with a gold coating that prevents allergic reactions after the device is implanted.
[31] Further, the device itself includes a small form factor rendering it light in weight. In an exemplary embodiment, the weight of the device ranges from 90 gm to 200 gm. The reduced weight and small form factor of the device makes the device almost unnoticeable to the user having the device implanted as the device does not cause an undue stress on the heart.
[32] Even after having a compact size, the device provides a high flow rate of more than 4 liters per minute to 5 liters per minute. The device generates less heat and vibration, thus, improving the quality of life for the user.
[33] Now referring to the figures, Fig. 1 shows an exploded view of a device 100. The device 100 may extend between a first end 100a and a second end 100b. A length of a portion of the device 100 that stays outside, for example, the apex of the left ventricle (after implantation) ranges from 20 mm to 36 mm. In other words, the length of the portion of the device 100 excluding an inflow port ranges from 20 mm to 36 mm. The device 100 includes a first housing 110 and a second housing 120. The first housing 110 is disposed at the first end 100a and the second housing 120 is disposed at the second end 100b.
[34] The first housing 110 may have a pre-defined shape including cylindrical, spiral profile, etc. In an exemplary embodiment, as shown in Fig. 1, the first housing 110 is cylindrical in shape. In an exemplary embodiment, the first housing 110 is made of titanium. The first housing 110 may have a pre-defined height ranging from 15 mm to 20 mm. The first housing 110 may have a pre-defined diameter ranging from 35 mm to 50 mm. In an exemplary embodiment, the height and diameter of the first housing 110 is 20 mm and 35 mm respectively. In an exemplary embodiment, an outer surface of the first housing 110 is provided with a gold coating that prevents allergic reactions after the device 100 is implanted.
[35] The first housing 110 may define a lumen (not shown) to house a motor 111. The first housing 110 may have at least one lateral cutout 110a to facilitate passage of a driveline (not shown) that electrically couples the motor 111 with a controller (not shown). The controller enables the user to control the device 100 via the driveline.
[36] The first housing 110 is provided with a plate 110b disposed towards the second end 100b, i.e., the plate 110b is disposed between the lumen of the first housing 110 and a lumen 120a of the second housing 120. The plate 110b may have a diameter equal to the diameter of the first housing 110. In an exemplary embodiment, the plate 110b forms an integral structure with the first housing 110. The plate 110b separates the motor 111 from getting exposed to the blood, thus safeguarding the blood cells from the motor 111.
[37] The motor 111 is rotatably disposed within the lumen of the first housing 110. The motor 111 may include at least a stator 111a, a disc 111b, etc.
[38] In an exemplary embodiment, as shown in Fig. 1, the stator 111a of the motor 111 includes six silicone steel laminated cores. The cores are arranged in a radial manner over a disc 111b made of mild steel to increase the magnetic permeability and completion of the magnetic flux. Enamel coated copper wires are wound around each of the cores in star connection to create three-phase coil system nominated as ‘R’, ‘Y’, and ‘B’. The three-phase coil system is connected to the controller to create a magnetic flux. The disc 111b is magnetically permeable and helps in completion of the magnetic flux.
[39] Other functionally equivalent structure instead of the motor 111 as described is within the scope of the teachings of the present disclosure.
[40] Additionally or optionally, the motor 111 may be provided with one or more hall sensors (not shown) that detects the position of a rotor 125 (described below) and reports it to the controller. In an exemplary embodiment, the motor 111 is provided with three hall sensors between the coils of the stator 111a.
[41] Additionally or optionally, the motor 111 may be provided with at least one temperature sensor (not shown). In an exemplary embodiment, the core of the motor 111 is provided with a temperature sensor that reports the temperature of the motor 111 to the controller.
[42] The hall sensor and the temperature sensor help the controller to regulate the operation of the motor 111. The inputs from the hall sensor and the temperature sensor enables the controller to compute data like flow rate, pressure range, battery percentage, etc. The inputs from the hall sensor and the temperature sensor also helps the controller to determine occurrence of any malfunction of the device 100 during its operation.
