120 results about "Ventricle" patented technology

The present application relates to the field of medical devices, and specifically to a repair device for preventing valve regurgitation, comprising a mounting bracket, a single anti-reflux prosthesis for replacing the function of a single native valve leaflet, and a fixing member, wherein one end of the single anti-reflux prosthesis is fixed on the mounting bracket, and an atrial segment is provided at the distal end of the mounting bracket, and the atrial segment is configured to adapt to the morphology of the native valve ring tissue, and the atrial segment includes a leak-proof portion, and the proximal end portion of the mounting bracket is anchored in the ventricle by the fixing member, wherein, after the mounting bracket is installed in place, the leak-proof portion abuts against or fits the native valve ring tissue, and when the native valve opens and closes so that the morphology of the native valve ring changes, the leak-proof portion follows the morphological change of the native valve ring and produces adaptive deformation, so that the leak-proof portion always abuts against or fits the native valve ring tissue.

The invention discloses a stereotactic puncture path planning method based on reinforcement learning. The stereotactic puncture path planning method comprises the following steps: S1, constructing a risk weight map; s2, establishing a puncture constraint set; s3, performing global search on the frog group initial population by adopting a discrete frog leaping optimization algorithm to obtain an initial puncture path set with consistent constraints; s4, mapping the real-time navigation state vector template into a state set; s5, when Q value updating is executed, strategy smooth regularization is introduced, and state-action-award closed-loop iteration is completed; and S6, when the simulation navigation system judges that the puncture instrument reaches the target ventricle coordinate or the navigation state vector triggers the risk threshold early warning of the puncture constraint set, the final simulated refined puncture path is output to a surgical navigation interface. The probability of damaging a key structure in an operation is obviously reduced.

The application provides an ultrahigh frequency electrocardiogram mapping analysis method and system, through a Hilbert transform algorithm, time-frequency characteristics of high-frequency electrocardiogram signals can be retained, and influence of complex clutter on the high-frequency electrocardiogram signals can be reduced to the maximum extent; through drawing of an electrical activation map, time-space distribution of electrical activity is described in a graphical manner, and atrium / ventricle asynchrony or myocardial ischemia problems can be more accurately revealed; through transfer learning, a model can better understand and process new data, and the problem of poor model training effect caused by less high-frequency electrocardiogram data is effectively solved; through construction of an intelligent diagnosis system, the automation level of diagnosis is improved, and auxiliary diagnosis of inputting an electrical activation map and outputting a classification result is realized.

The invention relates to an instrument for transferring cerebrospinal fluid in a ventricle into a body cavity of other parts of a human body, and particularly discloses an intraventricular hydrops drainage device which comprises a base used for being attached to a bone window of a skull, a confluence cavity and a liquid outlet connector communicated with the confluence cavity are arranged on the base, and the liquid outlet connector is provided with a liquid inlet and a liquid outlet. The flow guide hose is connected to the liquid outlet joint; a tip axially remote from the base; the drainage main body component is used for guiding cerebrospinal fluid in the ventricle to the confluence cavity; the drainage main body component comprises a plurality of micro-catheters; the near end and the far end of each micro catheter are attached to the base and the end respectively, and the near end of the micro central hole of each micro catheter is communicated with the confluence cavity; the micro-conduits are arranged in a plurality of circles in the circumferential direction and the radial direction; a micro drainage structure communicated with the micro central hole is arranged on the tube wall of each micro catheter, and the micro drainage structures are arranged in the circumferential direction and the axial direction of the tube wall of the micro catheter so as to allow cerebrospinal fluid to enter the micro central hole through the tube wall of the micro catheter.

The invention relates to a cerebrospinal fluid dynamic monitoring management method. Comprising the following steps: performing mode identification by using dynamic characteristics of cerebrospinal fluid pressure and flow velocity; by monitoring the flow velocity and pressure fluctuation of cerebrospinal fluid in real time, a comparison library of a normal mode and an abnormal mode is established; deep learning is carried out by using a fluid mechanics model and a neural network, and abnormal points of non-linear change are identified; through combination of a pressure sensor array and a flow velocity sensor, dynamic flow changes are captured in different areas of a cerebrospinal fluid system including a ventricle and a subarachnoid space, and abnormal fluctuations are identified through continuous analysis of time sequence data; by analyzing the interaction between the intracranial flow mode of cerebrospinal fluid and the compression expansion effect of brain tissues, an intelligent adjustment mechanism based on the flow pressure coupling effect is introduced; under the influence of cerebrospinal fluid pressure changes, deformation of brain tissue including ventricular expansion influences blood flow and tissue pressure in other intracranial areas.

