Development of Stress Management System for Prevention of a Mental Disease using Smart Finger Plethysmogram Measurement

Introduction

The survey of patients in Japan by the Ministry of Health, Labor and Welfare (MHLW, 2011) revealed the total number of estimated patients per day with mood disorders included depressions climbed to more than 103.6 thousand people in 2011 (They are not included in Fukushima and a part of Miyagi prefecture): number of people with mood disorders was 60.3 thousand in 1996 (Figure 1). This disease, called “modern-day illness”, is largely the result physical stress and psychological stress (Lazarus and Folkman, 1984; Kawakami and Haratani, 1999; Stansfeld et al, 1999). In modern society, we have a broad range of stressors which load to depression; therefore, we are at an increased risk for this illness. However, there are many potential patients despite being affected by a disease. Depression can be defined subjectively or objectively; thus, patients with depression to accept or be aware of their disease. Although a diagnostic test which examines stress level has been invented, it is difficult to help conscious about their disease. The reason is that the test is easily affected arbitrary and subjective elements (Haas, 1979; Aasman et al, 1987). There are three phases of prevention of mental illness based on preventive medicine.

Figure 1.

Estimated number of patients (per day)

• A.

  Primary prophylaxis by getting rid of the stressor.

• B.

  Secondary prophylaxis by early detection and early medical examination.

• C.

  Tertiary prophylaxis by recurrence prevention treatment.

In particular, early detection and early medical examination is the most important process for prevention serious cases, and to help shorten the length of treatment. Based on this information, it is necessary for patients to assess their risk of mental disease themselves by measuring their daily stress level. This study focuses on pulse beat of finger plethysmogram which is biological information affected by stress proposes a supportive system of developing risk management by frequently analyzing changes in stress levels.

System Outline

This study proposes a system using “visual studio net flame work, “The C# Programming Language” and Arduino (Arudino, 2005), A.P.Sheild (KORESS, 2010) for open source hard ware (Figure 2, Figure 3).

Figure 2.

Arudino

Figure 3.

Arduino and A.P.Sheild

A.P.Sheild is an expansion board for Arduino compatible computers using photo sensors which make it possible to change an electric currency by catching infrared light emitted from the expansion board. We detect a change of blood flow by using finger photo sensors to measure finger plethysmogram (Fujimoto et al, 2004; Fujimoto et al, 2005) as shown in Figure 4. This system can be used by connecting a personal computer and Arduino attached to A.P.Sheild with a USB cable (Figure 5). This system makes it possible to measure and visualize stress level easily, such as like taking ones temperature, measuring one’s weight, or measuring blood pressure to self-assess the risk of disease as developing a prototype. The system we invented aims for measuring of stress level as a means of management in the home such as measuring weight, blood pressure and body temperature.