[43] A connector hub 113 is disposed within the lumen of the first housing 110 and coupled to the lateral cutout 110a of the first housing 110. In an exemplary embodiment, the connector hub 113 is made of titanium. The connector hub 113 helps to cover the lateral cutout 110a and guide the driveline so that no damage occurs during movement of driveline.
[44] A cover 115 may be used to seal the motor 111 within the first housing 110. In an exemplary embodiment, the cover 115 is made of titanium. The cover 115 may be removably coupled to the first housing 110 at the first end 100a of the device 100 via threads, glue, press fit, etc. In an exemplary embodiment, the cover 115 is coupled to the first housing 110 using a press fit mechanism. In an exemplary embodiment, an outer surface of the cover 115 is provided with a gold coating that prevents allergic reactions after the device 100 is implanted.
[45] In an exemplary embodiment, the second housing 120 may be operationally coupled to the first housing 110 via a plurality of complementing threads 100c. In an exemplary embodiment, the second housing 120 is made from titanium. The second housing 120 may have a pre-defined shape including volute, cylindrical, spiral profile, etc. In an exemplary embodiment, the second housing 120 is volute shaped. The second housing 120 includes a pre-defined height ranging from 15 mm to 18 mm. In an exemplary embodiment, the height of the second housing 120 is 18 mm. The second housing 120 may have a diameter corresponding to the diameter of the first housing 110. In an exemplary embodiment, an outer surface of the second housing 120 is provided with a gold coating that prevents allergic reactions after the device 100 is implanted. In an exemplary embodiment, an inner surface the second housing 120 is provided with a textured rough surface of aluminum oxide coating to prevent allergic reactions.
[46] The second housing 120 is provided with at least two ports, namely an inflow port 121 and an outflow port 123. In an exemplary embodiment, the inflow port 121 is disposed longitudinally to the second housing 120, towards the second end 100b. The inflow port 121 may have a length ranging from 20 mm to 35 mm. The inflow port 121 may have a diameter ranging from 19.5 mm to 20 mm. In an exemplary embodiment, the length and diameter of the inflow port 121 is 35 mm and 20 mm respectively. After the device 100 is implanted, the inflow port 121 receives blood flow from the left ventricle of the heart.
[47] At least one cuff body 121a, one circlip 121b, one cover ring 121c, one cuff ring 121d and one felt ring 121e together constitute an attachment assembly. In an exemplary embodiment, as shown in Fig. 1, the attachment assembly is coaxially disposed around the inflow port 121. The attachment assembly is used to couple the device 100 to the apex (adjacent to the left ventricle) of the heart.
[48] In an exemplary embodiment, the cuff body 121a made of titanium is welded to the second housing 120 adjacent to the inflow port 121. The cuff body 121a includes at least one slot 121a1 configured to receive the circlip 121b. The cuff body 121a helps to hold and support the cuff ring 121d.
[49] The circlip 121b is removably coupled to the slot 121a1 of the cuff body 121a. In an exemplary embodiment, the circlip 121b is made of spring steel which enables the circlip 121b to retain its shape before and after coupling the circlip 121b to the slot 121a1 of the cuff body 121a. The circlip 121b helps to couple the cuff body 121a to the cuff ring 121d.
[50] The cover ring 121c is removably coupled to the slot 121a1 of the cuff body 121a. In an exemplary embodiment, the cover ring 121c helps to cover the circlip 121b disposed within the slot 121a1 of the cuff body 121a. In an exemplary embodiment, the cover ring 121c is made of titanium.
[51] The cuff ring 121d may be provided with a fabric covering (not shown). The fabric covering may be made of a material including but not limited to polytetrafluoroethylene (PTFE), felt, etc. In an exemplary embodiment, the fabric covering is made of PTFE felt and the cuff ring 121d is made of titanium. The cuff ring 121d is coupled to the cuff body 121a by the circlip 121b. In an exemplary embodiment, the fabric covering is used to suture the device 100 to the apex of the heart during implanting the device 100.