The utility model discloses an intracranial pressure monitoring and drainage management device, and particularly relates to the technical field of medical treatment, the intracranial pressure monitoring and drainage management device comprises a main control device and a lifting device, the lifting device is fixedly installed on the main control device, and a suspension bracket is fixedly installed at the top end of the lifting device; a first height positioning signal generator is fixedly mounted at the top of the suspension bracket, a drainage bottle and a drainage collection bag are mounted on the suspension bracket and the main control equipment respectively and are communicated with the ventricle of a patient through ventricle drainage tubes, and a second height positioning signal generator is attached to the external auditory canal of the patient and is connected with the first height positioning signal generator. A temperature and pressure integrated sensor is fixedly mounted at one end of the ventricular drainage tube, and a height positioning signal receiver is fixedly mounted in the main control equipment. The UWB technology is used for achieving the purpose that the lifting device regulates and controls the height of the drainage bottle, then the intracranial pressure of a patient is kept stable, and the effects of intracranial pressure monitoring and drainage management are achieved.

The invention relates to a ventricle connecting mechanism and a ventricle auxiliary system. The ventricle connecting mechanism comprises a suture ring, a clamping ring, a pressing ring and a connecting piece. The suture ring is provided with a mounting hole for an inlet pipe of the ventricular auxiliary device to penetrate through, and a mounting groove surrounding the mounting hole is formed in the suture ring. And the clamping ring is embedded in the mounting groove. The inner diameter of the clamping ring is adjustable, and the hole diameter of the mounting hole can be adjusted by adjusting the inner diameter of the clamping ring. The pressing ring is arranged on the suture ring and abuts against the clamping ring so that the clamping ring can be limited in the installation groove. The connecting piece is fixedly connected with the suture ring and the pressing ring. According to the ventricle connecting mechanism, the clamping ring is pressed against the clamping ring through the pressing ring, and the connecting piece is arranged to fixedly connect the suture ring and the pressing ring, so that the clamping ring is clamped between the pressing ring and the bottom wall of the mounting groove, and the risk that the clamping ring falls off from the suture ring is reduced.

The invention provides a stator iron core, a magnetic suspension blood pump and a ventricular auxiliary device, the stator iron core comprises a yoke part and a plurality of tooth parts, and the plurality of tooth parts are connected to the same side of the yoke part and are arranged at intervals along the circumferential direction of the yoke part; the tooth part extends in the axial direction of the yoke part, a matching face is formed at the end, away from the yoke part, of the tooth part, the matching face inclines relative to the axis of the yoke part, and the matching face is a part of a conical face coaxial with the yoke part. When the stator core is applied to the magnetic suspension blood pump, the position of the rotor can be actively adjusted in the axial direction, and the position of the rotor can also be actively adjusted in the radial direction.

The invention discloses an accurate regulation and control instrument for ventricular drainage, and relates to the technical field of neurosurgical medical equipment, the accurate regulation and control instrument for ventricular drainage comprises a fish-shaped clamp, the clamp is formed by connecting symmetrical arc-shaped clamping blocks through a rotating shaft, the inner wall of the clamp is provided with a fixing groove and an arc-shaped air bag I, and the air bag I is embedded with a flow sensor and is provided with semispherical anti-skid grains; the clamp is matched with an elastic plate to form fixation, a controller, an air pump and an electromagnetic valve are arranged on the side portion of the clamp, a second pressing type air bag is additionally arranged, an air path is matched with a pressure gauge, and all the components are in signal connection with the controller. During work, the first air bag is inflated to flexibly extrude the drainage tube, the flow sensor collects data in real time, and the controller is linked with the air pump and the electromagnetic valve to regulate and control the opening degree of a tube cavity in a closed loop mode so as to accurately control flow. Continuous drainage is guaranteed through double-mode air supply, operation is convenient through a convenient clamping structure, the precision is high, the device is suitable for drainage tubes of multiple specifications, the medical care load is reduced, and the clinical treatment safety and continuity are improved.

