Regulation Of Arterial Pressure

Published Date: 02 Nov 2017

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Urine analyzer

Research proposal

Authors:

J.C. Akkerman and K.D. Vos

Date: 13 February 2013

Version: 0.1

Authors:

J.C. Akkerman and K.D. Vos

Date: 27 February 2013

Version: 2.4 for review

Index

1. Introduction

The kidneys are an important organ that helps to control the human body. Although the majority of the people only know one important function of the kidney, namely get rid of waste material. These waste materials consist of ingested materials (food, medicines and water) or produced by the metabolism. The most important function that the kidneys perform is filtering plasma and removing substances from the filtrate. This is happening at variable rates, which depends on the needs of the body. Eventually the kidneys are responsible for cleaning the filtrate, so that all unwanted substances will be excreted in urine and all the substances that are needed are returned to the blood. (Appendix 1: A detailed working of the kidneys)

The kidneys serve multiple functions like:

·         Excretion of metabolic waste products and foreign chemicals

·         Regulation of water and electrolyte balances

·         Regulation of body fluid osmolality

·         Regulation of arterial pressure

·         Regulation of acid-base balance

·         Secretion, metabolism and excretion of hormones

Figure : The kidney and the position·         Gluconeogenesis

(Guyton and Hall, 2006)

When the urine leaves the body of a person, the urine consist a lot of valuable information that tells something about mortality risk, fitness and unhealthy eating habits. This is the finding of nephrologists Gerjan Navis (2013) from the Universitair Medisch Centrum Groningen (UMCG). The UMCG is conducting population studies like Lifelines and Prevend. In the lifelines project 113.000 respondents are participating and within the prevent project they are monitoring, for over ten years, thousands of respondents. The respondents deliver their urine in a urine container. When the urine is analyzed, they can find substances that says something about the health of a person e.g. medicinal usages, diabetes, kidney disease, does the respondent exercises enough, does the respondent eat enough vegetables and fruits. All this information can be found in urine. With this knowledge they want to identify people that are vulnerable to health problems like, kidney disease or heart problems.  (Van Wijngaarden, 2013)

In the intensive care identifying health problems is important. To get the right diagnoses for patients in a hospital, the values of blood and urine is measured. The urine and blood values are complementary to each other and can form the result which leads to a diagnosis. In an intensive care (IC) it is important that the results are quickly and accurately obtained, the patients in the IC need intensive care. There are a number of cases in which a patient can be placed in the intensive care:

- With severe illnesses, in which treatment is necessary with intensive monitoring and care

- When key body functions (respiratory, kidney function, blood pressure etc.) have to be replaced by

artificial devices

- Standard after a major surgery

- When after a surgery complications are expected (for example with impaired function of the heart or

lungs).

In order to give an adequate medical examination of a patient to the intensive care, constant monitoring is required. The monitoring is done by a range of different devices that are implemented in a hospital bed. Patients in a hospital bed are connected with multiple cords and wires to a monitoring device. This allows a nurse to monitor a variety of things like; respiration, the working of the heart, blood pressure, body temperature and oxygen level (UMCG, 2013)

The patient receives artificial support through the devices when key body functions like; respiratory, kidney function, blood pressure etc. are not working correctly. The devices can replace a body function for a long or short period of time. Measurements are also done in the intensive care, the blood, urine and stomach and- or wound infection fluids are measured. This gives specific indicators that provide a lot of information about the body of a patient at that point, for example if the patient has diabetes or a kidney disease.

As explained, patients in the Intensive Care are monitored constantly. During the day the patients excrete urine, which is also monitored by the nurses. They look at the colour of the urine and the volume that is produced per hour with this information they can e.g. adjust the hydration of the patient, if the patients excretes not enough urine, this could mean that the patient is not hydrated properly and therefore they should hydrate the patient. During the day, the urine drains into a catheter bag. When they have collected about 24 hours of urine then there is enough urine for a sample (Appendix 3: Task analysis taking a sample) to be analyzed by the laboratory. When the urine is analyzed, they send the data to the nurses (Appendix 4: Analyzed urine results). Then the data is interpreted by a nurse and then double checked by another nurse and then they discuss the treatment, if necessary. Per patient the meaning of the values can vary. What is normal for one patient can be life threatening for another patient. This is the way of working according to Annemieke Oude Lansink internist-intensivist at UMCG.