[52] The felt ring 121e is coupled to the cuff ring 121d to support and reinforce the fabric covering over the cuff ring 121d.
[53] In an alternate embodiment, as shown in Fig. 1a, a locking cuff 121f is coaxially disposed around the inflow port 121, instead of the attachment assembly depicted in Fig. 1. The locking cuff 121f may be provided with one or more legs 121f1 (as shown in Figs. 1a1, 1a2, 1a3). In an exemplary embodiment, as shown in Fig. 1a, the legs 121f1 are L-shaped. The legs 121f1 help the locking cuff 121f to be coupled to an outer periphery of the second housing 120 via press-fit locking mechanism. The locking cuff 121f is made of stainless steel 316 or spring steel which enables locking cuff 121f to retain its shape after/before it is coupled to the outer periphery of the second housing 120. The locking cuff 121f helps to quickly couple the inflow port 121 of the device 100 to the apex of the heart at the time of device 100 implantation which helps to reduce implantation time and excessive bleeding during the procedure.
[54] In an exemplary embodiment, a cuff (not shown) made of Polytetrafluoroethylene (PTFE) and/or fabric is coupled to an upper surface of the locking cuff 121f. At the time of implantation, the cuff is sutured with the apex of left ventricle of the heart, along with the locking cuff 121f. The inflow port 121 of the device 100 is then inserted in the left ventricle such that the locking cuff 121f quickly couples the outer periphery of the second housing 120, thereby, securing the device 100 to the apex of the heart.
[55] In an exemplary embodiment, the outflow port 123 is disposed laterally to the second housing 120. The outflow port 123 may have a length ranging from 25 mm to 30 mm. The outflow port 123 may have a diameter ranging from 10 mm to 17 mm. In an exemplary embodiment, the length and diameter of the outflow port 123 is 30 mm and 17 mm respectively. After the device 100 is implanted, the outflow port 123 pushes (or pumps) blood flow out of the device 100 to the Aorta of the heart.
[56] In an exemplary embodiment, the outflow port 123 is coupled to a conduit graft 123a via an assembly of a graft connector 123b, a graft holder (not shown), an O-ring (not shown) and a screw ring 123c. The conduit graft 123a is coupled to the graft holder with the help of a medical grade glue or epoxy. The said coupling between the conduit graft 123a and the graft holder is reinforced by the graft connector 123b. Thereafter, the conduit graft 123a is assembled inside the screw ring 123c through the O-ring. The screw ring 123c is then coupled to the outflow port 123 of the second housing 120 by complementing threads.
[57] In an exemplary embodiment, the conduit graft 123a is made of collagen coated polyester. The conduit graft 123a fluidically couples the outflow port 123 of the second housing 120 to the aorta of the heart.
[58] A flexible sheath 123d may at least partially be disposed over the conduit graft 123a. In an exemplary embodiment, the flexible sheath 123d is made of polytetrafluoroethylene (PTFE) tube. The flexible sheath 123d prevents kinking of the conduit graft 123a.
[59] A rotor 125 may be disposed adjacent to the plate 110b and rotatably housed within the lumen 120a of the second housing 120. The lumen 120a defined by the second housing 120 is depicted in Fig. 1b. In an exemplary embodiment, the rotor 125 is made of neodymium. The rotor 125 may have a diameter ranging from 28 mm to 35 mm. In an exemplary embodiment, the diameter of the rotor 125 is 30 mm. The rotor 125 magnetically levitates within the lumen 120a of the second housing 120, thus defining a pre-defined gap with the plate 110b of the first housing 110. The pre-defined gap ranges from 0.5 mm to 1 mm. The rotor 125 is coupled to an impeller 127a. In an exemplary embodiment, the rotor 125 is removably coupled to the impeller 127a via medical grade glue or laser welding. In an alternate embodiment, the rotor 125 forms an integral structure with the impeller 127a.
