Cardiotocography (CTG) provides safe and effective monitoring of fetal cardiovascular status before and during labor, and allows for more efficient utilization of dedicated patient care time provided by nurses, midwives, and physicians. However, current external fetal ultrasound transducers (US) and tocodynamometers (TOCO) are cumbersome in design and often produce false data due to loss of the fetal heart rate (FHR) signal, loss of the uterine contraction signal, and improper fit. The current model lacks freedom of maternal movement as it is rigid, requires minimally adjustable belts, and is tethered to a cart based CTG monitor. Simple movement of the laboring mother often causes signal interference, leading to gaps in data pertaining to fetal well-being, chronic repositioning of the external US and TOCO devices, and consequent alarm fatigue of the clinical staff. The high incidence of malpractice claims in obstetric care and the importance of CTG strips in birth injury liability claims further underscore the need for more reliable US and TOCO devices. Farus proposes to assess the feasibility of a vastly improved CTG system that features wearable US and TOCO devices. The wearable US and TOCO devices will be soft, conformal, adhere to the skin, and have wireless and belt-free operation. The improved devices will provide more reliable output of FHR and uterine contractions, independent of maternal movement or repositioning. The ultimate goals are to reduce the need for chronic repositioning of the US and TOCO, reduce the rate at which alarms are activated by false data or interference, and encourage freedom of maternal movement. The improved devices offer clinical staff the assurance of safe and effective CTG monitoring, while improving patient comfort and satisfaction. Further, a complete wireless telemetry system solution will be developed, improving maternal mobility that is currently limited by the length of wires connected to the CTG monitor. Together, these innovations will provide significant improvement over existing rigid and hard-wired devices, bettering patient care and the practice of nurses and practitioners involved in obstetric care. The hypothesis of the Fast-Track SBIR is that wearable US and TOCO devices can more consistently maintain the FHR and uterine contraction signals than standard devices, with improved signal quality and superior patient and clinician satisfaction. The goal of the Phase I SBIR effort is to build an alpha prototype of a wearable TOCO, integrate it with an accompanying wearable US and wireless base-station, and verify performance of the components and integrated system through benchtop laboratory tests and a pilot clinical study. The goal of the Phase II SBIR effort is to develop a refined beta prototype of the complete wearable CTG system, including a wearable US and TOCO, to validate its performance through antenatal and intrapartum clinical trials, and to perform regulatory testing. It is anticipated that the complete SBIR effort will lead to an FDA 510(k) application and commercialization of the technology.
Current external fetal ultrasound transducers and tocodynamometers are rigid, require belts to maintain their position on the abdomen, and are typically tethered to a stationary cardiotocography monitor. The cumbersome design restricts patient comfort and mobility, and shifting of the external devices on the abdomen due to maternal movement frequently leads to loss of the fetal heart rate (FHR) and uterine contraction signals. A wearable cardiotocography solution has the potential to improve patient mobility, minimize the need for frequent repositioning of the external devices, reduce false alarms, eliminate gaps in relevant FHR and uterine contraction signal data, reduce the number of cables in the labor & delivery environment, and increase the overall effectiveness of cardiotocography.