The present invention discloses a ventricular volume reduction puncture device, which includes a puncture structure and a control structure; the puncture structure includes a puncture catheter and a mapping catheter. A first limiting member is provided at the proximal end of the puncture catheter, and a puncture needle is provided at the distal end of the puncture catheter. The mapping catheter is sleeved outside the puncture catheter; the control structure includes a fixed sleeve. The proximal end of the mapping catheter is fixed in the fixed sleeve, and a guide groove adapted to the first limiting member is provided on the fixed sleeve so that the first limiting member moves axially along the guide groove, thereby driving the puncture catheter to move axially.

The invention relates to an instrument for transferring cerebrospinal fluid in a ventricle into a body cavity of other parts of a human body, and particularly discloses a cerebrospinal fluid drainage catheter component and a drainage system.The cerebrospinal fluid drainage catheter component comprises a catheter body, a plurality of rows of main long holes which extend in the circumferential direction and are distributed at intervals in the axial direction are formed in the wall of the catheter body, and a plurality of drainage holes are formed in the main long holes; a plurality of protruding parts are arranged on the two linear hole walls of the main long hole so that the main long hole can be divided into a plurality of micro holes. The pipe wall occupied by each row of main long holes is a first section, and the pipe wall between each two adjacent rows of main long holes is a second section; the driving component is used for driving one of every two adjacent second sections to axially move relative to the other second section, so that one end, in the circumferential direction, of the main long hole axially moves relative to the other end of the main long hole, and the two linear hole walls of the main long hole generate relative dislocation movement in the circumferential direction; therefore, the protruding part disturbs the interior of the main long hole.

The invention provides a position monitoring device and method of a catheter pump and a ventricular assist device and equipment, and relates to the field of medical instrument control. The position monitoring device comprises a pressure difference monitoring module, a position judgment module and a position detection module, the differential pressure monitoring module is used for calculating the differential pressure of the conduit pump according to the rotating speed of the motor and the flow of the conduit pump; wherein the motor drives the conduit pump to work; the position judgment module is used for judging whether the position of the catheter pump is correct or not according to the pressure difference of the catheter pump; and the position detection module is used for determining the wrong position of the conduit pump according to the fluid outlet pressure of the fluid outlet of the conduit pump under the condition that the position of the conduit pump is incorrect. By using the position monitoring device provided by the embodiment of the invention, whether the position of the catheter pump of the ventricular assist device (VAD) is correct or not can be monitored in real time, and a foundation is laid for providing stable auxiliary flow for the ventricular assist device.

The present application relates to a ventricular assist device. Apparatus and methods are described herein, including a blood pump (20) configured to be placed within a subject's body, the blood pump comprising an impeller (50) and a frame (34) disposed around the impeller, the impeller comprising proximal and distal bushings (64, 58), the frame comprising proximal and distal bearings (116, 118). An axial shaft (92) passes through the proximal and distal bearings (116, 118) of the frame and the proximal and distal bushings (64, 58) of the impeller (50). The impeller (50) defines a radially constrained configuration in which the impeller (50) is introduced into the subject's body and a non-radially constrained configuration in which the impeller (50) is configured to pump blood within the subject's body. The impeller (50) is changed from its radially constrained configuration to its non-radially constrained configuration by sliding the distal bushing (58) over the axial shaft (92). Other applications are also described herein.

The utility model discloses a rotor assembly, a motor and a ventricular auxiliary blood pumping device. The rotor assembly comprises a permanent magnet which comprises a body, a first cavity enclosed by the body, and a protective layer covering the outer surface, back to the first cavity, of the body; a part of the rotating shaft extends into the first cavity, a gap cavity is formed between the part of the rotating shaft and the permanent magnet, and the two ends, opposite in the axial direction, of the rotating shaft extend out of the permanent magnet; and the sealing connector blocks the gap cavity along two opposite ends of the axial direction of the gap cavity, and the sealing connector is respectively connected with the protective layers at the two ends in a sealing manner, so that the surface of the body is isolated from the external environment. The rotor assembly blocks the two axially opposite ends of the gap cavity through the sealing connectors and is in sealing connection with the protection layers at the two ends, the surface of the body is isolated from the external environment, and the permanent magnets are effectively protected against corrosion. And meanwhile, the inner surface of the body has high processing precision and can be assembled with a rotating shaft to obtain a high-precision rotor assembly, so that the yield of the motor is improved.

