Intra-articular needle placement device and method of using
The present invention relates to a device for measuring, recording, and acting in response to changes in air pressures encountered through the lumen of a connected needle. The device signals when it has been powered and signals when the device recognizes both pressures and pressure change rates indicative of synovial cavity joint penetration, such as knee joint penetration. Synovial cavity pressures detected and acted upon may either be supra- (positive) or sub-atmospheric (negative). Internal light emitting diodes and a laptop connected display are demonstrated as signaling and communication mechanisms. Methods for delivering medicaments into human and animal intra-articular cavities or joints such as synovial cavities are provided. Furthermore, methods for facilitating the diagnoses of joint effusion also are provided.
1 . A device for synovial cavity injections, said device comprising:
a. a power source;
b. a non-conductive pull-tab or power isolator;
c. a pressure transducer;
d. a microprocessor;
e. male and female luer locks; and
f. a path connecting a syringe to a needle;
wherein the microprocessor is configured to:
measure and record pressure changes at predefined time intervals,
responsive to determining that pressure is positive, greater than 0.5 mmHg, and exceeds previously defined thresholds for a predefined time period, calculate a change in pressure over change in time slope between two time points, and
responsive to determining that a magnitude of the slope is greater than a predefined minimum and that a stability check criteria is satisfied, generate a signal to confirm that the needle has been placed within the synovial cavity.
2 . The device of claim 1 , additionally comprising: one or more light emitting diodes of different colors that illuminate when the needle connected to the device is exposed to the synovial cavity.
3 . The device of claim 1 , wherein said device has dimensions of about 27 to about 47 mm in length, about 10 to about 30 mm height and about 10 to about 30 mm width.
4 . The device of claim 3 , said device further comprising: a pressure sensor configured to read and share pressure readings in real time.
5 . The device of claim 4 , wherein the device is used in the synovial cavity of a human being.
6 . The device of claim 5 , wherein the synovial cavity is found within a knee, hip, shoulder, or spine.
7 . The device of claim 1 , wherein the pressure changes comprise biological tissue pressure, and/or biological cavity pressure measurements obtained over time.
8 . The device of claim 3 , wherein the power source is a lithium-manganese dioxide cell battery.
9 . The device of claim 3 , wherein the pressure transducer is a piezoresistive pressure sensor.
10 . The device of claim 3 , wherein the microprocessor is a low-voltage microcontroller with flash memory, static random access memory, and processor.