Increased Precision and Safety in Spinal Tap with PASS – An Ultrasound-Guided Lumbar Puncture Procedure

PASS (Point-Assisted Spinal Sonography), an ultrasound-guided lumbar puncture system from Chula medical doctors and engineers, helps enhance the precision and confidence in spinal faucet procedures whereas decreasing dangers and ache for sufferers. 

Newswise — Nobody needs to get jabbed repeatedly with a needle, particularly when that needle is poking into the spinal wire.  All of us pray that the physician can do it exactly in a single fell swoop. However, errors occur relying on the physician’s expertise and experience, in addition to the bodily circumstances of the affected person.

“A mistake in performing lumbar puncture (LP)  could affect the patient’s entire life! We don’t want to see patients suffering from pain and being harmed by our treatment,” Associate Professor Ketchada Uerpairojkit, M.D., Department of Anesthesiology, Faculty of Medicine, Chulalongkorn University, discusses the motivation to design the ultrasound-guided lumbar puncture system or PASS — Point-Assisted Spinal Sonography to boost the usual of care and security for sufferers.                                               

This innovation is a collaboration between the Faculties of Medicine and Engineering of Chulalongkorn University which embody, other than  Assoc. Prof. Dr. Ketchada, Associate Professor Dr. Wirinaree  Kampitak, and Dr. Banjobphorn Songthammawat from the Department of Anesthesiology, Faculty of Medicine, Chula, Assistant Professor Dr. Werayut Srituravanich, and Mr. Thiwa Nantapak from the Department of Mechanical Engineering, Faculty of Engineering, Chula.


The Origin of PASSS Innovation

Assoc. Prof. Dr. Ketchada defined that lumbar puncture (LP) or spinal faucet is a technique utilized in decreasing ache throughout an operation, also referred to as epidural or spinal block.  It sedates the sensory nerves by anesthesia by way of the spinal canal, inflicting the affected person’s physique to be motionless and numb from the stomach to the toes. This technique is commonly used for surgical procedures comparable to cesarean part, surgical procedure on the uterus, ovaries, hernia, hip, knee, and leg, or blocking the ache from pure childbirth, and many others.  Moreover, LP can be utilized in chemotherapy, and prognosis of leukemia, meningitis, and so forth.

“An anesthesiologist will have the patient lying down in the fetus position, or sitting and bending forward so that he/she can palpate the patient’s spine to find the spot to insert the needle and give a regional block so that the patient does not feel pain during and after surgery. This reduces the use of anesthetics. The patient will feel comfortable during surgery, which is safer and less costly than general anesthesia. It will also reduce the spread of respiratory pathogens, including COVID-19.  Anesthesia can also be given in combination with regional block to accelerate post-op recovery and early discharge.”

Generally, to manage LP, the physician must palpate the iliac crest, and the backbone whereas gauging the path and depth of insertion of the needle into the spinal canal. Approximating the lumbar spinal canal at ranges 2 – 3 or 3 – 4 might not be profitable each time.                    

“Performing spinal tap may not be successful in a single try.  Patients may have to suffer multiple attempts before the procedure is complete as the spinal canal is quite deep and obscured by bones, tissues, and ligaments, so the needle must pass through a small opening that is invisible to the eye.”

According to Assoc. Prof. Dr. Ketchada, the possibility of error in LP is roughly 10-50 % relying on the expertise and experience of the anesthesiologist, in addition to the age and bodily circumstances of sufferers which will add obstacles to the process, like weight problems, irregular spinal curvature, or spinal stenosis.

“With patients being overweight, having spinal deformity, spinal stenosis, or spinal fuse, there is a higher risk for failure and a greater chance of hitting the bone or nerves causing excruciating pain for the patients.  Some may have internal bleeding and also the risk of paralysis.”

Therefore, the introduction of ultrasound to assist entry the spinal canal is without doubt one of the components that enhance the chance of success, because it permits for correct visualization of the place, orientation, and depth of the needle.


PASS exactly defines the LP location, rising affected person security.

The Point-Assisted Spinal Sonography (PASS) is an ultrasound-guided system designed to interact the ultrasound probe that scans for the exact location, diploma, and depth of needle penetration into the spinal canal to scale back the possibility of the needle hitting the backbone and reduce the ache for the affected person.

