Oesophageal Manometry

An extruded multi-lumen catheter with one side-hole per lumen, spaced along the assembly, each lumen carried out of the patient to its own external transducer on a bank beside the workstation. A capillary pump driven from a pressurised reservoir pushes a small steady flow down every lumen and out of every hole, so the pressure at each transducer is the pressure needed to keep that flow leaving that hole. A sleeve sensor spans the lower sphincter, because a sphincter three centimetres long cannot be relied on to contain any hole at this spacing.

Also called: Esophageal Manometry, High-Resolution Manometry. Arabic: قياس ضغط المريء. Device Lab 44 of 69 in BMEssentia Medical City, 2 configurations.

Overview: the configurations

Water-perfused side-holes with external transducers

Solid-state circumferential sensors at one centimetre

Thirty-six pressure-sensing elements built into the catheter itself at one centimetre intervals across the same span, each element made of sectors distributed around the circumference whose outputs are averaged into one number. There is no perfusate, no lumen and no external transducer, so there is nothing to infuse, nothing to flush and nothing to level. The sleeve reading over the lower sphincter is computed from the sensors that span it rather than provided by a physical sleeve, which is only possible because there are enough of them.

How it works: the main parts

What each part does, from the Oesophageal Manometry lessons in the 3D Device Lab.

Catheter assembly, its size and its depth markings: An extruded tube a little over four millimetres across and about a metre long, graduated in centimetres from the tip, with a moulded hub at the outside end and a serial number printed on the shaft. It is the only object in this device that decides where every sensing station is, and the marks along it are the only link between a channel number and a place inside a person.
Transnasal route, anaesthesia and the gag: A nostril, a gel, a swallow of water and a person who has to tolerate a tube through the back of the throat for half an hour while being asked to swallow on command. No part of the airway or the pharynx is drawn in this model; the assembly enters at the nostril and the model stops there.
Nasal fixation and the catheter clip: A strip of tape at the nose, a clip on the shoulder of the gown, and a loop of slack between the two. Nothing about it is electronic and nothing about it is optional, because the horizontal axis of every plot in the study is a geometry that this is the only thing holding.
The swallow protocol and its timing: Ten swallows, one at a time, on command, separated by twenty to thirty seconds, with a period of quiet before them and the whole sequence written on a card beside the workstation. It is the least mechanical component in the device and it is the one that decides how many independent looks at the field the study gets.
The measured bolus and its syringe: A small syringe of water, a stated volume, and a cup. Five millilitres per swallow is the usual figure.
The spatial pressure plot and the interpolation in it: A rectangle of colour with time across it and position up it, apparently a continuous picture of pressure everywhere along the tube at every instant. It is the single most persuasive object on this machine and almost none of it is data.
Finding the two sphincters and following them as they move: A pair of horizontal bands on the plot that are darker than the body between them, and a tool for saying where their edges are. The upper one sits near the top of the span and the lower one near the bottom, and both of them move while the study is running.
The sleeve reading and the relaxation window: A channel that does not report the pressure at a point. It reports the highest pressure anywhere along a stretch of the assembly, and on one configuration it is a physical object while on the other it is a calculation.

Explore it in the Device Lab

What one column of the plot loses, and why it goes as the square: Generate a single travelling band of stated length, sample it at one spacing, then at the other, and read the highest value the reconstruction offers across the body at a single instant. Compare it against the highest value the field actually has at that instant. Then sweep the phase of the grid against the band and keep the worst case.
The same sampling, two thirds as much lost: Take the same band and, instead of the maximum, compute the double integral above the twenty millimetre contour over the axial window and over the record - which is what the study actually quotes, and whose unit says so: millimetres of mercury times seconds times centimetres. Compute it from the samples with a trapezoidal rule and again from the closed form of the field, at both spacings.
A finer spacing is worse at speed, and then it is not: Time the crossing of the thirty millimetre contour on two neighbouring sensors and divide the spacing by the difference between the two instants. Do it for a single pair on each configuration. Then do it the way the device does it, averaging every adjacent pair that lies inside the tubular body, and compare the two answers.
A rate limit is not a bandwidth, and the obvious answer is wrong: Drive one channel with a slow rise and then with a fast one of the same amplitude, and read what comes out of each. A body contraction reaching a hundred millimetres of mercury in two seconds is fifty a second. A pharyngeal transient reaching two hundred in a hundred and fifty milliseconds is thirteen hundred and thirty-three a second.
A gap shorter than one spacing has somewhere to hide: Put a break of a stated length into the contractile band on the bench model, then slide the break along the axis in small steps and, at every position, count how many sensors lie inside it. Do it with a break longer than the spacing and again with one shorter.
An average round a closed circle removes something exactly: Write the pressure round one axial station as a mean plus a single harmonic - a constant plus an amplitude times the cosine of the angle minus a phase - and read it two ways. First as the average of twelve sectors distributed evenly round the circumference. Then as one unidirectional hole facing in one direction.

Common faults and what to check

Most reported device problems (FDA MAUDE)

Device problem	Reports
Material Separation	2
Break	1
Device Reprocessing Problem	1
Nonstandard Device	1

Raw counts of adverse event reports for this device type (FDA product code KLA), all years. Not adjusted for the number of units in use, so they show what gets reported, not failure rates. Report text is never copied.

Planned maintenance checks

From the BMEssentia procedure library: every 12 months, about 45 minutes, electrical class I, applied part type BF.

Check	Pass when
Catheter, interface and cables Inspect the catheter sensors, the interface module and cables.	No damage.
Electrical safety Test to IEC 62353.	Within limits.
Calibration Run the calibration chamber sequence.	Pass.

Test instruments: Manufacturer's calibration chamber.

Recent FDA recalls

Recall	Product and reason
Z-1159-06 2006-06-22	Medtronic Gastroenterology / Urology: Medtronic Zinetics Manometric Catheter, Model 9012P2271. Water perfused, motility catheter. Distributed by Medtronic, Mislabeling- The 8 ports of the manometric catheter were incorrectly labeled 1,3,5,7,8,2,4,6 from the distal to the proximal end of the catheter. Root cause: Other.

From the FDA recall database (openFDA), newest first, imported 2026-10-22. 1 recalls on record for this device type. Recall text is the FDA's public text; each recall links to the official record.

Learn it, see it in 3D, ask about it

Ask Essentia about the Oesophageal Manometry: answers from named sources, with the device open in its 3D Device Lab beside the answer.
The Oesophageal Manometry on the BMEssentia Platform: the Device Library course, 13 sections from physics to maintenance.
BMEssentia Medical City: Device Lab 44, the Oesophageal Manometry fully assembled in 3D, with lab tasks and the simulations.

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