The Universitair Medisch Centrum in Groningen (UMCG) approached the Hanze Institute of Technology (HIT) to develop a urine analyzer for the Intensive Care that can measure the urine "real-time". With this they hope to prevent organ failure. They also want to confirm an assumption namely, that the urine should give quicker results about the organs unlike blood measurements. In figure 1 you can see how the concept of the urine analyzer works, also an explanation is given.

Urine analyzer

1. Patient with a catheter

2. Measuring urine level

3. Urine analyzer

4. Waste bag

5. Detergent solution bag

6. Computer analysis the data

7. No analyzing

7

1

6

5

4

2

3

Figure : Visualization, the working of the proof of concept.

The patient in the intensive care gets a catheter to drain the urine (1), the urine is transported through a small tube into a device that measures the quantity of urine (2), if there is sufficient urine available then the urine will be pumped towards the urine analyzer (3) this device measures sodium (Na+), potassium (K+), calcium (Ca++), chloride (CL-) and the pH value. When the urine is analyzed the data is sent towards a computer (6) and then device automatically cleans itself (5), all the urine and detergent solution, will be collected into a waste bag (4). Proof of concept 2012.jpg

Figure 3: Demonstration model urine analyzerWhen there is no analyzing needed, the urine goes directly towards the waste bag (7). This is basically the working of the urine analyzer. In figure 3 the proof of concept is shown, which is made by students at the Hanze Institute of Technology in Assen.

Problem

The client UMCG wants to have a urine analyzer to monitor patients in the intensive care to prevent organ failure. There is already a proof of concept build of the urine analyzer, with this they proofed that the concept works. Unfortunately this device cannot be implemented in the intensive care of the UMCG for testing. The problem definition is: What is required to implement the urine analyzer on the IC of the UMCG?

The goal of this research is to redesign, build and test the urine analyzer technology in order to be implemented on the intensive care of the UMCG for further research. This leads to the following main question: 

What is necessary in order to redesign the urine analyzer technology towards a user-centred solution so it can be implemented on the Intensive care of the Universitair Medisch Centrum Groningen for validation?

The central question is divided in sub-questions, in this report these questions will be researched:

1. What is for the users the ideal way of working with the urine analyzer?

2. What are the requirements for medical testing equipment?

3. Which technical improvements can be made?

4. How does the final prototype look like when all necessary requirements are integrated?

5. Can the urine analyzer measure the exact values in the urine, in comparison with the lab results of the UMCG?

2. Methods

In order to conduct the research properly different methods are used to answer the sub-question. By answering the sub-question, the main question can be answered. Therefore an operationalisation scheme is made, see table 1. In the first row you can see the sub-questions, these are divided in aspects in order to select the best method.

Sub question

Aspects

Methods

1. What is for the users the ideal way of working with the urine analyzer?

Users

Placement device

Interaction with device

Interface

Equipment

Layout

Users analyses

Persona

Environment analyses

Layout plan

Use analyses

Task analyses

LCA

2. What are the requirements for medical testing equipment?

Regulations

Safety

Hygiene

Medical

Electronics

Privacy

Testing

Expert review

Expert interview

3. Which technical improvements can be made?

Improvements

Materials

Water resistant

Insulation

Tube flow/transport

Valves

Integrated system

Expert review

Expert interview

4. How does the final prototype look like when all necessary requirements are integrated?

Prototype

Sketches

Technical drawings

Building device

Testing/iteration

Hardware

Mock-up prototyping

High fidelity prototype

Software

Wire framing

Paper prototyping

FMEA

5. Can the urine analyzer measure the exact values in the (real) urine?

Validation

Lab results

Comparison

Urine testing

Validation

Table 1: Operationalisation scheme.

