VAD integrated flow sensor
A blood pump with an integrated flow sensor is provided. The blood pump may include an implantable pump for pumping blood having a housing, a flow path extending within the housing and at least one movable element within the housing for impelling blood along the flow path and a sensor for measuring the flow rate of blood through the pump. According to one embodiment, the sensor may be mounted to the housing of the pump. In accordance with a further embodiment, the housing may have an exterior surface defining a cavity, and the sensor may be located within the cavity.
1. A blood pump comprising:
an implantable pump for pumping blood having a rigid housing, a flow path extending within the housing in upstream and downstream directions and at least one movable element within the housing for impelling blood along the flow path;
a first housing element and a second housing element within the housing having respectively a first interior surface and a second interior surface, the first and second interior surfaces confronting each other and cooperatively defining therebetween at least a portion of the flow path, the first housing element having an exterior surface defining a cavity external to the flow path;
wherein the first housing element defines a first platform surface facing downstream at an oblique angle to a flow path axis and a second platform surface facing upstream at an oblique angle to the flow path axis, in which the first and second platform surfaces overlie the portion of the flow path, in which the first and second platform surfaces are within the cavity and extend respectively from first and second portions of the first interior surface which face in a same direction and confront the second interior surface, and
wherein a first flow sensor is mounted to the first platform surface at an oblique angle to the flow path axis and a second flow sensor is mounted to the second platform surface at an oblique angle to the flow path axis.
2. The blood pump of claim 1 , wherein the sensor includes at least two ultrasonic transducers.
3. The blood pump of claim 1 , wherein each of the platforms has a slope of substantially 45 degrees to the flow path axis.
4. The blood pump of claim 2 , wherein the ultrasonic transducers are mounted to the platforms with an adhesive, at a slope of substantially 45 degrees to the flow path axis.
5. The blood pump of claim 2 , the first and second transducers being arranged so that an ultrasound signal emitted from the first transducer passes through the flow path to the second housing element, reflects from the second housing element and is received by the second transducer, wherein the ultrasound signal is emitted and received at an angle oblique to the flow path axis.
6. The blood pump of claim 5 , wherein the pump is a rotary pump.
7. The blood pump of claim 1 wherein the housing further includes a cover overlying the cavity in the first housing element.
8. The blood pump of claim 1 further comprising an electronic circuit disposed within the cavity and connected to the sensors.
9. The blood pump of claim 1 , wherein the sensors are mounted adjacent an inflow end of the flow path.
10. The blood pump of claim 1 , wherein the sensors are mounted adjacent an outflow end of the portion of the flow path.
11. The blood pump of claim 1 wherein the pump includes one or more electrical elements for moving the movable element, the blood pump further comprising an external control unit operative to power the electrical elements, and a driveline for connecting the pump and at least one ultrasonic sensor to the external control unit.
12. The blood pump of claim 11 , wherein the sensors are connected to the external control unit through the driveline.
13. The blood pump of claim 12 , wherein the driveline is the only connection between the pump and the external control unit.