[60] In an exemplary embodiment, as the electric current passes through the coils (not shown) of the motor 111, the coils create magnetic flux to the rotor 125. Thereafter, the rotor 125 creates electromagnetic field which prompts the rotor 125 to levitate and rotate.
[61] The impeller 127a is rotatably disposed within the second housing 120. The impeller 127a magnetically levitates because of the levitation of the rotor 125. The impeller 127a may mimic the rotational motion of the rotor 125 when the motor 111 rotates the rotor 125.
[62] As shown in Fig. 2, the impeller 127a includes a first plate 127a1 and a second plate 127a2. having a thickness ranging from 0.5 mm to 1 mm. In an exemplary embodiment, the impeller 127a is made of titanium having a thickness of 0.5 mm. The first plate 127a1 may be disposed towards the inflow port 121 of the second housing 120. The first plate 127a1 may have a diameter ranging from 25 mm to 32 mm. In an exemplary embodiment, the diameter of the first plate 127a1 is 30 mm.
[63] The first plate 127a1 may have a hole 127a3 aligned with the inflow port 121. The hole 127a3 may be concentric to the first plate 127a1. The hole 127a3 may have a diameter ranging from 10 mm to 15 mm. In an exemplary embodiment, the diameter of the hole 127a3 is 15 mm. The hole 127a3 enables the blood to flow from the inflow port 121 and enter the impeller 127a.
[64] The second plate 127a2 may be disposed towards and coupled to the rotor 125. The second plate 127a2 may be coaxial to the first plate 127a1.
[65] The second plate 127a2 may have a hole 127a4. The hole 127a4 may be concentric to the second plate 127a2. The hole 127a4 may have a diameter ranging from 2 mm to 5 mm. In an exemplary embodiment, the diameter of the hole 127a4 is 3 mm. The hole 127a4 provides a center axis for impeller 127a to rotate.
[66] The first plate 127a1 and the second plate 127a2 may be coupled to each other via one or more blades 127a5. In an exemplary embodiment, the first plate 127a1 and the second plate 127a2 are coupled with four equally spaced blades 127a5. The blades 127a5 may have a height ranging from 4 mm to 6 mm. In an exemplary embodiment, the height of the blades 127a5 is 5 mm. The blades 127a5 may have a pre-defined shaped including but not limited to convex, concave, etc. In an exemplary embodiment, as shown in Fig. 2, the blades 127a5 are concave shaped in the direction of impeller rotation.
[67] This impeller 127a provides low hemolysis index, constant and efficient blood flow. The curvaceous structure of the impeller 127a (and the blades 127a5) without any sharp edges reduces the hemolysis level significantly. The blades 127a5 helps in maintaining uniform blood flow. The impeller 127a pumps the blood out of the outflow port 123 with pressure and speed.
[68] Fig. 2a depicts an exemplary embodiment of the device 100 with the impeller 127a and the locking cuff 121f.
[69] Fig. 3 depicts another embodiment of an impeller 127b that may be rotatably disposed within the lumen 120a (as shown in Fig. 1b) of the second housing 120 (as shown in Fig. 3a) instead of the impeller 127a. The impeller 127b may also be coupled to the rotor 125 within the second housing 120. The impeller 127b may magnetically levitate and mimic the rotational motion of the rotor 125 when the motor 111 rotates the rotor 125. The impeller 127b may have a thickness ranging from 0.5 mm to 1 mm. In an exemplary embodiment, the impeller 127b is made of titanium having a thickness of 0.5 mm.
