A Valveless Cystometer Delivering an Uninterrupted Stream

A VALVELESS CYSTOMETER DELIVERING UNINTERRUPTED STREAM LELAND M. McKINLAY Division of Surgery, Urological Scclion, Butterworth I-l ospital, Grand Rap'ids, Michigan

The development by Rose (1) of an instrument which enabled him to graphically record the variations of pressure within the filling bladder, opened a new field in Urology. This field includes consideration of factors related to the integrity of the main path-

FIG. l 727

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LELAND M. McKINLAY

way of nerve impulses to and from the bladder. It also imparts graphic explanation of many of the common disturbances of the bladder encountered in urologic practice. The desire for an instrument with which the bladder could be filled with an unbroken stream of fluid stimulated the development of the apparatus herewith described.

FIG. 2 CONSTRUCTION PRINCIPLES

The central fluid chamber with a capacity of 1000 cc. is filled or emptied by means of a plunger, which is operated by turning a handle. Outside of the fluid chamber is a cylinder connected so that it revolves as the handle is turned. This cylinder carries

729

A VALVELESS CYSTOMETER ADDRESS _ _ _ _ _ _ _ _ _ _ _ __

DA,~-------

L

--- ........ D

IJ' .I.UV.LS Temperatu~e ,;,eri:.eptiM~~»o~n~•----

Desire to vo,wld~I'~s~cc,o,.____ __

ful~--=----

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Ch/lnfo
Frn. 3.

CYSTOMETRIC CURVE IN A PATIENT WITH LIMITED BLADDER CAPACITY

FL, involunta:ry detruso:r contraction; L, leakage around the catheter NAM"--""-""'""------------

Temperature perception-"='----

FIG.

4.

ADDRESS------------- DA,~-------

Desire to v o i d . - , = = - - -

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CYSTOMETRIC CURVE DEMONSTRATING INCREASED BLADDER CAPACITY

Low INTRACYSTIC PRESSURE PV, voluntary attempt to urinate

ASSOCIATED WITH

730

LELAND M. McKINLAY

the graft or chart. The recording part of the instrument consists of an air chamber, connected by a rubber tube to a mercury reservoir, which acts as one limb of a U-tube. A float in the other limb of the U-tube transmits any change in the mercury level to a recording styelus that rests against the chart. OPERATION

The fluid chamber is filled with the solution to be used. The two tubes leading from the apparatus are connected to the openings of a two-way catheter which has been inserted into the bladder. Turning the handle causes a steady stream of solution to flow through one tube into the bladder, the pressure within the latter being transmitted back through the other tube to the recording apparatus. In this manner we obtain a record of the amount of fluid within the bladder simultaneously with the intracystic pressure. By inserting a properly fitted aspirator bottle between the patient and the machine, a curve of bladder emptying may be obtained. We are uncertain of the true value of this curve at the present -time. Our work to date in this field impresses me with its importance. I feel that the data obtained by means of a cystometric examination will be conducive to better clinical results.

1416 Grand Rapids National Bank Bldg., Grand Rapids, Michigan REFERENCE (1) RosE, D. K.: Determination of bladder pressure with cystomet er; new

principle in diagnosis. Jour. Amer. Med. Assoc., 1927, lxxxviii, 151.