Spinal canal access and probe positioning, devices and methods
Inventors
Hulvershorn, Justin • Schmidt, Karl • Swartz, Douglas
Assignees
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Publication Number
US-9358038-B2
Publication Date
2016-06-07
Expiration Date
Abstract
Methods and devices for detecting positioning of a probe in a tissue of a patient. A method can include providing a detection device; advancing a device coupled probe through the tissue of the patient and toward the patient's spinal canal; detecting a change in pressure about the distal portion of the coupled probe during advancing, where the detected pressure change indicates probe positioning in the patient's spinal canal; outputting the detected pressure change or indication of probe positioning to a visual display.
Core Innovation
The invention relates to pressure-sensing spinal canal access devices and methods that detect positioning of a coupled probe in a patient’s tissue as the probe advances toward the patient’s spinal canal. The device includes a housing with a proximal portion and a distal portion coupled to the probe, and a housing fluid passage arrangement that includes a main fluid passage and a chamber connected in parallel by a proximal port and a distal port. A pressure sensing system receives pressure sensor signals in communication with the chamber and determines a pressure value of an environment about the distal portion of the coupled probe.
The method advances the device distally such that the distal portion of a probe advances through tissue toward the spinal canal, while detecting a change in pressure about the distal portion of the coupled probe during advancing. A corresponding reporting signal is output to a visual display indicating the determined pressure value and/or positioning of the probe in the tissue. The disclosed concept includes using pressure changes and pressure-waveform characteristics to indicate probe positioning in spinal compartments.
The invention further supports distinguishing positioning associated with lumbar puncture and epidural access by monitoring characteristic pressure behavior. In lumbar puncture, the disclosure includes rapid detection of CSF entry and monitoring opening and closing pressure, with optional confirmation aspects based on fluid backflow and visualization/collection. In epidural access, the disclosure includes detecting the epidural space via pressure drop and waveform, and differentiating epidural CSF/vein/muscle-related environments using aspiration and waveform presence or absence.
The device architecture supports integration of pressure sensing, processing, and patient-facing output within the housing. The disclosure includes processing unit and output unit components that determine and report pressure value and/or positioning via a visual display, with optional wireless communication/storage, and optional pressure relief/buffer system features designed to reduce handling-induced pressure artifacts through a pressure reservoir/valves and re-zeroing/recalibration concepts. The processing logic includes transition detection and waveform recognition to generate alerts and reporting values.
Claims Coverage
The partial content provides two independent claims (a method claim and a device claim). Across the independent claims, the core coverage centers on a pressure sensing system using a chamber in parallel with a main fluid passage, coupled to a coupled probe, and reporting determined pressure values and/or probe positioning via a visual display during spinal canal access.
Pressure sensing chamber parallel to main fluid passage
The housing includes a main fluid passage and a chamber in parallel with and connected to a portion of the main fluid passage by a proximal port and a distal port, wherein a pressure sensor system is in communication with the chamber.
Determine pressure value about distal portion of probe from pressure sensor
A pressure sensing system at least partially carried by the housing includes a processing unit coupled with a pressure sensor to receive signal from the pressure sensor and determine from the received signal a pressure value of an environment about a distal portion of the coupled probe, with the pressure sensor in communication with the chamber.
Visual reporting of determined pressure value and/or probe positioning
An output unit carried by the housing comprises a visual display, coupled to the pressure sensing system to receive pressure value signal and output a reporting signal indicating the determined pressure value and/or positioning of the probe in the tissue of the patient (method) or in a spinal canal of the patient (device).
Detect pressure change during distal advancement toward spinal canal
Advancing the device distally such that a distal portion of a probe advances through tissue and toward the patient’s spinal canal, detecting a change in pressure about the distal portion of the coupled probe during advancing indicating probe positioning in the patient’s spinal canal, and outputting a corresponding reporting signal to the visual display.
Substantially between first port and proximal portion housing placement of pressure sensing, processor, and output
The pressure sensing system, processor, and output unit are disposed substantially between the first port and the proximal portion of the housing.
Together, the independent claims cover (i) a housing fluid passage and parallel chamber architecture communicating with a pressure sensor, (ii) processing of pressure sensor signals to determine a pressure value about the probe tip environment, (iii) visual output of determined pressure values and/or positioning, and (iv) for the method, detecting pressure changes during distal advancement toward the spinal canal.
Stated Advantages
Faster, more precise positioning of a probe during spinal canal access.
Reduced risk of dural puncture and bloody tap.
Reduced need for multiple assistants.
Improved monitoring for pediatric procedures and for conditions like IIH and post-dural puncture headache management.
Documented Applications
Lumbar puncture including rapid detection of CSF entry, and monitoring opening and closing pressure.
Epidural access including detection of epidural space and differentiation of CSF/vein/muscle-related environments and verification of catheter placement via waveform presence or absence.
Monitoring and management related to pediatric procedures.
Support for conditions including idiopathic intracranial hypertension (IIH).
Support for post-dural puncture headache (PDPH) management.
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