Intelligent Needle Tip Tracking Using Ultrasound Imaging for Lumbar Plexus Blocks

Study Overview
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Brief Summary
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In a randomized controlled crossover study design, ultrasound guided lumbar plexus blocks will be performed with and without the aid of a needle tip tracking (NTT) system. Specialists in anaesthesiology with average experience in ultrasound guided peripheral nerve block (PNB) techniques will perform the blocks. 27 volunteers will be included. The primary objective is to investigate the effect of the NTT system on performance time, as a measure for improved block performance. Secondary objectives are the effects of the NTT system on dexterity, peripheral nerve block characteristics, subjective experience, and peripheral block performance.

Official Title
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Intelligent Needle Tip Tracking Using Ultrasound Imaging for Lumbar Plexus Blocks

Conditions
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Nerve Block

Intervention / Treatment
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* Procedure: Lumbar plexus block using NTT
* Procedure: Lumbar plexus block without NTT


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anesthesiologists (ASA) physical status 1 or 2 Volunteers that have given informed written consent Exclusion Criteria: BMI < 18 kg/m2 BMI > 35 kg/m2 Body weight > 95 kg Volunteers that cannot cooperate during the examination Volunteers that do not speak or understand Norwegian language Volunteers with neurologic disease, nerve- or vascular impairment Volunteers with known coagulopathy Volunteers that are allergic to Lidocaine or other local anaesthetic agents Medications at the investigators discretion Volunteers with concomitant medical treatments interfering with PNB treatment Skin disease or infection affecting the whole-body surface or within the area of examination Any reason why, in the opinion of the investigators, the volunteer should not participate Subject participates in a potentially confounding drug or device trial during the course of the study Pregnancy and lactation period Women of childbearing potential who do not use an effective and secure method for birth control

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active needle tip tracking<br>A needle tip tracking system is used when performing an ultrasound guided lumbar plexus block. | Procedure: Lumbar plexus block using NTT<br>* An lumbar plexus block is performed using ultrasound guidance with needle tip tracking.<br>|
| Other: Inactive needle tip tracking<br>No needle tip tracking system is used when performing an ultrasound guided lumbar plexus block. | Procedure: Lumbar plexus block without NTT<br>* An lumbar plexus block is performed using ultrasound guidance without needle tip tracking.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Performance time | Performance time is defined as the time from insertion of the block needle (skin puncture) until finishing local anaesthetic (LA) injection | During peripheral nerve block procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Distance travelled by needling hand | Measured by motion analysis from insertion of the block needle (skin puncture) until finishing LA injection | During peripheral nerve block procedure | 
| Distance travelled by probe hand | Measured by motion analysis from insertion of the block needle (skin puncture) until finishing LA injection | During peripheral nerve block procedure | 
| Number of intended movements (needling hand) | Measured by motion analysis from insertion of the block needle (skin puncture) until finishing LA injection | During peripheral nerve block procedure | 
| Number of intended movements (probe hand) | Measured by motion analysis from insertion of the block needle (skin puncture) until finishing LA injection | During peripheral nerve block procedure | 
| Block success | A sensory block is defined as successful when there is analgesia (no sensation for touch) or anaesthesia (no sensation at all) involving all five nerves distal to the elbow | 30 minutes after peripheral nerve block procedure | 
| Block onset time | Block onset time is defined as the time between the end of LA injection and development of a successful sensory block | Within 30 minutes after peripheral nerve block procedure | 
| Block duration | Block duration is the time from the end of LA injection until at least one of the nerves involved in the sensory block has recovered | Within 240 minutes after peripheral nerve block procedure | 
| Quantified discomfort during block performance | The participants are asked about discomfort during the block procedure using a numeric rating scale (scale range 0 - 10; 0 = no discomfort; 10 = worst discomfort imaginable) | Immediately after peripheral nerve block procedure | 
| Confidence in block success | The anaesthetist is asked if he expects the block to be successful using a numeric rating scale (scale range 0 - 10; 0 = block success unlikely; 10 = block success very likely) | Immediately after peripheral nerve block procedure |