With the input from the operationalisation scheme (figure 5: conceptual model of the process) a conceptual model is made, that shows the process of this research. Some parts are conducted parallel, for example the prototype process is done in all the stages of this research. This conceptual model gives a good and global insight of the process.

Figure 4: Conceptual model of the process.

The urine analyzer can be implemented on the Intensive Care of the UMCG!

Conceptual model of the process

2.1 Explanation methods

Based on the conceptual model of the process in figure 4, the methods are separated and divided into phases. The phases of the process are:

Research

Analyze

Prototyping

Testing

Validation

2.2 Research and analyze

In this phase of the process, the requirements are gathered that will be the first input for building a working prototype. The requirements that are needed for the input are obtained by doing research towards:

User analyses

Environment analyses

Use analyses

Regulations

All the requirements that are found will be analyzed. Then only the most important requirements that are needed for a working urine analyzer will be used in the prototype.

2.2.1 User analyses

The product that is developed will be used by a certain group of users, to make a good end product it is necessary to learn the end-user. In this project the target group is already known, namely the employees on an intensive care. This could be a nurse or a specialist. To get a good image of this target group, personas are made.

Persona

A persona is basically a short story about a user that describes different subjects like:

Personal details e.g. like income, profession, age and so on

Lifestyle

Their work and the problems they face

Experience with products

All this information will provide a good image about the future users of the product. In this research the persona is used to get a connection with the user group and also to keep in mind for whom the Urine analyzer is made. The input for the personas in this research is based on conversations with involved users on the intensive care.

2.2.2 Environment analyses

To make sure that the Urine analyzer fits in the environment of the intensive care, the intensive care needs be mapped. This is done by a method called a layout-plan combined with the walking route.

Layout-plan

A layout-plan shows the amount of space that is available in a room, the layout can be made in different ways, making a rough sketch with the measurements or digital drawings. When there is a layout, it is easy to put the walking route into the drawing.

The goal of this method is to map the intensive care, to discover the placement, problems and the amount of space available for the Urine analyzer.

2.2.3 Use analyses

The interaction between the user and the product is important. During this phase a foam mock-up model is made, together with real parts. This model should represent the Urine analyzer. With this model the use of the product will be tested, the method used is a task analyses.

Task analyses

A task analyses is what the user is required to do, in term of actions and/or cognitive processes, to achieve a task objective. The user is given a small task he/she has to perform, the researchers will observe what the user is doing and ask questions about things that are unclear or unusual.

The goal with this task analyses it to find out what the ideal placement is of the urine analyzer according to the user, regarding to placement monitor and device, detergent solution, catheter and other important aspects.

Life cycle analysis (LCA)

An LCA is a methodical approach to analyzing and assessing the life of a product, from building towards the end of the life of a product, system, building or other things that are manmade (Vogtländer, 2010). In each phase of the life of a product you can think about certain things for example the transport of your product. Where should the product being produced, if you are an eco-company you will not produce the product in a country that is 8000 kilometres away! Or production is cheap in China, but you have not considered the transport costs. These are just some examples

In this research an LCA is made to look at the use of the product and the disposal of the waste materials. The use of the product also contains; maintenance, errors, fragile components and problems that users possible encounter. By conducting this in the early stage of the research, a lot of problems can already be found and new research areas can be considered.

2.2.4 Regulations

Expert interview (semi-structured interview):

Expert interviews are sessions where one or more people, who are considered experts in a particular subject e.g., program, process, policy, etc., meet with others to share their knowledge. The format of the sessions can range from an informal one-on-one meeting in a large group session with a panel of experts. The interview will be done in the form of a semi-structured interview because it is flexible, allowing new questions to be brought up during the interview as a result of what the interviewee says.

Expert review

An expert review is a research where one or more experts give their opinion about a certain subject. Based on their expertise they can give very valuable information which can be beneficial for a product.