The invention provides an intelligent temperature-control ventricular double-circulation washing system and method based on dynamic pressure feedback, the system comprises a temperature-control water inlet device, a double-circulation washing catheter and a balloon type pressure buffer, the double-circulation washing catheter is internally provided with a centrally-arranged sensing cavity, a flushing cavity and a drainage cavity, and the flushing cavity and the drainage cavity wrap the two sides of the sensing cavity; a pressure sensor and a temperature sensor are arranged in the sensing cavity; a water outlet of the temperature control water inlet device is communicated with the starting end of the flushing cavity, the starting end of the drainage cavity is used for being connected with an external drainage device, the balloon type pressure buffer is arranged at the tail end of the double-circulation washing catheter, and the tail end of the double-circulation washing catheter is used for being placed in the ventricle of a patient. The ventricle flushing device can improve ventricle flushing efficiency and safety.

To improve the performance of a ventricular assist device.SOLUTION: Apparatus and methods are described including an impeller (50) that includes a proximal bushing (64) and a distal bushing (58). Two or more helical elongate elements (52) extend from the proximal bushing (64) to the distal bushing (58). An axial structure (54) is disposed inside the two or more helical elongate elements (52), and along an axis around which the helical elongate elements (52) are wound. The impeller (50) includes an impeller-overexpansion-prevention element (72). The impeller-overexpansion-prevention element is a single integrated structure that includes a ring (73) disposed around the axial structure (54), and a plurality of elongate elements (67). Each of the elongate elements (67) extends from the ring to a respective helical elongate element (52) and is coupled to each helical elongate element (52) so as to prevent radial expansion of the impeller (50). Other applications are also described.SELECTED DRAWING: Figure 3E

This invention discloses a method for constructing an early prediction model of hydrocephalus secondary to intraventricular tumors based on the dynamic changes of inflammatory factors after surgery, belonging to the field of medical data processing and model construction. The method includes: acquiring the concentration values ​​of inflammatory factors and the hydrocephalus outcome of biological samples at multiple postoperative time points; calculating quantitative characteristic parameters characterizing the dynamic evolution of the inflammatory response, such as the dynamic change rate, cumulative load, and acceleration, based on the concentration values; and training a deep learning model using the quantitative characteristic parameters and clinical baseline data as input features, with the hydrocephalus outcome as the label. This invention achieves early quantitative warning of hydrocephalus risk, significantly improving the accuracy, sensitivity, and specificity of prediction. It solves the technical problem of existing technologies relying on post-operative monitoring methods such as imaging and lacking early biochemical warning capabilities.

Aspects of the disclosure include transcatheter delivery devices for delivery and deployment of a cardiac prosthesis, such as a prosthetic heart valve. Various embodiments include a one or two part capsule for maintaining the prosthesis during delivery. Embodiments include a flexible capsule that can deflect, either automatically or in response to contact with the anatomy, to reduce a delivery depth within a ventricle necessary to fully unsheathe the prosthesis, which increases the patient population and valve locations suitable for prosthesis delivery with the delivery device.

The invention discloses a neural network-based hydrocephalus imaging feature detection method, electronic equipment and a storage medium, and the method comprises the steps: collecting and marking the brain image data of a normal pressure hydrocephalus patient, and carrying out the preprocessing; segmenting a ventricle region in the thick-layer brain image data by using a neural network to generate a binary image sequence; training a neural network model for interpolation through thin-layer brain image data, and continuously adjusting parameters until the parameters are optimal; inputting the binary segmentation result of the thick-layer image and the original thick-layer image into a trained interpolation network, and outputting a binary segmentation image after interpolation processing; and counting the voxel number of the ventricle part in the binary segmentation image after interpolation, and calculating the actual volume of the ventricle lumen by combining image scanning interval information. According to the method, the error generated when the ventricular volume is calculated through image segmentation when the scanning interval is too large is reduced so as to obtain accurate ventricular volume data, and therefore the computer-aided diagnosis process of hydrocephalus is optimized.

The present application relates to the field of medical device technology, and in particular to a perfusion and drainage system and control method. The system includes: a perfusion unit, a drainage unit, an interactive control unit, and a drainage tube; the interactive control unit is used to obtain intracranial pressure parameters and drainage volume parameters of the patient's ventricles, dynamically determine the current perfusion and drainage mode based on the intracranial pressure parameters and drainage volume parameters, and generate control instructions corresponding to the current perfusion and drainage mode. The current perfusion and drainage mode is one of the normal perfusion and drainage mode, the dredging mode, and the drainage mode. The dredging mode is used to remove the blockage of the drainage tube; the drainage tube is used to connect the perfusion unit and the drainage unit to the patient's ventricles respectively; the perfusion unit and the drainage unit are used to receive the control instructions sent by the interactive control unit, and perfuse and / or drain the patient's ventricles according to the control instructions. The present application simplifies the perfusion and drainage control process and improves treatment efficiency.

