Pre­ven­ting car­dio­vascu­lar dama­ge — VASCASSIST: The revo­lu­tio­na­ry mul­ti­func­tio­n­al tool

Pre­ven­ting car­diac and vascu­lar damage


The revo­lu­tio­na­ry mul­ti­func­tio­n­al tool

The abi­li­ty to “read out” a patient’s pul­se wave in detail puts any car­dio­vascu­lar dia­gnostics on the insi­de track. Both arte­ri­al and car­diac para­me­ters deter­mi­ned with the help of Model-based Pul­se Wave Ana­ly­sis gua­ran­tee a clear advan­ce in know­ledge com­pa­red to the often inac­cu­ra­te and error-pro­ne stan­dard dia­gnostics. Working with the VASCASSIST device enab­les phy­si­ci­ans to offer pre­ven­ti­on, dia­gno­sis, and tre­at­ment of car­dio­vascu­lar dise­a­ses at an ent­i­re­ly new level of insight. Put to use both on time and regu­lar­ly for fol­low-up pur­po­ses, VASCASSIST hel­ps to effec­tively pro­tect the heart and arte­ries with its varie­ty of para­me­ters and mea­ning­ful mea­su­re­ment data, using the glo­bal­ly uni­que Model-based Pul­se Wave Ana­ly­sis (mbPWA) as a dif­fe­ren­ti­al dia­gnostic “all­round man” tool.

The dia­gnostic princip­le reli­es on oscil­lo­metric blood pres­su­re mea­su­re­ment employ­ing cuffs pla­ced on the upper arms, wrists, and ankles. Both peri­pheral and aor­tic values are deter­mi­ned. The algo­rithm-based mea­su­re­ment method of Model-based Pul­se Wave Ana­ly­sis (mbPWA) opens up a wide ran­ge of dia­gnostic opti­ons — inclu­ding, in par­ti­cu­lar, the detec­tion of rare car­dio­vascu­lar dise­a­ses. In addi­ti­on, tho­se dise­a­ses can be loca­li­zed and dia­gno­sed much ear­lier than pos­si­ble with con­ven­tio­nal methods.

Gene­ral notes on operation

The ope­ra­ti­on of VASCASSIST is intui­ti­ve and, the­re­fo­re, easy to learn and dele­ga­te. In addi­ti­on, the user gui­de, which requi­res only a few but­ton clicks, is desi­gned to be easi­ly per­for­med by medi­cal assistants.

The ope­ra­tor must app­ly cuffs to the pati­ent, which are con­nec­ted to the device via tubes. Infla­ti­on hap­pens ent­i­re­ly auto­ma­ti­cal­ly. Depen­ding on the selec­ted mea­su­re­ment method, eit­her two cuffs are app­lied to the upper arms and wrists or the upper arms and ankles. It is pos­si­ble to “deselect” indi­vi­du­al lim­bs at the click of a but­ton on the VASCASSIST dis­play and thus exclu­de them from a mea­su­re­ment, e.g., in pati­ents with ampu­ta­ted or inju­red lim­bs or with vascu­lar acces­ses (shunts).

The app­li­ca­ti­on of the cuffs

When put­ting on the cuffs on the upper arms, wrists, and ankles, the­re are a few points to keep in mind:

  • Illus­tra­ti­ons, labels, and color codes are atta­ched or prin­ted on the cuffs to avoid side swaps. Among other things, an “arte­ri­al man” in a pic­to­gram still clear­ly indi­ca­tes the cor­rect mea­su­re­ment loca­ti­on of the cuff. Each cuff must be app­lied accord­ing to its mar­king on the right arm/wrist or the right ankle side.
  • App­ly the cuffs tight­ly, but not too tight­ly, ana­lo­gous to a blood pres­su­re mea­su­re­ment. Howe­ver, a high­ly exact align­ment of the arte­ries is optio­nal becau­se it is an oscil­lo­metric mea­su­re­ment method. Here, the pul­se pres­su­res are recor­ded over the ent­i­re cuff. Nevertheless, it is still hel­pful to ensu­re that the mar­king with the inscrip­ti­on “Arte­ry” is loca­ted as clo­se as pos­si­ble to the cor­re­spon­ding arte­ries — ide­al­ly, the prin­ted arrow points ver­ti­cal­ly exact­ly to the arte­ry. This align­ment favors a mea­su­re­ment under stan­dar­di­zed con­di­ti­ons. Do not place the cuffs on clot­hing, but always on bare skin. In par­ti­cu­lar, bul­ky garments such as thick swea­ters or jackets distort the recor­ded pul­se pres­su­re cur­ves and, con­se­quent­ly, the mea­su­re­ment results.
  • In this con­text, also ensu­re that garments do not cau­se con­ges­ti­on at the extre­mi­ties when pushed up while put­ting on the cuffs.