2.2.5. Requirements

The requirements that are obtained are documented in a list that will be divided in several subject e.g. user, functional, technical, materials, hygiene etc. The methodology used in this research to document and formulate the requirements is created by the company Synergio and it is called ‘begin bij het einde’. This is book provides a lot of regulations, which lead into a good requirement (smart).

2.3 Prototyping and testing

During these two phases the prototype is built and tested with the users. The prototype consists out of two components namely, hardware and software development. The hardware part consists out physical aspects, like electronics, framework, tube, valves, analyzer, computers etc. The software part contains the interface for the urine analyzer.

The prototype process is based on an approach called iteration. Iteration is basically a review/test of a product and analyze what went wrong or could be improved and finally adjust or solve the problem. This is a process that repeats multiple times. This ultimately should lead into a prototype that meets the expectations of the user. When the prototype meets the expectations of the user, a failure mode and effects analyses is made, to detect possible failures which can cause severe damage.

To build a working prototype the following methods are used:

Prototyping + user testing

FMEA

2.3.1 Prototyping

The product that is built consist out of two parts namely, the interface (software) and the analyzer (hardware) itself. Therefore these two are separated, because they are each developed with different methods. The focus of this research is to implement the hardware within intensive care and design the interface.

Hardware

Mock-up prototype:

The first model will be a mock-up model, made out of foam. The scale is identical to the product in the future, but it is not a working prototype. Just to research the user interaction between the prototype and environment.

High fidelity prototype:

Together with the input from the requirements, user testing and expert review. A start can be made by building the ‘working prototype’. To build a working Urine analyzer, starts with a low fidelity prototype and by making iterations the prototype is developed into a high fidelity end product.

The given feedback, problems or other gained information is analyzed and then the prototype is adjusted.

Software

To make an interface two methods are used, namely paper prototyping and wire framing.

Paper prototyping:

This is a prototyping session that is done with paper, in order to obtain requirements regarding the interface. Paper is a good way to start a prototype session, it is easily adaptable and because it is on paper it gives the user a lot of freedom to draw what he or she wants. Also the order of importance of functions can determine, in order to get the ideal layout.

Wire framing:

A wireframe is a digital elaboration of a paper prototype. It provides a framework of the interface that is interactive, giving more options to test subjects like; interaction and feedback.

2.3.2. FMEA

An FMEA or failure mode and effects analyses are a tool that explores the effect of a possible failure in a product. All the components of the product are analyzed on possible failures and then it is ranked on:

-Change that this failure occurs (Probability)

-The change that it is detected (Detected in time)

-The damage the failure causes (Severeness)

The scores each failure gets is determined by a Risk Priority Number (RPN), this number can vary per product (start from 0 up to 1000). The aviator companies use an RPN 125. So if the calculation (PxDxS) is above 125 RPN, then there is a serious risk of failure. Therefore they need to solve this problem.

An FMEA is a time consuming tool, if an FMEA is conducted completely it takes up to hundreds of working hours, therefore in this research the FMEA is used as a general analysis in which the most important information is gathered. In this case electronics and some of the hardware are analyzed (the heart of the device).

2.4 Validation

The validation in this research is a check, to see if the analyze is equal towards the analysis of the lab. This test gives an indication of the performances of the urine analyzer. The test does not confirm if the urine analyze is better than the traditional way of testing. To prove this the hospital should do a research.

A number of urine samples that are tested in the laboratory will provide an analysis, the same urine samples will also be ran through the urine analyzer. Then the analyzed results of the urine analyzer are compared with the lab results, the deviations between them will be calculated.

3. Expected results

In this chapter the expected results that are obtained from this research are described. The results are divided per method and explained, this provides a good insight of the assumed research results.