[70] As shown in Fig. 3, the impeller 127b includes a body 127b1 with a roof 127b2. In an exemplary embodiment, the rotor 125 is coupled to the body 127b1 of the impeller 127b. The body 127b1 may have a shape including but not limited to cylindrical, etc. In an exemplary embodiment, the body 127b1 includes a hollow tubular structure. The body 127b1 may have a height ranging from 7 mm to 15 mm. The body 127b1 may have a diameter ranging from 25 mm to 35 mm. In an exemplary embodiment, the height and diameter of the body 127b1 is 7 mm and 30 mm.
[71] The roof 127b2 may be coupled to the body 127b1 towards the inflow port 121 (when the impeller 127b is disposed within the lumen 120a of the second housing 120). The roof 127b2 may have a shape including but not limited to conical, etc. In an exemplary embodiment, as shown in Fig. 3, the roof 127b2 is conically shaped.
[72] The roof 127b2 may have a hole 127b3 aligned with the inflow port 121. The hole 127b3 may be concentric to the roof 127b2. The hole 127b3 may either be depressed or elevated with respect to the roof 127b2. In an exemplary embodiment, the hole 127b3 is elevated from the roof 127b2. The hole 127b3 partially enables the blood to flow from the inflow port 121 and enter the impeller 127b.
[73] The impeller 127b may be provided with one or more blades 127b4. In an exemplary embodiment, the impeller 127b is provided with six equally spaced blades 127b4. In an exemplary embodiment, as shown in Fig. 3, the blades 127b4 are shaped as concave spades. The blades 127b4 are embedded to the impeller 127b such that the blades 127b4 are at least partially disposed within the body 127b1 and partially outside the body 127b1 (as shown in Fig. 3). The blade 127b4 helps to guide the blood to a lower portion of the impeller 127b which forces the blood to flow outward with increased pressure and speed.
[74] The impeller 127b directs (or pumps) the blood towards the lower portions of the impeller 127b and then out of the outflow port 123 with pressure and speed.
[75] Fig. 4 depicts another embodiment of an impeller 127c that may be rotatably disposed within the lumen 120a (as shown in Fig. 1b) of the second housing 120 (as shown in Fig. 4a) instead of the impeller 127a. The impeller 127c may also be coupled to the rotor 125 within the second housing 120. The impeller 127c may levitate and mimic the rotational motion of the rotor 125 when the motor 111 rotates the rotor 125. The impeller 127c may have a thickness ranging from 0.5 mm to 1 mm. In an exemplary embodiment, the impeller 127c is made of titanium having a thickness of 0.5 mm.
[76] The impeller 127c includes a base plate 127c1 disposed towards and coupled to the rotor 125. In an exemplary embodiment, the base plate 127c1 is circular shaped. The base plate 127c1 may have a diameter ranging from 25 mm to 35 mm. In an exemplary embodiment, the diameter of the base plate 127c1 is 31 mm.
[77] The base plate 127c1 may have a hole 127c2 aligned with the inflow port 121. The hole 127c2 may be concentric to the base plate 127c1. The hole 127c2 may have a diameter ranging from 3 mm to 5 mm. In an exemplary embodiment, the diameter of the hole 127c2 is 4 mm. The hole 127c2 provides a center axis for impeller 127c to rotate.
[78] One or more vanes 127c3 may be disposed over the base plate 127c1. In an exemplary embodiment, as shown in Fig. 4, the impeller 127c includes four equally spaced vanes 127c3. The vanes 127c3 may have a shape including but not limited to, concave, convex, etc. In an exemplary embodiment, the vanes 127c3 are comma shaped.
[79] The vanes 127c3 may have uniform height or variable height. In an exemplary embodiment, as shown in Fig. 4, the height of the vanes 127c3 increases from the periphery of the base plate 127c1 to the center of the base plate 127c1. The height of the vanes 127c3 may range from 4 mm to 6 mm. In an exemplary embodiment, the height of the vane 127c3 towards the periphery of the base plate 127c1 is 0 mm and the height of the vane 127c3 towards the center of the base plate 127c1 is 5 mm.
