Reciprocating Blood Pump for Pulsatile Flow With Lower Cell Damage
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Solution Overview
Problem
Existing cardiac assist pumps with rotary designs cause excessive damage to blood cells and interfere with the natural pulsatile flow of the heart due to high rotational speeds and constant flow characteristics.
Innovation Solution
Development of linearly reciprocating blood pumps with expandable housings and valve members, such as flexible diaphragms or valve cones, that mimic the natural pulsatile flow of the heart, minimizing red blood cell damage and maintaining compatibility with the heart's pumping action.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If rotary type pumps are used to provide sufficient pressure and blood flow, then the pumping performance is improved, but red blood cell damage increases and operating time is limited
Solution Approach 1:
The patent replaces the rotary mechanical pump system with a linear reciprocating pump system. The linear pump uses a piston moving back and forth in a linear motion rather than a rotary impeller, fundamentally changing the mechanical approach to blood pumping. This substitution eliminates the high-speed rotation that causes red blood cell damage while maintaining adequate blood flow capability.
Solution Approach 2:
The linear reciprocating pump operates through periodic back-and-forth motion of the piston, creating alternating fill and pump strokes. This periodic linear action mimics the natural pulsatile flow pattern of the heart, providing sufficient blood flow in a manner that is gentler on red blood cells compared to continuous high-speed rotation.
2Stress or pressure
If high rotational speed pumps are used to provide sufficient pressure, then the pressure output is improved, but damage to blood cells occurs
Solution Approach 1:
The patent substitutes high-speed rotary mechanical action with linear reciprocating motion. The linear pump achieves necessary pressure through the reciprocating piston action and valve mechanism rather than high rotational speed, thereby generating adequate pressure output without the harmful effects of rapid rotation on blood cells.
Solution Approach 2:
The patent changes the operational parameters from high rotational speed to linear reciprocating motion. By altering the type of motion and the speed characteristics (slower linear motion compared to high-speed rotation), the system maintains pressure generation capability while eliminating the parameter (rotational speed) that causes blood cell damage.
3Stability of the object's composition
If constant flow pumps are used to maintain steady blood flow, then the flow stability is improved, but interference with heart valve action occurs
Solution Approach 1:
The linear reciprocating pump naturally produces periodic pulsatile flow through its alternating fill and pump strokes. This periodic action creates flow variations that synchronize with the heart's natural rhythm, preventing interference with heart valve operation. The pulsatile flow pattern allows the heart to maintain its normal valve timing and pumping action without the constant flow imposed by rotary pumps.
Solution Approach 2:
The patent employs dynamic pulsatile flow rather than static constant flow. The linear pump's moving piston creates dynamically varying flow rates that adapt to the heart's pumping cycle, allowing the system to work cooperatively with the heart's natural dynamics rather than imposing a rigid constant flow that would interfere with valve function.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The linearly reciprocating pumps generate pulsatile blood flow compatible with the heart's operation, reducing cell damage and enhancing the efficiency and safety of blood circulation support systems.
Implementation Method 1
a valve member disposed within the expandable housing that linearly reciprocates therein
Implementation Method 2
The valve members may include an inlet side that faces the inlet of the expandable housing, and an outlet side that faces the outlet side of the expandable housing
Implementation Method 3
The expandable housing may include an interior surface and an expanded configuration, and may define a chamber for collecting blood
Data Source
AI summary
Described herein are pumps that linearly reciprocate to assist with circulating blood within the body of a patient. Red blood cell damage may be avoided or minimized by such linear pump movement. The linearly reciprocating movement may also generate a pulsatile pumping cycle that mimics the natural pumping cycle of the heart. The pumps may be configured to reside at various body locations. For example, the pumps may be situated within the right ventricle, the left ventricle, the ascending aorta, the descending aorta, the thoracic aorta, or the abdominal aorta. In some instances, the pump may be deployed within the venous circulation. In other instances, the pump may reside outside the patient.