unruptured brain aneurysm idea
neuropace, dbs, licox monitors cant be used bc they cant measure intracranial arterial pressure
the first idea a device under the skull -maybe on the dura- that measures the intracranial pressure is out
current idea:
anterior communicating artery aneurysms are the most common places for aneuryms
this ACoA is very thin and has smaller veins connecting to it so the device has to be very small
the thin biosimilar sensor which is also vascular specific and can expand to certain levels of pressure
app part:
the sensor will notice and measure the high levels of pressure which can be a sign of an aneurysm and will notify the patient via an app than later send a signal to a hospital -if the aneurysm is about to rupture or smth-
people who have a genetic predisposition or are at increased risk for aneurysms
the sensor:
must be small enough to fit in, on, or around a blood vessel.
it needs to be Vascular Specific. It needs to be dynamic - able to adjust to arterial pressures when someone exercises or defecates (pressures increase) or fall asleep (pressure may slightly decrease). The algorithm, when programmed to interpret pressure changes and interpret them in the app will have to be sensitive enough to interpret the changes through calcified (atherosclerotic) blood vessels.
background:
In a healthy person, normal ICP measured in the ventricles can vary between 7 mmHg and 15 mmHg when lying down and is around 10 mmHg when standing
If compensatory mechanisms are impaired, ICP increases and CPP decreases, limiting the flow of blood to brain tissue. The decrease in perfusion is normally met with autoregulatory vasodilation, which has the result of increasing cerebral blood volume, further increasing ICP. The reduction of flow of blood to brain tissue deprives the tissue of oxygen and nutrients and often leads to ischemia and death if untreated.
reasons:
It is also often important to measure a patient’s ICP during their recovery from a neurosurgical procedure, as an elevated ICP can indicate bleeding or infection.
Alternatively, a pressure-sensitive probe can be placed in the brain parenchymal space and measure the pressure of the brain tissue.
parenchymal pressure probes provide measurements of ICP, the insertion procedures are highly invasive, carrying with them the risk of bleeding, infection, and damage to vital brain structures. These risks have motivated the development of noninvasive methods for estimating ICP (nICP
ABP can be measured either through the insertion of a pressure-sensing fluid catheter into an artery or through the vascular unloading technique. In the vascular unloading technique, an air cuff is secured around one of the fingers and the volume of the finger is measured with a plethysmograph. As blood pulsates through the finger, a computer system measures changes in the plethysmographic data and applies a pressure through the air cuff to keep the volume of the finger constant.
bu tarz bir cihazın küçük ve bluetooth benzeri bir teknolojiye uyumlu versiyonu artery’ye takılabilir(cuff olmasına rağmen esneyebilir olmalı ve tek tarafı önce açık sonra surgeon tarafından bağlanabilir olmalı)
CBFV is measured through transcranial Doppler ultrasound (TCD), which measures the Doppler shift in ultrasound waves applied through the skull as they reflect off of the red blood cells (mostly) moving through arteries.
IOP is measured through applanation tonometry whereby an external pressure is applied to the eye until the corneal surface is flattened; this “applanation” pressure corresponds to IOP.
One such method is based on a model of blood flow through the central retinal artery whereby the intracranial segment of the artery is compressed by ICP and the extracra- nial segment is compressed by IOP
ICP can then be estimated by applying an external pressure to the eye until features of the CBFV waveform are the same in both segments.
the essay:
This thesis presents a microcontroller-based medical device prototype (Figure 1-3) that applies the Kashif algorithm to ABP and CBFV signals acquired in real-time to produce an estimate of mean ICP once every 60 seconds and can perform the necessary computations in less than one second.
ICP estimates, as well as the ABP and CBFV signals, are displayed on an LCD screen on the front panel and are also saved to a SecureDigital (SD) card within the device. The device is powered by a USB port that also provides serial streaming of ICP estimates to a computer. The embedded device offers the advantages of low cost and size as well as product modularity over a general-purpose computer,
Chapter 3 focuses on the detailed implementation and testing of the device, and also enumerates and explains the software and hardware tools that were used. I also mention the challenges that were encountered during the device development.
Chapter 4 presents the performance of the device including comparison to the batch-mode implementation and invasive ICP, the speed and memory usage of the algorithm, and the physical specifications of the final assembled prototype device.
An accurate noninvasive method for estimating intracranial pressure (ICP) could have a tremendous impact on lowering the risk of neurocritical monitoring and could benefit a much larger patient population as a diagnostic tool for hemorrhagic or ischemic stroke, traumatic brain injury, hydrocephalus, and brain tumors
the kashif method:
The Kashif noninvasive ICP estimation algorithm is motivated by a model of cerebrovascular physiology that relates ICP to arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV).
The device described in this thesis is based on the Kashif algorithm for noninvasive ICP estimation, which is of the physiologically-motivated class of approaches [4]. The Kashif algorithm is based on a lumped-parameter model of blood flow through the cerebrovascular system and uses ABP and CBFV measurements at the middle cerebral artery (MCA) to estimate the mean ICP. A detailed description of the algorithm will be presented in Chapter 2.
İntrakraniyal basıncın (ICP) izlenmesi, birçok nörolojik durumda teşhis ve tedaviyi yönlendirmek için anahtardır. Mevcut izleme yöntemleri oldukça invazivdir ve kullanımlarını en kritik hastalarla sınırlandırmaktadır. Serebral kan akış hızı (CBFV) ve arteriyel kan basıncı (ABP) dalga formlarından invaziv olmayan ICP tahminine yönelik daha önce geliştirilmiş bir yaklaşıma dayanarak, algoritmayı gerçek zamanlı ICP tahminleri üretebilen gömülü bir cihaza (LPC4337 mikrodenetleyici) uyguladım. noninvaziv olarak elde edilen ABP ve CBFV ölçümleri. Ayrıca, ABP ve CBFV izleme donanımı için çevresel arabirimler ve klinik kullanım ve alım sonrası analiz için görüntüleme ve kayıt işlevleriyle eksiksiz bir tıbbi cihaz prototipi ürettim. Mevcut cihaz, dakikada bir ortalama ICP tahmini üretiyor ve gerekli hesaplamaları ortalama 410 ms'de gerçekleştirebiliyor. İnvaziv olmayan ICP'nin gerçek zamanlı tahminleri, algoritmanın orijinal toplu mod MATLAB uygulamasından 0,34 mmHg (RMSE) farklıydı. Bu tezin katkıları, çeşitli klinik ortamlarda gerçek zamanlı invazif olmayan ICP tahmini hedefine doğru bir adım atmaktadır.
the procedure
ACoA can be reached microsurgically this way we can place the sensor on the artery via a microsurgerical procedure
updated idea
doppler sound effect monitor measuring icp from the back of cerebellum
non-invasive 7/24 monitoring
not artery specific
mostly for patients with an aneurysm background and ppl who do extreme sports that require high levels of pressure change and continous motion