The invention discloses an interventional medical instrument device which comprises a flexible transmission shaft and a catheter arranged outside the flexible transmission shaft in a sleeving mode, and the catheter comprises an inner catheter layer, a buffer layer and a woven layer; the inner wall of the inner pipe layer defines an inner cavity of the catheter, and the flexible transmission shaft is rotatably arranged in the inner cavity in a penetrating mode; the buffer layer is arranged between the outer wall of the inner pipe layer and the inner wall of the braid layer, and the buffer layer is used for buffering extrusion of the braid layer to the inner pipe layer so as to maintain the inner wall of the inner pipe layer to be in a smooth and flat state. According to the interventional medical instrument device, the smoothness and roundness of the inner wall of the inner pipe layer are improved, so that the flatness and abrasion resistance of the inner surface of the inner pipe layer are kept, and abrasion to the inner pipe layer during rotation of the flexible transmission shaft is reduced. The invention further provides a ventricle assisting device.

The application relates to a perfusion guide device, a method, a ventricular assist system, a storage medium and equipment for a ventricular assist device, which comprises a pressure detection module, a state judgment module and an auxiliary confirmation module, wherein the pressure detection module is used for detecting the pipeline pressure after at least one pipeline exhaust operation is completed, the state judgment module is used for comparing the detected pressure value with a preset threshold value to identify the leakage or blockage state of the pipeline, and the auxiliary confirmation module is used for instructing to disconnect the connection between the perfusion pump and the catheter pump when it is confirmed that the reason for excluding the pipeline blockage cannot be confirmed, and is also used for controlling the infusion motor to drive the perfusion pump to operate at a preset rotating speed for a preset auxiliary confirmation time period, and judging whether the blockage is located in the perfusion pump pipeline or the catheter pump pipeline based on whether the measured pressure value during the operation exceeds the preset threshold value.

An embodiment of the present invention provides a method and device for detecting aspiration events of a ventricular catheter pump, which relates to the technical field of medical devices. The above method includes: during the operation of the ventricular catheter pump, obtaining the rotational speed data and current data of the ventricular catheter pump, and obtaining the flow rate data of the blood passing through the ventricular catheter pump; for each type of target data, based on the data sequence order of the target data of this type, extracting aspiration features from the target data of this type, wherein the types of the target data include: rotational speed data type, current data type, and blood flow rate data type; based on the extracted aspiration features of the target data, predicting whether an aspiration event occurs in the ventricular catheter pump. When applying the solution provided in this embodiment, it is possible to detect whether an aspiration event occurs in the ventricular catheter pump.

The application relates to a medical image segmentation method and device, computer equipment and a storage medium, wherein the medical image segmentation method comprises the following steps: acquiring a threshold image of a medical image; determining a plurality of connected domains in the threshold image, and generating a connected domain image corresponding to each connected domain; matching the threshold image with a standard template image containing a ventricle region label to obtain an initial ventricle mask image; further, comparing each connected domain image with the initial ventricle mask image, and selecting the connected domain image for fusion based on the comparison result to obtain a target ventricle mask image, thereby solving the problem that the spatial position and shape information of the ventricle is ignored, resulting in inaccurate image segmentation results, and improving the accuracy of the image segmentation result.

The present invention provides an impeller and a ventricular assist device. The impeller includes at least one cover plate and a plurality of blades. The cover plate has a first assembly surface and a second assembly surface facing each other. The plurality of blades are disposed on the first assembly surface. The second assembly surface includes a connected supporting surface and an inclined surface. The inclined surface has a first side edge and a second side edge facing each other along the radial direction of the impeller. The first side edge is connected to the supporting surface. From the first side edge to the second side edge, the inclined surface extends obliquely toward a side close to the blade. The angle between the inclined surface and the supporting surface is no greater than 5°. In a cross section passing through the central axis of the impeller, the ratio of the length of the supporting surface to the length of the second assembly surface is 1 / 5 to 3 / 5. The impeller and ventricular assist device of the present invention reduce the axial force on the impeller as a whole by controlling the pressure on the upper and lower surfaces of the impeller, making the impeller easier to levitate and control.