Set­tings on the device befo­re star­ting the measurement

Pro­vi­ded all cuffs are tight (but not too clo­se!) and cor­rect­ly posi­tio­ned on the right sides of the body, with the arrow poin­ting to the arte­ry as well as pos­si­ble. The next step is to make a few cri­ti­cal set­tings on the device: Befo­re star­ting a mea­su­re­ment, the ope­ra­tor has to deter­mi­ne the patient’s initi­als (ID). Sin­ce body size plays a role in the ABI cal­cu­la­ti­on, this infor­ma­ti­on must be set befo­re a peri­pheral mea­su­re­ment. Fur­ther­mo­re, deter­mi­ne a pre-rest peri­od. A rest peri­od of about 5–10 minu­tes befo­re the actu­al start of the mea­su­re­ment effec­tively hel­ps to relax the pati­ent. Let­ting pati­ents rest makes the mea­su­red values more reli­able and repro­du­ci­ble — the pre-rest peri­od is the­re­fo­re essential.

Pro­ce­du­re of the measurements

After selec­ting the desi­red mea­su­re­ment pro­ce­du­re by pres­sing a but­ton, VASCASSIST starts with a short cuff test and then pro­ceeds auto­ma­ti­cal­ly to the actu­al mea­su­re­ment. During this time, the device does not requi­re any fur­ther “super­vi­si­on” from the medi­cal assi­stant. Thus, if desi­red, it is pos­si­ble to lea­ve the room while the pati­ent is lying rela­xed while being mea­su­red from “head to toe.” Some pati­ents often find this moment of com­ple­te rest without fur­ther obser­va­ti­on plea­sant. Not being pre­sent during mea­su­re­ment usual­ly posi­tively affects the mea­su­re­ment results and hel­ps avoid the so-cal­led “white coat effect.” This effect can occur in the pre­sence of a phy­si­ci­an or medi­cal staff and lead to an unde­s­i­ra­ble mea­su­re­ment-fal­si­fy­ing exci­te­ment or nervousness.

VASCASSIST indi­ca­tes the end of the mea­su­re­ment with a beep. Repeat the mea­su­re­ments for ankle-bra­chi­al index (ABI) and pul­se wave velo­ci­ty (PWV) several times at inter­vals of a few minu­tes, and com­pa­re the mea­su­re­ment results. The more the mea­su­red values of the respec­ti­ve indi­vi­du­al mea­su­re­ments agree, the more reli­able they are.

PAVD scree­ning: the ABI measurement

First, place two cuffs on each patient’s upper arms and ankles accord­ing to the descrip­ti­on abo­ve. Once the pati­ent has assu­med a com­for­ta­ble lying posi­ti­on, check that the ang­le of incli­na­ti­on of the couch is at most 10%.

Assign a pati­ent ID on the unit via the key­pad, defi­ne the body height, and set the pre-rest time. Then select the “Mode” selec­tion menu on the device by cli­cking the but­ton and using the arrow keys to select “Peri­pheral mea­su­re­ment” as the mea­su­re­ment mode. Then start the mea­su­re­ment cycle by cli­cking on “OK.”

First, VASCASSIST auto­ma­ti­cal­ly mea­su­res the blood pres­su­res on the upper arm and ankle of the right side, then tho­se on the left side of the body. All blood pres­su­re values, pul­se rates, and the cal­cu­la­ted ABI values of the left and right hal­ves of the body are immedia­te­ly avail­ab­le to you on the device’s dis­play after the mea­su­re­ment has ended.

After­ward, you can also have the pul­se wave velo­ci­ties of the left and right hal­ves of the body deter­mi­ned by pres­sing a but­ton while the cuffs remain. This mea­su­re­ment also takes only a few minu­tes and ends with the dis­play of the mea­su­red values.

Tracking down car­dio­vascu­lar dise­a­ses: the cen­tral measurement

You can also per­form a cen­tral mea­su­re­ment direct­ly after an ABI mea­su­re­ment. In this case, exchan­ge the ankle cuffs for wrist cuffs; the upper arm cuffs remain. The same rules app­ly to the app­li­ca­ti­on of the­se cuffs in terms of align­ment with the arte­ri­al mar­kings and pla­ce­ment on the right side of the body. The pre-res­ting time is omit­ted if the cen­tral mea­su­re­ment is taken after the ABI mea­su­re­ment. Con­firm the device’s accep­t­ance of the same pati­ent ID and body size and select “Cen­tral mea­su­re­ment” in the menu area using the arrow keys. Con­firm with “OK.” VASCASSIST now mea­su­res the pul­se wave velo­ci­ties of the left and right hal­ves of the body in the same way as the ABI mea­su­re­ment. This mea­su­re­ment also takes only a few minu­tes and ends after a signal tone with the dis­play of the mea­su­red values.

Per­forming a pure cen­tral mea­su­re­ment without pri­or peri­pheral mea­su­re­ment is also pos­si­ble. To do this, place a wrist cuff and an upper arm cuff on each arm, select “Cen­tral mea­su­re­ment” as the pre­set mode on dis­play and start the mea­su­re­ment by pres­sing “OK.”