3.1 Research and analyze

3.1.1. User analyses

Persona

-Understanding the users

-Their goals

-Motivation

3.1.2. Environment analyses

Layout-plan:

The expected results are:

-Size of the Intensive Care

-Room available for medical devices

-Ideal placement of the urine analyzer and the monitor (technical)

-On the ground

-Attached to the bed

-Underneath the bed

-Monitor on the device or separated

-Walking route nurses

- Equipment

3.1.3. Use analyses

Task analyses:

The expected results are:

-Ideal placement of the urine analyzer and the monitor (user)

-Device itself

-Detergent solution (in or outside the device)

-Catheter (in or outside the device)

-Monitor (in the device or placed outside)

-Different user goals

-Information about the future use

-Automatic or manual volume and colour check (or both)

-Real time urine measurement or selectable (per 15 min, hour or 4 hours)

-Interface, with touch or physical knobs or both

-Waste bag (collect urine and detergent, or both separate)

Life cycle analysis (LCA)

The expected results are:

-Future use

-Installation

-Risks that can arise

-Design

-Maintenance

-First time usage (user)

-Disposal

3.1.4. Regulations

Expert interview

The expected results are:

-Regulations about

-Hygiene

-Safety

-Privacy

-Electronics

Expert review

-Technical improvements

-Noise (insulation)

-Transport system (reliable tubing)

-Portable device

-Microcontroller and HDD

-Pump

-Volume meter

-Materials

-Valves

-Sensor expansion

3.1.5. Requirements

The expected results are:

-A list of requirements based on different subjects

-User

-Technical

-Hardware components

-Electronics

-Software

-Hygiene

-Safety

-Functions

-Materials

-Ergonomics

3.2. Prototyping and testing

3.2.1. Prototyping + user testing

Mock-up

The expected results are:

-A model which can be tested with users

Paper

-The way the user thinks about the device

-The functions

-Layout

-Information

Wire

-Digital interface based on the user requirements

User testing:

-Input from the users to improve the product

At the end of the prototype process, a working urine analyzer should be the output that matches the mental model of the user.

3.2.2. FMEA

The expected results are:

-Finding risks that could harm the user, patient or the environment.

-Solutions to solve the risk

3.3. Validation

The sensors measure the exact values in the urine, in comparison with the lab results.

4. Discussion

In this chapter the internal and external points that can influence the research process negatively will be described, in terms of; time, money, materials and respondents.

4.1 Research and analyze

4.1.1. User analyses

Persona

Some of the information in a persona is based on fictive information, so it is just a tool to have an impression of the user.

4.1.2. Environment analyses

Layout-plan

Probably the IC with patients cannot be measured because the ill patients need care, also families are visiting the patient. The researchers can interrupt the work process of the nurse and disturb a private moment between patient and visitors Therefore it should be possible to measure up an IC that is used by students. The problem could be that the practice room for students is bigger or different medical devices are used.

4.1.3. Use analyses

There are a lot of nurses in the intensive care, so there should be enough respondents that can participate in the research. The only problem is that the nurses have a tight time schedule, so there is a possibility that the respondents have a limited amount of time available for participating in the research. The effects of this research could be:

- Less iteration, only the necessary iteration can be executed

- A reduced execution of the methods

4.1.4. Regulations

Expert interview & Expert review

It is necessary to find at least two experts in the same field, this can be difficult for some expert areas.

4.1.5. Requirements

The requirements need to be clear, so if another research develops the urine analyzer further, they must understand the requirements. So identifying what is clear will be important.

4.2. Prototyping and testing

4.2.1. Prototyping

During this stage several things could be considered as a problem, first of all to build a prototype materials are needed and machinery are necessary to manufacture parts. The second problem is to build an interface and finally the proof of concept should be disassembled and rebuild.

To build a prototype materials are needed, the materials are not the problem. This will be ordered by the Hanze Institute of Technology. The only concern is how to make the mechanical parts, because here at the HIT they do not have machines like a milling machine, turning lathe, saw, etc.

The knowledge of the researchers about software development is poor, therefore it is difficult to make a working interface and a specialist is needed to program the interface.

And finally rebuilding the machine, there are a lot of electronic components in the proof of concept. All the wires should be removed separately and then wires need to be soldered into the new prototype. Therefore some expertise is necessary.

