This nanofluidic pump is well suited for a range of applications in the medical field, such as withdrawal of fluids or delivery of therapeutics through a parenteral implant in a human patient. Companies in the pharmaceutical space may be interested in leveraging the pump’s ability to perform micro-invasive label-free liquid biopsies by tracking the onset and progression of disease in animal models of human pathologies. This could drive the discovery of new biomarkers of human disease and guide the creation of novel therapeutic drugs. Likewise, pharmaceutical and medical device companies may want to deploy this pump for the parenteral delivery of extremely low volumes of therapeutic drugs, enabling accurate individualized dosing with minimal off-target effects. There are also potential applications of this pump outside the biomedical industry. A range of industries rely on microfluidic and nanofluidic devices, and this pump can drive bidirectional flow within such devices with high precision while retaining its compact design and small physical footprint.
Conventional pumps are unsuitable for clinical applications requiring chronic implantation in delicate tissues or applications that require precise low-volume fluid control (single nanoliter stroke volumes, negligible dead volumes) and bidirectional flow. Precision medicine requires the identification of an individual’s unique pathology followed by accurate drug delivery to target tissues. Ideally, implantable fluid pumps for this application would have the capacity to offer long-term micro-invasive fluid sampling while also facilitating targeted drug delivery. Existing syringe-based and peristaltic positive displacement pumps have large dead volumes (> 200 nanoliters), and thus cannot deliver or sample extremely small volumes of liquid. Most implantable pumps, moreover, are designed for unidirectional operation and operate at microliter/second flow rates. They also often contain magnetically susceptible materials that are not compatible with common medical imaging modalities such as magnetic resonance imaging (MRI). This invention is a peristaltic pump that is actuated by MRI-compatible materials and is capable of low-volume bidirectional fluid control (single stroke volume < 3 nanoliters, dead volume < 30 nanoliters). This pump can be manufactured in either an implantable or wearable form and can interface with a parenteral implanted probe inserted into the pump’s fluidic channel. This enables acute and chronic micro-invasive withdrawal of small-volume liquid biopsies for diagnostics and delivery of precise drug volumes into a target tissue.
The present technology is a peristaltic pump that enables bidirectional fluid flow with nanoliter precision. The pump is comprised of a series of wire actuators comprised of a nickel titanium alloy (nitinol) that control fluid flow within a tube or channel. Nitinol is MRI-compatible and has a high electrical resistance which drives ohmic heating when current is passed through the wire. This heat triggers a martensite to austenite phase transition in the nitinol, leading to physical contraction of the wire. Wire contraction displaces fluid within the tube. Sequential contraction of the wire actuators thus drives directional fluid flow. The direction and rate of fluid flow is regulated by the specific, changeable sequence of wire contractions within the actuator series. This mechanism enables precisely controlled bidirectional fluid flow with nanoliter precision, which can facilitate both liquid biopsy, such as cerebrospinal fluid sampling, as well as drug delivery when the pump is interfaced with an implant in the target tissue, such as a patient’s brain. The pump can be manufactured and used in either an implantable or wearable form, with a wearable detachable form being preferable for pump designs that contain control circuitry or batteries that are not MRI-compatible.
- Achieves precise fluid flow of low volumes in a bidirectional manner
- Able to both deliver therapeutics and acquire liquid biopsies
- MRI-compatible pump composition enables compatibility with medical imaging modalities
- Slim-profile design enables ready miniaturization for long-term implantation