WO2019240686A2 - New medical device for measuring human cerebrospinal fluid (csf) pressure - Google Patents

Abstract

The measurement of "CSF pressure" has an important role in diagnosis of many nervous system disorders and measuring brain functions after head trauma. Plastic manometers currently being used for this purpose have some undesirable effects. During lumbar puncture, a spinal needle (10 cm long needle inserted from the lumbar vertebrae into the cerebrospinal fluid) is used to reach the cerebrospinal fluid in subarachnoid space ( the compartment which CSF circulates in brain and spinal space). Without any contact with the CSF and the spinal needle, CSF pressure can be measured via calculating the time between CSF drops contacting with a digital surface (digital sensor) clearing the need to use plastic manometers for this purpose. This method is first and unique method in CSF measurement applications. The device consists of an infrared sensor and a digital circuit and a chronometer to make digital calculations. The time between each CSF drops touching the infrared sensor is detected by a digital circuit and converted to CSF pressure by the measuring instrument loaded in the digital circuit. Key words: CSF pressure measurement device intracranial pressure lumbar puncture CSF openning pressure spinal needles spinal puncture

Description

New medical device for measuring human cerebro-spinal fluid (CSF) pressure

This invention is comprised of measurement of pressure of a bodily fluid termed as cerebrospinal fluid. It is of interest to the medical doctors from fields of anesthesia, algologists, neurosurgery and neurology and has a wide market.

In humans, CSF pressure is measured from the lumbar region (the bottom part of the spine) with two conventional methods.

Devices used for the lumbar region are indicated below:

The device with a patent number of US 3529592 A is comprised of a plastic tube with grades and a set to connect the plastic tube to the CSF.

In this technique, the patient is lying or sitting position during the application of intrathecal (compartment of the brain and spinal cord where the CSF circulates Application and then inside the connection set and graduated plastic tube is filled with 0.9% NaCl.

In order to calibrate the manometer and the patient the red bar next to the graduated tube moves upwards or downwards direction till the liquid column inside the tube shows "0".". Following this, the connector of the serum set is connected to the spinal needle in the patient and the CSF pressure is measured.

The other conventional methods are the measurement using a pressure gauge with patent number US5218970A and US 4036216A. For this, the instrument is pre-sterilized. The patient is then placed in, then the spinal needle advanced through the subarachnoid space and the device is connected to the spinal needle till the CSF in the subarachnoid region rise with pressure in the device. This process can take 3-5 minutes.

TECHNICAL PROBLEMS DETERMINED BY PREVIOUS TECHNIQUES

1 -MEASURING WITH NUMBERED PLASTIC MANOMETER:

a- It is necessary to open the set and fill it with saline.

b- For the measurement of the CSF pressure , the tip level of the water in the manometer needs to be calibrated with the spinal needle inserted to the patients subarachnoid space. (About 3-5 min)

c- If the needle gauge is below a certain diameter, the method does not give enough correct results.

d- The physical contact with the spinal needle increases the a risk of infection.

2- MEASURING WITH PRESSURE MANOMETER:

a-The use of pressure manometer always requires prior sterilization and this sterilization takes time and is costly.

b- Although the device is sterilized, there is still a risk of infection. c- Satisfactory results cannot be obtained on needles below a certain gauge (22 g).

ADVANTAGES OBTAINED BY THE INVENTION

1 -Since there is no contact with the patient, sterilization is not required.

2-The device can be used repeatedly for CSF pressure measurements in the same patient or in different patients.

3- There is no risk of infection because the operator do not have to touch the needle.

4- The measurement time can be as short as between two CSF drops ,so the device it can gives the pressure results in seconds.

5- The diameter (gauge) of the spinal needle does not affect the measurement of the CSF pressure

DETAILED DESCRIPTION OF THE INVENTION

This invention is based on measurement of the cerebrospinal fluid pressure via an electronic circuit which is activated with CSF drops contacting a sensor.

As shown in fig.l the device is composed of CSF drops (3) coming from the spinal needle (2) which is attached to a CSF simulation model(l) and contacts the sensor (4) of the device(5).

The infrared sensor (4), which CSF drops (3) contacts and opens and closes the circuit (5), forms the first '5' pieces of the device.

A circuit (5) that performs digital calculations is activated with every CSF drop (3) touching the infrared sensor (4), the time between these drops is precisely detected by the digital stopwatch (6) and converted to pressure values by the software loaded in the digital circuit.

Figure 1 A and IB: Schematic representation of the new device. (1) Spinal needle (3) CSF drops (4) Infrared sensor (5) Circuit (6) Digital stopwatch (Picture pages 1 and 2 / Total page 2)

Claims

1-This invention which is a medical device is composed of an infrared sensor, a circuit and a digital chronometer.

2- The infrared sensor in claim 1, is made up of a motion-sensing transmitter and a receiver for detecting CSF drops.

3- In claim 1, the circuit is comprised of electrical conductors for transmitting the on / off signals to operate the chronometer.

4- In claim 1, the stopwatch is comprised of a two-digit, digital screen that responds to each signal by operating or stopping.