4.2.2. User testing

As mentioned in 3.1.3. Use analyses:

There are a lot of nurses in the Intensive Care, so there should be enough respondents that can participate in the research. The only problem is that the nurses have a tight time schedule, so there is a possibility that the respondents have a limited amount of time available for participating in the research.

4.2.3. FMEA

An FMEA can become a massive document, so in this case it is necessary to only conduct an FMEA for the most important parts of the product, otherwise it is time consuming and the end results of a working prototype will not be achieved.

4.3. Validation

The validation in this research is a check, to see if the analyze is equal towards the analysis of the lab. This test gives an indication of the performances of the urine analyzer. The test does not confirm if the urine analyze is better than the traditional way of testing. To prove this the hospital should do a research.

4.4 Common

Design history log

This document has to be updated after each revision. The researchers are not familiar with the design history log, it will take time to learn and conduct it. This document is important in order to get a certificate for medical use. An introduction lessons for the design history log will be arranged.

5. References

Dijkgraaf, W & Van Spall, M (2008) ‘begin bij het einde’. Chaam: Synergio.

Guyton, A.C. & Hall, J.E (2006). Textbook of Medical Physiology. Philadelphia: Elsevier Saunders.

UMCG, 2013. Intensive Care voor volwassenen. Consulted at 14 February 2013, http://www.umcg.nl/nl/umcg/afdelingen/umcg_centrum_voor_congenitale_Hartafwijkingen/Patienten/volwassenen/Intensive_care_voor_volwassenen/Pages/default.aspx

Van Wijngaarden, A (2013). Ongezonde levenstijl blijk uit urine. Dagblad van het Noorden, 11 januari 2013.

Vogtländer, J.G. (2010). LCA, a practical guide for students, designers and business managers. Delft: VSSD.

6. Appendices

Appendix 1:

A detailed working of the kidneys.

Figure 1: Section of the human kidney, which shows the major vessels that supplies blood to the kidney.

There are two kidneys in a human body, they are positioned nearby the middle of the back, just below the rib cage and one on each side of the spine. A kidney from a human adult weighs about 150 grams and is about the size of a fist. Each kidney contains an indented region called hilum, and transmits the vessels, nerves and ureter. The ureter carries the final urine from the kidneys to the bladder, where the urine is stored. The kidneys are surrounded by a fibrous capsule, to protect the delicate inner structure.

Figure 2: The basic tubular segments of the nephron.Inside the kidneys there are about one million nephrons, which remove the waste or unwanted substances out of the blood. A nephron consist out of glomerules, this is a tiny blood vessel with a tiny urine collecting tube called a tubule. The glomerules are the filtering unit or sieve and keep normal proteins and cells in the bloodstream. Then through a chemical exchange, waste materials and water leave the blood and is transported towards the medullary collecting duct. In each kidney, there are about 250 large collecting ducts that can store urine from 4000 nephrons. The urine stored in the collecting ducts will be emptied into the renal pelvis and then transported through the ureter into the bladder.

The process of emptying the bladder when it becomes filled is called micturition. This process consists out of two steps, namely:

1. The bladder fills progressively until the tension in its walls rises above the threshold level.

2. Through a nervous reflex (micturition reflex) the bladder will be emptied if this fails, at least it should cause a conscious desire to urinate. (Guyton & Hall, 2006)

Figure : The human bladder.

Appendix 2:

Article Dagblad van het Noorden: " ongezonde levenstijl blijkt uit urine".

C:\Documents and Settings\CENSI-HIT\My Documents\Dropbox\HIT - Urinemeter\D.2 Research proposal\Newspaper article.jpg

Figure : ongezonde levenstijl blijkt uit urine.

Appendix 3:

Task analysis current situation

During a guided tour within the ward of the Intensive Care, there was a lot of information gathered. This task analysis, see figure 5 is based on the information of an internist-intensivist, who works daily with patients that need intensive care. The urine is measured every day.

Figure : Task analyses urine sampling.