The device comprises a neuroendoscope, a drainage tube and a base, a fixing assembly is arranged on one side of the upper end of the base, an electric push rod is installed at the upper end of the fixing assembly, a connecting rod is rotationally connected to the upper end of the electric push rod, and a positioning assembly is rotationally connected to one side of the upper end of the connecting rod; a first shooting assembly is arranged at the lower end of the inner wall of the positioning assembly, a laser indicating assembly is installed at the lower end of one side of the outer wall of the positioning assembly, a laser distance measuring sensor is installed at the lower end of the other side of the outer wall of the positioning assembly, and a channel pipe slides on the inner wall of the positioning assembly. One side of the upper end of the base is rotationally connected with a display assembly, and the other side of the upper end of the base is provided with a control panel. Accurate position positioning can be achieved, a neuroendoscope and a drainage tube body can enter at the same time when a channel is established, and fine structures around a focus and in the ventricle can be seen clearly while position fine adjustment is conducted.

The application provides a pump shell, which comprises a first shell, a second shell and an assembling part, the second shell is connected with the first shell to form a receiving cavity capable of receiving an impeller, at least one of the first shell and the second shell is provided with a groove with an opening facing the receiving cavity, the groove has a first side surface, the assembling part comprises a connecting assembling surface and a second side surface; the assembling part is accommodated in the groove, the assembling surface can be opposite to the surface of the impeller received in the receiving cavity, and the second side surface is in contact with the first side surface.The pump shell provided by the application is installed on at least one of the first shell and the second shell through the additionally provided assembling part, thus the first shell, the second shell and the assembling part can be machined respectively, the flatness of the assembling surface can be controlled, the basis for the substantial improvement of the flatness of the assembling surface is provided, and the thrombus can be avoided on the basis of improving the overall operation accuracy of the ventricular assist device.The application further provides a pump body and a ventricular assist device.

The application discloses an intracranial ventricle temporal horn-frontal horn bypass shunt pipeline, which comprises a three-way flow guide pipe, a frontal horn liquid passage pipe and a connecting joint, the first end of the three-way flow guide pipe is arranged in the ventricle temporal horn, the second end of the three-way flow guide pipe is detachably connected with one end of the frontal horn liquid passage pipe through the connecting joint, the connecting joint is used for blocking / communicating the second end of the three-way flow guide pipe and the frontal horn liquid passage pipe, the other end of the frontal horn liquid passage pipe is arranged in the ventricle frontal horn, and the third end of the three-way flow guide pipe is used for connecting a liquid storage bag under the scalp or leading out of the scalp. The bypass shunt pipeline of the application adopts the three-way flow guide pipe, the third end of the three-way flow guide pipe is used for connecting the liquid storage bag or leading out of the scalp, the third end of the three-way flow guide pipe can be used for taking cerebrospinal fluid samples for testing, thereby assisting clinical diagnosis; meanwhile, the end can be used for implementing liquid pumping and pressure reduction operation, so as to reduce intracranial pressure.

The present application discloses a ventricular assist system, a flushing method, a consumable material, a control apparatus, and a control device for a medical catheter pump system, and belongs to the technical field of medical devices. In the ventricular assist system, the first three-way valve includes a first valve port, a second valve port, and a third valve port, wherein the first valve port is connected to a first flushing path driven by the flushing pump assembly, and the second valve port is connected to a first flushing interface of the medical catheter pump; the second three-way valve includes a fourth valve port, a fifth valve port, and a sixth valve port, wherein the fourth valve port is connected to a second flushing path driven by the flushing pump assembly, and the fifth valve port is connected to a second flushing interface of the medical catheter pump.

This application relates to ventricular assist devices. Described herein are devices and methods, including a blood pump (20) configured to be placed within a body of a subject, the blood pump including an impeller (50) and a frame (34) disposed about the impeller, the impeller including proximal and distal bushings (64, 58), the frame including proximal and distal bearings (116, 118). An axial shaft (92) passes through the proximal and distal bearings (116, 118) of the frame and the proximal and distal bushings (64, 58) of the impeller (50). The impeller (50) defines a radially constrained configuration in which the impeller (50) is introduced into the body of the subject and a non-radially constrained configuration in which the impeller (50) is configured to pump blood within the body of the subject. The impeller (50) changes from its radially constrained configuration to its non-radially constrained configuration by sliding the distal bushing (58) over the axial shaft (92). Other applications are also described herein.