The existing health care system requires an individual to visit a health care facility to conduct point-in-time tests to monitor even the most basic healt status markers, which can miss fluctuations in body chemistries that are vital to accurate diagnoses, particularly in high-risk populations. Continuous multi-analyte health sensors have the potential to dramatically change health care by paving the way for decentralization of health care delivery and shifting the focus away from reactive treatment to preventative maintenance. PROFUSA, Inc. proposes to transform current biosensing paradigms by developing highly miniaturized, implantable, multi-analyte sensors composed of luminescent tissue integrating materials for continuous monitoring of body chemistries. The largest hurdle in developing implantable sensors is the foreign body response (FBR). Through the use of unique tissue integrating scaffolds, which are a major innovative improvement compared to current implantable sensors in that they induce capillary formation and in-growth rather than the typical FBR fibrous capsule formation, intimate access to metabolic markers and other analytes of interest is achieved. Analyte-specific luminescent sensing chemistries, are embedded in these hydrogel scaffolds. The resultant sensors are injected under the skin and monitored optically using a miniaturized, wireless, Band-Aid-like reader for continuous measurement or a hand-held wand for periodic self-measurement, depending on the clinical need. The proposed monitoring system is inconspicuously small and the form factor meets patient demands for widespread adoption of real-time, long-term monitoring body chemistries. Additionally, viewing of the collected data can be done remotely, allowing the physician access to medical data without the need for the patient to be present until a critical threshold is met. Past efforts by PROFUSA and collaborators have resulted in the successful development of prototype glucose sensors using this technology. Here, the development of a multi-analyte continuous monitor using the same platform is proposed with extended longevity. Glucose and creatinine are proposed to demonstrate the multi-analyte concept due to their importance as markers of food intake, metabolism and kidney function. Glucose and creatinine sensing nanospheres will be developed and optimized individually and incorporated into the tissue-integrating scaffolds to generate prototype sensors. Sensor longevity and accuracy will be enhanced to attain the desired 90-day functionality in vivo, with an ultimate goal of one year functionality. The development of PROFUSA's multi-analyte sensor platform, which has the potential for being customized to various disease states by integrating sensing nanospheres specific to analytes of interest, could potentially transform health care. Clinical adoption of a continuous multi-anlayte sensor will empower patients to take control of their own health, helping them to make decisions to maintain their health, while at the same time enabling physicians to more accurately reach a diagnosis and prescribe treatment.

Public Health Relevance

Our health care system requires individuals to visit a health care facility for even the most basic health status evaluations, relying on lab tests that provide single point-in-time snapshot, which may miss fluctuations critical to proper diagnoses. We propose to shift current paradigms in healthcare through the development of continuous, implantable, long-term total health sensors, which will provide real-time, continuous wireless data for remote viewing, reducing frequency of doctor visits until a critical threshold is reached. Adoption of PROFUSA's total health monitor will empower patients to make the appropriate decisions for health maintenance and, by having access to historical data, will enable physicians to reach more accurate diagnoses.

National Institute of Health (NIH)
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Research Project (R01)
Project #
Application #
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Lash, Tiffani Bailey
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Profusa, Inc.
South San Francisco
United States
Zip Code
Nichols, Scott P; Balaconis, Mary K; Gant, Rebecca M et al. (2018) Long-Term In Vivo Oxygen Sensors for Peripheral Artery Disease Monitoring. Adv Exp Med Biol 1072:351-356
Bornhoeft, Lindsey R; Biswas, Aniket; McShane, Michael J (2017) Composite Hydrogels with Engineered Microdomains for Optical Glucose Sensing at Low Oxygen Conditions. Biosensors (Basel) 7:
Wisniewski, Natalie A; Nichols, Scott P; Gamsey, Soya J et al. (2017) Tissue-Integrating Oxygen Sensors: Continuous Tracking of Tissue Hypoxia. Adv Exp Med Biol 977:377-383
Montero-Baker, Miguel F; Au-Yeung, Kit Yee; Wisniewski, Natalie A et al. (2015) The First-in-Man ""Si Se Puede"" Study for the use of micro-oxygen sensors (MOXYs) to determine dynamic relative oxygen indices in the feet of patients with limb-threatening ischemia during endovascular therapy. J Vasc Surg 61:1501-9.e1
Andrus, Liam P; Unruh, Rachel; Wisniewski, Natalie A et al. (2015) Characterization of Lactate Sensors Based on Lactate Oxidase and Palladium Benzoporphyrin Immobilized in Hydrogels. Biosensors (Basel) 5:398-416
Collier, Bradley B; McShane, Michael J (2015) Enzymatic Glucose Sensor Compensation for Variations in Ambient Oxygen Concentration. Proc SPIE Int Soc Opt Eng 8591:
Unruh, Rachel M; Roberts, Jason R; Nichols, Scott P et al. (2015) Preclinical Evaluation of Poly(HEMA-co-acrylamide) Hydrogels Encapsulating Glucose Oxidase and Palladium Benzoporphyrin as Fully Implantable Glucose Sensors. J Diabetes Sci Technol 9:985-92
Collier, Bradley B; McShane, Michael J (2014) Temperature Compensation of Oxygen Sensing Films Utilizing a Dynamic Dual Lifetime Calculation Technique. IEEE Sens J 14:2755-2764
Ritter, D W; Newton, J M; McShane, M J (2014) Modification of PEGylated enzyme with glutaraldehyde can enhance stability while avoiding intermolecular crosslinking. RSC Adv 4:28036-28040
Roberts, Jason R; Ritter, Dustin W; McShane, Michael J (2013) A Design Full of Holes: Functional Nanofilm-Coated Microdomains in Alginate Hydrogels. J Mater Chem B 107:3195-3201