Needle dislodgement detection systems and methods
Inventors
Sinha, Dipen N. • Schaefer, Robert • OSTERHOUDT, Curtis • Espina, Peter G. • Crnkovich, Martin J. • Wang, Fei • BOWMAN, Steve M. • Urban, Martin
Assignees
Fresenius Medical Care Deutschland GmbH • Awe Technologies LLC • Fresenius Medical Care Holdings Inc
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Publication Number
US-12390571-B2
Publication Date
2025-08-19
Expiration Date
Abstract
This disclosure teaches a system and method for monitoring an extracorporeal blood circuit of a patient and identifying a needle dislodgement. The method includes identifying a potential needle dislodgement event based on changes in pressure of the extracorporeal blood circuit, searching for a heart rate of a patient by analyzing an optical backscatter signal from an optical sensor attached to the extracorporeal blood circuit or by analyzing a pressure signal representative of the pressure in the extracorporeal blood circuit, and verifying the potential needle dislodgement event is a needle dislodgement based on the absence of the heart rate.
Core Innovation
The invention relates to monitoring an extracorporeal blood circuit of a patient and identifying a needle dislodgement. A potential needle dislodgement event is identified based on changes in pressure of the extracorporeal blood circuit using pressure monitoring, and the method searches for a heart rate of the patient by analyzing an optical backscatter signal from an optical sensor attached to the extracorporeal blood circuit.
The potential needle dislodgement event is verified as a needle dislodgement based on the absence of the heart rate. In the system and dialysis machine, venous pressure and arterial pressure signals are received along with an optical backscatter signal from an optical sensor attached to a venous line, and after identifying a potential needle dislodgement event based on changes in the arterial pressure signal and the venous pressure signal, the device verifies the event as a needle dislodgement when the heart rate is absent.
The disclosed logic supports generating a needle dislodgement value from pressure features and flagging the event when the value falls below a threshold. Heart rate determination from the optical backscatter signal uses filtered optical backscatter data and peak-based analysis, including peak-to-peak and prominence metrics and peak detection to derive heart rate from peak times. Additional verification can be based on multi-parameter checks using heart rate, variance of the filtered optical backscatter signal, and blood pump rate within respective set ranges.
The disclosed system can include a blood pump response after reducing blood pump speed while searching for or validating the heart rate, and it can return the blood pump to a previous speed after verification. The dialysis machine includes a blood pump, an extracorporeal blood circuit configured to connect the blood pump and a dialyzer to a patient, arterial and venous pressure monitors, and an optical sensor attached to a venous line, together with a computing device configured to perform the event identification, heart rate searching, and absence-based verification.
Claims Coverage
The independent claims define a combined pressure-based detection and optical backscatter-based verification approach for needle dislodgement, with three independent claim families covering methods, systems, and a dialysis machine. Across the independent claims, the core inventive features are the absence-of-heart-rate verification of a pressure-flagged event using optical backscatter from an optical sensor attached to the extracorporeal circuit, specifically a venous line in narrower embodiments.
Absence-of-heart-rate verification of pressure-flagged needle dislodgement
Identifying a potential needle dislodgement event based on changes in pressure of the extracorporeal blood circuit, searching for a heart rate by analyzing an optical backscatter signal from an optical sensor attached to the extracorporeal blood circuit, and verifying the potential needle dislodgement event is a needle dislodgement based on the absence of the heart rate.
Pressure-event identification from arterial and venous pressure signals combined with optical-backscatter heart-rate search
Receiving a venous pressure signal, an arterial pressure signal, and an optical backscatter signal from an optical sensor attached to a venous line of the extracorporeal blood circuit, identifying a potential needle dislodgement event based on changes in the arterial pressure signal and the venous pressure signal, searching for a heart rate by analyzing the optical backscatter signal, and verifying the potential needle dislodgement event is a needle dislodgement based on the absence of the heart rate.
Dialysis machine architecture with pressure monitors and venous-line optical backscatter verification
Providing a dialysis machine with an arterial pressure monitor and a venous pressure monitor and an optical sensor attached to a venous line, receiving venous pressure, arterial pressure, and optical backscatter signals, identifying a potential needle dislodgement event based on changes in the arterial pressure and venous pressure, searching for a heart rate by analyzing the optical backscatter signal, and verifying the potential needle dislodgement event is a needle dislodgement based on the absence of the heart rate.
Across the independent claims, needle dislodgement detection is initiated by pressure change analysis and is verified by searching for patient heart rate from optical backscatter and confirming needle dislodgement when the heart rate is absent. In the system and dialysis machine, arterial and venous pressure signals are combined with optical backscatter from an optical sensor attached to the venous line, and the machine components are arranged to implement the same absence-based verification workflow.
Stated Advantages
Enables verification of a potential needle dislodgement event as a true needle dislodgement based on the absence of the heart rate.
Distinguishes needle dislodgement using presence or absence of patient heart rate derived from optical backscatter.
Documented Applications
Extracorporeal blood circuit monitoring in a patient for identifying and verifying needle dislodgement using arterial/venous pressure changes and optical backscatter heart-rate searching.
Use in a dialysis machine including integration of arterial pressure monitor, venous pressure monitor, and an optical sensor attached to a venous line to detect and verify needle dislodgement based on absence of heart rate.
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