[80] The vanes 127c3 may have a thickness ranging from 4 mm to 6 mm. In an exemplary embodiment, the thickness of the vanes 127c3 is 5 mm.
[81] The impeller 127c will direct (or pump) the blood flow outward (of the outflow port 123) by the vanes 127c3 with reduced mechanical stress on the blood cells.
[82] Example 1 (Prior art): Conventional LVAD
[83] A conventionally available LVAD was set up to circulate blood for 8 hours. Blood samples were taken periodically after every 30 minutes and tested for hemolysis. Further, the flow rate, blood pressure and rotation of the impeller was monitored.
[84] It was observed that a significant amount of the blood cells was hemolyzed by the LVAD. Further, the impeller of the LVAD was rotating at a very high-speed of 2000 rpm to 2700 rpm to maintain a flow rate of 3 to 5LPM and a blood pressure of 70mmHg to 100mmHg. Such high rotation speed of the impeller produced a lot of vibrations and raised the temperature of the LVAD.
[85] Furthermore, it was observed that the LVAD was very bulky and weighed about 90g to 200g. Thus, it was concluded that the LVAD would cause quality of life issues to the prospective user of the LVAD.
[86] Example 2 (Present disclosure): Hemolysis index
[87] The device 100 of the present invention was operated each with impellers 127a, 127b and 127c, separately. Blood was circulated between the inflow port 121 and outflow port 123 of the device 100 for 8 hours. During the said 8 hours of operation, blood samples were collected periodically every 30 minutes. The blood samples collected were tested for hemolysis and other blood-related properties.
[88] It was observed that the hemolysis index of the blood samples collected were very low. Thus, it was concluded that the device 100 of the present disclosure is safe to use.
[89] Example 3 (Present disclosure): Performance evaluation
[90] The device 100 of the present invention was operated each with impellers 127a, 127b and 127c, separately. Blood was circulated between the inflow port 121 and outflow port 123 of the device 100 for 8 hours. The flow rate and blood pressure were monitored at the outflow port 123 of the device 100. Further, the rotation speed of the rotor 125 was monitored.
[91] It was observed that all the impellers 127a, 127b, 127c provided a very high flow rate of 4 liters/min to 5 liters/min while the impellers 127a, 127b, 127c were rotating at a low speed of only 2000 RPM to 2700 RPM. Further, the impellers 127a, 127b, 127c provided a blood pressure of 70 mmHg to 100 mmHg. Thus, it was concluded that the device 100 provided excellent pumping performance without any noticeable heating or vibrational discomfort to the prospective user.
[92] [36] The scope of the invention is only limited by the appended patent claims. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used. , Claims:WE CLAIM
1. A device (100), comprising:
a. a first housing (110) defining a lumen to house a motor (111);
b. a second housing (120) removably coupled to the first housing (110), the second housing (120) including an inflow port (121), an outflow port (123) and a rotor (125), the second housing (120) defining a lumen (120a) to rotatably house the rotor (125);
c. a plate (110b) disposed between the lumen of the first housing (110) and the lumen (120a) of the second housing (120), the rotor (125) magnetically levitates inside the lumen (120a) of the second housing (120) such that the rotor (125) defines a pre-defined gap with the plate (110b);
d. an impeller (127b) disposed within the lumen (120a) of the second housing (120), the impeller (127b) coupled to the rotor (125) such that the impeller (127b) magnetically levitates and rotates along with the rotor (125) to pump blood out of the outflow port (123),
wherein the impeller (127b) includes a body (127b1) coupled to a roof (127b2), the roof (127b2) including a hole (127b3) aligned with the inflow port (121), one or more blades (127b4) are at least partially disposed within the body (127b1) and partially outside the body (127b1), the blades (127b4) are concave-spade shaped, wherein the rotor (125) is coupled to the body (127b1).
2. The device (100) as claimed in claim 1, wherein the pre-defined gap ranges from 0.5 mm to 1 mm.
3. The device (100) as claimed in claim 1, wherein the first housing (110) including a pre-defined diameter ranging from 35 mm to 50 mm and a pre-defined height ranging from 15 mm to 20 mm.
