PCA Device Bolus Refill Prevention via Dual-Direction Clamp
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing patient-controlled analgesic (PCA) devices require continuous effort to administer drugs, are difficult to prime, and can lead to unintended drug delivery due to bolus refill or pump malfunction, posing risks of overdose or continuous drug delivery.
Innovation Solution
A PCA device with a clamp system that prevents bolus refill during delivery and automatically initiates the intake stroke, allowing for quick and effortless self-administration of drugs with a single button press, featuring a dual-direction clamp to control outlet and inlet flow, and a priming tab for rapid device preparation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a reciprocating pump with manual plunger compression is used for PCA device, then the patient can self-administer drug boluses, but the patient must continuously exert force throughout the compression stroke which may take several seconds or minutes, and some patients may not be physically capable of such prolonged exertion
Solution Approach 1:
The pump operation is segmented into two distinct phases: a brief patient-initiated compression stroke and an automatic extended intake stroke. The patient only needs to initiate the compression phase by depressing the button, while the intake phase occurs automatically without requiring continuous patient effort. This segmentation allows the total operation time to be extended without increasing patient burden.
Solution Approach 2:
The pump performs the intake stroke automatically without patient intervention. After the patient initiates the compression stroke, the pump autonomously executes the intake phase, drawing in the next bolus of medication. This self-service capability eliminates the need for continuous patient effort throughout the entire pump cycle.
2Ease of operation
If a reciprocating pump with manual button activation is used, then the patient can trigger the compression stroke, but the patient must push a first button to effect compression then push a second button to initiate intake stroke, requiring monitoring of plunger position
Solution Approach 1:
Both the compression and intake stroke initiation functions are merged into a single button mechanism. Depressing the button simultaneously initiates the compression stroke, and upon completion, automatically triggers the intake stroke. This consolidation eliminates the need for separate buttons and reduces the cognitive burden of monitoring plunger position.
Solution Approach 2:
The pump incorporates automatic detection of plunger position to control the transition between compression and intake strokes. The system monitors when the compression stroke is complete and automatically initiates the intake phase, eliminating the need for patient monitoring and manual intervention.
3Reliability
If a reciprocating pump requires priming to replace air with liquid drug, then the device must be prepared before use, but it requires an extended period of time and careful manipulation by a health care professional since air bubbles could form dangerous embolism
Solution Approach 1:
The pump is pre-filled with the liquid medication in a sealed reservoir before use, eliminating the need for on-site priming. The device is manufactured and prepared in advance with the drug already in place, so no time-consuming priming procedure is required at the point of use. This preliminary action ensures safety by preventing air bubble formation without delaying treatment.
Solution Approach 2:
The priming function is extracted from the device operation and performed during manufacturing. The pump reservoir is pre-filled and sealed, removing the priming step from the clinical workflow. This extraction eliminates both the time loss and the need for careful professional manipulation during patient care.
4Reliability
If a flow restrictor is placed at the inlet of the pump to limit refill rate, then the patient self-administration rate is controlled, but the rate at which the pump refills and hence the rate at which the patient may self-administer the drug is limited
Solution Approach 1:
The drug delivery is segmented into controlled bolus doses delivered during the compression stroke and automatic refilling during the intake stroke. The flow restrictor limits refill during the intake phase to prevent overdose, while the compression phase delivers the full bolus dose to the patient. This segmentation allows safety control during refilling without limiting the therapeutic delivery rate to the patient.
Data Source
AI summary
A device for dispensing fluid to a patient enabling either or both of a continuous flow, as well as successive, large-volume boluses. A first reservoir provides a source of fluid under pressure. A bolus flow path provides for the delivery of a bolus dose of fluid and an optional continuous flow path provides a continuous flow rate of fluid. Both flow paths are in fluid communication with the source of fluid. A bolus delivery system in fluid communication with the bolus flow path receives fluid from the first reservoir, expands to pressurize fluid, stores the pressurized fluid, and dispenses the pressurized fluid while avoiding bolus refill until enabled to expand in a subsequent delivery cycle. An actuator releases fluid from the bolus delivery system such that when actuated by the patient, fluid is permitted to flow out of the bolus reservoir to the patient without further action by the patient.