“Practically, the anesthesiologist cannot insert the needle in the best position from the obtained image because the ultrasound probe is blocking the needle’s position, but PASS makes precise needle insertion possible with less chance of the needle hitting the bone or internal vessels,” says Assoc. Prof. Dr. Ketchada.

PASS has two parts: a “frame” designed to suit over the ultrasound probe, and a “needle guide slot” to manage the path of the needle to penetrate the spinal canal. The needle information slot is disposable to forestall an infection, however the body might be disinfected and reused 10 occasions.

Assoc. Prof. Dr. Ketchada defined the PASS operation as follows:

  1. Assemble the sterilized body and needle information slot.
  2. Put PASS on the ultrasound probe.
  3. Perform an ultrasound scan till the spinal canal is seen.
  4. Pause the imaging to measure the situation and place of LP from the show.
  5. Unscrew the ultrasound probe from the PASS body
  6. Insert the needle by way of the “needle guide slot”, which can manually information the needle in the direction of the goal (as an alternative of drawing a line on the affected person’s pores and skin), it can journey by way of the pores and skin into the subarachnoid house of the spinal wire till the measured depth is reached.
  7. Slowly take away the PASS body. Be cautious to not let the needle transfer.
  8. Aspirate the spinal fluid from the puncture level.

PASS and its 4 distinctive designs

PASS is designed to optimize the efficiency of anesthesiologists when administering epidural, and common practitioners or neurologists who should diagnose the illness by spinal faucet. Assoc. Prof. Dr. Ketchada summarized the 4 strengths of PASS as follows:

  1. Safety – PASS is manufactured from non-toxic, medical-grade resin for medical units which are gentle and secure.
  2. Ergonomic design – designed to be straightforward to make use of with the ultrasound probe.
  3. Accessible value – the PASS body might be reused after sterilization, thus decreasing waste and saving prices, however the needle information slot, which is available in direct contact with the needle is contaminated and have to be disposed of.
  4. Distribution – Collaboration with ultrasound tools corporations is feasible to design a PASS that matches the assorted fashions of ultrasound probes. It is straightforward to supply.  Production capability might be elevated rapidly.

However, PASS has some limitations.

“Each brand of ultrasound machine has different probes, so we have to create a model that fits each probe. We also have to calibrate the device to be more precise, since there are still a few errors,” Assoc. Prof. Dr. Ketchada defined.


Chula Piloting using PASS for secure remedy.

PASS was a prototype medical system on the International Conference of Anesthesiologists on the finish of 2020. Since then, anesthesiologists at King Chulalongkorn Memorial Hospital have been utilizing PASS in troublesome instances. It can be used as a pilot coaching for Sixth-year medical college students within the Department of Anesthesiology, Faculty of Medicine, by practising with cadavers.

Currently, the PASS analysis and improvement workforce plans to increase its use right into a enterprise context and is supported by Chulalongkorn University Technology Center (UTC).

“The team has already registered with the FDA and applied for a patent since September 2021.  Medgateways has been entrusted with production and development.  PASS is now available for sale at 2,000 baht/set. One pass consists of 1 frame and 10 needle guide slots,” says Assoc. Prof. Dr. Ketchada.

In the long run, the workforce will likely be producing ultrasound-guided PASS with cell phones/tablets connection, which can make it even safer and extra handy for medical doctors to carry out the process.  Training for medical college students and residents in hospitals and facilities will even be organized.

“We hope that PASS will provide physicians with a more accurate tool to help patients and help bridge the gap in access to safe treatment in the future,” Assoc. Prof. Dr. Ketchada stated.

For extra particulars, please contact Assoc. Prof. Dr. Ketchada Uerpairojkit, Department of Anesthesiology, Faculty of Medicine, Chulalongkorn University, Rattanawithayapat Building, ninth Floor, Rama 4 Road, Pathumwan, Bangkok Tel. +66-2256-4000 ext. 60904-9, electronic mail: [email protected]

Hospitals, medical establishments, or corporations enthusiastic about utilizing PASS to extend the success of spinal faucets and scale back the danger to sufferers can contact Medgateways, producer, and distributor of PASS, 222/113 Teparak Road Bangplee Yai, Bangplee, Samutprakarn 10540, Tel: +668-4754-9493,