4. The device (100) as claimed in claim 1, wherein the second housing (120) including a pre-defined height ranging from 15 mm to 18 mm.
5. The device (100) as claimed in claim 1, wherein a cover (115) removably coupled to the first housing (110) at a first end (100a) of the device (100).
6. The device (100) as claimed in claim 1, wherein an attachment assembly including at least one cuff body (121a), one circlip (121b), one cover ring (121c), one cuff ring (121d) and one felt ring (121e) is coaxially disposed around the inflow port (121).
7. The device (100) as claimed in claim 1, wherein a locking cuff (121f) is coaxially disposed around the inflow port (121).
8. The device (100) as claimed in claim 7, wherein the locking cuff (121f) provided with one or more legs (121f1) coupled to an outer periphery of the second housing (120).
9. The device (100) as claimed in claim 8, wherein the legs (121f1) are L-shaped.
10. The device (100) as claimed in claim 1, wherein the outflow port (123) is coupled to a conduit graft 123a via an assembly of a graft connector (123b), a graft holder, an O-ring and a screw ring (123c).
11. The device (100) as claimed in claim 1, wherein the body (127b1) has a hollow tubular structure and the roof (127b2) is conically shaped.
12. The device (100) as claimed in claim 1, wherein the body (127b1) includes a height ranging from 7 mm to 15 mm and a diameter ranging from 25 mm to 35 mm.
13. The device (100) as claimed in claim 1, wherein the weight of the device (100) ranges from 90g to 200g.
14. A device (100), comprising:
a. a first housing (110) defining a lumen to house a motor (111);
b. a second housing (120) removably coupled to the first housing (110), the second housing (120) including an inflow port (121), an outflow port (123) and a rotor (125), the second housing (120) defining a lumen (120a) to rotatably house the rotor (125);
c. a plate (110b) disposed between the lumen of the first housing (110) and the lumen (120a) of the second housing (120), the rotor (125) magnetically levitates inside the lumen (120a) of the second housing (120) such that the rotor (125) defines a pre-defined gap with the plate (110b);
d. an impeller (127a) disposed within the lumen (120a) of the second housing (120), the impeller (127a) coupled to the rotor (125) such that the impeller (127a) magnetically levitates and rotates along with the rotor (125) to pump blood out of the outflow port (123),
wherein the impeller (127a) includes a first plate (127a1) coupled to a second plate (127a2) via one or more blades (127a5), the blades (127a5) are concave shaped, the first plate (127a1) including a hole (127a3) aligned with the inflow port (121), wherein the rotor (125) is coupled to the second plate (127a2).
15. A device (100), comprising:
a. a first housing (110) defining a lumen to house a motor (111);
b. a second housing (120) removably coupled to the first housing (110), the second housing (120) including an inflow port (121), an outflow port (123) and a rotor (125), the second housing (120) defining a lumen (120a) to rotatably house the rotor (125);
c. a plate (110b) disposed between the lumen of the first housing (110) and the lumen (120a) of the second housing (120), the rotor (125) magnetically levitates inside the lumen (120a) of the second housing (120) such that the rotor (125) defines a pre-defined gap with the plate (110b);
d. an impeller (127c) disposed within the lumen (120a) of the second housing (120), the impeller (127c) coupled to the rotor (125) such that the impeller (127c) magnetically levitates and rotates along with the rotor (125) to pump blood out of the outflow port (123),
wherein the impeller (127c) includes a base plate (127c1) having a hole (127c2) aligned with the inflow port (121), one or more vanes (127c3) disposed over the base plate (127c1), the vanes (127c3) are comma shaped, a height of the vanes (127c3) increases from a periphery of the base plate (127c1) to the center of the base plate (127c1), wherein the rotor (125) is coupled to the base plate (127c1).